Set the SigHashType of remote htlc signatures w/ anchors to SinglePlusAnyoneCanPay

[rust-lightning] / lightning / src / ln / channel.rs

// This file is Copyright its original authors, visible in version control
// history.
//
// This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
// or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
// You may not use this file except in accordance with one or both of these
// licenses.

use bitcoin::blockdata::script::{Script,Builder};
use bitcoin::blockdata::transaction::{Transaction, SigHashType};
use bitcoin::util::bip143;
use bitcoin::consensus::encode;

use bitcoin::hashes::Hash;
use bitcoin::hashes::sha256::Hash as Sha256;
use bitcoin::hashes::sha256d::Hash as Sha256d;
use bitcoin::hash_types::{Txid, BlockHash};

use bitcoin::secp256k1::constants::PUBLIC_KEY_SIZE;
use bitcoin::secp256k1::key::{PublicKey,SecretKey};
use bitcoin::secp256k1::{Secp256k1,Signature};
use bitcoin::secp256k1;

use ln::{PaymentPreimage, PaymentHash};
use ln::features::{ChannelFeatures, ChannelTypeFeatures, InitFeatures};
use ln::msgs;
use ln::msgs::{DecodeError, OptionalField, DataLossProtect};
use ln::script::{self, ShutdownScript};
use ln::channelmanager::{CounterpartyForwardingInfo, PendingHTLCStatus, HTLCSource, HTLCFailReason, HTLCFailureMsg, PendingHTLCInfo, RAACommitmentOrder, BREAKDOWN_TIMEOUT, MIN_CLTV_EXPIRY_DELTA, MAX_LOCAL_BREAKDOWN_TIMEOUT};
use ln::chan_utils::{CounterpartyCommitmentSecrets, TxCreationKeys, HTLCOutputInCommitment, HTLC_SUCCESS_TX_WEIGHT, HTLC_TIMEOUT_TX_WEIGHT, make_funding_redeemscript, ChannelPublicKeys, CommitmentTransaction, HolderCommitmentTransaction, ChannelTransactionParameters, CounterpartyChannelTransactionParameters, MAX_HTLCS, get_commitment_transaction_number_obscure_factor, ClosingTransaction};
use ln::chan_utils;
use chain::BestBlock;
use chain::chaininterface::{FeeEstimator,ConfirmationTarget};
use chain::channelmonitor::{ChannelMonitor, ChannelMonitorUpdate, ChannelMonitorUpdateStep, LATENCY_GRACE_PERIOD_BLOCKS};
use chain::transaction::{OutPoint, TransactionData};
use chain::keysinterface::{Sign, KeysInterface};
use util::events::ClosureReason;
use util::ser::{Readable, ReadableArgs, Writeable, Writer, VecWriter};
use util::logger::Logger;
use util::errors::APIError;
use util::config::{UserConfig,ChannelConfig};
use util::scid_utils::scid_from_parts;

use io;
use prelude::*;
use core::{cmp,mem,fmt};
use core::ops::Deref;
#[cfg(any(test, feature = "fuzztarget", debug_assertions))]
use sync::Mutex;
use bitcoin::hashes::hex::ToHex;

#[cfg(test)]
pub struct ChannelValueStat {
        pub value_to_self_msat: u64,
        pub channel_value_msat: u64,
        pub channel_reserve_msat: u64,
        pub pending_outbound_htlcs_amount_msat: u64,
        pub pending_inbound_htlcs_amount_msat: u64,
        pub holding_cell_outbound_amount_msat: u64,
        pub counterparty_max_htlc_value_in_flight_msat: u64, // outgoing
        pub counterparty_dust_limit_msat: u64,
}

#[derive(Debug, Clone, Copy, PartialEq)]
enum FeeUpdateState {
        // Inbound states mirroring InboundHTLCState
        RemoteAnnounced,
        AwaitingRemoteRevokeToAnnounce,
        // Note that we do not have a AwaitingAnnouncedRemoteRevoke variant here as it is universally
        // handled the same as `Committed`, with the only exception in `InboundHTLCState` being the
        // distinction of when we allow ourselves to forward the HTLC. Because we aren't "forwarding"
        // the fee update anywhere, we can simply consider the fee update `Committed` immediately
        // instead of setting it to AwaitingAnnouncedRemoteRevoke.

        // Outbound state can only be `LocalAnnounced` or `Committed`
        Outbound,
}

enum InboundHTLCRemovalReason {
        FailRelay(msgs::OnionErrorPacket),
        FailMalformed(([u8; 32], u16)),
        Fulfill(PaymentPreimage),
}

enum InboundHTLCState {
        /// Offered by remote, to be included in next local commitment tx. I.e., the remote sent an
        /// update_add_htlc message for this HTLC.
        RemoteAnnounced(PendingHTLCStatus),
        /// Included in a received commitment_signed message (implying we've
        /// revoke_and_ack'd it), but the remote hasn't yet revoked their previous
        /// state (see the example below). We have not yet included this HTLC in a
        /// commitment_signed message because we are waiting on the remote's
        /// aforementioned state revocation. One reason this missing remote RAA
        /// (revoke_and_ack) blocks us from constructing a commitment_signed message
        /// is because every time we create a new "state", i.e. every time we sign a
        /// new commitment tx (see [BOLT #2]), we need a new per_commitment_point,
        /// which are provided one-at-a-time in each RAA. E.g., the last RAA they
        /// sent provided the per_commitment_point for our current commitment tx.
        /// The other reason we should not send a commitment_signed without their RAA
        /// is because their RAA serves to ACK our previous commitment_signed.
        ///
        /// Here's an example of how an HTLC could come to be in this state:
        /// remote --> update_add_htlc(prev_htlc)   --> local
        /// remote --> commitment_signed(prev_htlc) --> local
        /// remote <-- revoke_and_ack               <-- local
        /// remote <-- commitment_signed(prev_htlc) <-- local
        /// [note that here, the remote does not respond with a RAA]
        /// remote --> update_add_htlc(this_htlc)   --> local
        /// remote --> commitment_signed(prev_htlc, this_htlc) --> local
        /// Now `this_htlc` will be assigned this state. It's unable to be officially
        /// accepted, i.e. included in a commitment_signed, because we're missing the
        /// RAA that provides our next per_commitment_point. The per_commitment_point
        /// is used to derive commitment keys, which are used to construct the
        /// signatures in a commitment_signed message.
        /// Implies AwaitingRemoteRevoke.
        ///
        /// [BOLT #2]: https://github.com/lightningnetwork/lightning-rfc/blob/master/02-peer-protocol.md
        AwaitingRemoteRevokeToAnnounce(PendingHTLCStatus),
        /// Included in a received commitment_signed message (implying we've revoke_and_ack'd it).
        /// We have also included this HTLC in our latest commitment_signed and are now just waiting
        /// on the remote's revoke_and_ack to make this HTLC an irrevocable part of the state of the
        /// channel (before it can then get forwarded and/or removed).
        /// Implies AwaitingRemoteRevoke.
        AwaitingAnnouncedRemoteRevoke(PendingHTLCStatus),
        Committed,
        /// Removed by us and a new commitment_signed was sent (if we were AwaitingRemoteRevoke when we
        /// created it we would have put it in the holding cell instead). When they next revoke_and_ack
        /// we'll drop it.
        /// Note that we have to keep an eye on the HTLC until we've received a broadcastable
        /// commitment transaction without it as otherwise we'll have to force-close the channel to
        /// claim it before the timeout (obviously doesn't apply to revoked HTLCs that we can't claim
        /// anyway). That said, ChannelMonitor does this for us (see
        /// ChannelMonitor::should_broadcast_holder_commitment_txn) so we actually remove the HTLC from
        /// our own local state before then, once we're sure that the next commitment_signed and
        /// ChannelMonitor::provide_latest_local_commitment_tx will not include this HTLC.
        LocalRemoved(InboundHTLCRemovalReason),
}

struct InboundHTLCOutput {
        htlc_id: u64,
        amount_msat: u64,
        cltv_expiry: u32,
        payment_hash: PaymentHash,
        state: InboundHTLCState,
}

enum OutboundHTLCState {
        /// Added by us and included in a commitment_signed (if we were AwaitingRemoteRevoke when we
        /// created it we would have put it in the holding cell instead). When they next revoke_and_ack
        /// we will promote to Committed (note that they may not accept it until the next time we
        /// revoke, but we don't really care about that:
        ///  * they've revoked, so worst case we can announce an old state and get our (option on)
        ///    money back (though we won't), and,
        ///  * we'll send them a revoke when they send a commitment_signed, and since only they're
        ///    allowed to remove it, the "can only be removed once committed on both sides" requirement
        ///    doesn't matter to us and it's up to them to enforce it, worst-case they jump ahead but
        ///    we'll never get out of sync).
        /// Note that we Box the OnionPacket as it's rather large and we don't want to blow up
        /// OutboundHTLCOutput's size just for a temporary bit
        LocalAnnounced(Box<msgs::OnionPacket>),
        Committed,
        /// Remote removed this (outbound) HTLC. We're waiting on their commitment_signed to finalize
        /// the change (though they'll need to revoke before we fail the payment).
        RemoteRemoved(Option<HTLCFailReason>),
        /// Remote removed this and sent a commitment_signed (implying we've revoke_and_ack'ed it), but
        /// the remote side hasn't yet revoked their previous state, which we need them to do before we
        /// can do any backwards failing. Implies AwaitingRemoteRevoke.
        /// We also have not yet removed this HTLC in a commitment_signed message, and are waiting on a
        /// remote revoke_and_ack on a previous state before we can do so.
        AwaitingRemoteRevokeToRemove(Option<HTLCFailReason>),
        /// Remote removed this and sent a commitment_signed (implying we've revoke_and_ack'ed it), but
        /// the remote side hasn't yet revoked their previous state, which we need them to do before we
        /// can do any backwards failing. Implies AwaitingRemoteRevoke.
        /// We have removed this HTLC in our latest commitment_signed and are now just waiting on a
        /// revoke_and_ack to drop completely.
        AwaitingRemovedRemoteRevoke(Option<HTLCFailReason>),
}

struct OutboundHTLCOutput {
        htlc_id: u64,
        amount_msat: u64,
        cltv_expiry: u32,
        payment_hash: PaymentHash,
        state: OutboundHTLCState,
        source: HTLCSource,
}

/// See AwaitingRemoteRevoke ChannelState for more info
enum HTLCUpdateAwaitingACK {
        AddHTLC { // TODO: Time out if we're getting close to cltv_expiry
                // always outbound
                amount_msat: u64,
                cltv_expiry: u32,
                payment_hash: PaymentHash,
                source: HTLCSource,
                onion_routing_packet: msgs::OnionPacket,
        },
        ClaimHTLC {
                payment_preimage: PaymentPreimage,
                htlc_id: u64,
        },
        FailHTLC {
                htlc_id: u64,
                err_packet: msgs::OnionErrorPacket,
        },
}

/// There are a few "states" and then a number of flags which can be applied:
/// We first move through init with OurInitSent -> TheirInitSent -> FundingCreated -> FundingSent.
/// TheirFundingLocked and OurFundingLocked then get set on FundingSent, and when both are set we
/// move on to ChannelFunded.
/// Note that PeerDisconnected can be set on both ChannelFunded and FundingSent.
/// ChannelFunded can then get all remaining flags set on it, until we finish shutdown, then we
/// move on to ShutdownComplete, at which point most calls into this channel are disallowed.
enum ChannelState {
        /// Implies we have (or are prepared to) send our open_channel/accept_channel message
        OurInitSent = 1 << 0,
        /// Implies we have received their open_channel/accept_channel message
        TheirInitSent = 1 << 1,
        /// We have sent funding_created and are awaiting a funding_signed to advance to FundingSent.
        /// Note that this is nonsense for an inbound channel as we immediately generate funding_signed
        /// upon receipt of funding_created, so simply skip this state.
        FundingCreated = 4,
        /// Set when we have received/sent funding_created and funding_signed and are thus now waiting
        /// on the funding transaction to confirm. The FundingLocked flags are set to indicate when we
        /// and our counterparty consider the funding transaction confirmed.
        FundingSent = 8,
        /// Flag which can be set on FundingSent to indicate they sent us a funding_locked message.
        /// Once both TheirFundingLocked and OurFundingLocked are set, state moves on to ChannelFunded.
        TheirFundingLocked = 1 << 4,
        /// Flag which can be set on FundingSent to indicate we sent them a funding_locked message.
        /// Once both TheirFundingLocked and OurFundingLocked are set, state moves on to ChannelFunded.
        OurFundingLocked = 1 << 5,
        ChannelFunded = 64,
        /// Flag which is set on ChannelFunded and FundingSent indicating remote side is considered
        /// "disconnected" and no updates are allowed until after we've done a channel_reestablish
        /// dance.
        PeerDisconnected = 1 << 7,
        /// Flag which is set on ChannelFunded, FundingCreated, and FundingSent indicating the user has
        /// told us they failed to update our ChannelMonitor somewhere and we should pause sending any
        /// outbound messages until they've managed to do so.
        MonitorUpdateFailed = 1 << 8,
        /// Flag which implies that we have sent a commitment_signed but are awaiting the responding
        /// revoke_and_ack message. During this time period, we can't generate new commitment_signed
        /// messages as then we will be unable to determine which HTLCs they included in their
        /// revoke_and_ack implicit ACK, so instead we have to hold them away temporarily to be sent
        /// later.
        /// Flag is set on ChannelFunded.
        AwaitingRemoteRevoke = 1 << 9,
        /// Flag which is set on ChannelFunded or FundingSent after receiving a shutdown message from
        /// the remote end. If set, they may not add any new HTLCs to the channel, and we are expected
        /// to respond with our own shutdown message when possible.
        RemoteShutdownSent = 1 << 10,
        /// Flag which is set on ChannelFunded or FundingSent after sending a shutdown message. At this
        /// point, we may not add any new HTLCs to the channel.
        LocalShutdownSent = 1 << 11,
        /// We've successfully negotiated a closing_signed dance. At this point ChannelManager is about
        /// to drop us, but we store this anyway.
        ShutdownComplete = 4096,
}
const BOTH_SIDES_SHUTDOWN_MASK: u32 = ChannelState::LocalShutdownSent as u32 | ChannelState::RemoteShutdownSent as u32;
const MULTI_STATE_FLAGS: u32 = BOTH_SIDES_SHUTDOWN_MASK | ChannelState::PeerDisconnected as u32 | ChannelState::MonitorUpdateFailed as u32;

pub const INITIAL_COMMITMENT_NUMBER: u64 = (1 << 48) - 1;

/// The "channel disabled" bit in channel_update must be set based on whether we are connected to
/// our counterparty or not. However, we don't want to announce updates right away to avoid
/// spamming the network with updates if the connection is flapping. Instead, we "stage" updates to
/// our channel_update message and track the current state here.
/// See implementation at [`super::channelmanager::ChannelManager::timer_tick_occurred`].
#[derive(Clone, Copy, PartialEq)]
pub(super) enum ChannelUpdateStatus {
        /// We've announced the channel as enabled and are connected to our peer.
        Enabled,
        /// Our channel is no longer live, but we haven't announced the channel as disabled yet.
        DisabledStaged,
        /// Our channel is live again, but we haven't announced the channel as enabled yet.
        EnabledStaged,
        /// We've announced the channel as disabled.
        Disabled,
}

/// An enum indicating whether the local or remote side offered a given HTLC.
enum HTLCInitiator {
        LocalOffered,
        RemoteOffered,
}

/// An enum gathering stats on pending HTLCs, either inbound or outbound side.
struct HTLCStats {
        pending_htlcs: u32,
        pending_htlcs_value_msat: u64,
        on_counterparty_tx_dust_exposure_msat: u64,
        on_holder_tx_dust_exposure_msat: u64,
        holding_cell_msat: u64,
        on_holder_tx_holding_cell_htlcs_count: u32, // dust HTLCs *non*-included
}

/// An enum gathering stats on commitment transaction, either local or remote.
struct CommitmentStats<'a> {
        tx: CommitmentTransaction, // the transaction info
        feerate_per_kw: u32, // the feerate included to build the transaction
        total_fee_sat: u64, // the total fee included in the transaction
        num_nondust_htlcs: usize,  // the number of HTLC outputs (dust HTLCs *non*-included)
        htlcs_included: Vec<(HTLCOutputInCommitment, Option<&'a HTLCSource>)>, // the list of HTLCs (dust HTLCs *included*) which were not ignored when building the transaction
        local_balance_msat: u64, // local balance before fees but considering dust limits
        remote_balance_msat: u64, // remote balance before fees but considering dust limits
}

/// Used when calculating whether we or the remote can afford an additional HTLC.
struct HTLCCandidate {
        amount_msat: u64,
        origin: HTLCInitiator,
}

impl HTLCCandidate {
        fn new(amount_msat: u64, origin: HTLCInitiator) -> Self {
                Self {
                        amount_msat,
                        origin,
                }
        }
}

/// A return value enum for get_update_fulfill_htlc. See UpdateFulfillCommitFetch variants for
/// description
enum UpdateFulfillFetch {
        NewClaim {
                monitor_update: ChannelMonitorUpdate,
                htlc_value_msat: u64,
                msg: Option<msgs::UpdateFulfillHTLC>,
        },
        DuplicateClaim {},
}

/// The return type of get_update_fulfill_htlc_and_commit.
pub enum UpdateFulfillCommitFetch {
        /// Indicates the HTLC fulfill is new, and either generated an update_fulfill message, placed
        /// it in the holding cell, or re-generated the update_fulfill message after the same claim was
        /// previously placed in the holding cell (and has since been removed).
        NewClaim {
                /// The ChannelMonitorUpdate which places the new payment preimage in the channel monitor
                monitor_update: ChannelMonitorUpdate,
                /// The value of the HTLC which was claimed, in msat.
                htlc_value_msat: u64,
                /// The update_fulfill message and commitment_signed message (if the claim was not placed
                /// in the holding cell).
                msgs: Option<(msgs::UpdateFulfillHTLC, msgs::CommitmentSigned)>,
        },
        /// Indicates the HTLC fulfill is duplicative and already existed either in the holding cell
        /// or has been forgotten (presumably previously claimed).
        DuplicateClaim {},
}

/// The return value of `revoke_and_ack` on success, primarily updates to other channels or HTLC
/// state.
pub(super) struct RAAUpdates {
        pub commitment_update: Option<msgs::CommitmentUpdate>,
        pub accepted_htlcs: Vec<(PendingHTLCInfo, u64)>,
        pub failed_htlcs: Vec<(HTLCSource, PaymentHash, HTLCFailReason)>,
        pub finalized_claimed_htlcs: Vec<HTLCSource>,
        pub monitor_update: ChannelMonitorUpdate,
        pub holding_cell_failed_htlcs: Vec<(HTLCSource, PaymentHash)>,
}

/// The return value of `monitor_updating_restored`
pub(super) struct MonitorRestoreUpdates {
        pub raa: Option<msgs::RevokeAndACK>,
        pub commitment_update: Option<msgs::CommitmentUpdate>,
        pub order: RAACommitmentOrder,
        pub accepted_htlcs: Vec<(PendingHTLCInfo, u64)>,
        pub failed_htlcs: Vec<(HTLCSource, PaymentHash, HTLCFailReason)>,
        pub finalized_claimed_htlcs: Vec<HTLCSource>,
        pub funding_broadcastable: Option<Transaction>,
        pub funding_locked: Option<msgs::FundingLocked>,
}

/// If the majority of the channels funds are to the fundee and the initiator holds only just
/// enough funds to cover their reserve value, channels are at risk of getting "stuck". Because the
/// initiator controls the feerate, if they then go to increase the channel fee, they may have no
/// balance but the fundee is unable to send a payment as the increase in fee more than drains
/// their reserve value. Thus, neither side can send a new HTLC and the channel becomes useless.
/// Thus, before sending an HTLC when we are the initiator, we check that the feerate can increase
/// by this multiple without hitting this case, before sending.
/// This multiple is effectively the maximum feerate "jump" we expect until more HTLCs flow over
/// the channel. Sadly, there isn't really a good number for this - if we expect to have no new
/// HTLCs for days we may need this to suffice for feerate increases across days, but that may
/// leave the channel less usable as we hold a bigger reserve.
#[cfg(any(fuzzing, test))]
pub const FEE_SPIKE_BUFFER_FEE_INCREASE_MULTIPLE: u64 = 2;
#[cfg(not(any(fuzzing, test)))]
const FEE_SPIKE_BUFFER_FEE_INCREASE_MULTIPLE: u64 = 2;

/// If we fail to see a funding transaction confirmed on-chain within this many blocks after the
/// channel creation on an inbound channel, we simply force-close and move on.
/// This constant is the one suggested in BOLT 2.
pub(crate) const FUNDING_CONF_DEADLINE_BLOCKS: u32 = 2016;

/// In case of a concurrent update_add_htlc proposed by our counterparty, we might
/// not have enough balance value remaining to cover the onchain cost of this new
/// HTLC weight. If this happens, our counterparty fails the reception of our
/// commitment_signed including this new HTLC due to infringement on the channel
/// reserve.
/// To prevent this case, we compute our outbound update_fee with an HTLC buffer of
/// size 2. However, if the number of concurrent update_add_htlc is higher, this still
/// leads to a channel force-close. Ultimately, this is an issue coming from the
/// design of LN state machines, allowing asynchronous updates.
pub(crate) const CONCURRENT_INBOUND_HTLC_FEE_BUFFER: u32 = 2;

/// When a channel is opened, we check that the funding amount is enough to pay for relevant
/// commitment transaction fees, with at least this many HTLCs present on the commitment
/// transaction (not counting the value of the HTLCs themselves).
pub(crate) const MIN_AFFORDABLE_HTLC_COUNT: usize = 4;

// TODO: We should refactor this to be an Inbound/OutboundChannel until initial setup handshaking
// has been completed, and then turn into a Channel to get compiler-time enforcement of things like
// calling channel_id() before we're set up or things like get_outbound_funding_signed on an
// inbound channel.
//
// Holder designates channel data owned for the benefice of the user client.
// Counterparty designates channel data owned by the another channel participant entity.
pub(super) struct Channel<Signer: Sign> {
        #[cfg(any(test, feature = "_test_utils"))]
        pub(crate) config: ChannelConfig,
        #[cfg(not(any(test, feature = "_test_utils")))]
        config: ChannelConfig,

        user_id: u64,

        channel_id: [u8; 32],
        channel_state: u32,
        secp_ctx: Secp256k1<secp256k1::All>,
        channel_value_satoshis: u64,

        latest_monitor_update_id: u64,

        holder_signer: Signer,
        shutdown_scriptpubkey: Option<ShutdownScript>,
        destination_script: Script,

        // Our commitment numbers start at 2^48-1 and count down, whereas the ones used in transaction
        // generation start at 0 and count up...this simplifies some parts of implementation at the
        // cost of others, but should really just be changed.

        cur_holder_commitment_transaction_number: u64,
        cur_counterparty_commitment_transaction_number: u64,
        value_to_self_msat: u64, // Excluding all pending_htlcs, excluding fees
        pending_inbound_htlcs: Vec<InboundHTLCOutput>,
        pending_outbound_htlcs: Vec<OutboundHTLCOutput>,
        holding_cell_htlc_updates: Vec<HTLCUpdateAwaitingACK>,

        /// When resending CS/RAA messages on channel monitor restoration or on reconnect, we always
        /// need to ensure we resend them in the order we originally generated them. Note that because
        /// there can only ever be one in-flight CS and/or one in-flight RAA at any time, it is
        /// sufficient to simply set this to the opposite of any message we are generating as we
        /// generate it. ie when we generate a CS, we set this to RAAFirst as, if there is a pending
        /// in-flight RAA to resend, it will have been the first thing we generated, and thus we should
        /// send it first.
        resend_order: RAACommitmentOrder,

        monitor_pending_funding_locked: bool,
        monitor_pending_revoke_and_ack: bool,
        monitor_pending_commitment_signed: bool,
        monitor_pending_forwards: Vec<(PendingHTLCInfo, u64)>,
        monitor_pending_failures: Vec<(HTLCSource, PaymentHash, HTLCFailReason)>,
        monitor_pending_finalized_fulfills: Vec<HTLCSource>,

        // pending_update_fee is filled when sending and receiving update_fee.
        //
        // Because it follows the same commitment flow as HTLCs, `FeeUpdateState` is either `Outbound`
        // or matches a subset of the `InboundHTLCOutput` variants. It is then updated/used when
        // generating new commitment transactions with exactly the same criteria as inbound/outbound
        // HTLCs with similar state.
        pending_update_fee: Option<(u32, FeeUpdateState)>,
        // If a `send_update_fee()` call is made with ChannelState::AwaitingRemoteRevoke set, we place
        // it here instead of `pending_update_fee` in the same way as we place outbound HTLC updates in
        // `holding_cell_htlc_updates` instead of `pending_outbound_htlcs`. It is released into
        // `pending_update_fee` with the same criteria as outbound HTLC updates but can be updated by
        // further `send_update_fee` calls, dropping the previous holding cell update entirely.
        holding_cell_update_fee: Option<u32>,
        next_holder_htlc_id: u64,
        next_counterparty_htlc_id: u64,
        feerate_per_kw: u32,

        /// The timestamp set on our latest `channel_update` message for this channel. It is updated
        /// when the channel is updated in ways which may impact the `channel_update` message or when a
        /// new block is received, ensuring it's always at least moderately close to the current real
        /// time.
        update_time_counter: u32,

        #[cfg(debug_assertions)]
        /// Max to_local and to_remote outputs in a locally-generated commitment transaction
        holder_max_commitment_tx_output: Mutex<(u64, u64)>,
        #[cfg(debug_assertions)]
        /// Max to_local and to_remote outputs in a remote-generated commitment transaction
        counterparty_max_commitment_tx_output: Mutex<(u64, u64)>,

        last_sent_closing_fee: Option<(u64, Signature)>, // (fee, holder_sig)
        target_closing_feerate_sats_per_kw: Option<u32>,

        /// If our counterparty sent us a closing_signed while we were waiting for a `ChannelMonitor`
        /// update, we need to delay processing it until later. We do that here by simply storing the
        /// closing_signed message and handling it in `maybe_propose_closing_signed`.
        pending_counterparty_closing_signed: Option<msgs::ClosingSigned>,

        /// The minimum and maximum absolute fee, in satoshis, we are willing to place on the closing
        /// transaction. These are set once we reach `closing_negotiation_ready`.
        #[cfg(test)]
        pub(crate) closing_fee_limits: Option<(u64, u64)>,
        #[cfg(not(test))]
        closing_fee_limits: Option<(u64, u64)>,

        /// The hash of the block in which the funding transaction was included.
        funding_tx_confirmed_in: Option<BlockHash>,
        funding_tx_confirmation_height: u32,
        short_channel_id: Option<u64>,
        /// Either the height at which this channel was created or the height at which it was last
        /// serialized if it was serialized by versions prior to 0.0.103.
        /// We use this to close if funding is never broadcasted.
        channel_creation_height: u32,

        counterparty_dust_limit_satoshis: u64,

        #[cfg(test)]
        pub(super) holder_dust_limit_satoshis: u64,
        #[cfg(not(test))]
        holder_dust_limit_satoshis: u64,

        #[cfg(test)]
        pub(super) counterparty_max_htlc_value_in_flight_msat: u64,
        #[cfg(not(test))]
        counterparty_max_htlc_value_in_flight_msat: u64,

        #[cfg(test)]
        pub(super) holder_max_htlc_value_in_flight_msat: u64,
        #[cfg(not(test))]
        holder_max_htlc_value_in_flight_msat: u64,

        /// minimum channel reserve for self to maintain - set by them.
        counterparty_selected_channel_reserve_satoshis: Option<u64>,

        #[cfg(test)]
        pub(super) holder_selected_channel_reserve_satoshis: u64,
        #[cfg(not(test))]
        holder_selected_channel_reserve_satoshis: u64,

        counterparty_htlc_minimum_msat: u64,
        holder_htlc_minimum_msat: u64,
        #[cfg(test)]
        pub counterparty_max_accepted_htlcs: u16,
        #[cfg(not(test))]
        counterparty_max_accepted_htlcs: u16,
        //implied by OUR_MAX_HTLCS: max_accepted_htlcs: u16,
        minimum_depth: Option<u32>,

        counterparty_forwarding_info: Option<CounterpartyForwardingInfo>,

        pub(crate) channel_transaction_parameters: ChannelTransactionParameters,
        funding_transaction: Option<Transaction>,

        counterparty_cur_commitment_point: Option<PublicKey>,
        counterparty_prev_commitment_point: Option<PublicKey>,
        counterparty_node_id: PublicKey,

        counterparty_shutdown_scriptpubkey: Option<Script>,

        commitment_secrets: CounterpartyCommitmentSecrets,

        channel_update_status: ChannelUpdateStatus,
        /// Once we reach `closing_negotiation_ready`, we set this, indicating if closing_signed does
        /// not complete within a single timer tick (one minute), we should force-close the channel.
        /// This prevents us from keeping unusable channels around forever if our counterparty wishes
        /// to DoS us.
        /// Note that this field is reset to false on deserialization to give us a chance to connect to
        /// our peer and start the closing_signed negotiation fresh.
        closing_signed_in_flight: bool,

        /// Our counterparty's channel_announcement signatures provided in announcement_signatures.
        /// This can be used to rebroadcast the channel_announcement message later.
        announcement_sigs: Option<(Signature, Signature)>,

        // We save these values so we can make sure `next_local_commit_tx_fee_msat` and
        // `next_remote_commit_tx_fee_msat` properly predict what the next commitment transaction fee will
        // be, by comparing the cached values to the fee of the tranaction generated by
        // `build_commitment_transaction`.
        #[cfg(any(test, feature = "fuzztarget"))]
        next_local_commitment_tx_fee_info_cached: Mutex<Option<CommitmentTxInfoCached>>,
        #[cfg(any(test, feature = "fuzztarget"))]
        next_remote_commitment_tx_fee_info_cached: Mutex<Option<CommitmentTxInfoCached>>,

        /// lnd has a long-standing bug where, upon reconnection, if the channel is not yet confirmed
        /// they will not send a channel_reestablish until the channel locks in. Then, they will send a
        /// funding_locked *before* sending the channel_reestablish (which is clearly a violation of
        /// the BOLT specs). We copy c-lightning's workaround here and simply store the funding_locked
        /// message until we receive a channel_reestablish.
        ///
        /// See-also <https://github.com/lightningnetwork/lnd/issues/4006>
        pub workaround_lnd_bug_4006: Option<msgs::FundingLocked>,

        #[cfg(any(test, feature = "fuzztarget"))]
        // When we receive an HTLC fulfill on an outbound path, we may immediately fulfill the
        // corresponding HTLC on the inbound path. If, then, the outbound path channel is
        // disconnected and reconnected (before we've exchange commitment_signed and revoke_and_ack
        // messages), they may re-broadcast their update_fulfill_htlc, causing a duplicate claim. This
        // is fine, but as a sanity check in our failure to generate the second claim, we check here
        // that the original was a claim, and that we aren't now trying to fulfill a failed HTLC.
        historical_inbound_htlc_fulfills: HashSet<u64>,

        /// This channel's type, as negotiated during channel open
        channel_type: ChannelTypeFeatures,
}

#[cfg(any(test, feature = "fuzztarget"))]
struct CommitmentTxInfoCached {
        fee: u64,
        total_pending_htlcs: usize,
        next_holder_htlc_id: u64,
        next_counterparty_htlc_id: u64,
        feerate: u32,
}

pub const OUR_MAX_HTLCS: u16 = 50; //TODO

#[cfg(not(test))]
const COMMITMENT_TX_BASE_WEIGHT: u64 = 724;
#[cfg(test)]
pub const COMMITMENT_TX_BASE_WEIGHT: u64 = 724;
#[cfg(not(test))]
const COMMITMENT_TX_WEIGHT_PER_HTLC: u64 = 172;
#[cfg(test)]
pub const COMMITMENT_TX_WEIGHT_PER_HTLC: u64 = 172;

pub const ANCHOR_OUTPUT_VALUE_SATOSHI: u64 = 330;

/// Maximum `funding_satoshis` value, according to the BOLT #2 specification
/// it's 2^24.
pub const MAX_FUNDING_SATOSHIS: u64 = 1 << 24;

/// The maximum network dust limit for standard script formats. This currently represents the
/// minimum output value for a P2SH output before Bitcoin Core 22 considers the entire
/// transaction non-standard and thus refuses to relay it.
/// We also use this as the maximum counterparty `dust_limit_satoshis` allowed, given many
/// implementations use this value for their dust limit today.
pub const MAX_STD_OUTPUT_DUST_LIMIT_SATOSHIS: u64 = 546;

/// The maximum channel dust limit we will accept from our counterparty.
pub const MAX_CHAN_DUST_LIMIT_SATOSHIS: u64 = MAX_STD_OUTPUT_DUST_LIMIT_SATOSHIS;

/// The dust limit is used for both the commitment transaction outputs as well as the closing
/// transactions. For cooperative closing transactions, we require segwit outputs, though accept
/// *any* segwit scripts, which are allowed to be up to 42 bytes in length.
/// In order to avoid having to concern ourselves with standardness during the closing process, we
/// simply require our counterparty to use a dust limit which will leave any segwit output
/// standard.
/// See https://github.com/lightningnetwork/lightning-rfc/issues/905 for more details.
pub const MIN_CHAN_DUST_LIMIT_SATOSHIS: u64 = 354;

/// Used to return a simple Error back to ChannelManager. Will get converted to a
/// msgs::ErrorAction::SendErrorMessage or msgs::ErrorAction::IgnoreError as appropriate with our
/// channel_id in ChannelManager.
pub(super) enum ChannelError {
        Ignore(String),
        Warn(String),
        Close(String),
        CloseDelayBroadcast(String),
}

impl fmt::Debug for ChannelError {
        fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
                match self {
                        &ChannelError::Ignore(ref e) => write!(f, "Ignore : {}", e),
                        &ChannelError::Warn(ref e) => write!(f, "Warn : {}", e),
                        &ChannelError::Close(ref e) => write!(f, "Close : {}", e),
                        &ChannelError::CloseDelayBroadcast(ref e) => write!(f, "CloseDelayBroadcast : {}", e)
                }
        }
}

macro_rules! secp_check {
        ($res: expr, $err: expr) => {
                match $res {
                        Ok(thing) => thing,
                        Err(_) => return Err(ChannelError::Close($err)),
                }
        };
}

impl<Signer: Sign> Channel<Signer> {
        // Convert constants + channel value to limits:
        fn get_holder_max_htlc_value_in_flight_msat(channel_value_satoshis: u64) -> u64 {
                channel_value_satoshis * 1000 / 10 //TODO
        }

        /// Returns a minimum channel reserve value the remote needs to maintain,
        /// required by us.
        ///
        /// Guaranteed to return a value no larger than channel_value_satoshis
        ///
        /// This is used both for new channels and to figure out what reserve value we sent to peers
        /// for channels serialized before we included our selected reserve value in the serialized
        /// data explicitly.
        pub(crate) fn get_holder_selected_channel_reserve_satoshis(channel_value_satoshis: u64) -> u64 {
                let (q, _) = channel_value_satoshis.overflowing_div(100);
                cmp::min(channel_value_satoshis, cmp::max(q, 1000)) //TODO
        }

        pub(crate) fn opt_anchors(&self) -> bool {
                self.channel_transaction_parameters.opt_anchors.is_some()
        }

        // Constructors:
        pub fn new_outbound<K: Deref, F: Deref>(
                fee_estimator: &F, keys_provider: &K, counterparty_node_id: PublicKey, their_features: &InitFeatures,
                channel_value_satoshis: u64, push_msat: u64, user_id: u64, config: &UserConfig, current_chain_height: u32
        ) -> Result<Channel<Signer>, APIError>
        where K::Target: KeysInterface<Signer = Signer>,
              F::Target: FeeEstimator,
        {
                let holder_selected_contest_delay = config.own_channel_config.our_to_self_delay;
                let holder_signer = keys_provider.get_channel_signer(false, channel_value_satoshis);
                let pubkeys = holder_signer.pubkeys().clone();

                if channel_value_satoshis >= MAX_FUNDING_SATOSHIS {
                        return Err(APIError::APIMisuseError{err: format!("funding_value must be smaller than {}, it was {}", MAX_FUNDING_SATOSHIS, channel_value_satoshis)});
                }
                let channel_value_msat = channel_value_satoshis * 1000;
                if push_msat > channel_value_msat {
                        return Err(APIError::APIMisuseError { err: format!("Push value ({}) was larger than channel_value ({})", push_msat, channel_value_msat) });
                }
                if holder_selected_contest_delay < BREAKDOWN_TIMEOUT {
                        return Err(APIError::APIMisuseError {err: format!("Configured with an unreasonable our_to_self_delay ({}) putting user funds at risks", holder_selected_contest_delay)});
                }
                let holder_selected_channel_reserve_satoshis = Channel::<Signer>::get_holder_selected_channel_reserve_satoshis(channel_value_satoshis);
                if holder_selected_channel_reserve_satoshis < MIN_CHAN_DUST_LIMIT_SATOSHIS {
                        return Err(APIError::APIMisuseError { err: format!("Holder selected channel  reserve below implemention limit dust_limit_satoshis {}", holder_selected_channel_reserve_satoshis) });
                }

                let feerate = fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Normal);

                let value_to_self_msat = channel_value_satoshis * 1000 - push_msat;
                let commitment_tx_fee = Self::commit_tx_fee_msat(feerate, MIN_AFFORDABLE_HTLC_COUNT);
                if value_to_self_msat < commitment_tx_fee {
                        return Err(APIError::APIMisuseError{ err: format!("Funding amount ({}) can't even pay fee for initial commitment transaction fee of {}.", value_to_self_msat / 1000, commitment_tx_fee / 1000) });
                }

                let mut secp_ctx = Secp256k1::new();
                secp_ctx.seeded_randomize(&keys_provider.get_secure_random_bytes());

                let shutdown_scriptpubkey = if config.channel_options.commit_upfront_shutdown_pubkey {
                        Some(keys_provider.get_shutdown_scriptpubkey())
                } else { None };

                if let Some(shutdown_scriptpubkey) = &shutdown_scriptpubkey {
                        if !shutdown_scriptpubkey.is_compatible(&their_features) {
                                return Err(APIError::IncompatibleShutdownScript { script: shutdown_scriptpubkey.clone() });
                        }
                }

                Ok(Channel {
                        user_id,
                        config: config.channel_options.clone(),

                        channel_id: keys_provider.get_secure_random_bytes(),
                        channel_state: ChannelState::OurInitSent as u32,
                        secp_ctx,
                        channel_value_satoshis,

                        latest_monitor_update_id: 0,

                        holder_signer,
                        shutdown_scriptpubkey,
                        destination_script: keys_provider.get_destination_script(),

                        cur_holder_commitment_transaction_number: INITIAL_COMMITMENT_NUMBER,
                        cur_counterparty_commitment_transaction_number: INITIAL_COMMITMENT_NUMBER,
                        value_to_self_msat,

                        pending_inbound_htlcs: Vec::new(),
                        pending_outbound_htlcs: Vec::new(),
                        holding_cell_htlc_updates: Vec::new(),
                        pending_update_fee: None,
                        holding_cell_update_fee: None,
                        next_holder_htlc_id: 0,
                        next_counterparty_htlc_id: 0,
                        update_time_counter: 1,

                        resend_order: RAACommitmentOrder::CommitmentFirst,

                        monitor_pending_funding_locked: false,
                        monitor_pending_revoke_and_ack: false,
                        monitor_pending_commitment_signed: false,
                        monitor_pending_forwards: Vec::new(),
                        monitor_pending_failures: Vec::new(),
                        monitor_pending_finalized_fulfills: Vec::new(),

                        #[cfg(debug_assertions)]
                        holder_max_commitment_tx_output: Mutex::new((channel_value_satoshis * 1000 - push_msat, push_msat)),
                        #[cfg(debug_assertions)]
                        counterparty_max_commitment_tx_output: Mutex::new((channel_value_satoshis * 1000 - push_msat, push_msat)),

                        last_sent_closing_fee: None,
                        pending_counterparty_closing_signed: None,
                        closing_fee_limits: None,
                        target_closing_feerate_sats_per_kw: None,

                        funding_tx_confirmed_in: None,
                        funding_tx_confirmation_height: 0,
                        short_channel_id: None,
                        channel_creation_height: current_chain_height,

                        feerate_per_kw: feerate,
                        counterparty_dust_limit_satoshis: 0,
                        holder_dust_limit_satoshis: MIN_CHAN_DUST_LIMIT_SATOSHIS,
                        counterparty_max_htlc_value_in_flight_msat: 0,
                        holder_max_htlc_value_in_flight_msat: Self::get_holder_max_htlc_value_in_flight_msat(channel_value_satoshis),
                        counterparty_selected_channel_reserve_satoshis: None, // Filled in in accept_channel
                        holder_selected_channel_reserve_satoshis,
                        counterparty_htlc_minimum_msat: 0,
                        holder_htlc_minimum_msat: if config.own_channel_config.our_htlc_minimum_msat == 0 { 1 } else { config.own_channel_config.our_htlc_minimum_msat },
                        counterparty_max_accepted_htlcs: 0,
                        minimum_depth: None, // Filled in in accept_channel

                        counterparty_forwarding_info: None,

                        channel_transaction_parameters: ChannelTransactionParameters {
                                holder_pubkeys: pubkeys,
                                holder_selected_contest_delay: config.own_channel_config.our_to_self_delay,
                                is_outbound_from_holder: true,
                                counterparty_parameters: None,
                                funding_outpoint: None,
                                opt_anchors: None,
                        },
                        funding_transaction: None,

                        counterparty_cur_commitment_point: None,
                        counterparty_prev_commitment_point: None,
                        counterparty_node_id,

                        counterparty_shutdown_scriptpubkey: None,

                        commitment_secrets: CounterpartyCommitmentSecrets::new(),

                        channel_update_status: ChannelUpdateStatus::Enabled,
                        closing_signed_in_flight: false,

                        announcement_sigs: None,

                        #[cfg(any(test, feature = "fuzztarget"))]
                        next_local_commitment_tx_fee_info_cached: Mutex::new(None),
                        #[cfg(any(test, feature = "fuzztarget"))]
                        next_remote_commitment_tx_fee_info_cached: Mutex::new(None),

                        workaround_lnd_bug_4006: None,

                        #[cfg(any(test, feature = "fuzztarget"))]
                        historical_inbound_htlc_fulfills: HashSet::new(),

                        // We currently only actually support one channel type, so don't retry with new types
                        // on error messages. When we support more we'll need fallback support (assuming we
                        // want to support old types).
                        channel_type: ChannelTypeFeatures::only_static_remote_key(),
                })
        }

        fn check_remote_fee<F: Deref>(fee_estimator: &F, feerate_per_kw: u32) -> Result<(), ChannelError>
                where F::Target: FeeEstimator
        {
                let lower_limit = fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Background);
                // Some fee estimators round up to the next full sat/vbyte (ie 250 sats per kw), causing
                // occasional issues with feerate disagreements between an initiator that wants a feerate
                // of 1.1 sat/vbyte and a receiver that wants 1.1 rounded up to 2. Thus, we always add 250
                // sat/kw before the comparison here.
                if feerate_per_kw + 250 < lower_limit {
                        return Err(ChannelError::Close(format!("Peer's feerate much too low. Actual: {}. Our expected lower limit: {} (- 250)", feerate_per_kw, lower_limit)));
                }
                // We only bound the fee updates on the upper side to prevent completely absurd feerates,
                // always accepting up to 25 sat/vByte or 10x our fee estimator's "High Priority" fee.
                // We generally don't care too much if they set the feerate to something very high, but it
                // could result in the channel being useless due to everything being dust.
                let upper_limit = cmp::max(250 * 25,
                        fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority) as u64 * 10);
                if feerate_per_kw as u64 > upper_limit {
                        return Err(ChannelError::Close(format!("Peer's feerate much too high. Actual: {}. Our expected upper limit: {}", feerate_per_kw, upper_limit)));
                }
                Ok(())
        }

        /// Creates a new channel from a remote sides' request for one.
        /// Assumes chain_hash has already been checked and corresponds with what we expect!
        pub fn new_from_req<K: Deref, F: Deref, L: Deref>(
                fee_estimator: &F, keys_provider: &K, counterparty_node_id: PublicKey, their_features: &InitFeatures,
                msg: &msgs::OpenChannel, user_id: u64, config: &UserConfig, current_chain_height: u32, logger: &L
        ) -> Result<Channel<Signer>, ChannelError>
                where K::Target: KeysInterface<Signer = Signer>,
                      F::Target: FeeEstimator,
                      L::Target: Logger,
        {
                // First check the channel type is known, failing before we do anything else if we don't
                // support this channel type.
                let channel_type = if let Some(channel_type) = &msg.channel_type {
                        if channel_type.supports_any_optional_bits() {
                                return Err(ChannelError::Close("Channel Type field contained optional bits - this is not allowed".to_owned()));
                        }
                        if *channel_type != ChannelTypeFeatures::only_static_remote_key() {
                                return Err(ChannelError::Close("Channel Type was not understood".to_owned()));
                        }
                        channel_type.clone()
                } else {
                        ChannelTypeFeatures::from_counterparty_init(&their_features)
                };
                if !channel_type.supports_static_remote_key() {
                        return Err(ChannelError::Close("Channel Type was not understood - we require static remote key".to_owned()));
                }

                let holder_signer = keys_provider.get_channel_signer(true, msg.funding_satoshis);
                let pubkeys = holder_signer.pubkeys().clone();
                let counterparty_pubkeys = ChannelPublicKeys {
                        funding_pubkey: msg.funding_pubkey,
                        revocation_basepoint: msg.revocation_basepoint,
                        payment_point: msg.payment_point,
                        delayed_payment_basepoint: msg.delayed_payment_basepoint,
                        htlc_basepoint: msg.htlc_basepoint
                };
                let mut local_config = (*config).channel_options.clone();

                if config.own_channel_config.our_to_self_delay < BREAKDOWN_TIMEOUT {
                        return Err(ChannelError::Close(format!("Configured with an unreasonable our_to_self_delay ({}) putting user funds at risks. It must be greater than {}", config.own_channel_config.our_to_self_delay, BREAKDOWN_TIMEOUT)));
                }

                // Check sanity of message fields:
                if msg.funding_satoshis >= MAX_FUNDING_SATOSHIS {
                        return Err(ChannelError::Close(format!("Funding must be smaller than {}. It was {}", MAX_FUNDING_SATOSHIS, msg.funding_satoshis)));
                }
                if msg.channel_reserve_satoshis > msg.funding_satoshis {
                        return Err(ChannelError::Close(format!("Bogus channel_reserve_satoshis ({}). Must be not greater than funding_satoshis: {}", msg.channel_reserve_satoshis, msg.funding_satoshis)));
                }
                let funding_value = (msg.funding_satoshis - msg.channel_reserve_satoshis) * 1000;
                if msg.push_msat > funding_value {
                        return Err(ChannelError::Close(format!("push_msat {} was larger than funding value {}", msg.push_msat, funding_value)));
                }
                if msg.dust_limit_satoshis > msg.funding_satoshis {
                        return Err(ChannelError::Close(format!("dust_limit_satoshis {} was larger than funding_satoshis {}. Peer never wants payout outputs?", msg.dust_limit_satoshis, msg.funding_satoshis)));
                }
                let full_channel_value_msat = (msg.funding_satoshis - msg.channel_reserve_satoshis) * 1000;
                if msg.htlc_minimum_msat >= full_channel_value_msat {
                        return Err(ChannelError::Close(format!("Minimum htlc value ({}) was larger than full channel value ({})", msg.htlc_minimum_msat, full_channel_value_msat)));
                }
                Channel::<Signer>::check_remote_fee(fee_estimator, msg.feerate_per_kw)?;

                let max_counterparty_selected_contest_delay = u16::min(config.peer_channel_config_limits.their_to_self_delay, MAX_LOCAL_BREAKDOWN_TIMEOUT);
                if msg.to_self_delay > max_counterparty_selected_contest_delay {
                        return Err(ChannelError::Close(format!("They wanted our payments to be delayed by a needlessly long period. Upper limit: {}. Actual: {}", max_counterparty_selected_contest_delay, msg.to_self_delay)));
                }
                if msg.max_accepted_htlcs < 1 {
                        return Err(ChannelError::Close("0 max_accepted_htlcs makes for a useless channel".to_owned()));
                }
                if msg.max_accepted_htlcs > MAX_HTLCS {
                        return Err(ChannelError::Close(format!("max_accepted_htlcs was {}. It must not be larger than {}", msg.max_accepted_htlcs, MAX_HTLCS)));
                }

                // Now check against optional parameters as set by config...
                if msg.funding_satoshis < config.peer_channel_config_limits.min_funding_satoshis {
                        return Err(ChannelError::Close(format!("Funding satoshis ({}) is less than the user specified limit ({})", msg.funding_satoshis, config.peer_channel_config_limits.min_funding_satoshis)));
                }
                if msg.htlc_minimum_msat > config.peer_channel_config_limits.max_htlc_minimum_msat {
                        return Err(ChannelError::Close(format!("htlc_minimum_msat ({}) is higher than the user specified limit ({})", msg.htlc_minimum_msat,  config.peer_channel_config_limits.max_htlc_minimum_msat)));
                }
                if msg.max_htlc_value_in_flight_msat < config.peer_channel_config_limits.min_max_htlc_value_in_flight_msat {
                        return Err(ChannelError::Close(format!("max_htlc_value_in_flight_msat ({}) is less than the user specified limit ({})", msg.max_htlc_value_in_flight_msat, config.peer_channel_config_limits.min_max_htlc_value_in_flight_msat)));
                }
                if msg.channel_reserve_satoshis > config.peer_channel_config_limits.max_channel_reserve_satoshis {
                        return Err(ChannelError::Close(format!("channel_reserve_satoshis ({}) is higher than the user specified limit ({})", msg.channel_reserve_satoshis, config.peer_channel_config_limits.max_channel_reserve_satoshis)));
                }
                if msg.max_accepted_htlcs < config.peer_channel_config_limits.min_max_accepted_htlcs {
                        return Err(ChannelError::Close(format!("max_accepted_htlcs ({}) is less than the user specified limit ({})", msg.max_accepted_htlcs, config.peer_channel_config_limits.min_max_accepted_htlcs)));
                }
                if msg.dust_limit_satoshis < MIN_CHAN_DUST_LIMIT_SATOSHIS {
                        return Err(ChannelError::Close(format!("dust_limit_satoshis ({}) is less than the implementation limit ({})", msg.dust_limit_satoshis, MIN_CHAN_DUST_LIMIT_SATOSHIS)));
                }
                if msg.dust_limit_satoshis >  MAX_CHAN_DUST_LIMIT_SATOSHIS {
                        return Err(ChannelError::Close(format!("dust_limit_satoshis ({}) is greater than the implementation limit ({})", msg.dust_limit_satoshis, MAX_CHAN_DUST_LIMIT_SATOSHIS)));
                }

                // Convert things into internal flags and prep our state:

                let announce = if (msg.channel_flags & 1) == 1 { true } else { false };
                if config.peer_channel_config_limits.force_announced_channel_preference {
                        if local_config.announced_channel != announce {
                                return Err(ChannelError::Close("Peer tried to open channel but their announcement preference is different from ours".to_owned()));
                        }
                }
                // we either accept their preference or the preferences match
                local_config.announced_channel = announce;

                let holder_selected_channel_reserve_satoshis = Channel::<Signer>::get_holder_selected_channel_reserve_satoshis(msg.funding_satoshis);
                if holder_selected_channel_reserve_satoshis < MIN_CHAN_DUST_LIMIT_SATOSHIS {
                        return Err(ChannelError::Close(format!("Suitable channel reserve not found. remote_channel_reserve was ({}). dust_limit_satoshis is ({}).", holder_selected_channel_reserve_satoshis, MIN_CHAN_DUST_LIMIT_SATOSHIS)));
                }
                if msg.channel_reserve_satoshis < MIN_CHAN_DUST_LIMIT_SATOSHIS {
                        log_debug!(logger, "channel_reserve_satoshis ({}) is smaller than our dust limit ({}). We can broadcast stale states without any risk, implying this channel is very insecure for our counterparty.",
                                msg.channel_reserve_satoshis, MIN_CHAN_DUST_LIMIT_SATOSHIS);
                }
                if holder_selected_channel_reserve_satoshis < msg.dust_limit_satoshis {
                        return Err(ChannelError::Close(format!("Dust limit ({}) too high for the channel reserve we require the remote to keep ({})", msg.dust_limit_satoshis, holder_selected_channel_reserve_satoshis)));
                }

                // check if the funder's amount for the initial commitment tx is sufficient
                // for full fee payment plus a few HTLCs to ensure the channel will be useful.
                let funders_amount_msat = msg.funding_satoshis * 1000 - msg.push_msat;
                let commitment_tx_fee = Self::commit_tx_fee_msat(msg.feerate_per_kw, MIN_AFFORDABLE_HTLC_COUNT) / 1000;
                if funders_amount_msat / 1000 < commitment_tx_fee {
                        return Err(ChannelError::Close(format!("Funding amount ({} sats) can't even pay fee for initial commitment transaction fee of {} sats.", funders_amount_msat / 1000, commitment_tx_fee)));
                }

                let to_remote_satoshis = funders_amount_msat / 1000 - commitment_tx_fee;
                // While it's reasonable for us to not meet the channel reserve initially (if they don't
                // want to push much to us), our counterparty should always have more than our reserve.
                if to_remote_satoshis < holder_selected_channel_reserve_satoshis {
                        return Err(ChannelError::Close("Insufficient funding amount for initial reserve".to_owned()));
                }

                let counterparty_shutdown_scriptpubkey = if their_features.supports_upfront_shutdown_script() {
                        match &msg.shutdown_scriptpubkey {
                                &OptionalField::Present(ref script) => {
                                        // Peer is signaling upfront_shutdown and has opt-out with a 0-length script. We don't enforce anything
                                        if script.len() == 0 {
                                                None
                                        } else {
                                                if !script::is_bolt2_compliant(&script, their_features) {
                                                        return Err(ChannelError::Close(format!("Peer is signaling upfront_shutdown but has provided an unacceptable scriptpubkey format: {}", script)))
                                                }
                                                Some(script.clone())
                                        }
                                },
                                // Peer is signaling upfront shutdown but don't opt-out with correct mechanism (a.k.a 0-length script). Peer looks buggy, we fail the channel
                                &OptionalField::Absent => {
                                        return Err(ChannelError::Close("Peer is signaling upfront_shutdown but we don't get any script. Use 0-length script to opt-out".to_owned()));
                                }
                        }
                } else { None };

                let shutdown_scriptpubkey = if config.channel_options.commit_upfront_shutdown_pubkey {
                        Some(keys_provider.get_shutdown_scriptpubkey())
                } else { None };

                if let Some(shutdown_scriptpubkey) = &shutdown_scriptpubkey {
                        if !shutdown_scriptpubkey.is_compatible(&their_features) {
                                return Err(ChannelError::Close(format!("Provided a scriptpubkey format not accepted by peer: {}", shutdown_scriptpubkey)));
                        }
                }

                let mut secp_ctx = Secp256k1::new();
                secp_ctx.seeded_randomize(&keys_provider.get_secure_random_bytes());

                let chan = Channel {
                        user_id,
                        config: local_config,

                        channel_id: msg.temporary_channel_id,
                        channel_state: (ChannelState::OurInitSent as u32) | (ChannelState::TheirInitSent as u32),
                        secp_ctx,

                        latest_monitor_update_id: 0,

                        holder_signer,
                        shutdown_scriptpubkey,
                        destination_script: keys_provider.get_destination_script(),

                        cur_holder_commitment_transaction_number: INITIAL_COMMITMENT_NUMBER,
                        cur_counterparty_commitment_transaction_number: INITIAL_COMMITMENT_NUMBER,
                        value_to_self_msat: msg.push_msat,

                        pending_inbound_htlcs: Vec::new(),
                        pending_outbound_htlcs: Vec::new(),
                        holding_cell_htlc_updates: Vec::new(),
                        pending_update_fee: None,
                        holding_cell_update_fee: None,
                        next_holder_htlc_id: 0,
                        next_counterparty_htlc_id: 0,
                        update_time_counter: 1,

                        resend_order: RAACommitmentOrder::CommitmentFirst,

                        monitor_pending_funding_locked: false,
                        monitor_pending_revoke_and_ack: false,
                        monitor_pending_commitment_signed: false,
                        monitor_pending_forwards: Vec::new(),
                        monitor_pending_failures: Vec::new(),
                        monitor_pending_finalized_fulfills: Vec::new(),

                        #[cfg(debug_assertions)]
                        holder_max_commitment_tx_output: Mutex::new((msg.push_msat, msg.funding_satoshis * 1000 - msg.push_msat)),
                        #[cfg(debug_assertions)]
                        counterparty_max_commitment_tx_output: Mutex::new((msg.push_msat, msg.funding_satoshis * 1000 - msg.push_msat)),

                        last_sent_closing_fee: None,
                        pending_counterparty_closing_signed: None,
                        closing_fee_limits: None,
                        target_closing_feerate_sats_per_kw: None,

                        funding_tx_confirmed_in: None,
                        funding_tx_confirmation_height: 0,
                        short_channel_id: None,
                        channel_creation_height: current_chain_height,

                        feerate_per_kw: msg.feerate_per_kw,
                        channel_value_satoshis: msg.funding_satoshis,
                        counterparty_dust_limit_satoshis: msg.dust_limit_satoshis,
                        holder_dust_limit_satoshis: MIN_CHAN_DUST_LIMIT_SATOSHIS,
                        counterparty_max_htlc_value_in_flight_msat: cmp::min(msg.max_htlc_value_in_flight_msat, msg.funding_satoshis * 1000),
                        holder_max_htlc_value_in_flight_msat: Self::get_holder_max_htlc_value_in_flight_msat(msg.funding_satoshis),
                        counterparty_selected_channel_reserve_satoshis: Some(msg.channel_reserve_satoshis),
                        holder_selected_channel_reserve_satoshis,
                        counterparty_htlc_minimum_msat: msg.htlc_minimum_msat,
                        holder_htlc_minimum_msat: if config.own_channel_config.our_htlc_minimum_msat == 0 { 1 } else { config.own_channel_config.our_htlc_minimum_msat },
                        counterparty_max_accepted_htlcs: msg.max_accepted_htlcs,
                        minimum_depth: Some(config.own_channel_config.minimum_depth),

                        counterparty_forwarding_info: None,

                        channel_transaction_parameters: ChannelTransactionParameters {
                                holder_pubkeys: pubkeys,
                                holder_selected_contest_delay: config.own_channel_config.our_to_self_delay,
                                is_outbound_from_holder: false,
                                counterparty_parameters: Some(CounterpartyChannelTransactionParameters {
                                        selected_contest_delay: msg.to_self_delay,
                                        pubkeys: counterparty_pubkeys,
                                }),
                                funding_outpoint: None,
                                opt_anchors: None
                        },
                        funding_transaction: None,

                        counterparty_cur_commitment_point: Some(msg.first_per_commitment_point),
                        counterparty_prev_commitment_point: None,
                        counterparty_node_id,

                        counterparty_shutdown_scriptpubkey,

                        commitment_secrets: CounterpartyCommitmentSecrets::new(),

                        channel_update_status: ChannelUpdateStatus::Enabled,
                        closing_signed_in_flight: false,

                        announcement_sigs: None,

                        #[cfg(any(test, feature = "fuzztarget"))]
                        next_local_commitment_tx_fee_info_cached: Mutex::new(None),
                        #[cfg(any(test, feature = "fuzztarget"))]
                        next_remote_commitment_tx_fee_info_cached: Mutex::new(None),

                        workaround_lnd_bug_4006: None,

                        #[cfg(any(test, feature = "fuzztarget"))]
                        historical_inbound_htlc_fulfills: HashSet::new(),

                        channel_type,
                };

                Ok(chan)
        }

        /// Transaction nomenclature is somewhat confusing here as there are many different cases - a
        /// transaction is referred to as "a's transaction" implying that a will be able to broadcast
        /// the transaction. Thus, b will generally be sending a signature over such a transaction to
        /// a, and a can revoke the transaction by providing b the relevant per_commitment_secret. As
        /// such, a transaction is generally the result of b increasing the amount paid to a (or adding
        /// an HTLC to a).
        /// @local is used only to convert relevant internal structures which refer to remote vs local
        /// to decide value of outputs and direction of HTLCs.
        /// @generated_by_local is used to determine *which* HTLCs to include - noting that the HTLC
        /// state may indicate that one peer has informed the other that they'd like to add an HTLC but
        /// have not yet committed it. Such HTLCs will only be included in transactions which are being
        /// generated by the peer which proposed adding the HTLCs, and thus we need to understand both
        /// which peer generated this transaction and "to whom" this transaction flows.
        #[inline]
        fn build_commitment_transaction<L: Deref>(&self, commitment_number: u64, keys: &TxCreationKeys, local: bool, generated_by_local: bool, logger: &L) -> CommitmentStats
                where L::Target: Logger
        {
                let mut included_dust_htlcs: Vec<(HTLCOutputInCommitment, Option<&HTLCSource>)> = Vec::new();
                let num_htlcs = self.pending_inbound_htlcs.len() + self.pending_outbound_htlcs.len();
                let mut included_non_dust_htlcs: Vec<(HTLCOutputInCommitment, Option<&HTLCSource>)> = Vec::with_capacity(num_htlcs);

                let broadcaster_dust_limit_satoshis = if local { self.holder_dust_limit_satoshis } else { self.counterparty_dust_limit_satoshis };
                let mut remote_htlc_total_msat = 0;
                let mut local_htlc_total_msat = 0;
                let mut value_to_self_msat_offset = 0;

                let mut feerate_per_kw = self.feerate_per_kw;
                if let Some((feerate, update_state)) = self.pending_update_fee {
                        if match update_state {
                                // Note that these match the inclusion criteria when scanning
                                // pending_inbound_htlcs below.
                                FeeUpdateState::RemoteAnnounced => { debug_assert!(!self.is_outbound()); !generated_by_local },
                                FeeUpdateState::AwaitingRemoteRevokeToAnnounce => { debug_assert!(!self.is_outbound()); !generated_by_local },
                                FeeUpdateState::Outbound => { assert!(self.is_outbound());  generated_by_local },
                        } {
                                feerate_per_kw = feerate;
                        }
                }

                log_trace!(logger, "Building commitment transaction number {} (really {} xor {}) for channel {} for {}, generated by {} with fee {}...",
                        commitment_number, (INITIAL_COMMITMENT_NUMBER - commitment_number),
                        get_commitment_transaction_number_obscure_factor(&self.get_holder_pubkeys().payment_point, &self.get_counterparty_pubkeys().payment_point, self.is_outbound()),
                        log_bytes!(self.channel_id), if local { "us" } else { "remote" }, if generated_by_local { "us" } else { "remote" }, feerate_per_kw);

                macro_rules! get_htlc_in_commitment {
                        ($htlc: expr, $offered: expr) => {
                                HTLCOutputInCommitment {
                                        offered: $offered,
                                        amount_msat: $htlc.amount_msat,
                                        cltv_expiry: $htlc.cltv_expiry,
                                        payment_hash: $htlc.payment_hash,
                                        transaction_output_index: None
                                }
                        }
                }

                macro_rules! add_htlc_output {
                        ($htlc: expr, $outbound: expr, $source: expr, $state_name: expr) => {
                                if $outbound == local { // "offered HTLC output"
                                        let htlc_in_tx = get_htlc_in_commitment!($htlc, true);
                                        if $htlc.amount_msat / 1000 >= broadcaster_dust_limit_satoshis + (feerate_per_kw as u64 * HTLC_TIMEOUT_TX_WEIGHT / 1000) {
                                                log_trace!(logger, "   ...including {} {} HTLC {} (hash {}) with value {}", if $outbound { "outbound" } else { "inbound" }, $state_name, $htlc.htlc_id, log_bytes!($htlc.payment_hash.0), $htlc.amount_msat);
                                                included_non_dust_htlcs.push((htlc_in_tx, $source));
                                        } else {
                                                log_trace!(logger, "   ...including {} {} dust HTLC {} (hash {}) with value {} due to dust limit", if $outbound { "outbound" } else { "inbound" }, $state_name, $htlc.htlc_id, log_bytes!($htlc.payment_hash.0), $htlc.amount_msat);
                                                included_dust_htlcs.push((htlc_in_tx, $source));
                                        }
                                } else {
                                        let htlc_in_tx = get_htlc_in_commitment!($htlc, false);
                                        if $htlc.amount_msat / 1000 >= broadcaster_dust_limit_satoshis + (feerate_per_kw as u64 * HTLC_SUCCESS_TX_WEIGHT / 1000) {
                                                log_trace!(logger, "   ...including {} {} HTLC {} (hash {}) with value {}", if $outbound { "outbound" } else { "inbound" }, $state_name, $htlc.htlc_id, log_bytes!($htlc.payment_hash.0), $htlc.amount_msat);
                                                included_non_dust_htlcs.push((htlc_in_tx, $source));
                                        } else {
                                                log_trace!(logger, "   ...including {} {} dust HTLC {} (hash {}) with value {}", if $outbound { "outbound" } else { "inbound" }, $state_name, $htlc.htlc_id, log_bytes!($htlc.payment_hash.0), $htlc.amount_msat);
                                                included_dust_htlcs.push((htlc_in_tx, $source));
                                        }
                                }
                        }
                }

                for ref htlc in self.pending_inbound_htlcs.iter() {
                        let (include, state_name) = match htlc.state {
                                InboundHTLCState::RemoteAnnounced(_) => (!generated_by_local, "RemoteAnnounced"),
                                InboundHTLCState::AwaitingRemoteRevokeToAnnounce(_) => (!generated_by_local, "AwaitingRemoteRevokeToAnnounce"),
                                InboundHTLCState::AwaitingAnnouncedRemoteRevoke(_) => (true, "AwaitingAnnouncedRemoteRevoke"),
                                InboundHTLCState::Committed => (true, "Committed"),
                                InboundHTLCState::LocalRemoved(_) => (!generated_by_local, "LocalRemoved"),
                        };

                        if include {
                                add_htlc_output!(htlc, false, None, state_name);
                                remote_htlc_total_msat += htlc.amount_msat;
                        } else {
                                log_trace!(logger, "   ...not including inbound HTLC {} (hash {}) with value {} due to state ({})", htlc.htlc_id, log_bytes!(htlc.payment_hash.0), htlc.amount_msat, state_name);
                                match &htlc.state {
                                        &InboundHTLCState::LocalRemoved(ref reason) => {
                                                if generated_by_local {
                                                        if let &InboundHTLCRemovalReason::Fulfill(_) = reason {
                                                                value_to_self_msat_offset += htlc.amount_msat as i64;
                                                        }
                                                }
                                        },
                                        _ => {},
                                }
                        }
                }

                for ref htlc in self.pending_outbound_htlcs.iter() {
                        let (include, state_name) = match htlc.state {
                                OutboundHTLCState::LocalAnnounced(_) => (generated_by_local, "LocalAnnounced"),
                                OutboundHTLCState::Committed => (true, "Committed"),
                                OutboundHTLCState::RemoteRemoved(_) => (generated_by_local, "RemoteRemoved"),
                                OutboundHTLCState::AwaitingRemoteRevokeToRemove(_) => (generated_by_local, "AwaitingRemoteRevokeToRemove"),
                                OutboundHTLCState::AwaitingRemovedRemoteRevoke(_) => (false, "AwaitingRemovedRemoteRevoke"),
                        };

                        if include {
                                add_htlc_output!(htlc, true, Some(&htlc.source), state_name);
                                local_htlc_total_msat += htlc.amount_msat;
                        } else {
                                log_trace!(logger, "   ...not including outbound HTLC {} (hash {}) with value {} due to state ({})", htlc.htlc_id, log_bytes!(htlc.payment_hash.0), htlc.amount_msat, state_name);
                                match htlc.state {
                                        OutboundHTLCState::AwaitingRemoteRevokeToRemove(None)|OutboundHTLCState::AwaitingRemovedRemoteRevoke(None) => {
                                                value_to_self_msat_offset -= htlc.amount_msat as i64;
                                        },
                                        OutboundHTLCState::RemoteRemoved(None) => {
                                                if !generated_by_local {
                                                        value_to_self_msat_offset -= htlc.amount_msat as i64;
                                                }
                                        },
                                        _ => {},
                                }
                        }
                }

                let mut value_to_self_msat: i64 = (self.value_to_self_msat - local_htlc_total_msat) as i64 + value_to_self_msat_offset;
                assert!(value_to_self_msat >= 0);
                // Note that in case they have several just-awaiting-last-RAA fulfills in-progress (ie
                // AwaitingRemoteRevokeToRemove or AwaitingRemovedRemoteRevoke) we may have allowed them to
                // "violate" their reserve value by couting those against it. Thus, we have to convert
                // everything to i64 before subtracting as otherwise we can overflow.
                let mut value_to_remote_msat: i64 = (self.channel_value_satoshis * 1000) as i64 - (self.value_to_self_msat as i64) - (remote_htlc_total_msat as i64) - value_to_self_msat_offset;
                assert!(value_to_remote_msat >= 0);

                #[cfg(debug_assertions)]
                {
                        // Make sure that the to_self/to_remote is always either past the appropriate
                        // channel_reserve *or* it is making progress towards it.
                        let mut broadcaster_max_commitment_tx_output = if generated_by_local {
                                self.holder_max_commitment_tx_output.lock().unwrap()
                        } else {
                                self.counterparty_max_commitment_tx_output.lock().unwrap()
                        };
                        debug_assert!(broadcaster_max_commitment_tx_output.0 <= value_to_self_msat as u64 || value_to_self_msat / 1000 >= self.counterparty_selected_channel_reserve_satoshis.unwrap() as i64);
                        broadcaster_max_commitment_tx_output.0 = cmp::max(broadcaster_max_commitment_tx_output.0, value_to_self_msat as u64);
                        debug_assert!(broadcaster_max_commitment_tx_output.1 <= value_to_remote_msat as u64 || value_to_remote_msat / 1000 >= self.holder_selected_channel_reserve_satoshis as i64);
                        broadcaster_max_commitment_tx_output.1 = cmp::max(broadcaster_max_commitment_tx_output.1, value_to_remote_msat as u64);
                }

                let total_fee_sat = Channel::<Signer>::commit_tx_fee_sat(feerate_per_kw, included_non_dust_htlcs.len());
                let (value_to_self, value_to_remote) = if self.is_outbound() {
                        (value_to_self_msat / 1000 - total_fee_sat as i64, value_to_remote_msat / 1000)
                } else {
                        (value_to_self_msat / 1000, value_to_remote_msat / 1000 - total_fee_sat as i64)
                };

                let mut value_to_a = if local { value_to_self } else { value_to_remote };
                let mut value_to_b = if local { value_to_remote } else { value_to_self };
                let (funding_pubkey_a, funding_pubkey_b) = if local {
                        (self.get_holder_pubkeys().funding_pubkey, self.get_counterparty_pubkeys().funding_pubkey)
                } else {
                        (self.get_counterparty_pubkeys().funding_pubkey, self.get_holder_pubkeys().funding_pubkey)
                };

                if value_to_a >= (broadcaster_dust_limit_satoshis as i64) {
                        log_trace!(logger, "   ...including {} output with value {}", if local { "to_local" } else { "to_remote" }, value_to_a);
                } else {
                        value_to_a = 0;
                }

                if value_to_b >= (broadcaster_dust_limit_satoshis as i64) {
                        log_trace!(logger, "   ...including {} output with value {}", if local { "to_remote" } else { "to_local" }, value_to_b);
                } else {
                        value_to_b = 0;
                }

                let num_nondust_htlcs = included_non_dust_htlcs.len();

                let channel_parameters =
                        if local { self.channel_transaction_parameters.as_holder_broadcastable() }
                        else { self.channel_transaction_parameters.as_counterparty_broadcastable() };
                let tx = CommitmentTransaction::new_with_auxiliary_htlc_data(commitment_number,
                                                                             value_to_a as u64,
                                                                             value_to_b as u64,
                                                                             self.channel_transaction_parameters.opt_anchors.is_some(),
                                                                             funding_pubkey_a,
                                                                             funding_pubkey_b,
                                                                             keys.clone(),
                                                                             feerate_per_kw,
                                                                             &mut included_non_dust_htlcs,
                                                                             &channel_parameters
                );
                let mut htlcs_included = included_non_dust_htlcs;
                // The unwrap is safe, because all non-dust HTLCs have been assigned an output index
                htlcs_included.sort_unstable_by_key(|h| h.0.transaction_output_index.unwrap());
                htlcs_included.append(&mut included_dust_htlcs);

                // For the stats, trimmed-to-0 the value in msats accordingly
                value_to_self_msat = if (value_to_self_msat * 1000) < broadcaster_dust_limit_satoshis as i64 { 0 } else { value_to_self_msat };
                value_to_remote_msat = if (value_to_remote_msat * 1000) < broadcaster_dust_limit_satoshis as i64 { 0 } else { value_to_remote_msat };

                CommitmentStats {
                        tx,
                        feerate_per_kw,
                        total_fee_sat,
                        num_nondust_htlcs,
                        htlcs_included,
                        local_balance_msat: value_to_self_msat as u64,
                        remote_balance_msat: value_to_remote_msat as u64,
                }
        }

        #[inline]
        fn get_closing_scriptpubkey(&self) -> Script {
                // The shutdown scriptpubkey is set on channel opening when option_upfront_shutdown_script
                // is signaled. Otherwise, it is set when sending a shutdown message. Calling this method
                // outside of those situations will fail.
                self.shutdown_scriptpubkey.clone().unwrap().into_inner()
        }

        #[inline]
        fn get_closing_transaction_weight(&self, a_scriptpubkey: Option<&Script>, b_scriptpubkey: Option<&Script>) -> u64 {
                let mut ret =
                (4 +                                           // version
                 1 +                                           // input count
                 36 +                                          // prevout
                 1 +                                           // script length (0)
                 4 +                                           // sequence
                 1 +                                           // output count
                 4                                             // lock time
                 )*4 +                                         // * 4 for non-witness parts
                2 +                                            // witness marker and flag
                1 +                                            // witness element count
                4 +                                            // 4 element lengths (2 sigs, multisig dummy, and witness script)
                self.get_funding_redeemscript().len() as u64 + // funding witness script
                2*(1 + 71);                                    // two signatures + sighash type flags
                if let Some(spk) = a_scriptpubkey {
                        ret += ((8+1) +                            // output values and script length
                                spk.len() as u64) * 4;                 // scriptpubkey and witness multiplier
                }
                if let Some(spk) = b_scriptpubkey {
                        ret += ((8+1) +                            // output values and script length
                                spk.len() as u64) * 4;                 // scriptpubkey and witness multiplier
                }
                ret
        }

        #[inline]
        fn build_closing_transaction(&self, proposed_total_fee_satoshis: u64, skip_remote_output: bool) -> (ClosingTransaction, u64) {
                assert!(self.pending_inbound_htlcs.is_empty());
                assert!(self.pending_outbound_htlcs.is_empty());
                assert!(self.pending_update_fee.is_none());

                let mut total_fee_satoshis = proposed_total_fee_satoshis;
                let mut value_to_holder: i64 = (self.value_to_self_msat as i64) / 1000 - if self.is_outbound() { total_fee_satoshis as i64 } else { 0 };
                let mut value_to_counterparty: i64 = ((self.channel_value_satoshis * 1000 - self.value_to_self_msat) as i64 / 1000) - if self.is_outbound() { 0 } else { total_fee_satoshis as i64 };

                if value_to_holder < 0 {
                        assert!(self.is_outbound());
                        total_fee_satoshis += (-value_to_holder) as u64;
                } else if value_to_counterparty < 0 {
                        assert!(!self.is_outbound());
                        total_fee_satoshis += (-value_to_counterparty) as u64;
                }

                if skip_remote_output || value_to_counterparty as u64 <= self.holder_dust_limit_satoshis {
                        value_to_counterparty = 0;
                }

                if value_to_holder as u64 <= self.holder_dust_limit_satoshis {
                        value_to_holder = 0;
                }

                assert!(self.shutdown_scriptpubkey.is_some());
                let holder_shutdown_script = self.get_closing_scriptpubkey();
                let counterparty_shutdown_script = self.counterparty_shutdown_scriptpubkey.clone().unwrap();
                let funding_outpoint = self.funding_outpoint().into_bitcoin_outpoint();

                let closing_transaction = ClosingTransaction::new(value_to_holder as u64, value_to_counterparty as u64, holder_shutdown_script, counterparty_shutdown_script, funding_outpoint);
                (closing_transaction, total_fee_satoshis)
        }

        fn funding_outpoint(&self) -> OutPoint {
                self.channel_transaction_parameters.funding_outpoint.unwrap()
        }

        #[inline]
        /// Creates a set of keys for build_commitment_transaction to generate a transaction which our
        /// counterparty will sign (ie DO NOT send signatures over a transaction created by this to
        /// our counterparty!)
        /// The result is a transaction which we can revoke broadcastership of (ie a "local" transaction)
        /// TODO Some magic rust shit to compile-time check this?
        fn build_holder_transaction_keys(&self, commitment_number: u64) -> Result<TxCreationKeys, ChannelError> {
                let per_commitment_point = self.holder_signer.get_per_commitment_point(commitment_number, &self.secp_ctx);
                let delayed_payment_base = &self.get_holder_pubkeys().delayed_payment_basepoint;
                let htlc_basepoint = &self.get_holder_pubkeys().htlc_basepoint;
                let counterparty_pubkeys = self.get_counterparty_pubkeys();

                Ok(secp_check!(TxCreationKeys::derive_new(&self.secp_ctx, &per_commitment_point, delayed_payment_base, htlc_basepoint, &counterparty_pubkeys.revocation_basepoint, &counterparty_pubkeys.htlc_basepoint), "Local tx keys generation got bogus keys".to_owned()))
        }

        #[inline]
        /// Creates a set of keys for build_commitment_transaction to generate a transaction which we
        /// will sign and send to our counterparty.
        /// If an Err is returned, it is a ChannelError::Close (for get_outbound_funding_created)
        fn build_remote_transaction_keys(&self) -> Result<TxCreationKeys, ChannelError> {
                //TODO: Ensure that the payment_key derived here ends up in the library users' wallet as we
                //may see payments to it!
                let revocation_basepoint = &self.get_holder_pubkeys().revocation_basepoint;
                let htlc_basepoint = &self.get_holder_pubkeys().htlc_basepoint;
                let counterparty_pubkeys = self.get_counterparty_pubkeys();

                Ok(secp_check!(TxCreationKeys::derive_new(&self.secp_ctx, &self.counterparty_cur_commitment_point.unwrap(), &counterparty_pubkeys.delayed_payment_basepoint, &counterparty_pubkeys.htlc_basepoint, revocation_basepoint, htlc_basepoint), "Remote tx keys generation got bogus keys".to_owned()))
        }

        /// Gets the redeemscript for the funding transaction output (ie the funding transaction output
        /// pays to get_funding_redeemscript().to_v0_p2wsh()).
        /// Panics if called before accept_channel/new_from_req
        pub fn get_funding_redeemscript(&self) -> Script {
                make_funding_redeemscript(&self.get_holder_pubkeys().funding_pubkey, self.counterparty_funding_pubkey())
        }

        fn get_update_fulfill_htlc<L: Deref>(&mut self, htlc_id_arg: u64, payment_preimage_arg: PaymentPreimage, logger: &L) -> UpdateFulfillFetch where L::Target: Logger {
                // Either ChannelFunded got set (which means it won't be unset) or there is no way any
                // caller thought we could have something claimed (cause we wouldn't have accepted in an
                // incoming HTLC anyway). If we got to ShutdownComplete, callers aren't allowed to call us,
                // either.
                if (self.channel_state & (ChannelState::ChannelFunded as u32)) != (ChannelState::ChannelFunded as u32) {
                        panic!("Was asked to fulfill an HTLC when channel was not in an operational state");
                }
                assert_eq!(self.channel_state & ChannelState::ShutdownComplete as u32, 0);

                let payment_hash_calc = PaymentHash(Sha256::hash(&payment_preimage_arg.0[..]).into_inner());

                // ChannelManager may generate duplicate claims/fails due to HTLC update events from
                // on-chain ChannelsMonitors during block rescan. Ideally we'd figure out a way to drop
                // these, but for now we just have to treat them as normal.

                let mut pending_idx = core::usize::MAX;
                let mut htlc_value_msat = 0;
                for (idx, htlc) in self.pending_inbound_htlcs.iter().enumerate() {
                        if htlc.htlc_id == htlc_id_arg {
                                assert_eq!(htlc.payment_hash, payment_hash_calc);
                                match htlc.state {
                                        InboundHTLCState::Committed => {},
                                        InboundHTLCState::LocalRemoved(ref reason) => {
                                                if let &InboundHTLCRemovalReason::Fulfill(_) = reason {
                                                } else {
                                                        log_warn!(logger, "Have preimage and want to fulfill HTLC with payment hash {} we already failed against channel {}", log_bytes!(htlc.payment_hash.0), log_bytes!(self.channel_id()));
                                                        debug_assert!(false, "Tried to fulfill an HTLC that was already failed");
                                                }
                                                return UpdateFulfillFetch::DuplicateClaim {};
                                        },
                                        _ => {
                                                debug_assert!(false, "Have an inbound HTLC we tried to claim before it was fully committed to");
                                                // Don't return in release mode here so that we can update channel_monitor
                                        }
                                }
                                pending_idx = idx;
                                htlc_value_msat = htlc.amount_msat;
                                break;
                        }
                }
                if pending_idx == core::usize::MAX {
                        #[cfg(any(test, feature = "fuzztarget"))]
                        // If we failed to find an HTLC to fulfill, make sure it was previously fulfilled and
                        // this is simply a duplicate claim, not previously failed and we lost funds.
                        debug_assert!(self.historical_inbound_htlc_fulfills.contains(&htlc_id_arg));
                        return UpdateFulfillFetch::DuplicateClaim {};
                }

                // Now update local state:
                //
                // We have to put the payment_preimage in the channel_monitor right away here to ensure we
                // can claim it even if the channel hits the chain before we see their next commitment.
                self.latest_monitor_update_id += 1;
                let monitor_update = ChannelMonitorUpdate {
                        update_id: self.latest_monitor_update_id,
                        updates: vec![ChannelMonitorUpdateStep::PaymentPreimage {
                                payment_preimage: payment_preimage_arg.clone(),
                        }],
                };

                if (self.channel_state & (ChannelState::AwaitingRemoteRevoke as u32 | ChannelState::PeerDisconnected as u32 | ChannelState::MonitorUpdateFailed as u32)) != 0 {
                        for pending_update in self.holding_cell_htlc_updates.iter() {
                                match pending_update {
                                        &HTLCUpdateAwaitingACK::ClaimHTLC { htlc_id, .. } => {
                                                if htlc_id_arg == htlc_id {
                                                        // Make sure we don't leave latest_monitor_update_id incremented here:
                                                        self.latest_monitor_update_id -= 1;
                                                        #[cfg(any(test, feature = "fuzztarget"))]
                                                        debug_assert!(self.historical_inbound_htlc_fulfills.contains(&htlc_id_arg));
                                                        return UpdateFulfillFetch::DuplicateClaim {};
                                                }
                                        },
                                        &HTLCUpdateAwaitingACK::FailHTLC { htlc_id, .. } => {
                                                if htlc_id_arg == htlc_id {
                                                        log_warn!(logger, "Have preimage and want to fulfill HTLC with pending failure against channel {}", log_bytes!(self.channel_id()));
                                                        // TODO: We may actually be able to switch to a fulfill here, though its
                                                        // rare enough it may not be worth the complexity burden.
                                                        debug_assert!(false, "Tried to fulfill an HTLC that was already failed");
                                                        return UpdateFulfillFetch::NewClaim { monitor_update, htlc_value_msat, msg: None };
                                                }
                                        },
                                        _ => {}
                                }
                        }
                        log_trace!(logger, "Adding HTLC claim to holding_cell in channel {}! Current state: {}", log_bytes!(self.channel_id()), self.channel_state);
                        self.holding_cell_htlc_updates.push(HTLCUpdateAwaitingACK::ClaimHTLC {
                                payment_preimage: payment_preimage_arg, htlc_id: htlc_id_arg,
                        });
                        #[cfg(any(test, feature = "fuzztarget"))]
                        self.historical_inbound_htlc_fulfills.insert(htlc_id_arg);
                        return UpdateFulfillFetch::NewClaim { monitor_update, htlc_value_msat, msg: None };
                }
                #[cfg(any(test, feature = "fuzztarget"))]
                self.historical_inbound_htlc_fulfills.insert(htlc_id_arg);

                {
                        let htlc = &mut self.pending_inbound_htlcs[pending_idx];
                        if let InboundHTLCState::Committed = htlc.state {
                        } else {
                                debug_assert!(false, "Have an inbound HTLC we tried to claim before it was fully committed to");
                                return UpdateFulfillFetch::NewClaim { monitor_update, htlc_value_msat, msg: None };
                        }
                        log_trace!(logger, "Upgrading HTLC {} to LocalRemoved with a Fulfill in channel {}!", log_bytes!(htlc.payment_hash.0), log_bytes!(self.channel_id));
                        htlc.state = InboundHTLCState::LocalRemoved(InboundHTLCRemovalReason::Fulfill(payment_preimage_arg.clone()));
                }

                UpdateFulfillFetch::NewClaim {
                        monitor_update,
                        htlc_value_msat,
                        msg: Some(msgs::UpdateFulfillHTLC {
                                channel_id: self.channel_id(),
                                htlc_id: htlc_id_arg,
                                payment_preimage: payment_preimage_arg,
                        }),
                }
        }

        pub fn get_update_fulfill_htlc_and_commit<L: Deref>(&mut self, htlc_id: u64, payment_preimage: PaymentPreimage, logger: &L) -> Result<UpdateFulfillCommitFetch, (ChannelError, ChannelMonitorUpdate)> where L::Target: Logger {
                match self.get_update_fulfill_htlc(htlc_id, payment_preimage, logger) {
                        UpdateFulfillFetch::NewClaim { mut monitor_update, htlc_value_msat, msg: Some(update_fulfill_htlc) } => {
                                let (commitment, mut additional_update) = match self.send_commitment_no_status_check(logger) {
                                        Err(e) => return Err((e, monitor_update)),
                                        Ok(res) => res
                                };
                                // send_commitment_no_status_check may bump latest_monitor_id but we want them to be
                                // strictly increasing by one, so decrement it here.
                                self.latest_monitor_update_id = monitor_update.update_id;
                                monitor_update.updates.append(&mut additional_update.updates);
                                Ok(UpdateFulfillCommitFetch::NewClaim { monitor_update, htlc_value_msat, msgs: Some((update_fulfill_htlc, commitment)) })
                        },
                        UpdateFulfillFetch::NewClaim { monitor_update, htlc_value_msat, msg: None } =>
                                Ok(UpdateFulfillCommitFetch::NewClaim { monitor_update, htlc_value_msat, msgs: None }),
                        UpdateFulfillFetch::DuplicateClaim {} => Ok(UpdateFulfillCommitFetch::DuplicateClaim {}),
                }
        }

        /// We can only have one resolution per HTLC. In some cases around reconnect, we may fulfill
        /// an HTLC more than once or fulfill once and then attempt to fail after reconnect. We cannot,
        /// however, fail more than once as we wait for an upstream failure to be irrevocably committed
        /// before we fail backwards.
        /// If we do fail twice, we debug_assert!(false) and return Ok(None). Thus, will always return
        /// Ok(_) if debug assertions are turned on or preconditions are met.
        pub fn get_update_fail_htlc<L: Deref>(&mut self, htlc_id_arg: u64, err_packet: msgs::OnionErrorPacket, logger: &L) -> Result<Option<msgs::UpdateFailHTLC>, ChannelError> where L::Target: Logger {
                if (self.channel_state & (ChannelState::ChannelFunded as u32)) != (ChannelState::ChannelFunded as u32) {
                        panic!("Was asked to fail an HTLC when channel was not in an operational state");
                }
                assert_eq!(self.channel_state & ChannelState::ShutdownComplete as u32, 0);

                // ChannelManager may generate duplicate claims/fails due to HTLC update events from
                // on-chain ChannelsMonitors during block rescan. Ideally we'd figure out a way to drop
                // these, but for now we just have to treat them as normal.

                let mut pending_idx = core::usize::MAX;
                for (idx, htlc) in self.pending_inbound_htlcs.iter().enumerate() {
                        if htlc.htlc_id == htlc_id_arg {
                                match htlc.state {
                                        InboundHTLCState::Committed => {},
                                        InboundHTLCState::LocalRemoved(ref reason) => {
                                                if let &InboundHTLCRemovalReason::Fulfill(_) = reason {
                                                } else {
                                                        debug_assert!(false, "Tried to fail an HTLC that was already failed");
                                                }
                                                return Ok(None);
                                        },
                                        _ => {
                                                debug_assert!(false, "Have an inbound HTLC we tried to claim before it was fully committed to");
                                                return Err(ChannelError::Ignore(format!("Unable to find a pending HTLC which matched the given HTLC ID ({})", htlc.htlc_id)));
                                        }
                                }
                                pending_idx = idx;
                        }
                }
                if pending_idx == core::usize::MAX {
                        #[cfg(any(test, feature = "fuzztarget"))]
                        // If we failed to find an HTLC to fail, make sure it was previously fulfilled and this
                        // is simply a duplicate fail, not previously failed and we failed-back too early.
                        debug_assert!(self.historical_inbound_htlc_fulfills.contains(&htlc_id_arg));
                        return Ok(None);
                }

                // Now update local state:
                if (self.channel_state & (ChannelState::AwaitingRemoteRevoke as u32 | ChannelState::PeerDisconnected as u32 | ChannelState::MonitorUpdateFailed as u32)) != 0 {
                        for pending_update in self.holding_cell_htlc_updates.iter() {
                                match pending_update {
                                        &HTLCUpdateAwaitingACK::ClaimHTLC { htlc_id, .. } => {
                                                if htlc_id_arg == htlc_id {
                                                        #[cfg(any(test, feature = "fuzztarget"))]
                                                        debug_assert!(self.historical_inbound_htlc_fulfills.contains(&htlc_id_arg));
                                                        return Ok(None);
                                                }
                                        },
                                        &HTLCUpdateAwaitingACK::FailHTLC { htlc_id, .. } => {
                                                if htlc_id_arg == htlc_id {
                                                        debug_assert!(false, "Tried to fail an HTLC that was already failed");
                                                        return Err(ChannelError::Ignore("Unable to find a pending HTLC which matched the given HTLC ID".to_owned()));
                                                }
                                        },
                                        _ => {}
                                }
                        }
                        log_trace!(logger, "Placing failure for HTLC ID {} in holding cell in channel {}.", htlc_id_arg, log_bytes!(self.channel_id()));
                        self.holding_cell_htlc_updates.push(HTLCUpdateAwaitingACK::FailHTLC {
                                htlc_id: htlc_id_arg,
                                err_packet,
                        });
                        return Ok(None);
                }

                log_trace!(logger, "Failing HTLC ID {} back with a update_fail_htlc message in channel {}.", htlc_id_arg, log_bytes!(self.channel_id()));
                {
                        let htlc = &mut self.pending_inbound_htlcs[pending_idx];
                        htlc.state = InboundHTLCState::LocalRemoved(InboundHTLCRemovalReason::FailRelay(err_packet.clone()));
                }

                Ok(Some(msgs::UpdateFailHTLC {
                        channel_id: self.channel_id(),
                        htlc_id: htlc_id_arg,
                        reason: err_packet
                }))
        }

        // Message handlers:

        pub fn accept_channel(&mut self, msg: &msgs::AcceptChannel, config: &UserConfig, their_features: &InitFeatures) -> Result<(), ChannelError> {
                // Check sanity of message fields:
                if !self.is_outbound() {
                        return Err(ChannelError::Close("Got an accept_channel message from an inbound peer".to_owned()));
                }
                if self.channel_state != ChannelState::OurInitSent as u32 {
                        return Err(ChannelError::Close("Got an accept_channel message at a strange time".to_owned()));
                }
                if msg.dust_limit_satoshis > 21000000 * 100000000 {
                        return Err(ChannelError::Close(format!("Peer never wants payout outputs? dust_limit_satoshis was {}", msg.dust_limit_satoshis)));
                }
                if msg.channel_reserve_satoshis > self.channel_value_satoshis {
                        return Err(ChannelError::Close(format!("Bogus channel_reserve_satoshis ({}). Must not be greater than ({})", msg.channel_reserve_satoshis, self.channel_value_satoshis)));
                }
                if msg.dust_limit_satoshis > self.holder_selected_channel_reserve_satoshis {
                        return Err(ChannelError::Close(format!("Dust limit ({}) is bigger than our channel reserve ({})", msg.dust_limit_satoshis, self.holder_selected_channel_reserve_satoshis)));
                }
                let full_channel_value_msat = (self.channel_value_satoshis - msg.channel_reserve_satoshis) * 1000;
                if msg.htlc_minimum_msat >= full_channel_value_msat {
                        return Err(ChannelError::Close(format!("Minimum htlc value ({}) is full channel value ({})", msg.htlc_minimum_msat, full_channel_value_msat)));
                }
                let max_delay_acceptable = u16::min(config.peer_channel_config_limits.their_to_self_delay, MAX_LOCAL_BREAKDOWN_TIMEOUT);
                if msg.to_self_delay > max_delay_acceptable {
                        return Err(ChannelError::Close(format!("They wanted our payments to be delayed by a needlessly long period. Upper limit: {}. Actual: {}", max_delay_acceptable, msg.to_self_delay)));
                }
                if msg.max_accepted_htlcs < 1 {
                        return Err(ChannelError::Close("0 max_accepted_htlcs makes for a useless channel".to_owned()));
                }
                if msg.max_accepted_htlcs > MAX_HTLCS {
                        return Err(ChannelError::Close(format!("max_accepted_htlcs was {}. It must not be larger than {}", msg.max_accepted_htlcs, MAX_HTLCS)));
                }

                // Now check against optional parameters as set by config...
                if msg.htlc_minimum_msat > config.peer_channel_config_limits.max_htlc_minimum_msat {
                        return Err(ChannelError::Close(format!("htlc_minimum_msat ({}) is higher than the user specified limit ({})", msg.htlc_minimum_msat, config.peer_channel_config_limits.max_htlc_minimum_msat)));
                }
                if msg.max_htlc_value_in_flight_msat < config.peer_channel_config_limits.min_max_htlc_value_in_flight_msat {
                        return Err(ChannelError::Close(format!("max_htlc_value_in_flight_msat ({}) is less than the user specified limit ({})", msg.max_htlc_value_in_flight_msat, config.peer_channel_config_limits.min_max_htlc_value_in_flight_msat)));
                }
                if msg.channel_reserve_satoshis > config.peer_channel_config_limits.max_channel_reserve_satoshis {
                        return Err(ChannelError::Close(format!("channel_reserve_satoshis ({}) is higher than the user specified limit ({})", msg.channel_reserve_satoshis, config.peer_channel_config_limits.max_channel_reserve_satoshis)));
                }
                if msg.max_accepted_htlcs < config.peer_channel_config_limits.min_max_accepted_htlcs {
                        return Err(ChannelError::Close(format!("max_accepted_htlcs ({}) is less than the user specified limit ({})", msg.max_accepted_htlcs, config.peer_channel_config_limits.min_max_accepted_htlcs)));
                }
                if msg.dust_limit_satoshis < MIN_CHAN_DUST_LIMIT_SATOSHIS {
                        return Err(ChannelError::Close(format!("dust_limit_satoshis ({}) is less than the implementation limit ({})", msg.dust_limit_satoshis, MIN_CHAN_DUST_LIMIT_SATOSHIS)));
                }
                if msg.dust_limit_satoshis > MAX_CHAN_DUST_LIMIT_SATOSHIS {
                        return Err(ChannelError::Close(format!("dust_limit_satoshis ({}) is greater than the implementation limit ({})", msg.dust_limit_satoshis, MAX_CHAN_DUST_LIMIT_SATOSHIS)));
                }
                if msg.minimum_depth > config.peer_channel_config_limits.max_minimum_depth {
                        return Err(ChannelError::Close(format!("We consider the minimum depth to be unreasonably large. Expected minimum: ({}). Actual: ({})", config.peer_channel_config_limits.max_minimum_depth, msg.minimum_depth)));
                }
                if msg.minimum_depth == 0 {
                        // Note that if this changes we should update the serialization minimum version to
                        // indicate to older clients that they don't understand some features of the current
                        // channel.
                        return Err(ChannelError::Close("Minimum confirmation depth must be at least 1".to_owned()));
                }

                let counterparty_shutdown_scriptpubkey = if their_features.supports_upfront_shutdown_script() {
                        match &msg.shutdown_scriptpubkey {
                                &OptionalField::Present(ref script) => {
                                        // Peer is signaling upfront_shutdown and has opt-out with a 0-length script. We don't enforce anything
                                        if script.len() == 0 {
                                                None
                                        } else {
                                                if !script::is_bolt2_compliant(&script, their_features) {
                                                        return Err(ChannelError::Close(format!("Peer is signaling upfront_shutdown but has provided an unacceptable scriptpubkey format: {}", script)));
                                                }
                                                Some(script.clone())
                                        }
                                },
                                // Peer is signaling upfront shutdown but don't opt-out with correct mechanism (a.k.a 0-length script). Peer looks buggy, we fail the channel
                                &OptionalField::Absent => {
                                        return Err(ChannelError::Close("Peer is signaling upfront_shutdown but we don't get any script. Use 0-length script to opt-out".to_owned()));
                                }
                        }
                } else { None };

                self.counterparty_dust_limit_satoshis = msg.dust_limit_satoshis;
                self.counterparty_max_htlc_value_in_flight_msat = cmp::min(msg.max_htlc_value_in_flight_msat, self.channel_value_satoshis * 1000);
                self.counterparty_selected_channel_reserve_satoshis = Some(msg.channel_reserve_satoshis);
                self.counterparty_htlc_minimum_msat = msg.htlc_minimum_msat;
                self.counterparty_max_accepted_htlcs = msg.max_accepted_htlcs;
                self.minimum_depth = Some(msg.minimum_depth);

                let counterparty_pubkeys = ChannelPublicKeys {
                        funding_pubkey: msg.funding_pubkey,
                        revocation_basepoint: msg.revocation_basepoint,
                        payment_point: msg.payment_point,
                        delayed_payment_basepoint: msg.delayed_payment_basepoint,
                        htlc_basepoint: msg.htlc_basepoint
                };

                self.channel_transaction_parameters.counterparty_parameters = Some(CounterpartyChannelTransactionParameters {
                        selected_contest_delay: msg.to_self_delay,
                        pubkeys: counterparty_pubkeys,
                });

                self.counterparty_cur_commitment_point = Some(msg.first_per_commitment_point);
                self.counterparty_shutdown_scriptpubkey = counterparty_shutdown_scriptpubkey;

                self.channel_state = ChannelState::OurInitSent as u32 | ChannelState::TheirInitSent as u32;

                Ok(())
        }

        fn funding_created_signature<L: Deref>(&mut self, sig: &Signature, logger: &L) -> Result<(Txid, CommitmentTransaction, Signature), ChannelError> where L::Target: Logger {
                let funding_script = self.get_funding_redeemscript();

                let keys = self.build_holder_transaction_keys(self.cur_holder_commitment_transaction_number)?;
                let initial_commitment_tx = self.build_commitment_transaction(self.cur_holder_commitment_transaction_number, &keys, true, false, logger).tx;
                {
                        let trusted_tx = initial_commitment_tx.trust();
                        let initial_commitment_bitcoin_tx = trusted_tx.built_transaction();
                        let sighash = initial_commitment_bitcoin_tx.get_sighash_all(&funding_script, self.channel_value_satoshis);
                        // They sign the holder commitment transaction...
                        log_trace!(logger, "Checking funding_created tx signature {} by key {} against tx {} (sighash {}) with redeemscript {} for channel {}.",
                                log_bytes!(sig.serialize_compact()[..]), log_bytes!(self.counterparty_funding_pubkey().serialize()),
                                encode::serialize_hex(&initial_commitment_bitcoin_tx.transaction), log_bytes!(sighash[..]),
                                encode::serialize_hex(&funding_script), log_bytes!(self.channel_id()));
                        secp_check!(self.secp_ctx.verify(&sighash, &sig, self.counterparty_funding_pubkey()), "Invalid funding_created signature from peer".to_owned());
                }

                let counterparty_keys = self.build_remote_transaction_keys()?;
                let counterparty_initial_commitment_tx = self.build_commitment_transaction(self.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, false, logger).tx;

                let counterparty_trusted_tx = counterparty_initial_commitment_tx.trust();
                let counterparty_initial_bitcoin_tx = counterparty_trusted_tx.built_transaction();
                log_trace!(logger, "Initial counterparty tx for channel {} is: txid {} tx {}",
                        log_bytes!(self.channel_id()), counterparty_initial_bitcoin_tx.txid, encode::serialize_hex(&counterparty_initial_bitcoin_tx.transaction));

                let counterparty_signature = self.holder_signer.sign_counterparty_commitment(&counterparty_initial_commitment_tx, &self.secp_ctx)
                                .map_err(|_| ChannelError::Close("Failed to get signatures for new commitment_signed".to_owned()))?.0;

                // We sign "counterparty" commitment transaction, allowing them to broadcast the tx if they wish.
                Ok((counterparty_initial_bitcoin_tx.txid, initial_commitment_tx, counterparty_signature))
        }

        fn counterparty_funding_pubkey(&self) -> &PublicKey {
                &self.get_counterparty_pubkeys().funding_pubkey
        }

        pub fn funding_created<L: Deref>(&mut self, msg: &msgs::FundingCreated, best_block: BestBlock, logger: &L) -> Result<(msgs::FundingSigned, ChannelMonitor<Signer>), ChannelError> where L::Target: Logger {
                if self.is_outbound() {
                        return Err(ChannelError::Close("Received funding_created for an outbound channel?".to_owned()));
                }
                if self.channel_state != (ChannelState::OurInitSent as u32 | ChannelState::TheirInitSent as u32) {
                        // BOLT 2 says that if we disconnect before we send funding_signed we SHOULD NOT
                        // remember the channel, so it's safe to just send an error_message here and drop the
                        // channel.
                        return Err(ChannelError::Close("Received funding_created after we got the channel!".to_owned()));
                }
                if self.commitment_secrets.get_min_seen_secret() != (1 << 48) ||
                                self.cur_counterparty_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER ||
                                self.cur_holder_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER {
                        panic!("Should not have advanced channel commitment tx numbers prior to funding_created");
                }

                let funding_txo = OutPoint { txid: msg.funding_txid, index: msg.funding_output_index };
                self.channel_transaction_parameters.funding_outpoint = Some(funding_txo);
                // This is an externally observable change before we finish all our checks.  In particular
                // funding_created_signature may fail.
                self.holder_signer.ready_channel(&self.channel_transaction_parameters);

                let (counterparty_initial_commitment_txid, initial_commitment_tx, signature) = match self.funding_created_signature(&msg.signature, logger) {
                        Ok(res) => res,
                        Err(ChannelError::Close(e)) => {
                                self.channel_transaction_parameters.funding_outpoint = None;
                                return Err(ChannelError::Close(e));
                        },
                        Err(e) => {
                                // The only error we know how to handle is ChannelError::Close, so we fall over here
                                // to make sure we don't continue with an inconsistent state.
                                panic!("unexpected error type from funding_created_signature {:?}", e);
                        }
                };

                let holder_commitment_tx = HolderCommitmentTransaction::new(
                        initial_commitment_tx,
                        msg.signature,
                        Vec::new(),
                        &self.get_holder_pubkeys().funding_pubkey,
                        self.counterparty_funding_pubkey()
                );

                self.holder_signer.validate_holder_commitment(&holder_commitment_tx)
                        .map_err(|_| ChannelError::Close("Failed to validate our commitment".to_owned()))?;

                // Now that we're past error-generating stuff, update our local state:

                let funding_redeemscript = self.get_funding_redeemscript();
                let funding_txo_script = funding_redeemscript.to_v0_p2wsh();
                let obscure_factor = get_commitment_transaction_number_obscure_factor(&self.get_holder_pubkeys().payment_point, &self.get_counterparty_pubkeys().payment_point, self.is_outbound());
                let shutdown_script = self.shutdown_scriptpubkey.clone().map(|script| script.into_inner());
                let channel_monitor = ChannelMonitor::new(self.secp_ctx.clone(), self.holder_signer.clone(),
                                                          shutdown_script, self.get_holder_selected_contest_delay(),
                                                          &self.destination_script, (funding_txo, funding_txo_script.clone()),
                                                          &self.channel_transaction_parameters,
                                                          funding_redeemscript.clone(), self.channel_value_satoshis,
                                                          obscure_factor,
                                                          holder_commitment_tx, best_block);

                channel_monitor.provide_latest_counterparty_commitment_tx(counterparty_initial_commitment_txid, Vec::new(), self.cur_counterparty_commitment_transaction_number, self.counterparty_cur_commitment_point.unwrap(), logger);

                self.channel_state = ChannelState::FundingSent as u32;
                self.channel_id = funding_txo.to_channel_id();
                self.cur_counterparty_commitment_transaction_number -= 1;
                self.cur_holder_commitment_transaction_number -= 1;

                log_info!(logger, "Generated funding_signed for peer for channel {}", log_bytes!(self.channel_id()));

                Ok((msgs::FundingSigned {
                        channel_id: self.channel_id,
                        signature
                }, channel_monitor))
        }

        /// Handles a funding_signed message from the remote end.
        /// If this call is successful, broadcast the funding transaction (and not before!)
        pub fn funding_signed<L: Deref>(&mut self, msg: &msgs::FundingSigned, best_block: BestBlock, logger: &L) -> Result<(ChannelMonitor<Signer>, Transaction), ChannelError> where L::Target: Logger {
                if !self.is_outbound() {
                        return Err(ChannelError::Close("Received funding_signed for an inbound channel?".to_owned()));
                }
                if self.channel_state & !(ChannelState::MonitorUpdateFailed as u32) != ChannelState::FundingCreated as u32 {
                        return Err(ChannelError::Close("Received funding_signed in strange state!".to_owned()));
                }
                if self.commitment_secrets.get_min_seen_secret() != (1 << 48) ||
                                self.cur_counterparty_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER ||
                                self.cur_holder_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER {
                        panic!("Should not have advanced channel commitment tx numbers prior to funding_created");
                }

                let funding_script = self.get_funding_redeemscript();

                let counterparty_keys = self.build_remote_transaction_keys()?;
                let counterparty_initial_commitment_tx = self.build_commitment_transaction(self.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, false, logger).tx;
                let counterparty_trusted_tx = counterparty_initial_commitment_tx.trust();
                let counterparty_initial_bitcoin_tx = counterparty_trusted_tx.built_transaction();

                log_trace!(logger, "Initial counterparty tx for channel {} is: txid {} tx {}",
                        log_bytes!(self.channel_id()), counterparty_initial_bitcoin_tx.txid, encode::serialize_hex(&counterparty_initial_bitcoin_tx.transaction));

                let holder_signer = self.build_holder_transaction_keys(self.cur_holder_commitment_transaction_number)?;
                let initial_commitment_tx = self.build_commitment_transaction(self.cur_holder_commitment_transaction_number, &holder_signer, true, false, logger).tx;
                {
                        let trusted_tx = initial_commitment_tx.trust();
                        let initial_commitment_bitcoin_tx = trusted_tx.built_transaction();
                        let sighash = initial_commitment_bitcoin_tx.get_sighash_all(&funding_script, self.channel_value_satoshis);
                        // They sign our commitment transaction, allowing us to broadcast the tx if we wish.
                        if let Err(_) = self.secp_ctx.verify(&sighash, &msg.signature, &self.get_counterparty_pubkeys().funding_pubkey) {
                                return Err(ChannelError::Close("Invalid funding_signed signature from peer".to_owned()));
                        }
                }

                let holder_commitment_tx = HolderCommitmentTransaction::new(
                        initial_commitment_tx,
                        msg.signature,
                        Vec::new(),
                        &self.get_holder_pubkeys().funding_pubkey,
                        self.counterparty_funding_pubkey()
                );

                self.holder_signer.validate_holder_commitment(&holder_commitment_tx)
                        .map_err(|_| ChannelError::Close("Failed to validate our commitment".to_owned()))?;


                let funding_redeemscript = self.get_funding_redeemscript();
                let funding_txo = self.get_funding_txo().unwrap();
                let funding_txo_script = funding_redeemscript.to_v0_p2wsh();
                let obscure_factor = get_commitment_transaction_number_obscure_factor(&self.get_holder_pubkeys().payment_point, &self.get_counterparty_pubkeys().payment_point, self.is_outbound());
                let shutdown_script = self.shutdown_scriptpubkey.clone().map(|script| script.into_inner());
                let channel_monitor = ChannelMonitor::new(self.secp_ctx.clone(), self.holder_signer.clone(),
                                                          shutdown_script, self.get_holder_selected_contest_delay(),
                                                          &self.destination_script, (funding_txo, funding_txo_script),
                                                          &self.channel_transaction_parameters,
                                                          funding_redeemscript.clone(), self.channel_value_satoshis,
                                                          obscure_factor,
                                                          holder_commitment_tx, best_block);

                channel_monitor.provide_latest_counterparty_commitment_tx(counterparty_initial_bitcoin_tx.txid, Vec::new(), self.cur_counterparty_commitment_transaction_number, self.counterparty_cur_commitment_point.unwrap(), logger);

                assert_eq!(self.channel_state & (ChannelState::MonitorUpdateFailed as u32), 0); // We have no had any monitor(s) yet to fail update!
                self.channel_state = ChannelState::FundingSent as u32;
                self.cur_holder_commitment_transaction_number -= 1;
                self.cur_counterparty_commitment_transaction_number -= 1;

                log_info!(logger, "Received funding_signed from peer for channel {}", log_bytes!(self.channel_id()));

                Ok((channel_monitor, self.funding_transaction.as_ref().cloned().unwrap()))
        }

        pub fn funding_locked<L: Deref>(&mut self, msg: &msgs::FundingLocked, logger: &L) -> Result<(), ChannelError> where L::Target: Logger {
                if self.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 {
                        self.workaround_lnd_bug_4006 = Some(msg.clone());
                        return Err(ChannelError::Ignore("Peer sent funding_locked when we needed a channel_reestablish. The peer is likely lnd, see https://github.com/lightningnetwork/lnd/issues/4006".to_owned()));
                }

                let non_shutdown_state = self.channel_state & (!MULTI_STATE_FLAGS);

                if non_shutdown_state == ChannelState::FundingSent as u32 {
                        self.channel_state |= ChannelState::TheirFundingLocked as u32;
                } else if non_shutdown_state == (ChannelState::FundingSent as u32 | ChannelState::OurFundingLocked as u32) {
                        self.channel_state = ChannelState::ChannelFunded as u32 | (self.channel_state & MULTI_STATE_FLAGS);
                        self.update_time_counter += 1;
                } else if (self.channel_state & (ChannelState::ChannelFunded as u32) != 0 &&
                                 // Note that funding_signed/funding_created will have decremented both by 1!
                                 self.cur_holder_commitment_transaction_number == INITIAL_COMMITMENT_NUMBER - 1 &&
                                 self.cur_counterparty_commitment_transaction_number == INITIAL_COMMITMENT_NUMBER - 1) ||
                                // If we reconnected before sending our funding locked they may still resend theirs:
                                (self.channel_state & (ChannelState::FundingSent as u32 | ChannelState::TheirFundingLocked as u32) ==
                                                      (ChannelState::FundingSent as u32 | ChannelState::TheirFundingLocked as u32)) {
                        if self.counterparty_cur_commitment_point != Some(msg.next_per_commitment_point) {
                                return Err(ChannelError::Close("Peer sent a reconnect funding_locked with a different point".to_owned()));
                        }
                        // They probably disconnected/reconnected and re-sent the funding_locked, which is required
                        return Ok(());
                } else {
                        return Err(ChannelError::Close("Peer sent a funding_locked at a strange time".to_owned()));
                }

                self.counterparty_prev_commitment_point = self.counterparty_cur_commitment_point;
                self.counterparty_cur_commitment_point = Some(msg.next_per_commitment_point);

                log_info!(logger, "Received funding_locked from peer for channel {}", log_bytes!(self.channel_id()));

                Ok(())
        }

        /// Returns transaction if there is pending funding transaction that is yet to broadcast
        pub fn unbroadcasted_funding(&self) -> Option<Transaction> {
                 if self.channel_state & (ChannelState::FundingCreated as u32) != 0 {
                         self.funding_transaction.clone()
                 } else {
                         None
                 }
        }

        /// Returns a HTLCStats about inbound pending htlcs
        fn get_inbound_pending_htlc_stats(&self, outbound_feerate_update: Option<u32>) -> HTLCStats {
                let mut stats = HTLCStats {
                        pending_htlcs: self.pending_inbound_htlcs.len() as u32,
                        pending_htlcs_value_msat: 0,
                        on_counterparty_tx_dust_exposure_msat: 0,
                        on_holder_tx_dust_exposure_msat: 0,
                        holding_cell_msat: 0,
                        on_holder_tx_holding_cell_htlcs_count: 0,
                };

                let counterparty_dust_limit_timeout_sat = (self.get_dust_buffer_feerate(outbound_feerate_update) as u64 * HTLC_TIMEOUT_TX_WEIGHT / 1000) + self.counterparty_dust_limit_satoshis;
                let holder_dust_limit_success_sat = (self.get_dust_buffer_feerate(outbound_feerate_update) as u64 * HTLC_SUCCESS_TX_WEIGHT / 1000) + self.holder_dust_limit_satoshis;
                for ref htlc in self.pending_inbound_htlcs.iter() {
                        stats.pending_htlcs_value_msat += htlc.amount_msat;
                        if htlc.amount_msat / 1000 < counterparty_dust_limit_timeout_sat {
                                stats.on_counterparty_tx_dust_exposure_msat += htlc.amount_msat;
                        }
                        if htlc.amount_msat / 1000 < holder_dust_limit_success_sat {
                                stats.on_holder_tx_dust_exposure_msat += htlc.amount_msat;
                        }
                }
                stats
        }

        /// Returns a HTLCStats about pending outbound htlcs, *including* pending adds in our holding cell.
        fn get_outbound_pending_htlc_stats(&self, outbound_feerate_update: Option<u32>) -> HTLCStats {
                let mut stats = HTLCStats {
                        pending_htlcs: self.pending_outbound_htlcs.len() as u32,
                        pending_htlcs_value_msat: 0,
                        on_counterparty_tx_dust_exposure_msat: 0,
                        on_holder_tx_dust_exposure_msat: 0,
                        holding_cell_msat: 0,
                        on_holder_tx_holding_cell_htlcs_count: 0,
                };

                let counterparty_dust_limit_success_sat = (self.get_dust_buffer_feerate(outbound_feerate_update) as u64 * HTLC_SUCCESS_TX_WEIGHT / 1000) + self.counterparty_dust_limit_satoshis;
                let holder_dust_limit_timeout_sat = (self.get_dust_buffer_feerate(outbound_feerate_update) as u64 * HTLC_TIMEOUT_TX_WEIGHT / 1000) + self.holder_dust_limit_satoshis;
                for ref htlc in self.pending_outbound_htlcs.iter() {
                        stats.pending_htlcs_value_msat += htlc.amount_msat;
                        if htlc.amount_msat / 1000 < counterparty_dust_limit_success_sat {
                                stats.on_counterparty_tx_dust_exposure_msat += htlc.amount_msat;
                        }
                        if htlc.amount_msat / 1000 < holder_dust_limit_timeout_sat {
                                stats.on_holder_tx_dust_exposure_msat += htlc.amount_msat;
                        }
                }

                for update in self.holding_cell_htlc_updates.iter() {
                        if let &HTLCUpdateAwaitingACK::AddHTLC { ref amount_msat, .. } = update {
                                stats.pending_htlcs += 1;
                                stats.pending_htlcs_value_msat += amount_msat;
                                stats.holding_cell_msat += amount_msat;
                                if *amount_msat / 1000 < counterparty_dust_limit_success_sat {
                                        stats.on_counterparty_tx_dust_exposure_msat += amount_msat;
                                }
                                if *amount_msat / 1000 < holder_dust_limit_timeout_sat {
                                        stats.on_holder_tx_dust_exposure_msat += amount_msat;
                                } else {
                                        stats.on_holder_tx_holding_cell_htlcs_count += 1;
                                }
                        }
                }
                stats
        }

        /// Get the available (ie not including pending HTLCs) inbound and outbound balance in msat.
        /// Doesn't bother handling the
        /// if-we-removed-it-already-but-haven't-fully-resolved-they-can-still-send-an-inbound-HTLC
        /// corner case properly.
        /// The channel reserve is subtracted from each balance.
        /// See also [`Channel::get_balance_msat`]
        pub fn get_inbound_outbound_available_balance_msat(&self) -> (u64, u64) {
                // Note that we have to handle overflow due to the above case.
                (
                        cmp::max(self.channel_value_satoshis as i64 * 1000
                                - self.value_to_self_msat as i64
                                - self.get_inbound_pending_htlc_stats(None).pending_htlcs_value_msat as i64
                                - self.holder_selected_channel_reserve_satoshis as i64 * 1000,
                        0) as u64,
                        cmp::max(self.value_to_self_msat as i64
                                - self.get_outbound_pending_htlc_stats(None).pending_htlcs_value_msat as i64
                                - self.counterparty_selected_channel_reserve_satoshis.unwrap_or(0) as i64 * 1000,
                        0) as u64
                )
        }

        /// Get our total balance in msat.
        /// This is the amount that would go to us if we close the channel, ignoring any on-chain fees.
        /// See also [`Channel::get_inbound_outbound_available_balance_msat`]
        pub fn get_balance_msat(&self) -> u64 {
                self.value_to_self_msat
                        - self.get_outbound_pending_htlc_stats(None).pending_htlcs_value_msat
        }

        pub fn get_holder_counterparty_selected_channel_reserve_satoshis(&self) -> (u64, Option<u64>) {
                (self.holder_selected_channel_reserve_satoshis, self.counterparty_selected_channel_reserve_satoshis)
        }

        // Get the fee cost in MSATS of a commitment tx with a given number of HTLC outputs.
        // Note that num_htlcs should not include dust HTLCs.
        fn commit_tx_fee_msat(feerate_per_kw: u32, num_htlcs: usize) -> u64 {
                // Note that we need to divide before multiplying to round properly,
                // since the lowest denomination of bitcoin on-chain is the satoshi.
                (COMMITMENT_TX_BASE_WEIGHT + num_htlcs as u64 * COMMITMENT_TX_WEIGHT_PER_HTLC) * feerate_per_kw as u64 / 1000 * 1000
        }

        // Get the fee cost in SATS of a commitment tx with a given number of HTLC outputs.
        // Note that num_htlcs should not include dust HTLCs.
        #[inline]
        fn commit_tx_fee_sat(feerate_per_kw: u32, num_htlcs: usize) -> u64 {
                feerate_per_kw as u64 * (COMMITMENT_TX_BASE_WEIGHT + num_htlcs as u64 * COMMITMENT_TX_WEIGHT_PER_HTLC) / 1000
        }

        // Get the commitment tx fee for the local's (i.e. our) next commitment transaction based on the
        // number of pending HTLCs that are on track to be in our next commitment tx, plus an additional
        // HTLC if `fee_spike_buffer_htlc` is Some, plus a new HTLC given by `new_htlc_amount`. Dust HTLCs
        // are excluded.
        fn next_local_commit_tx_fee_msat(&self, htlc: HTLCCandidate, fee_spike_buffer_htlc: Option<()>) -> u64 {
                assert!(self.is_outbound());

                let real_dust_limit_success_sat = (self.feerate_per_kw as u64 * HTLC_SUCCESS_TX_WEIGHT / 1000) + self.holder_dust_limit_satoshis;
                let real_dust_limit_timeout_sat = (self.feerate_per_kw as u64 * HTLC_TIMEOUT_TX_WEIGHT / 1000) + self.holder_dust_limit_satoshis;

                let mut addl_htlcs = 0;
                if fee_spike_buffer_htlc.is_some() { addl_htlcs += 1; }
                match htlc.origin {
                        HTLCInitiator::LocalOffered => {
                                if htlc.amount_msat / 1000 >= real_dust_limit_timeout_sat {
                                        addl_htlcs += 1;
                                }
                        },
                        HTLCInitiator::RemoteOffered => {
                                if htlc.amount_msat / 1000 >= real_dust_limit_success_sat {
                                        addl_htlcs += 1;
                                }
                        }
                }

                let mut included_htlcs = 0;
                for ref htlc in self.pending_inbound_htlcs.iter() {
                        if htlc.amount_msat / 1000 < real_dust_limit_success_sat {
                                continue
                        }
                        // We include LocalRemoved HTLCs here because we may still need to broadcast a commitment
                        // transaction including this HTLC if it times out before they RAA.
                        included_htlcs += 1;
                }

                for ref htlc in self.pending_outbound_htlcs.iter() {
                        if htlc.amount_msat / 1000 < real_dust_limit_timeout_sat {
                                continue
                        }
                        match htlc.state {
                                OutboundHTLCState::LocalAnnounced {..} => included_htlcs += 1,
                                OutboundHTLCState::Committed => included_htlcs += 1,
                                OutboundHTLCState::RemoteRemoved {..} => included_htlcs += 1,
                                // We don't include AwaitingRemoteRevokeToRemove HTLCs because our next commitment
                                // transaction won't be generated until they send us their next RAA, which will mean
                                // dropping any HTLCs in this state.
                                _ => {},
                        }
                }

                for htlc in self.holding_cell_htlc_updates.iter() {
                        match htlc {
                                &HTLCUpdateAwaitingACK::AddHTLC { amount_msat, .. } => {
                                        if amount_msat / 1000 < real_dust_limit_timeout_sat {
                                                continue
                                        }
                                        included_htlcs += 1
                                },
                                _ => {}, // Don't include claims/fails that are awaiting ack, because once we get the
                                         // ack we're guaranteed to never include them in commitment txs anymore.
                        }
                }

                let num_htlcs = included_htlcs + addl_htlcs;
                let res = Self::commit_tx_fee_msat(self.feerate_per_kw, num_htlcs);
                #[cfg(any(test, feature = "fuzztarget"))]
                {
                        let mut fee = res;
                        if fee_spike_buffer_htlc.is_some() {
                                fee = Self::commit_tx_fee_msat(self.feerate_per_kw, num_htlcs - 1);
                        }
                        let total_pending_htlcs = self.pending_inbound_htlcs.len() + self.pending_outbound_htlcs.len()
                                + self.holding_cell_htlc_updates.len();
                        let commitment_tx_info = CommitmentTxInfoCached {
                                fee,
                                total_pending_htlcs,
                                next_holder_htlc_id: match htlc.origin {
                                        HTLCInitiator::LocalOffered => self.next_holder_htlc_id + 1,
                                        HTLCInitiator::RemoteOffered => self.next_holder_htlc_id,
                                },
                                next_counterparty_htlc_id: match htlc.origin {
                                        HTLCInitiator::LocalOffered => self.next_counterparty_htlc_id,
                                        HTLCInitiator::RemoteOffered => self.next_counterparty_htlc_id + 1,
                                },
                                feerate: self.feerate_per_kw,
                        };
                        *self.next_local_commitment_tx_fee_info_cached.lock().unwrap() = Some(commitment_tx_info);
                }
                res
        }

        // Get the commitment tx fee for the remote's next commitment transaction based on the number of
        // pending HTLCs that are on track to be in their next commitment tx, plus an additional HTLC if
        // `fee_spike_buffer_htlc` is Some, plus a new HTLC given by `new_htlc_amount`. Dust HTLCs are
        // excluded.
        fn next_remote_commit_tx_fee_msat(&self, htlc: HTLCCandidate, fee_spike_buffer_htlc: Option<()>) -> u64 {
                assert!(!self.is_outbound());

                let real_dust_limit_success_sat = (self.feerate_per_kw as u64 * HTLC_SUCCESS_TX_WEIGHT / 1000) + self.counterparty_dust_limit_satoshis;
                let real_dust_limit_timeout_sat = (self.feerate_per_kw as u64 * HTLC_TIMEOUT_TX_WEIGHT / 1000) + self.counterparty_dust_limit_satoshis;

                let mut addl_htlcs = 0;
                if fee_spike_buffer_htlc.is_some() { addl_htlcs += 1; }
                match htlc.origin {
                        HTLCInitiator::LocalOffered => {
                                if htlc.amount_msat / 1000 >= real_dust_limit_success_sat {
                                        addl_htlcs += 1;
                                }
                        },
                        HTLCInitiator::RemoteOffered => {
                                if htlc.amount_msat / 1000 >= real_dust_limit_timeout_sat {
                                        addl_htlcs += 1;
                                }
                        }
                }

                // When calculating the set of HTLCs which will be included in their next commitment_signed, all
                // non-dust inbound HTLCs are included (as all states imply it will be included) and only
                // committed outbound HTLCs, see below.
                let mut included_htlcs = 0;
                for ref htlc in self.pending_inbound_htlcs.iter() {
                        if htlc.amount_msat / 1000 <= real_dust_limit_timeout_sat {
                                continue
                        }
                        included_htlcs += 1;
                }

                for ref htlc in self.pending_outbound_htlcs.iter() {
                        if htlc.amount_msat / 1000 <= real_dust_limit_success_sat {
                                continue
                        }
                        // We only include outbound HTLCs if it will not be included in their next commitment_signed,
                        // i.e. if they've responded to us with an RAA after announcement.
                        match htlc.state {
                                OutboundHTLCState::Committed => included_htlcs += 1,
                                OutboundHTLCState::RemoteRemoved {..} => included_htlcs += 1,
                                OutboundHTLCState::LocalAnnounced { .. } => included_htlcs += 1,
                                _ => {},
                        }
                }

                let num_htlcs = included_htlcs + addl_htlcs;
                let res = Self::commit_tx_fee_msat(self.feerate_per_kw, num_htlcs);
                #[cfg(any(test, feature = "fuzztarget"))]
                {
                        let mut fee = res;
                        if fee_spike_buffer_htlc.is_some() {
                                fee = Self::commit_tx_fee_msat(self.feerate_per_kw, num_htlcs - 1);
                        }
                        let total_pending_htlcs = self.pending_inbound_htlcs.len() + self.pending_outbound_htlcs.len();
                        let commitment_tx_info = CommitmentTxInfoCached {
                                fee,
                                total_pending_htlcs,
                                next_holder_htlc_id: match htlc.origin {
                                        HTLCInitiator::LocalOffered => self.next_holder_htlc_id + 1,
                                        HTLCInitiator::RemoteOffered => self.next_holder_htlc_id,
                                },
                                next_counterparty_htlc_id: match htlc.origin {
                                        HTLCInitiator::LocalOffered => self.next_counterparty_htlc_id,
                                        HTLCInitiator::RemoteOffered => self.next_counterparty_htlc_id + 1,
                                },
                                feerate: self.feerate_per_kw,
                        };
                        *self.next_remote_commitment_tx_fee_info_cached.lock().unwrap() = Some(commitment_tx_info);
                }
                res
        }

        pub fn update_add_htlc<F, L: Deref>(&mut self, msg: &msgs::UpdateAddHTLC, mut pending_forward_status: PendingHTLCStatus, create_pending_htlc_status: F, logger: &L) -> Result<(), ChannelError>
        where F: for<'a> Fn(&'a Self, PendingHTLCStatus, u16) -> PendingHTLCStatus, L::Target: Logger {
                // We can't accept HTLCs sent after we've sent a shutdown.
                let local_sent_shutdown = (self.channel_state & (ChannelState::ChannelFunded as u32 | ChannelState::LocalShutdownSent as u32)) != (ChannelState::ChannelFunded as u32);
                if local_sent_shutdown {
                        pending_forward_status = create_pending_htlc_status(self, pending_forward_status, 0x4000|8);
                }
                // If the remote has sent a shutdown prior to adding this HTLC, then they are in violation of the spec.
                let remote_sent_shutdown = (self.channel_state & (ChannelState::ChannelFunded as u32 | ChannelState::RemoteShutdownSent as u32)) != (ChannelState::ChannelFunded as u32);
                if remote_sent_shutdown {
                        return Err(ChannelError::Close("Got add HTLC message when channel was not in an operational state".to_owned()));
                }
                if self.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 {
                        return Err(ChannelError::Close("Peer sent update_add_htlc when we needed a channel_reestablish".to_owned()));
                }
                if msg.amount_msat > self.channel_value_satoshis * 1000 {
                        return Err(ChannelError::Close("Remote side tried to send more than the total value of the channel".to_owned()));
                }
                if msg.amount_msat == 0 {
                        return Err(ChannelError::Close("Remote side tried to send a 0-msat HTLC".to_owned()));
                }
                if msg.amount_msat < self.holder_htlc_minimum_msat {
                        return Err(ChannelError::Close(format!("Remote side tried to send less than our minimum HTLC value. Lower limit: ({}). Actual: ({})", self.holder_htlc_minimum_msat, msg.amount_msat)));
                }

                let inbound_stats = self.get_inbound_pending_htlc_stats(None);
                let outbound_stats = self.get_outbound_pending_htlc_stats(None);
                if inbound_stats.pending_htlcs + 1 > OUR_MAX_HTLCS as u32 {
                        return Err(ChannelError::Close(format!("Remote tried to push more than our max accepted HTLCs ({})", OUR_MAX_HTLCS)));
                }
                if inbound_stats.pending_htlcs_value_msat + msg.amount_msat > self.holder_max_htlc_value_in_flight_msat {
                        return Err(ChannelError::Close(format!("Remote HTLC add would put them over our max HTLC value ({})", self.holder_max_htlc_value_in_flight_msat)));
                }
                // Check holder_selected_channel_reserve_satoshis (we're getting paid, so they have to at least meet
                // the reserve_satoshis we told them to always have as direct payment so that they lose
                // something if we punish them for broadcasting an old state).
                // Note that we don't really care about having a small/no to_remote output in our local
                // commitment transactions, as the purpose of the channel reserve is to ensure we can
                // punish *them* if they misbehave, so we discount any outbound HTLCs which will not be
                // present in the next commitment transaction we send them (at least for fulfilled ones,
                // failed ones won't modify value_to_self).
                // Note that we will send HTLCs which another instance of rust-lightning would think
                // violate the reserve value if we do not do this (as we forget inbound HTLCs from the
                // Channel state once they will not be present in the next received commitment
                // transaction).
                let mut removed_outbound_total_msat = 0;
                for ref htlc in self.pending_outbound_htlcs.iter() {
                        if let OutboundHTLCState::AwaitingRemoteRevokeToRemove(None) = htlc.state {
                                removed_outbound_total_msat += htlc.amount_msat;
                        } else if let OutboundHTLCState::AwaitingRemovedRemoteRevoke(None) = htlc.state {
                                removed_outbound_total_msat += htlc.amount_msat;
                        }
                }

                let exposure_dust_limit_timeout_sats = (self.get_dust_buffer_feerate(None) as u64 * HTLC_TIMEOUT_TX_WEIGHT / 1000) + self.counterparty_dust_limit_satoshis;
                if msg.amount_msat / 1000 < exposure_dust_limit_timeout_sats {
                        let on_counterparty_tx_dust_htlc_exposure_msat = inbound_stats.on_counterparty_tx_dust_exposure_msat + outbound_stats.on_counterparty_tx_dust_exposure_msat + msg.amount_msat;
                        if on_counterparty_tx_dust_htlc_exposure_msat > self.get_max_dust_htlc_exposure_msat() {
                                log_info!(logger, "Cannot accept value that would put our exposure to dust HTLCs at {} over the limit {} on counterparty commitment tx",
                                        on_counterparty_tx_dust_htlc_exposure_msat, self.get_max_dust_htlc_exposure_msat());
                                pending_forward_status = create_pending_htlc_status(self, pending_forward_status, 0x1000|7);
                        }
                }

                let exposure_dust_limit_success_sats = (self.get_dust_buffer_feerate(None) as u64 * HTLC_SUCCESS_TX_WEIGHT / 1000) + self.holder_dust_limit_satoshis;
                if msg.amount_msat / 1000 < exposure_dust_limit_success_sats {
                        let on_holder_tx_dust_htlc_exposure_msat = inbound_stats.on_holder_tx_dust_exposure_msat + outbound_stats.on_holder_tx_dust_exposure_msat + msg.amount_msat;
                        if on_holder_tx_dust_htlc_exposure_msat > self.get_max_dust_htlc_exposure_msat() {
                                log_info!(logger, "Cannot accept value that would put our exposure to dust HTLCs at {} over the limit {} on holder commitment tx",
                                        on_holder_tx_dust_htlc_exposure_msat, self.get_max_dust_htlc_exposure_msat());
                                pending_forward_status = create_pending_htlc_status(self, pending_forward_status, 0x1000|7);
                        }
                }

                let pending_value_to_self_msat =
                        self.value_to_self_msat + inbound_stats.pending_htlcs_value_msat - removed_outbound_total_msat;
                let pending_remote_value_msat =
                        self.channel_value_satoshis * 1000 - pending_value_to_self_msat;
                if pending_remote_value_msat < msg.amount_msat {
                        return Err(ChannelError::Close("Remote HTLC add would overdraw remaining funds".to_owned()));
                }

                // Check that the remote can afford to pay for this HTLC on-chain at the current
                // feerate_per_kw, while maintaining their channel reserve (as required by the spec).
                let remote_commit_tx_fee_msat = if self.is_outbound() { 0 } else {
                        let htlc_candidate = HTLCCandidate::new(msg.amount_msat, HTLCInitiator::RemoteOffered);
                        self.next_remote_commit_tx_fee_msat(htlc_candidate, None) // Don't include the extra fee spike buffer HTLC in calculations
                };
                if pending_remote_value_msat - msg.amount_msat < remote_commit_tx_fee_msat {
                        return Err(ChannelError::Close("Remote HTLC add would not leave enough to pay for fees".to_owned()));
                };

                if pending_remote_value_msat - msg.amount_msat - remote_commit_tx_fee_msat < self.holder_selected_channel_reserve_satoshis * 1000 {
                        return Err(ChannelError::Close("Remote HTLC add would put them under remote reserve value".to_owned()));
                }

                if !self.is_outbound() {
                        // `2 *` and `Some(())` is for the fee spike buffer we keep for the remote. This deviates from
                        // the spec because in the spec, the fee spike buffer requirement doesn't exist on the
                        // receiver's side, only on the sender's.
                        // Note that when we eventually remove support for fee updates and switch to anchor output
                        // fees, we will drop the `2 *`, since we no longer be as sensitive to fee spikes. But, keep
                        // the extra htlc when calculating the next remote commitment transaction fee as we should
                        // still be able to afford adding this HTLC plus one more future HTLC, regardless of being
                        // sensitive to fee spikes.
                        let htlc_candidate = HTLCCandidate::new(msg.amount_msat, HTLCInitiator::RemoteOffered);
                        let remote_fee_cost_incl_stuck_buffer_msat = 2 * self.next_remote_commit_tx_fee_msat(htlc_candidate, Some(()));
                        if pending_remote_value_msat - msg.amount_msat - self.holder_selected_channel_reserve_satoshis * 1000 < remote_fee_cost_incl_stuck_buffer_msat {
                                // Note that if the pending_forward_status is not updated here, then it's because we're already failing
                                // the HTLC, i.e. its status is already set to failing.
                                log_info!(logger, "Attempting to fail HTLC due to fee spike buffer violation in channel {}. Rebalancing is required.", log_bytes!(self.channel_id()));
                                pending_forward_status = create_pending_htlc_status(self, pending_forward_status, 0x1000|7);
                        }
                } else {
                        // Check that they won't violate our local required channel reserve by adding this HTLC.
                        let htlc_candidate = HTLCCandidate::new(msg.amount_msat, HTLCInitiator::RemoteOffered);
                        let local_commit_tx_fee_msat = self.next_local_commit_tx_fee_msat(htlc_candidate, None);
                        if self.value_to_self_msat < self.counterparty_selected_channel_reserve_satoshis.unwrap() * 1000 + local_commit_tx_fee_msat {
                                return Err(ChannelError::Close("Cannot accept HTLC that would put our balance under counterparty-announced channel reserve value".to_owned()));
                        }
                }
                if self.next_counterparty_htlc_id != msg.htlc_id {
                        return Err(ChannelError::Close(format!("Remote skipped HTLC ID (skipped ID: {})", self.next_counterparty_htlc_id)));
                }
                if msg.cltv_expiry >= 500000000 {
                        return Err(ChannelError::Close("Remote provided CLTV expiry in seconds instead of block height".to_owned()));
                }

                if self.channel_state & ChannelState::LocalShutdownSent as u32 != 0 {
                        if let PendingHTLCStatus::Forward(_) = pending_forward_status {
                                panic!("ChannelManager shouldn't be trying to add a forwardable HTLC after we've started closing");
                        }
                }

                // Now update local state:
                self.next_counterparty_htlc_id += 1;
                self.pending_inbound_htlcs.push(InboundHTLCOutput {
                        htlc_id: msg.htlc_id,
                        amount_msat: msg.amount_msat,
                        payment_hash: msg.payment_hash,
                        cltv_expiry: msg.cltv_expiry,
                        state: InboundHTLCState::RemoteAnnounced(pending_forward_status),
                });
                Ok(())
        }

        /// Marks an outbound HTLC which we have received update_fail/fulfill/malformed
        #[inline]
        fn mark_outbound_htlc_removed(&mut self, htlc_id: u64, check_preimage: Option<PaymentHash>, fail_reason: Option<HTLCFailReason>) -> Result<&OutboundHTLCOutput, ChannelError> {
                for htlc in self.pending_outbound_htlcs.iter_mut() {
                        if htlc.htlc_id == htlc_id {
                                match check_preimage {
                                        None => {},
                                        Some(payment_hash) =>
                                                if payment_hash != htlc.payment_hash {
                                                        return Err(ChannelError::Close(format!("Remote tried to fulfill HTLC ({}) with an incorrect preimage", htlc_id)));
                                                }
                                };
                                match htlc.state {
                                        OutboundHTLCState::LocalAnnounced(_) =>
                                                return Err(ChannelError::Close(format!("Remote tried to fulfill/fail HTLC ({}) before it had been committed", htlc_id))),
                                        OutboundHTLCState::Committed => {
                                                htlc.state = OutboundHTLCState::RemoteRemoved(fail_reason);
                                        },
                                        OutboundHTLCState::AwaitingRemoteRevokeToRemove(_) | OutboundHTLCState::AwaitingRemovedRemoteRevoke(_) | OutboundHTLCState::RemoteRemoved(_) =>
                                                return Err(ChannelError::Close(format!("Remote tried to fulfill/fail HTLC ({}) that they'd already fulfilled/failed", htlc_id))),
                                }
                                return Ok(htlc);
                        }
                }
                Err(ChannelError::Close("Remote tried to fulfill/fail an HTLC we couldn't find".to_owned()))
        }

        pub fn update_fulfill_htlc(&mut self, msg: &msgs::UpdateFulfillHTLC) -> Result<(HTLCSource, u64), ChannelError> {
                if (self.channel_state & (ChannelState::ChannelFunded as u32)) != (ChannelState::ChannelFunded as u32) {
                        return Err(ChannelError::Close("Got fulfill HTLC message when channel was not in an operational state".to_owned()));
                }
                if self.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 {
                        return Err(ChannelError::Close("Peer sent update_fulfill_htlc when we needed a channel_reestablish".to_owned()));
                }

                let payment_hash = PaymentHash(Sha256::hash(&msg.payment_preimage.0[..]).into_inner());
                self.mark_outbound_htlc_removed(msg.htlc_id, Some(payment_hash), None).map(|htlc| (htlc.source.clone(), htlc.amount_msat))
        }

        pub fn update_fail_htlc(&mut self, msg: &msgs::UpdateFailHTLC, fail_reason: HTLCFailReason) -> Result<(), ChannelError> {
                if (self.channel_state & (ChannelState::ChannelFunded as u32)) != (ChannelState::ChannelFunded as u32) {
                        return Err(ChannelError::Close("Got fail HTLC message when channel was not in an operational state".to_owned()));
                }
                if self.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 {
                        return Err(ChannelError::Close("Peer sent update_fail_htlc when we needed a channel_reestablish".to_owned()));
                }

                self.mark_outbound_htlc_removed(msg.htlc_id, None, Some(fail_reason))?;
                Ok(())
        }

        pub fn update_fail_malformed_htlc(&mut self, msg: &msgs::UpdateFailMalformedHTLC, fail_reason: HTLCFailReason) -> Result<(), ChannelError> {
                if (self.channel_state & (ChannelState::ChannelFunded as u32)) != (ChannelState::ChannelFunded as u32) {
                        return Err(ChannelError::Close("Got fail malformed HTLC message when channel was not in an operational state".to_owned()));
                }
                if self.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 {
                        return Err(ChannelError::Close("Peer sent update_fail_malformed_htlc when we needed a channel_reestablish".to_owned()));
                }

                self.mark_outbound_htlc_removed(msg.htlc_id, None, Some(fail_reason))?;
                Ok(())
        }

        pub fn commitment_signed<L: Deref>(&mut self, msg: &msgs::CommitmentSigned, logger: &L) -> Result<(msgs::RevokeAndACK, Option<msgs::CommitmentSigned>, ChannelMonitorUpdate), (Option<ChannelMonitorUpdate>, ChannelError)>
                where L::Target: Logger
        {
                if (self.channel_state & (ChannelState::ChannelFunded as u32)) != (ChannelState::ChannelFunded as u32) {
                        return Err((None, ChannelError::Close("Got commitment signed message when channel was not in an operational state".to_owned())));
                }
                if self.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 {
                        return Err((None, ChannelError::Close("Peer sent commitment_signed when we needed a channel_reestablish".to_owned())));
                }
                if self.channel_state & BOTH_SIDES_SHUTDOWN_MASK == BOTH_SIDES_SHUTDOWN_MASK && self.last_sent_closing_fee.is_some() {
                        return Err((None, ChannelError::Close("Peer sent commitment_signed after we'd started exchanging closing_signeds".to_owned())));
                }

                let funding_script = self.get_funding_redeemscript();

                let keys = self.build_holder_transaction_keys(self.cur_holder_commitment_transaction_number).map_err(|e| (None, e))?;

                let commitment_stats = self.build_commitment_transaction(self.cur_holder_commitment_transaction_number, &keys, true, false, logger);
                let commitment_txid = {
                        let trusted_tx = commitment_stats.tx.trust();
                        let bitcoin_tx = trusted_tx.built_transaction();
                        let sighash = bitcoin_tx.get_sighash_all(&funding_script, self.channel_value_satoshis);

                        log_trace!(logger, "Checking commitment tx signature {} by key {} against tx {} (sighash {}) with redeemscript {} in channel {}",
                                log_bytes!(msg.signature.serialize_compact()[..]),
                                log_bytes!(self.counterparty_funding_pubkey().serialize()), encode::serialize_hex(&bitcoin_tx.transaction),
                                log_bytes!(sighash[..]), encode::serialize_hex(&funding_script), log_bytes!(self.channel_id()));
                        if let Err(_) = self.secp_ctx.verify(&sighash, &msg.signature, &self.counterparty_funding_pubkey()) {
                                return Err((None, ChannelError::Close("Invalid commitment tx signature from peer".to_owned())));
                        }
                        bitcoin_tx.txid
                };
                let mut htlcs_cloned: Vec<_> = commitment_stats.htlcs_included.iter().map(|htlc| (htlc.0.clone(), htlc.1.map(|h| h.clone()))).collect();

                // If our counterparty updated the channel fee in this commitment transaction, check that
                // they can actually afford the new fee now.
                let update_fee = if let Some((_, update_state)) = self.pending_update_fee {
                        update_state == FeeUpdateState::RemoteAnnounced
                } else { false };
                if update_fee {
                        debug_assert!(!self.is_outbound());
                        let counterparty_reserve_we_require_msat = self.holder_selected_channel_reserve_satoshis * 1000;
                        if commitment_stats.remote_balance_msat < commitment_stats.total_fee_sat * 1000 + counterparty_reserve_we_require_msat {
                                return Err((None, ChannelError::Close("Funding remote cannot afford proposed new fee".to_owned())));
                        }
                }
                #[cfg(any(test, feature = "fuzztarget"))]
                {
                        if self.is_outbound() {
                                let projected_commit_tx_info = self.next_local_commitment_tx_fee_info_cached.lock().unwrap().take();
                                *self.next_remote_commitment_tx_fee_info_cached.lock().unwrap() = None;
                                if let Some(info) = projected_commit_tx_info {
                                        let total_pending_htlcs = self.pending_inbound_htlcs.len() + self.pending_outbound_htlcs.len()
                                                + self.holding_cell_htlc_updates.len();
                                        if info.total_pending_htlcs == total_pending_htlcs
                                                && info.next_holder_htlc_id == self.next_holder_htlc_id
                                                && info.next_counterparty_htlc_id == self.next_counterparty_htlc_id
                                                && info.feerate == self.feerate_per_kw {
                                                        assert_eq!(commitment_stats.total_fee_sat, info.fee / 1000);
                                                }
                                }
                        }
                }

                if msg.htlc_signatures.len() != commitment_stats.num_nondust_htlcs {
                        return Err((None, ChannelError::Close(format!("Got wrong number of HTLC signatures ({}) from remote. It must be {}", msg.htlc_signatures.len(), commitment_stats.num_nondust_htlcs))));
                }

                // TODO: Sadly, we pass HTLCs twice to ChannelMonitor: once via the HolderCommitmentTransaction and once via the update
                let mut htlcs_and_sigs = Vec::with_capacity(htlcs_cloned.len());
                for (idx, (htlc, source)) in htlcs_cloned.drain(..).enumerate() {
                        if let Some(_) = htlc.transaction_output_index {
                                let htlc_tx = chan_utils::build_htlc_transaction(&commitment_txid, commitment_stats.feerate_per_kw,
                                        self.get_counterparty_selected_contest_delay().unwrap(), &htlc, self.opt_anchors(),
                                        &keys.broadcaster_delayed_payment_key, &keys.revocation_key);

                                let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, self.opt_anchors(), &keys);
                                let htlc_sighashtype = if self.opt_anchors() { SigHashType::SinglePlusAnyoneCanPay } else { SigHashType::All };
                                let htlc_sighash = hash_to_message!(&bip143::SigHashCache::new(&htlc_tx).signature_hash(0, &htlc_redeemscript, htlc.amount_msat / 1000, htlc_sighashtype)[..]);
                                log_trace!(logger, "Checking HTLC tx signature {} by key {} against tx {} (sighash {}) with redeemscript {} in channel {}.",
                                        log_bytes!(msg.htlc_signatures[idx].serialize_compact()[..]), log_bytes!(keys.countersignatory_htlc_key.serialize()),
                                        encode::serialize_hex(&htlc_tx), log_bytes!(htlc_sighash[..]), encode::serialize_hex(&htlc_redeemscript), log_bytes!(self.channel_id()));
                                if let Err(_) = self.secp_ctx.verify(&htlc_sighash, &msg.htlc_signatures[idx], &keys.countersignatory_htlc_key) {
                                        return Err((None, ChannelError::Close("Invalid HTLC tx signature from peer".to_owned())));
                                }
                                htlcs_and_sigs.push((htlc, Some(msg.htlc_signatures[idx]), source));
                        } else {
                                htlcs_and_sigs.push((htlc, None, source));
                        }
                }

                let holder_commitment_tx = HolderCommitmentTransaction::new(
                        commitment_stats.tx,
                        msg.signature,
                        msg.htlc_signatures.clone(),
                        &self.get_holder_pubkeys().funding_pubkey,
                        self.counterparty_funding_pubkey()
                );

                let next_per_commitment_point = self.holder_signer.get_per_commitment_point(self.cur_holder_commitment_transaction_number - 1, &self.secp_ctx);
                self.holder_signer.validate_holder_commitment(&holder_commitment_tx)
                        .map_err(|_| (None, ChannelError::Close("Failed to validate our commitment".to_owned())))?;
                let per_commitment_secret = self.holder_signer.release_commitment_secret(self.cur_holder_commitment_transaction_number + 1);

                // Update state now that we've passed all the can-fail calls...
                let mut need_commitment = false;
                if let &mut Some((_, ref mut update_state)) = &mut self.pending_update_fee {
                        if *update_state == FeeUpdateState::RemoteAnnounced {
                                *update_state = FeeUpdateState::AwaitingRemoteRevokeToAnnounce;
                                need_commitment = true;
                        }
                }

                self.latest_monitor_update_id += 1;
                let mut monitor_update = ChannelMonitorUpdate {
                        update_id: self.latest_monitor_update_id,
                        updates: vec![ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo {
                                commitment_tx: holder_commitment_tx,
                                htlc_outputs: htlcs_and_sigs
                        }]
                };

                for htlc in self.pending_inbound_htlcs.iter_mut() {
                        let new_forward = if let &InboundHTLCState::RemoteAnnounced(ref forward_info) = &htlc.state {
                                Some(forward_info.clone())
                        } else { None };
                        if let Some(forward_info) = new_forward {
                                log_trace!(logger, "Updating HTLC {} to AwaitingRemoteRevokeToAnnounce due to commitment_signed in channel {}.",
                                        log_bytes!(htlc.payment_hash.0), log_bytes!(self.channel_id));
                                htlc.state = InboundHTLCState::AwaitingRemoteRevokeToAnnounce(forward_info);
                                need_commitment = true;
                        }
                }
                for htlc in self.pending_outbound_htlcs.iter_mut() {
                        if let Some(fail_reason) = if let &mut OutboundHTLCState::RemoteRemoved(ref mut fail_reason) = &mut htlc.state {
                                Some(fail_reason.take())
                        } else { None } {
                                log_trace!(logger, "Updating HTLC {} to AwaitingRemoteRevokeToRemove due to commitment_signed in channel {}.",
                                        log_bytes!(htlc.payment_hash.0), log_bytes!(self.channel_id));
                                htlc.state = OutboundHTLCState::AwaitingRemoteRevokeToRemove(fail_reason);
                                need_commitment = true;
                        }
                }

                self.cur_holder_commitment_transaction_number -= 1;
                // Note that if we need_commitment & !AwaitingRemoteRevoke we'll call
                // send_commitment_no_status_check() next which will reset this to RAAFirst.
                self.resend_order = RAACommitmentOrder::CommitmentFirst;

                if (self.channel_state & ChannelState::MonitorUpdateFailed as u32) != 0 {
                        // In case we initially failed monitor updating without requiring a response, we need
                        // to make sure the RAA gets sent first.
                        self.monitor_pending_revoke_and_ack = true;
                        if need_commitment && (self.channel_state & (ChannelState::AwaitingRemoteRevoke as u32)) == 0 {
                                // If we were going to send a commitment_signed after the RAA, go ahead and do all
                                // the corresponding HTLC status updates so that get_last_commitment_update
                                // includes the right HTLCs.
                                self.monitor_pending_commitment_signed = true;
                                let (_, mut additional_update) = self.send_commitment_no_status_check(logger).map_err(|e| (None, e))?;
                                // send_commitment_no_status_check may bump latest_monitor_id but we want them to be
                                // strictly increasing by one, so decrement it here.
                                self.latest_monitor_update_id = monitor_update.update_id;
                                monitor_update.updates.append(&mut additional_update.updates);
                        }
                        log_debug!(logger, "Received valid commitment_signed from peer in channel {}, updated HTLC state but awaiting a monitor update resolution to reply.",
                                log_bytes!(self.channel_id));
                        return Err((Some(monitor_update), ChannelError::Ignore("Previous monitor update failure prevented generation of RAA".to_owned())));
                }

                let commitment_signed = if need_commitment && (self.channel_state & (ChannelState::AwaitingRemoteRevoke as u32)) == 0 {
                        // If we're AwaitingRemoteRevoke we can't send a new commitment here, but that's ok -
                        // we'll send one right away when we get the revoke_and_ack when we
                        // free_holding_cell_htlcs().
                        let (msg, mut additional_update) = self.send_commitment_no_status_check(logger).map_err(|e| (None, e))?;
                        // send_commitment_no_status_check may bump latest_monitor_id but we want them to be
                        // strictly increasing by one, so decrement it here.
                        self.latest_monitor_update_id = monitor_update.update_id;
                        monitor_update.updates.append(&mut additional_update.updates);
                        Some(msg)
                } else { None };

                log_debug!(logger, "Received valid commitment_signed from peer in channel {}, updating HTLC state and responding with{} a revoke_and_ack.",
                        log_bytes!(self.channel_id()), if commitment_signed.is_some() { " our own commitment_signed and" } else { "" });

                Ok((msgs::RevokeAndACK {
                        channel_id: self.channel_id,
                        per_commitment_secret,
                        next_per_commitment_point,
                }, commitment_signed, monitor_update))
        }

        /// Public version of the below, checking relevant preconditions first.
        /// If we're not in a state where freeing the holding cell makes sense, this is a no-op and
        /// returns `(None, Vec::new())`.
        pub fn maybe_free_holding_cell_htlcs<L: Deref>(&mut self, logger: &L) -> Result<(Option<(msgs::CommitmentUpdate, ChannelMonitorUpdate)>, Vec<(HTLCSource, PaymentHash)>), ChannelError> where L::Target: Logger {
                if self.channel_state >= ChannelState::ChannelFunded as u32 &&
                   (self.channel_state & (ChannelState::AwaitingRemoteRevoke as u32 | ChannelState::PeerDisconnected as u32 | ChannelState::MonitorUpdateFailed as u32)) == 0 {
                        self.free_holding_cell_htlcs(logger)
                } else { Ok((None, Vec::new())) }
        }

        /// Used to fulfill holding_cell_htlcs when we get a remote ack (or implicitly get it by them
        /// fulfilling or failing the last pending HTLC)
        fn free_holding_cell_htlcs<L: Deref>(&mut self, logger: &L) -> Result<(Option<(msgs::CommitmentUpdate, ChannelMonitorUpdate)>, Vec<(HTLCSource, PaymentHash)>), ChannelError> where L::Target: Logger {
                assert_eq!(self.channel_state & ChannelState::MonitorUpdateFailed as u32, 0);
                if self.holding_cell_htlc_updates.len() != 0 || self.holding_cell_update_fee.is_some() {
                        log_trace!(logger, "Freeing holding cell with {} HTLC updates{} in channel {}", self.holding_cell_htlc_updates.len(),
                                if self.holding_cell_update_fee.is_some() { " and a fee update" } else { "" }, log_bytes!(self.channel_id()));

                        let mut monitor_update = ChannelMonitorUpdate {
                                update_id: self.latest_monitor_update_id + 1, // We don't increment this yet!
                                updates: Vec::new(),
                        };

                        let mut htlc_updates = Vec::new();
                        mem::swap(&mut htlc_updates, &mut self.holding_cell_htlc_updates);
                        let mut update_add_htlcs = Vec::with_capacity(htlc_updates.len());
                        let mut update_fulfill_htlcs = Vec::with_capacity(htlc_updates.len());
                        let mut update_fail_htlcs = Vec::with_capacity(htlc_updates.len());
                        let mut htlcs_to_fail = Vec::new();
                        for htlc_update in htlc_updates.drain(..) {
                                // Note that this *can* fail, though it should be due to rather-rare conditions on
                                // fee races with adding too many outputs which push our total payments just over
                                // the limit. In case it's less rare than I anticipate, we may want to revisit
                                // handling this case better and maybe fulfilling some of the HTLCs while attempting
                                // to rebalance channels.
                                match &htlc_update {
                                        &HTLCUpdateAwaitingACK::AddHTLC {amount_msat, cltv_expiry, ref payment_hash, ref source, ref onion_routing_packet, ..} => {
                                                match self.send_htlc(amount_msat, *payment_hash, cltv_expiry, source.clone(), onion_routing_packet.clone(), logger) {
                                                        Ok(update_add_msg_option) => update_add_htlcs.push(update_add_msg_option.unwrap()),
                                                        Err(e) => {
                                                                match e {
                                                                        ChannelError::Ignore(ref msg) => {
                                                                                log_info!(logger, "Failed to send HTLC with payment_hash {} due to {} in channel {}",
                                                                                        log_bytes!(payment_hash.0), msg, log_bytes!(self.channel_id()));
                                                                                // If we fail to send here, then this HTLC should
                                                                                // be failed backwards. Failing to send here
                                                                                // indicates that this HTLC may keep being put back
                                                                                // into the holding cell without ever being
                                                                                // successfully forwarded/failed/fulfilled, causing
                                                                                // our counterparty to eventually close on us.
                                                                                htlcs_to_fail.push((source.clone(), *payment_hash));
                                                                        },
                                                                        _ => {
                                                                                panic!("Got a non-IgnoreError action trying to send holding cell HTLC");
                                                                        },
                                                                }
                                                        }
                                                }
                                        },
                                        &HTLCUpdateAwaitingACK::ClaimHTLC { ref payment_preimage, htlc_id, .. } => {
                                                // If an HTLC claim was previously added to the holding cell (via
                                                // `get_update_fulfill_htlc`, then generating the claim message itself must
                                                // not fail - any in between attempts to claim the HTLC will have resulted
                                                // in it hitting the holding cell again and we cannot change the state of a
                                                // holding cell HTLC from fulfill to anything else.
                                                let (update_fulfill_msg_option, mut additional_monitor_update) =
                                                        if let UpdateFulfillFetch::NewClaim { msg, monitor_update, .. } = self.get_update_fulfill_htlc(htlc_id, *payment_preimage, logger) {
                                                                (msg, monitor_update)
                                                        } else { unreachable!() };
                                                update_fulfill_htlcs.push(update_fulfill_msg_option.unwrap());
                                                monitor_update.updates.append(&mut additional_monitor_update.updates);
                                        },
                                        &HTLCUpdateAwaitingACK::FailHTLC { htlc_id, ref err_packet } => {
                                                match self.get_update_fail_htlc(htlc_id, err_packet.clone(), logger) {
                                                        Ok(update_fail_msg_option) => {
                                                                // If an HTLC failure was previously added to the holding cell (via
                                                                // `get_update_fail_htlc`) then generating the fail message itself
                                                                // must not fail - we should never end up in a state where we
                                                                // double-fail an HTLC or fail-then-claim an HTLC as it indicates
                                                                // we didn't wait for a full revocation before failing.
                                                                update_fail_htlcs.push(update_fail_msg_option.unwrap())
                                                        },
                                                        Err(e) => {
                                                                if let ChannelError::Ignore(_) = e {}
                                                                else {
                                                                        panic!("Got a non-IgnoreError action trying to fail holding cell HTLC");
                                                                }
                                                        }
                                                }
                                        },
                                }
                        }
                        if update_add_htlcs.is_empty() && update_fulfill_htlcs.is_empty() && update_fail_htlcs.is_empty() && self.holding_cell_update_fee.is_none() {
                                return Ok((None, htlcs_to_fail));
                        }
                        let update_fee = if let Some(feerate) = self.holding_cell_update_fee.take() {
                                self.send_update_fee(feerate, logger)
                        } else {
                                None
                        };

                        let (commitment_signed, mut additional_update) = self.send_commitment_no_status_check(logger)?;
                        // send_commitment_no_status_check and get_update_fulfill_htlc may bump latest_monitor_id
                        // but we want them to be strictly increasing by one, so reset it here.
                        self.latest_monitor_update_id = monitor_update.update_id;
                        monitor_update.updates.append(&mut additional_update.updates);

                        log_debug!(logger, "Freeing holding cell in channel {} resulted in {}{} HTLCs added, {} HTLCs fulfilled, and {} HTLCs failed.",
                                log_bytes!(self.channel_id()), if update_fee.is_some() { "a fee update, " } else { "" },
                                update_add_htlcs.len(), update_fulfill_htlcs.len(), update_fail_htlcs.len());

                        Ok((Some((msgs::CommitmentUpdate {
                                update_add_htlcs,
                                update_fulfill_htlcs,
                                update_fail_htlcs,
                                update_fail_malformed_htlcs: Vec::new(),
                                update_fee,
                                commitment_signed,
                        }, monitor_update)), htlcs_to_fail))
                } else {
                        Ok((None, Vec::new()))
                }
        }

        /// Handles receiving a remote's revoke_and_ack. Note that we may return a new
        /// commitment_signed message here in case we had pending outbound HTLCs to add which were
        /// waiting on this revoke_and_ack. The generation of this new commitment_signed may also fail,
        /// generating an appropriate error *after* the channel state has been updated based on the
        /// revoke_and_ack message.
        pub fn revoke_and_ack<L: Deref>(&mut self, msg: &msgs::RevokeAndACK, logger: &L) -> Result<RAAUpdates, ChannelError>
                where L::Target: Logger,
        {
                if (self.channel_state & (ChannelState::ChannelFunded as u32)) != (ChannelState::ChannelFunded as u32) {
                        return Err(ChannelError::Close("Got revoke/ACK message when channel was not in an operational state".to_owned()));
                }
                if self.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 {
                        return Err(ChannelError::Close("Peer sent revoke_and_ack when we needed a channel_reestablish".to_owned()));
                }
                if self.channel_state & BOTH_SIDES_SHUTDOWN_MASK == BOTH_SIDES_SHUTDOWN_MASK && self.last_sent_closing_fee.is_some() {
                        return Err(ChannelError::Close("Peer sent revoke_and_ack after we'd started exchanging closing_signeds".to_owned()));
                }

                let secret = secp_check!(SecretKey::from_slice(&msg.per_commitment_secret), "Peer provided an invalid per_commitment_secret".to_owned());

                if let Some(counterparty_prev_commitment_point) = self.counterparty_prev_commitment_point {
                        if PublicKey::from_secret_key(&self.secp_ctx, &secret) != counterparty_prev_commitment_point {
                                return Err(ChannelError::Close("Got a revoke commitment secret which didn't correspond to their current pubkey".to_owned()));
                        }
                }

                if self.channel_state & ChannelState::AwaitingRemoteRevoke as u32 == 0 {
                        // Our counterparty seems to have burned their coins to us (by revoking a state when we
                        // haven't given them a new commitment transaction to broadcast). We should probably
                        // take advantage of this by updating our channel monitor, sending them an error, and
                        // waiting for them to broadcast their latest (now-revoked claim). But, that would be a
                        // lot of work, and there's some chance this is all a misunderstanding anyway.
                        // We have to do *something*, though, since our signer may get mad at us for otherwise
                        // jumping a remote commitment number, so best to just force-close and move on.
                        return Err(ChannelError::Close("Received an unexpected revoke_and_ack".to_owned()));
                }

                #[cfg(any(test, feature = "fuzztarget"))]
                {
                        *self.next_local_commitment_tx_fee_info_cached.lock().unwrap() = None;
                        *self.next_remote_commitment_tx_fee_info_cached.lock().unwrap() = None;
                }

                self.holder_signer.validate_counterparty_revocation(
                        self.cur_counterparty_commitment_transaction_number + 1,
                        &secret
                ).map_err(|_| ChannelError::Close("Failed to validate revocation from peer".to_owned()))?;

                self.commitment_secrets.provide_secret(self.cur_counterparty_commitment_transaction_number + 1, msg.per_commitment_secret)
                        .map_err(|_| ChannelError::Close("Previous secrets did not match new one".to_owned()))?;
                self.latest_monitor_update_id += 1;
                let mut monitor_update = ChannelMonitorUpdate {
                        update_id: self.latest_monitor_update_id,
                        updates: vec![ChannelMonitorUpdateStep::CommitmentSecret {
                                idx: self.cur_counterparty_commitment_transaction_number + 1,
                                secret: msg.per_commitment_secret,
                        }],
                };

                // Update state now that we've passed all the can-fail calls...
                // (note that we may still fail to generate the new commitment_signed message, but that's
                // OK, we step the channel here and *then* if the new generation fails we can fail the
                // channel based on that, but stepping stuff here should be safe either way.
                self.channel_state &= !(ChannelState::AwaitingRemoteRevoke as u32);
                self.counterparty_prev_commitment_point = self.counterparty_cur_commitment_point;
                self.counterparty_cur_commitment_point = Some(msg.next_per_commitment_point);
                self.cur_counterparty_commitment_transaction_number -= 1;

                log_trace!(logger, "Updating HTLCs on receipt of RAA in channel {}...", log_bytes!(self.channel_id()));
                let mut to_forward_infos = Vec::new();
                let mut revoked_htlcs = Vec::new();
                let mut finalized_claimed_htlcs = Vec::new();
                let mut update_fail_htlcs = Vec::new();
                let mut update_fail_malformed_htlcs = Vec::new();
                let mut require_commitment = false;
                let mut value_to_self_msat_diff: i64 = 0;

                {
                        // Take references explicitly so that we can hold multiple references to self.
                        let pending_inbound_htlcs: &mut Vec<_> = &mut self.pending_inbound_htlcs;
                        let pending_outbound_htlcs: &mut Vec<_> = &mut self.pending_outbound_htlcs;

                        // We really shouldnt have two passes here, but retain gives a non-mutable ref (Rust bug)
                        pending_inbound_htlcs.retain(|htlc| {
                                if let &InboundHTLCState::LocalRemoved(ref reason) = &htlc.state {
                                        log_trace!(logger, " ...removing inbound LocalRemoved {}", log_bytes!(htlc.payment_hash.0));
                                        if let &InboundHTLCRemovalReason::Fulfill(_) = reason {
                                                value_to_self_msat_diff += htlc.amount_msat as i64;
                                        }
                                        false
                                } else { true }
                        });
                        pending_outbound_htlcs.retain(|htlc| {
                                if let &OutboundHTLCState::AwaitingRemovedRemoteRevoke(ref fail_reason) = &htlc.state {
                                        log_trace!(logger, " ...removing outbound AwaitingRemovedRemoteRevoke {}", log_bytes!(htlc.payment_hash.0));
                                        if let Some(reason) = fail_reason.clone() { // We really want take() here, but, again, non-mut ref :(
                                                revoked_htlcs.push((htlc.source.clone(), htlc.payment_hash, reason));
                                        } else {
                                                finalized_claimed_htlcs.push(htlc.source.clone());
                                                // They fulfilled, so we sent them money
                                                value_to_self_msat_diff -= htlc.amount_msat as i64;
                                        }
                                        false
                                } else { true }
                        });
                        for htlc in pending_inbound_htlcs.iter_mut() {
                                let swap = if let &InboundHTLCState::AwaitingRemoteRevokeToAnnounce(_) = &htlc.state {
                                        true
                                } else if let &InboundHTLCState::AwaitingAnnouncedRemoteRevoke(_) = &htlc.state {
                                        true
                                } else { false };
                                if swap {
                                        let mut state = InboundHTLCState::Committed;
                                        mem::swap(&mut state, &mut htlc.state);

                                        if let InboundHTLCState::AwaitingRemoteRevokeToAnnounce(forward_info) = state {
                                                log_trace!(logger, " ...promoting inbound AwaitingRemoteRevokeToAnnounce {} to AwaitingAnnouncedRemoteRevoke", log_bytes!(htlc.payment_hash.0));
                                                htlc.state = InboundHTLCState::AwaitingAnnouncedRemoteRevoke(forward_info);
                                                require_commitment = true;
                                        } else if let InboundHTLCState::AwaitingAnnouncedRemoteRevoke(forward_info) = state {
                                                match forward_info {
                                                        PendingHTLCStatus::Fail(fail_msg) => {
                                                                log_trace!(logger, " ...promoting inbound AwaitingAnnouncedRemoteRevoke {} to LocalRemoved due to PendingHTLCStatus indicating failure", log_bytes!(htlc.payment_hash.0));
                                                                require_commitment = true;
                                                                match fail_msg {
                                                                        HTLCFailureMsg::Relay(msg) => {
                                                                                htlc.state = InboundHTLCState::LocalRemoved(InboundHTLCRemovalReason::FailRelay(msg.reason.clone()));
                                                                                update_fail_htlcs.push(msg)
                                                                        },
                                                                        HTLCFailureMsg::Malformed(msg) => {
                                                                                htlc.state = InboundHTLCState::LocalRemoved(InboundHTLCRemovalReason::FailMalformed((msg.sha256_of_onion, msg.failure_code)));
                                                                                update_fail_malformed_htlcs.push(msg)
                                                                        },
                                                                }
                                                        },
                                                        PendingHTLCStatus::Forward(forward_info) => {
                                                                log_trace!(logger, " ...promoting inbound AwaitingAnnouncedRemoteRevoke {} to Committed", log_bytes!(htlc.payment_hash.0));
                                                                to_forward_infos.push((forward_info, htlc.htlc_id));
                                                                htlc.state = InboundHTLCState::Committed;
                                                        }
                                                }
                                        }
                                }
                        }
                        for htlc in pending_outbound_htlcs.iter_mut() {
                                if let OutboundHTLCState::LocalAnnounced(_) = htlc.state {
                                        log_trace!(logger, " ...promoting outbound LocalAnnounced {} to Committed", log_bytes!(htlc.payment_hash.0));
                                        htlc.state = OutboundHTLCState::Committed;
                                }
                                if let Some(fail_reason) = if let &mut OutboundHTLCState::AwaitingRemoteRevokeToRemove(ref mut fail_reason) = &mut htlc.state {
                                        Some(fail_reason.take())
                                } else { None } {
                                        log_trace!(logger, " ...promoting outbound AwaitingRemoteRevokeToRemove {} to AwaitingRemovedRemoteRevoke", log_bytes!(htlc.payment_hash.0));
                                        htlc.state = OutboundHTLCState::AwaitingRemovedRemoteRevoke(fail_reason);
                                        require_commitment = true;
                                }
                        }
                }
                self.value_to_self_msat = (self.value_to_self_msat as i64 + value_to_self_msat_diff) as u64;

                if let Some((feerate, update_state)) = self.pending_update_fee {
                        match update_state {
                                FeeUpdateState::Outbound => {
                                        debug_assert!(self.is_outbound());
                                        log_trace!(logger, " ...promoting outbound fee update {} to Committed", feerate);
                                        self.feerate_per_kw = feerate;
                                        self.pending_update_fee = None;
                                },
                                FeeUpdateState::RemoteAnnounced => { debug_assert!(!self.is_outbound()); },
                                FeeUpdateState::AwaitingRemoteRevokeToAnnounce => {
                                        debug_assert!(!self.is_outbound());
                                        log_trace!(logger, " ...promoting inbound AwaitingRemoteRevokeToAnnounce fee update {} to Committed", feerate);
                                        require_commitment = true;
                                        self.feerate_per_kw = feerate;
                                        self.pending_update_fee = None;
                                },
                        }
                }

                if (self.channel_state & ChannelState::MonitorUpdateFailed as u32) == ChannelState::MonitorUpdateFailed as u32 {
                        // We can't actually generate a new commitment transaction (incl by freeing holding
                        // cells) while we can't update the monitor, so we just return what we have.
                        if require_commitment {
                                self.monitor_pending_commitment_signed = true;
                                // When the monitor updating is restored we'll call get_last_commitment_update(),
                                // which does not update state, but we're definitely now awaiting a remote revoke
                                // before we can step forward any more, so set it here.
                                let (_, mut additional_update) = self.send_commitment_no_status_check(logger)?;
                                // send_commitment_no_status_check may bump latest_monitor_id but we want them to be
                                // strictly increasing by one, so decrement it here.
                                self.latest_monitor_update_id = monitor_update.update_id;
                                monitor_update.updates.append(&mut additional_update.updates);
                        }
                        self.monitor_pending_forwards.append(&mut to_forward_infos);
                        self.monitor_pending_failures.append(&mut revoked_htlcs);
                        self.monitor_pending_finalized_fulfills.append(&mut finalized_claimed_htlcs);
                        log_debug!(logger, "Received a valid revoke_and_ack for channel {} but awaiting a monitor update resolution to reply.", log_bytes!(self.channel_id()));
                        return Ok(RAAUpdates {
                                commitment_update: None, finalized_claimed_htlcs: Vec::new(),
                                accepted_htlcs: Vec::new(), failed_htlcs: Vec::new(),
                                monitor_update,
                                holding_cell_failed_htlcs: Vec::new()
                        });
                }

                match self.free_holding_cell_htlcs(logger)? {
                        (Some((mut commitment_update, mut additional_update)), htlcs_to_fail) => {
                                commitment_update.update_fail_htlcs.reserve(update_fail_htlcs.len());
                                for fail_msg in update_fail_htlcs.drain(..) {
                                        commitment_update.update_fail_htlcs.push(fail_msg);
                                }
                                commitment_update.update_fail_malformed_htlcs.reserve(update_fail_malformed_htlcs.len());
                                for fail_msg in update_fail_malformed_htlcs.drain(..) {
                                        commitment_update.update_fail_malformed_htlcs.push(fail_msg);
                                }

                                // free_holding_cell_htlcs may bump latest_monitor_id multiple times but we want them to be
                                // strictly increasing by one, so decrement it here.
                                self.latest_monitor_update_id = monitor_update.update_id;
                                monitor_update.updates.append(&mut additional_update.updates);

                                Ok(RAAUpdates {
                                        commitment_update: Some(commitment_update),
                                        finalized_claimed_htlcs,
                                        accepted_htlcs: to_forward_infos,
                                        failed_htlcs: revoked_htlcs,
                                        monitor_update,
                                        holding_cell_failed_htlcs: htlcs_to_fail
                                })
                        },
                        (None, htlcs_to_fail) => {
                                if require_commitment {
                                        let (commitment_signed, mut additional_update) = self.send_commitment_no_status_check(logger)?;

                                        // send_commitment_no_status_check may bump latest_monitor_id but we want them to be
                                        // strictly increasing by one, so decrement it here.
                                        self.latest_monitor_update_id = monitor_update.update_id;
                                        monitor_update.updates.append(&mut additional_update.updates);

                                        log_debug!(logger, "Received a valid revoke_and_ack for channel {}. Responding with a commitment update with {} HTLCs failed.",
                                                log_bytes!(self.channel_id()), update_fail_htlcs.len() + update_fail_malformed_htlcs.len());
                                        Ok(RAAUpdates {
                                                commitment_update: Some(msgs::CommitmentUpdate {
                                                        update_add_htlcs: Vec::new(),
                                                        update_fulfill_htlcs: Vec::new(),
                                                        update_fail_htlcs,
                                                        update_fail_malformed_htlcs,
                                                        update_fee: None,
                                                        commitment_signed
                                                }),
                                                finalized_claimed_htlcs,
                                                accepted_htlcs: to_forward_infos, failed_htlcs: revoked_htlcs,
                                                monitor_update, holding_cell_failed_htlcs: htlcs_to_fail
                                        })
                                } else {
                                        log_debug!(logger, "Received a valid revoke_and_ack for channel {} with no reply necessary.", log_bytes!(self.channel_id()));
                                        Ok(RAAUpdates {
                                                commitment_update: None,
                                                finalized_claimed_htlcs,
                                                accepted_htlcs: to_forward_infos, failed_htlcs: revoked_htlcs,
                                                monitor_update, holding_cell_failed_htlcs: htlcs_to_fail
                                        })
                                }
                        }
                }
        }

        /// Adds a pending update to this channel. See the doc for send_htlc for
        /// further details on the optionness of the return value.
        /// If our balance is too low to cover the cost of the next commitment transaction at the
        /// new feerate, the update is cancelled.
        /// You MUST call send_commitment prior to any other calls on this Channel
        fn send_update_fee<L: Deref>(&mut self, feerate_per_kw: u32, logger: &L) -> Option<msgs::UpdateFee> where L::Target: Logger {
                if !self.is_outbound() {
                        panic!("Cannot send fee from inbound channel");
                }
                if !self.is_usable() {
                        panic!("Cannot update fee until channel is fully established and we haven't started shutting down");
                }
                if !self.is_live() {
                        panic!("Cannot update fee while peer is disconnected/we're awaiting a monitor update (ChannelManager should have caught this)");
                }

                // Before proposing a feerate update, check that we can actually afford the new fee.
                let inbound_stats = self.get_inbound_pending_htlc_stats(Some(feerate_per_kw));
                let outbound_stats = self.get_outbound_pending_htlc_stats(Some(feerate_per_kw));
                let keys = if let Ok(keys) = self.build_holder_transaction_keys(self.cur_holder_commitment_transaction_number) { keys } else { return None; };
                let commitment_stats = self.build_commitment_transaction(self.cur_holder_commitment_transaction_number, &keys, true, true, logger);
                let buffer_fee_msat = Channel::<Signer>::commit_tx_fee_sat(feerate_per_kw, commitment_stats.num_nondust_htlcs + outbound_stats.on_holder_tx_holding_cell_htlcs_count as usize + CONCURRENT_INBOUND_HTLC_FEE_BUFFER as usize) * 1000;
                let holder_balance_msat = commitment_stats.local_balance_msat - outbound_stats.holding_cell_msat;
                if holder_balance_msat < buffer_fee_msat  + self.counterparty_selected_channel_reserve_satoshis.unwrap() * 1000 {
                        //TODO: auto-close after a number of failures?
                        log_debug!(logger, "Cannot afford to send new feerate at {}", feerate_per_kw);
                        return None;
                }

                // Note, we evaluate pending htlc "preemptive" trimmed-to-dust threshold at the proposed `feerate_per_kw`.
                let holder_tx_dust_exposure = inbound_stats.on_holder_tx_dust_exposure_msat + outbound_stats.on_holder_tx_dust_exposure_msat;
                let counterparty_tx_dust_exposure = inbound_stats.on_counterparty_tx_dust_exposure_msat + outbound_stats.on_counterparty_tx_dust_exposure_msat;
                if holder_tx_dust_exposure > self.get_max_dust_htlc_exposure_msat() {
                        log_debug!(logger, "Cannot afford to send new feerate at {} without infringing max dust htlc exposure", feerate_per_kw);
                        return None;
                }
                if counterparty_tx_dust_exposure > self.get_max_dust_htlc_exposure_msat() {
                        log_debug!(logger, "Cannot afford to send new feerate at {} without infringing max dust htlc exposure", feerate_per_kw);
                        return None;
                }

                if (self.channel_state & (ChannelState::AwaitingRemoteRevoke as u32 | ChannelState::MonitorUpdateFailed as u32)) != 0 {
                        self.holding_cell_update_fee = Some(feerate_per_kw);
                        return None;
                }

                debug_assert!(self.pending_update_fee.is_none());
                self.pending_update_fee = Some((feerate_per_kw, FeeUpdateState::Outbound));

                Some(msgs::UpdateFee {
                        channel_id: self.channel_id,
                        feerate_per_kw,
                })
        }

        pub fn send_update_fee_and_commit<L: Deref>(&mut self, feerate_per_kw: u32, logger: &L) -> Result<Option<(msgs::UpdateFee, msgs::CommitmentSigned, ChannelMonitorUpdate)>, ChannelError> where L::Target: Logger {
                match self.send_update_fee(feerate_per_kw, logger) {
                        Some(update_fee) => {
                                let (commitment_signed, monitor_update) = self.send_commitment_no_status_check(logger)?;
                                Ok(Some((update_fee, commitment_signed, monitor_update)))
                        },
                        None => Ok(None)
                }
        }

        /// Removes any uncommitted inbound HTLCs and resets the state of uncommitted outbound HTLC
        /// updates, to be used on peer disconnection. After this, update_*_htlc messages need to be
        /// resent.
        /// No further message handling calls may be made until a channel_reestablish dance has
        /// completed.
        pub fn remove_uncommitted_htlcs_and_mark_paused<L: Deref>(&mut self, logger: &L)  where L::Target: Logger {
                assert_eq!(self.channel_state & ChannelState::ShutdownComplete as u32, 0);
                if self.channel_state < ChannelState::FundingSent as u32 {
                        self.channel_state = ChannelState::ShutdownComplete as u32;
                        return;
                }
                // Upon reconnect we have to start the closing_signed dance over, but shutdown messages
                // will be retransmitted.
                self.last_sent_closing_fee = None;
                self.pending_counterparty_closing_signed = None;
                self.closing_fee_limits = None;

                let mut inbound_drop_count = 0;
                self.pending_inbound_htlcs.retain(|htlc| {
                        match htlc.state {
                                InboundHTLCState::RemoteAnnounced(_) => {
                                        // They sent us an update_add_htlc but we never got the commitment_signed.
                                        // We'll tell them what commitment_signed we're expecting next and they'll drop
                                        // this HTLC accordingly
                                        inbound_drop_count += 1;
                                        false
                                },
                                InboundHTLCState::AwaitingRemoteRevokeToAnnounce(_)|InboundHTLCState::AwaitingAnnouncedRemoteRevoke(_) => {
                                        // We received a commitment_signed updating this HTLC and (at least hopefully)
                                        // sent a revoke_and_ack (which we can re-transmit) and have heard nothing
                                        // in response to it yet, so don't touch it.
                                        true
                                },
                                InboundHTLCState::Committed => true,
                                InboundHTLCState::LocalRemoved(_) => {
                                        // We (hopefully) sent a commitment_signed updating this HTLC (which we can
                                        // re-transmit if needed) and they may have even sent a revoke_and_ack back
                                        // (that we missed). Keep this around for now and if they tell us they missed
                                        // the commitment_signed we can re-transmit the update then.
                                        true
                                },
                        }
                });
                self.next_counterparty_htlc_id -= inbound_drop_count;

                if let Some((_, update_state)) = self.pending_update_fee {
                        if update_state == FeeUpdateState::RemoteAnnounced {
                                debug_assert!(!self.is_outbound());
                                self.pending_update_fee = None;
                        }
                }

                for htlc in self.pending_outbound_htlcs.iter_mut() {
                        if let OutboundHTLCState::RemoteRemoved(_) = htlc.state {
                                // They sent us an update to remove this but haven't yet sent the corresponding
                                // commitment_signed, we need to move it back to Committed and they can re-send
                                // the update upon reconnection.
                                htlc.state = OutboundHTLCState::Committed;
                        }
                }

                self.channel_state |= ChannelState::PeerDisconnected as u32;
                log_trace!(logger, "Peer disconnection resulted in {} remote-announced HTLC drops on channel {}", inbound_drop_count, log_bytes!(self.channel_id()));
        }

        /// Indicates that a ChannelMonitor update failed to be stored by the client and further
        /// updates are partially paused.
        /// This must be called immediately after the call which generated the ChannelMonitor update
        /// which failed. The messages which were generated from that call which generated the
        /// monitor update failure must *not* have been sent to the remote end, and must instead
        /// have been dropped. They will be regenerated when monitor_updating_restored is called.
        pub fn monitor_update_failed(&mut self, resend_raa: bool, resend_commitment: bool,
                mut pending_forwards: Vec<(PendingHTLCInfo, u64)>,
                mut pending_fails: Vec<(HTLCSource, PaymentHash, HTLCFailReason)>,
                mut pending_finalized_claimed_htlcs: Vec<HTLCSource>
        ) {
                self.monitor_pending_revoke_and_ack |= resend_raa;
                self.monitor_pending_commitment_signed |= resend_commitment;
                self.monitor_pending_forwards.append(&mut pending_forwards);
                self.monitor_pending_failures.append(&mut pending_fails);
                self.monitor_pending_finalized_fulfills.append(&mut pending_finalized_claimed_htlcs);
                self.channel_state |= ChannelState::MonitorUpdateFailed as u32;
        }

        /// Indicates that the latest ChannelMonitor update has been committed by the client
        /// successfully and we should restore normal operation. Returns messages which should be sent
        /// to the remote side.
        pub fn monitor_updating_restored<L: Deref>(&mut self, logger: &L) -> MonitorRestoreUpdates where L::Target: Logger {
                assert_eq!(self.channel_state & ChannelState::MonitorUpdateFailed as u32, ChannelState::MonitorUpdateFailed as u32);
                self.channel_state &= !(ChannelState::MonitorUpdateFailed as u32);

                let funding_broadcastable = if self.channel_state & (ChannelState::FundingSent as u32) != 0 && self.is_outbound() {
                        self.funding_transaction.take()
                } else { None };

                // We will never broadcast the funding transaction when we're in MonitorUpdateFailed (and
                // we assume the user never directly broadcasts the funding transaction and waits for us to
                // do it). Thus, we can only ever hit monitor_pending_funding_locked when we're an inbound
                // channel which failed to persist the monitor on funding_created, and we got the funding
                // transaction confirmed before the monitor was persisted.
                let funding_locked = if self.monitor_pending_funding_locked {
                        assert!(!self.is_outbound(), "Funding transaction broadcast by the local client before it should have - LDK didn't do it!");
                        self.monitor_pending_funding_locked = false;
                        let next_per_commitment_point = self.holder_signer.get_per_commitment_point(self.cur_holder_commitment_transaction_number, &self.secp_ctx);
                        Some(msgs::FundingLocked {
                                channel_id: self.channel_id(),
                                next_per_commitment_point,
                        })
                } else { None };

                let mut accepted_htlcs = Vec::new();
                mem::swap(&mut accepted_htlcs, &mut self.monitor_pending_forwards);
                let mut failed_htlcs = Vec::new();
                mem::swap(&mut failed_htlcs, &mut self.monitor_pending_failures);
                let mut finalized_claimed_htlcs = Vec::new();
                mem::swap(&mut finalized_claimed_htlcs, &mut self.monitor_pending_finalized_fulfills);

                if self.channel_state & (ChannelState::PeerDisconnected as u32) != 0 {
                        self.monitor_pending_revoke_and_ack = false;
                        self.monitor_pending_commitment_signed = false;
                        return MonitorRestoreUpdates {
                                raa: None, commitment_update: None, order: RAACommitmentOrder::RevokeAndACKFirst,
                                accepted_htlcs, failed_htlcs, finalized_claimed_htlcs, funding_broadcastable, funding_locked
                        };
                }

                let raa = if self.monitor_pending_revoke_and_ack {
                        Some(self.get_last_revoke_and_ack())
                } else { None };
                let commitment_update = if self.monitor_pending_commitment_signed {
                        Some(self.get_last_commitment_update(logger))
                } else { None };

                self.monitor_pending_revoke_and_ack = false;
                self.monitor_pending_commitment_signed = false;
                let order = self.resend_order.clone();
                log_debug!(logger, "Restored monitor updating in channel {} resulting in {}{} commitment update and {} RAA, with {} first",
                        log_bytes!(self.channel_id()), if funding_broadcastable.is_some() { "a funding broadcastable, " } else { "" },
                        if commitment_update.is_some() { "a" } else { "no" }, if raa.is_some() { "an" } else { "no" },
                        match order { RAACommitmentOrder::CommitmentFirst => "commitment", RAACommitmentOrder::RevokeAndACKFirst => "RAA"});
                MonitorRestoreUpdates {
                        raa, commitment_update, order, accepted_htlcs, failed_htlcs, finalized_claimed_htlcs, funding_broadcastable, funding_locked
                }
        }

        pub fn update_fee<F: Deref>(&mut self, fee_estimator: &F, msg: &msgs::UpdateFee) -> Result<(), ChannelError>
                where F::Target: FeeEstimator
        {
                if self.is_outbound() {
                        return Err(ChannelError::Close("Non-funding remote tried to update channel fee".to_owned()));
                }
                if self.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 {
                        return Err(ChannelError::Close("Peer sent update_fee when we needed a channel_reestablish".to_owned()));
                }
                Channel::<Signer>::check_remote_fee(fee_estimator, msg.feerate_per_kw)?;
                let feerate_over_dust_buffer = msg.feerate_per_kw > self.get_dust_buffer_feerate(None);

                self.pending_update_fee = Some((msg.feerate_per_kw, FeeUpdateState::RemoteAnnounced));
                self.update_time_counter += 1;
                // If the feerate has increased over the previous dust buffer (note that
                // `get_dust_buffer_feerate` considers the `pending_update_fee` status), check that we
                // won't be pushed over our dust exposure limit by the feerate increase.
                if feerate_over_dust_buffer {
                        let inbound_stats = self.get_inbound_pending_htlc_stats(None);
                        let outbound_stats = self.get_outbound_pending_htlc_stats(None);
                        let holder_tx_dust_exposure = inbound_stats.on_holder_tx_dust_exposure_msat + outbound_stats.on_holder_tx_dust_exposure_msat;
                        let counterparty_tx_dust_exposure = inbound_stats.on_counterparty_tx_dust_exposure_msat + outbound_stats.on_counterparty_tx_dust_exposure_msat;
                        if holder_tx_dust_exposure > self.get_max_dust_htlc_exposure_msat() {
                                return Err(ChannelError::Close(format!("Peer sent update_fee with a feerate ({}) which may over-expose us to dust-in-flight on our own transactions (totaling {} msat)",
                                        msg.feerate_per_kw, holder_tx_dust_exposure)));
                        }
                        if counterparty_tx_dust_exposure > self.get_max_dust_htlc_exposure_msat() {
                                return Err(ChannelError::Close(format!("Peer sent update_fee with a feerate ({}) which may over-expose us to dust-in-flight on our counterparty's transactions (totaling {} msat)",
                                        msg.feerate_per_kw, counterparty_tx_dust_exposure)));
                        }
                }
                Ok(())
        }

        fn get_last_revoke_and_ack(&self) -> msgs::RevokeAndACK {
                let next_per_commitment_point = self.holder_signer.get_per_commitment_point(self.cur_holder_commitment_transaction_number, &self.secp_ctx);
                let per_commitment_secret = self.holder_signer.release_commitment_secret(self.cur_holder_commitment_transaction_number + 2);
                msgs::RevokeAndACK {
                        channel_id: self.channel_id,
                        per_commitment_secret,
                        next_per_commitment_point,
                }
        }

        fn get_last_commitment_update<L: Deref>(&self, logger: &L) -> msgs::CommitmentUpdate where L::Target: Logger {
                let mut update_add_htlcs = Vec::new();
                let mut update_fulfill_htlcs = Vec::new();
                let mut update_fail_htlcs = Vec::new();
                let mut update_fail_malformed_htlcs = Vec::new();

                for htlc in self.pending_outbound_htlcs.iter() {
                        if let &OutboundHTLCState::LocalAnnounced(ref onion_packet) = &htlc.state {
                                update_add_htlcs.push(msgs::UpdateAddHTLC {
                                        channel_id: self.channel_id(),
                                        htlc_id: htlc.htlc_id,
                                        amount_msat: htlc.amount_msat,
                                        payment_hash: htlc.payment_hash,
                                        cltv_expiry: htlc.cltv_expiry,
                                        onion_routing_packet: (**onion_packet).clone(),
                                });
                        }
                }

                for htlc in self.pending_inbound_htlcs.iter() {
                        if let &InboundHTLCState::LocalRemoved(ref reason) = &htlc.state {
                                match reason {
                                        &InboundHTLCRemovalReason::FailRelay(ref err_packet) => {
                                                update_fail_htlcs.push(msgs::UpdateFailHTLC {
                                                        channel_id: self.channel_id(),
                                                        htlc_id: htlc.htlc_id,
                                                        reason: err_packet.clone()
                                                });
                                        },
                                        &InboundHTLCRemovalReason::FailMalformed((ref sha256_of_onion, ref failure_code)) => {
                                                update_fail_malformed_htlcs.push(msgs::UpdateFailMalformedHTLC {
                                                        channel_id: self.channel_id(),
                                                        htlc_id: htlc.htlc_id,
                                                        sha256_of_onion: sha256_of_onion.clone(),
                                                        failure_code: failure_code.clone(),
                                                });
                                        },
                                        &InboundHTLCRemovalReason::Fulfill(ref payment_preimage) => {
                                                update_fulfill_htlcs.push(msgs::UpdateFulfillHTLC {
                                                        channel_id: self.channel_id(),
                                                        htlc_id: htlc.htlc_id,
                                                        payment_preimage: payment_preimage.clone(),
                                                });
                                        },
                                }
                        }
                }

                let update_fee = if self.is_outbound() && self.pending_update_fee.is_some() {
                        Some(msgs::UpdateFee {
                                channel_id: self.channel_id(),
                                feerate_per_kw: self.pending_update_fee.unwrap().0,
                        })
                } else { None };

                log_trace!(logger, "Regenerated latest commitment update in channel {} with{} {} update_adds, {} update_fulfills, {} update_fails, and {} update_fail_malformeds",
                                log_bytes!(self.channel_id()), if update_fee.is_some() { " update_fee," } else { "" },
                                update_add_htlcs.len(), update_fulfill_htlcs.len(), update_fail_htlcs.len(), update_fail_malformed_htlcs.len());
                msgs::CommitmentUpdate {
                        update_add_htlcs, update_fulfill_htlcs, update_fail_htlcs, update_fail_malformed_htlcs, update_fee,
                        commitment_signed: self.send_commitment_no_state_update(logger).expect("It looks like we failed to re-generate a commitment_signed we had previously sent?").0,
                }
        }

        /// May panic if some calls other than message-handling calls (which will all Err immediately)
        /// have been called between remove_uncommitted_htlcs_and_mark_paused and this call.
        pub fn channel_reestablish<L: Deref>(&mut self, msg: &msgs::ChannelReestablish, logger: &L) -> Result<(Option<msgs::FundingLocked>, Option<msgs::RevokeAndACK>, Option<msgs::CommitmentUpdate>, Option<ChannelMonitorUpdate>, RAACommitmentOrder, Vec<(HTLCSource, PaymentHash)>, Option<msgs::Shutdown>), ChannelError> where L::Target: Logger {
                if self.channel_state & (ChannelState::PeerDisconnected as u32) == 0 {
                        // While BOLT 2 doesn't indicate explicitly we should error this channel here, it
                        // almost certainly indicates we are going to end up out-of-sync in some way, so we
                        // just close here instead of trying to recover.
                        return Err(ChannelError::Close("Peer sent a loose channel_reestablish not after reconnect".to_owned()));
                }

                if msg.next_local_commitment_number >= INITIAL_COMMITMENT_NUMBER || msg.next_remote_commitment_number >= INITIAL_COMMITMENT_NUMBER ||
                        msg.next_local_commitment_number == 0 {
                        return Err(ChannelError::Close("Peer sent a garbage channel_reestablish".to_owned()));
                }

                if msg.next_remote_commitment_number > 0 {
                        match msg.data_loss_protect {
                                OptionalField::Present(ref data_loss) => {
                                        let expected_point = self.holder_signer.get_per_commitment_point(INITIAL_COMMITMENT_NUMBER - msg.next_remote_commitment_number + 1, &self.secp_ctx);
                                        let given_secret = SecretKey::from_slice(&data_loss.your_last_per_commitment_secret)
                                                .map_err(|_| ChannelError::Close("Peer sent a garbage channel_reestablish with unparseable secret key".to_owned()))?;
                                        if expected_point != PublicKey::from_secret_key(&self.secp_ctx, &given_secret) {
                                                return Err(ChannelError::Close("Peer sent a garbage channel_reestablish with secret key not matching the commitment height provided".to_owned()));
                                        }
                                        if msg.next_remote_commitment_number > INITIAL_COMMITMENT_NUMBER - self.cur_holder_commitment_transaction_number {
                                                return Err(ChannelError::CloseDelayBroadcast(
                                                        "We have fallen behind - we have received proof that if we broadcast remote is going to claim our funds - we can't do any automated broadcasting".to_owned()
                                                ));
                                        }
                                },
                                OptionalField::Absent => {}
                        }
                }

                // Go ahead and unmark PeerDisconnected as various calls we may make check for it (and all
                // remaining cases either succeed or ErrorMessage-fail).
                self.channel_state &= !(ChannelState::PeerDisconnected as u32);

                let shutdown_msg = if self.channel_state & (ChannelState::LocalShutdownSent as u32) != 0 {
                        assert!(self.shutdown_scriptpubkey.is_some());
                        Some(msgs::Shutdown {
                                channel_id: self.channel_id,
                                scriptpubkey: self.get_closing_scriptpubkey(),
                        })
                } else { None };

                if self.channel_state & (ChannelState::FundingSent as u32) == ChannelState::FundingSent as u32 {
                        // If we're waiting on a monitor update, we shouldn't re-send any funding_locked's.
                        if self.channel_state & (ChannelState::OurFundingLocked as u32) == 0 ||
                                        self.channel_state & (ChannelState::MonitorUpdateFailed as u32) != 0 {
                                if msg.next_remote_commitment_number != 0 {
                                        return Err(ChannelError::Close("Peer claimed they saw a revoke_and_ack but we haven't sent funding_locked yet".to_owned()));
                                }
                                // Short circuit the whole handler as there is nothing we can resend them
                                return Ok((None, None, None, None, RAACommitmentOrder::CommitmentFirst, Vec::new(), shutdown_msg));
                        }

                        // We have OurFundingLocked set!
                        let next_per_commitment_point = self.holder_signer.get_per_commitment_point(self.cur_holder_commitment_transaction_number, &self.secp_ctx);
                        return Ok((Some(msgs::FundingLocked {
                                channel_id: self.channel_id(),
                                next_per_commitment_point,
                        }), None, None, None, RAACommitmentOrder::CommitmentFirst, Vec::new(), shutdown_msg));
                }

                let required_revoke = if msg.next_remote_commitment_number + 1 == INITIAL_COMMITMENT_NUMBER - self.cur_holder_commitment_transaction_number {
                        // Remote isn't waiting on any RevokeAndACK from us!
                        // Note that if we need to repeat our FundingLocked we'll do that in the next if block.
                        None
                } else if msg.next_remote_commitment_number + 1 == (INITIAL_COMMITMENT_NUMBER - 1) - self.cur_holder_commitment_transaction_number {
                        if self.channel_state & (ChannelState::MonitorUpdateFailed as u32) != 0 {
                                self.monitor_pending_revoke_and_ack = true;
                                None
                        } else {
                                Some(self.get_last_revoke_and_ack())
                        }
                } else {
                        return Err(ChannelError::Close("Peer attempted to reestablish channel with a very old local commitment transaction".to_owned()));
                };

                // We increment cur_counterparty_commitment_transaction_number only upon receipt of
                // revoke_and_ack, not on sending commitment_signed, so we add one if have
                // AwaitingRemoteRevoke set, which indicates we sent a commitment_signed but haven't gotten
                // the corresponding revoke_and_ack back yet.
                let next_counterparty_commitment_number = INITIAL_COMMITMENT_NUMBER - self.cur_counterparty_commitment_transaction_number + if (self.channel_state & ChannelState::AwaitingRemoteRevoke as u32) != 0 { 1 } else { 0 };

                let resend_funding_locked = if msg.next_local_commitment_number == 1 && INITIAL_COMMITMENT_NUMBER - self.cur_holder_commitment_transaction_number == 1 {
                        // We should never have to worry about MonitorUpdateFailed resending FundingLocked
                        let next_per_commitment_point = self.holder_signer.get_per_commitment_point(self.cur_holder_commitment_transaction_number, &self.secp_ctx);
                        Some(msgs::FundingLocked {
                                channel_id: self.channel_id(),
                                next_per_commitment_point,
                        })
                } else { None };

                if msg.next_local_commitment_number == next_counterparty_commitment_number {
                        if required_revoke.is_some() {
                                log_debug!(logger, "Reconnected channel {} with only lost outbound RAA", log_bytes!(self.channel_id()));
                        } else {
                                log_debug!(logger, "Reconnected channel {} with no loss", log_bytes!(self.channel_id()));
                        }

                        if (self.channel_state & (ChannelState::AwaitingRemoteRevoke as u32 | ChannelState::MonitorUpdateFailed as u32)) == 0 {
                                // We're up-to-date and not waiting on a remote revoke (if we are our
                                // channel_reestablish should result in them sending a revoke_and_ack), but we may
                                // have received some updates while we were disconnected. Free the holding cell
                                // now!
                                match self.free_holding_cell_htlcs(logger) {
                                        Err(ChannelError::Close(msg)) => return Err(ChannelError::Close(msg)),
                                        Err(ChannelError::Warn(_)) | Err(ChannelError::Ignore(_)) | Err(ChannelError::CloseDelayBroadcast(_)) =>
                                                panic!("Got non-channel-failing result from free_holding_cell_htlcs"),
                                        Ok((Some((commitment_update, monitor_update)), htlcs_to_fail)) => {
                                                return Ok((resend_funding_locked, required_revoke, Some(commitment_update), Some(monitor_update), self.resend_order.clone(), htlcs_to_fail, shutdown_msg));
                                        },
                                        Ok((None, htlcs_to_fail)) => {
                                                return Ok((resend_funding_locked, required_revoke, None, None, self.resend_order.clone(), htlcs_to_fail, shutdown_msg));
                                        },
                                }
                        } else {
                                return Ok((resend_funding_locked, required_revoke, None, None, self.resend_order.clone(), Vec::new(), shutdown_msg));
                        }
                } else if msg.next_local_commitment_number == next_counterparty_commitment_number - 1 {
                        if required_revoke.is_some() {
                                log_debug!(logger, "Reconnected channel {} with lost outbound RAA and lost remote commitment tx", log_bytes!(self.channel_id()));
                        } else {
                                log_debug!(logger, "Reconnected channel {} with only lost remote commitment tx", log_bytes!(self.channel_id()));
                        }

                        if self.channel_state & (ChannelState::MonitorUpdateFailed as u32) != 0 {
                                self.monitor_pending_commitment_signed = true;
                                return Ok((resend_funding_locked, None, None, None, self.resend_order.clone(), Vec::new(), shutdown_msg));
                        }

                        return Ok((resend_funding_locked, required_revoke, Some(self.get_last_commitment_update(logger)), None, self.resend_order.clone(), Vec::new(), shutdown_msg));
                } else {
                        return Err(ChannelError::Close("Peer attempted to reestablish channel with a very old remote commitment transaction".to_owned()));
                }
        }

        /// Calculates and returns our minimum and maximum closing transaction fee amounts, in whole
        /// satoshis. The amounts remain consistent unless a peer disconnects/reconnects or we restart,
        /// at which point they will be recalculated.
        fn calculate_closing_fee_limits<F: Deref>(&mut self, fee_estimator: &F) -> (u64, u64)
                where F::Target: FeeEstimator
        {
                if let Some((min, max)) = self.closing_fee_limits { return (min, max); }

                // Propose a range from our current Background feerate to our Normal feerate plus our
                // force_close_avoidance_max_fee_satoshis.
                // If we fail to come to consensus, we'll have to force-close.
                let mut proposed_feerate = fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Background);
                let normal_feerate = fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Normal);
                let mut proposed_max_feerate = if self.is_outbound() { normal_feerate } else { u32::max_value() };

                // The spec requires that (when the channel does not have anchors) we only send absolute
                // channel fees no greater than the absolute channel fee on the current commitment
                // transaction. It's unclear *which* commitment transaction this refers to, and there isn't
                // very good reason to apply such a limit in any case. We don't bother doing so, risking
                // some force-closure by old nodes, but we wanted to close the channel anyway.

                if let Some(target_feerate) = self.target_closing_feerate_sats_per_kw {
                        let min_feerate = if self.is_outbound() { target_feerate } else { cmp::min(self.feerate_per_kw, target_feerate) };
                        proposed_feerate = cmp::max(proposed_feerate, min_feerate);
                        proposed_max_feerate = cmp::max(proposed_max_feerate, min_feerate);
                }

                // Note that technically we could end up with a lower minimum fee if one sides' balance is
                // below our dust limit, causing the output to disappear. We don't bother handling this
                // case, however, as this should only happen if a channel is closed before any (material)
                // payments have been made on it. This may cause slight fee overpayment and/or failure to
                // come to consensus with our counterparty on appropriate fees, however it should be a
                // relatively rare case. We can revisit this later, though note that in order to determine
                // if the funders' output is dust we have to know the absolute fee we're going to use.
                let tx_weight = self.get_closing_transaction_weight(Some(&self.get_closing_scriptpubkey()), Some(self.counterparty_shutdown_scriptpubkey.as_ref().unwrap()));
                let proposed_total_fee_satoshis = proposed_feerate as u64 * tx_weight / 1000;
                let proposed_max_total_fee_satoshis = if self.is_outbound() {
                                // We always add force_close_avoidance_max_fee_satoshis to our normal
                                // feerate-calculated fee, but allow the max to be overridden if we're using a
                                // target feerate-calculated fee.
                                cmp::max(normal_feerate as u64 * tx_weight / 1000 + self.config.force_close_avoidance_max_fee_satoshis,
                                        proposed_max_feerate as u64 * tx_weight / 1000)
                        } else {
                                self.channel_value_satoshis - (self.value_to_self_msat + 999) / 1000
                        };

                self.closing_fee_limits = Some((proposed_total_fee_satoshis, proposed_max_total_fee_satoshis));
                self.closing_fee_limits.clone().unwrap()
        }

        /// Returns true if we're ready to commence the closing_signed negotiation phase. This is true
        /// after both sides have exchanged a `shutdown` message and all HTLCs have been drained. At
        /// this point if we're the funder we should send the initial closing_signed, and in any case
        /// shutdown should complete within a reasonable timeframe.
        fn closing_negotiation_ready(&self) -> bool {
                self.pending_inbound_htlcs.is_empty() && self.pending_outbound_htlcs.is_empty() &&
                        self.channel_state &
                                (BOTH_SIDES_SHUTDOWN_MASK | ChannelState::AwaitingRemoteRevoke as u32 |
                                 ChannelState::PeerDisconnected as u32 | ChannelState::MonitorUpdateFailed as u32)
                                == BOTH_SIDES_SHUTDOWN_MASK &&
                        self.pending_update_fee.is_none()
        }

        /// Checks if the closing_signed negotiation is making appropriate progress, possibly returning
        /// an Err if no progress is being made and the channel should be force-closed instead.
        /// Should be called on a one-minute timer.
        pub fn timer_check_closing_negotiation_progress(&mut self) -> Result<(), ChannelError> {
                if self.closing_negotiation_ready() {
                        if self.closing_signed_in_flight {
                                return Err(ChannelError::Close("closing_signed negotiation failed to finish within two timer ticks".to_owned()));
                        } else {
                                self.closing_signed_in_flight = true;
                        }
                }
                Ok(())
        }

        pub fn maybe_propose_closing_signed<F: Deref, L: Deref>(&mut self, fee_estimator: &F, logger: &L)
                -> Result<(Option<msgs::ClosingSigned>, Option<Transaction>), ChannelError>
                where F::Target: FeeEstimator, L::Target: Logger
        {
                if self.last_sent_closing_fee.is_some() || !self.closing_negotiation_ready() {
                        return Ok((None, None));
                }

                if !self.is_outbound() {
                        if let Some(msg) = &self.pending_counterparty_closing_signed.take() {
                                return self.closing_signed(fee_estimator, &msg);
                        }
                        return Ok((None, None));
                }

                let (our_min_fee, our_max_fee) = self.calculate_closing_fee_limits(fee_estimator);

                assert!(self.shutdown_scriptpubkey.is_some());
                let (closing_tx, total_fee_satoshis) = self.build_closing_transaction(our_min_fee, false);
                log_trace!(logger, "Proposing initial closing_signed for our counterparty with a fee range of {}-{} sat (with initial proposal {} sats)",
                        our_min_fee, our_max_fee, total_fee_satoshis);

                let sig = self.holder_signer
                        .sign_closing_transaction(&closing_tx, &self.secp_ctx)
                        .map_err(|()| ChannelError::Close("Failed to get signature for closing transaction.".to_owned()))?;

                self.last_sent_closing_fee = Some((total_fee_satoshis, sig.clone()));
                Ok((Some(msgs::ClosingSigned {
                        channel_id: self.channel_id,
                        fee_satoshis: total_fee_satoshis,
                        signature: sig,
                        fee_range: Some(msgs::ClosingSignedFeeRange {
                                min_fee_satoshis: our_min_fee,
                                max_fee_satoshis: our_max_fee,
                        }),
                }), None))
        }

        pub fn shutdown<K: Deref>(
                &mut self, keys_provider: &K, their_features: &InitFeatures, msg: &msgs::Shutdown
        ) -> Result<(Option<msgs::Shutdown>, Option<ChannelMonitorUpdate>, Vec<(HTLCSource, PaymentHash)>), ChannelError>
        where K::Target: KeysInterface<Signer = Signer>
        {
                if self.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 {
                        return Err(ChannelError::Close("Peer sent shutdown when we needed a channel_reestablish".to_owned()));
                }
                if self.channel_state < ChannelState::FundingSent as u32 {
                        // Spec says we should fail the connection, not the channel, but that's nonsense, there
                        // are plenty of reasons you may want to fail a channel pre-funding, and spec says you
                        // can do that via error message without getting a connection fail anyway...
                        return Err(ChannelError::Close("Peer sent shutdown pre-funding generation".to_owned()));
                }
                for htlc in self.pending_inbound_htlcs.iter() {
                        if let InboundHTLCState::RemoteAnnounced(_) = htlc.state {
                                return Err(ChannelError::Close("Got shutdown with remote pending HTLCs".to_owned()));
                        }
                }
                assert_eq!(self.channel_state & ChannelState::ShutdownComplete as u32, 0);

                if !script::is_bolt2_compliant(&msg.scriptpubkey, their_features) {
                        return Err(ChannelError::Close(format!("Got a nonstandard scriptpubkey ({}) from remote peer", msg.scriptpubkey.to_bytes().to_hex())));
                }

                if self.counterparty_shutdown_scriptpubkey.is_some() {
                        if Some(&msg.scriptpubkey) != self.counterparty_shutdown_scriptpubkey.as_ref() {
                                return Err(ChannelError::Close(format!("Got shutdown request with a scriptpubkey ({}) which did not match their previous scriptpubkey.", msg.scriptpubkey.to_bytes().to_hex())));
                        }
                } else {
                        self.counterparty_shutdown_scriptpubkey = Some(msg.scriptpubkey.clone());
                }

                // If we have any LocalAnnounced updates we'll probably just get back an update_fail_htlc
                // immediately after the commitment dance, but we can send a Shutdown because we won't send
                // any further commitment updates after we set LocalShutdownSent.
                let send_shutdown = (self.channel_state & ChannelState::LocalShutdownSent as u32) != ChannelState::LocalShutdownSent as u32;

                let update_shutdown_script = match self.shutdown_scriptpubkey {
                        Some(_) => false,
                        None => {
                                assert!(send_shutdown);
                                let shutdown_scriptpubkey = keys_provider.get_shutdown_scriptpubkey();
                                if !shutdown_scriptpubkey.is_compatible(their_features) {
                                        return Err(ChannelError::Close(format!("Provided a scriptpubkey format not accepted by peer: {}", shutdown_scriptpubkey)));
                                }
                                self.shutdown_scriptpubkey = Some(shutdown_scriptpubkey);
                                true
                        },
                };

                // From here on out, we may not fail!

                self.channel_state |= ChannelState::RemoteShutdownSent as u32;
                self.update_time_counter += 1;

                let monitor_update = if update_shutdown_script {
                        self.latest_monitor_update_id += 1;
                        Some(ChannelMonitorUpdate {
                                update_id: self.latest_monitor_update_id,
                                updates: vec![ChannelMonitorUpdateStep::ShutdownScript {
                                        scriptpubkey: self.get_closing_scriptpubkey(),
                                }],
                        })
                } else { None };
                let shutdown = if send_shutdown {
                        Some(msgs::Shutdown {
                                channel_id: self.channel_id,
                                scriptpubkey: self.get_closing_scriptpubkey(),
                        })
                } else { None };

                // We can't send our shutdown until we've committed all of our pending HTLCs, but the
                // remote side is unlikely to accept any new HTLCs, so we go ahead and "free" any holding
                // cell HTLCs and return them to fail the payment.
                self.holding_cell_update_fee = None;
                let mut dropped_outbound_htlcs = Vec::with_capacity(self.holding_cell_htlc_updates.len());
                self.holding_cell_htlc_updates.retain(|htlc_update| {
                        match htlc_update {
                                &HTLCUpdateAwaitingACK::AddHTLC { ref payment_hash, ref source, .. } => {
                                        dropped_outbound_htlcs.push((source.clone(), payment_hash.clone()));
                                        false
                                },
                                _ => true
                        }
                });

                self.channel_state |= ChannelState::LocalShutdownSent as u32;
                self.update_time_counter += 1;

                Ok((shutdown, monitor_update, dropped_outbound_htlcs))
        }

        fn build_signed_closing_transaction(&self, closing_tx: &ClosingTransaction, counterparty_sig: &Signature, sig: &Signature) -> Transaction {
                let mut tx = closing_tx.trust().built_transaction().clone();

                tx.input[0].witness.push(Vec::new()); // First is the multisig dummy

                let funding_key = self.get_holder_pubkeys().funding_pubkey.serialize();
                let counterparty_funding_key = self.counterparty_funding_pubkey().serialize();
                if funding_key[..] < counterparty_funding_key[..] {
                        tx.input[0].witness.push(sig.serialize_der().to_vec());
                        tx.input[0].witness.push(counterparty_sig.serialize_der().to_vec());
                } else {
                        tx.input[0].witness.push(counterparty_sig.serialize_der().to_vec());
                        tx.input[0].witness.push(sig.serialize_der().to_vec());
                }
                tx.input[0].witness[1].push(SigHashType::All as u8);
                tx.input[0].witness[2].push(SigHashType::All as u8);

                tx.input[0].witness.push(self.get_funding_redeemscript().into_bytes());
                tx
        }

        pub fn closing_signed<F: Deref>(&mut self, fee_estimator: &F, msg: &msgs::ClosingSigned) -> Result<(Option<msgs::ClosingSigned>, Option<Transaction>), ChannelError>
                where F::Target: FeeEstimator
        {
                if self.channel_state & BOTH_SIDES_SHUTDOWN_MASK != BOTH_SIDES_SHUTDOWN_MASK {
                        return Err(ChannelError::Close("Remote end sent us a closing_signed before both sides provided a shutdown".to_owned()));
                }
                if self.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 {
                        return Err(ChannelError::Close("Peer sent closing_signed when we needed a channel_reestablish".to_owned()));
                }
                if !self.pending_inbound_htlcs.is_empty() || !self.pending_outbound_htlcs.is_empty() {
                        return Err(ChannelError::Close("Remote end sent us a closing_signed while there were still pending HTLCs".to_owned()));
                }
                if msg.fee_satoshis > 21_000_000 * 1_0000_0000 { //this is required to stop potential overflow in build_closing_transaction
                        return Err(ChannelError::Close("Remote tried to send us a closing tx with > 21 million BTC fee".to_owned()));
                }

                if self.is_outbound() && self.last_sent_closing_fee.is_none() {
                        return Err(ChannelError::Close("Remote tried to send a closing_signed when we were supposed to propose the first one".to_owned()));
                }

                if self.channel_state & ChannelState::MonitorUpdateFailed as u32 != 0 {
                        self.pending_counterparty_closing_signed = Some(msg.clone());
                        return Ok((None, None));
                }

                let funding_redeemscript = self.get_funding_redeemscript();
                let (mut closing_tx, used_total_fee) = self.build_closing_transaction(msg.fee_satoshis, false);
                if used_total_fee != msg.fee_satoshis {
                        return Err(ChannelError::Close(format!("Remote sent us a closing_signed with a fee other than the value they can claim. Fee in message: {}. Actual closing tx fee: {}", msg.fee_satoshis, used_total_fee)));
                }
                let sighash = closing_tx.trust().get_sighash_all(&funding_redeemscript, self.channel_value_satoshis);

                match self.secp_ctx.verify(&sighash, &msg.signature, &self.get_counterparty_pubkeys().funding_pubkey) {
                        Ok(_) => {},
                        Err(_e) => {
                                // The remote end may have decided to revoke their output due to inconsistent dust
                                // limits, so check for that case by re-checking the signature here.
                                closing_tx = self.build_closing_transaction(msg.fee_satoshis, true).0;
                                let sighash = closing_tx.trust().get_sighash_all(&funding_redeemscript, self.channel_value_satoshis);
                                secp_check!(self.secp_ctx.verify(&sighash, &msg.signature, self.counterparty_funding_pubkey()), "Invalid closing tx signature from peer".to_owned());
                        },
                };

                for outp in closing_tx.trust().built_transaction().output.iter() {
                        if !outp.script_pubkey.is_witness_program() && outp.value < MAX_STD_OUTPUT_DUST_LIMIT_SATOSHIS {
                                return Err(ChannelError::Close("Remote sent us a closing_signed with a dust output. Always use segwit closing scripts!".to_owned()));
                        }
                }

                assert!(self.shutdown_scriptpubkey.is_some());
                if let Some((last_fee, sig)) = self.last_sent_closing_fee {
                        if last_fee == msg.fee_satoshis {
                                let tx = self.build_signed_closing_transaction(&mut closing_tx, &msg.signature, &sig);
                                self.channel_state = ChannelState::ShutdownComplete as u32;
                                self.update_time_counter += 1;
                                return Ok((None, Some(tx)));
                        }
                }

                let (our_min_fee, our_max_fee) = self.calculate_closing_fee_limits(fee_estimator);

                macro_rules! propose_fee {
                        ($new_fee: expr) => {
                                let (closing_tx, used_fee) = if $new_fee == msg.fee_satoshis {
                                        (closing_tx, $new_fee)
                                } else {
                                        self.build_closing_transaction($new_fee, false)
                                };

                                let sig = self.holder_signer
                                        .sign_closing_transaction(&closing_tx, &self.secp_ctx)
                                        .map_err(|_| ChannelError::Close("External signer refused to sign closing transaction".to_owned()))?;

                                let signed_tx = if $new_fee == msg.fee_satoshis {
                                        self.channel_state = ChannelState::ShutdownComplete as u32;
                                        self.update_time_counter += 1;
                                        let tx = self.build_signed_closing_transaction(&closing_tx, &msg.signature, &sig);
                                        Some(tx)
                                } else { None };

                                self.last_sent_closing_fee = Some((used_fee, sig.clone()));
                                return Ok((Some(msgs::ClosingSigned {
                                        channel_id: self.channel_id,
                                        fee_satoshis: used_fee,
                                        signature: sig,
                                        fee_range: Some(msgs::ClosingSignedFeeRange {
                                                min_fee_satoshis: our_min_fee,
                                                max_fee_satoshis: our_max_fee,
                                        }),
                                }), signed_tx))
                        }
                }

                if let Some(msgs::ClosingSignedFeeRange { min_fee_satoshis, max_fee_satoshis }) = msg.fee_range {
                        if msg.fee_satoshis < min_fee_satoshis || msg.fee_satoshis > max_fee_satoshis {
                                return Err(ChannelError::Close(format!("Peer sent a bogus closing_signed - suggested fee of {} sat was not in their desired range of {} sat - {} sat", msg.fee_satoshis, min_fee_satoshis, max_fee_satoshis)));
                        }
                        if max_fee_satoshis < our_min_fee {
                                return Err(ChannelError::Warn(format!("Unable to come to consensus about closing feerate, remote's max fee ({} sat) was smaller than our min fee ({} sat)", max_fee_satoshis, our_min_fee)));
                        }
                        if min_fee_satoshis > our_max_fee {
                                return Err(ChannelError::Warn(format!("Unable to come to consensus about closing feerate, remote's min fee ({} sat) was greater than our max fee ({} sat)", min_fee_satoshis, our_max_fee)));
                        }

                        if !self.is_outbound() {
                                // They have to pay, so pick the highest fee in the overlapping range.
                                // We should never set an upper bound aside from their full balance
                                debug_assert_eq!(our_max_fee, self.channel_value_satoshis - (self.value_to_self_msat + 999) / 1000);
                                propose_fee!(cmp::min(max_fee_satoshis, our_max_fee));
                        } else {
                                if msg.fee_satoshis < our_min_fee || msg.fee_satoshis > our_max_fee {
                                        return Err(ChannelError::Close(format!("Peer sent a bogus closing_signed - suggested fee of {} sat was not in our desired range of {} sat - {} sat after we informed them of our range.",
                                                msg.fee_satoshis, our_min_fee, our_max_fee)));
                                }
                                // The proposed fee is in our acceptable range, accept it and broadcast!
                                propose_fee!(msg.fee_satoshis);
                        }
                } else {
                        // Old fee style negotiation. We don't bother to enforce whether they are complying
                        // with the "making progress" requirements, we just comply and hope for the best.
                        if let Some((last_fee, _)) = self.last_sent_closing_fee {
                                if msg.fee_satoshis > last_fee {
                                        if msg.fee_satoshis < our_max_fee {
                                                propose_fee!(msg.fee_satoshis);
                                        } else if last_fee < our_max_fee {
                                                propose_fee!(our_max_fee);
                                        } else {
                                                return Err(ChannelError::Close(format!("Unable to come to consensus about closing feerate, remote wants something ({} sat) higher than our max fee ({} sat)", msg.fee_satoshis, our_max_fee)));
                                        }
                                } else {
                                        if msg.fee_satoshis > our_min_fee {
                                                propose_fee!(msg.fee_satoshis);
                                        } else if last_fee > our_min_fee {
                                                propose_fee!(our_min_fee);
                                        } else {
                                                return Err(ChannelError::Close(format!("Unable to come to consensus about closing feerate, remote wants something ({} sat) lower than our min fee ({} sat)", msg.fee_satoshis, our_min_fee)));
                                        }
                                }
                        } else {
                                if msg.fee_satoshis < our_min_fee {
                                        propose_fee!(our_min_fee);
                                } else if msg.fee_satoshis > our_max_fee {
                                        propose_fee!(our_max_fee);
                                } else {
                                        propose_fee!(msg.fee_satoshis);
                                }
                        }
                }
        }

        // Public utilities:

        pub fn channel_id(&self) -> [u8; 32] {
                self.channel_id
        }

        pub fn minimum_depth(&self) -> Option<u32> {
                self.minimum_depth
        }

        /// Gets the "user_id" value passed into the construction of this channel. It has no special
        /// meaning and exists only to allow users to have a persistent identifier of a channel.
        pub fn get_user_id(&self) -> u64 {
                self.user_id
        }

        /// Guaranteed to be Some after both FundingLocked messages have been exchanged (and, thus,
        /// is_usable() returns true).
        /// Allowed in any state (including after shutdown)
        pub fn get_short_channel_id(&self) -> Option<u64> {
                self.short_channel_id
        }

        /// Returns the funding_txo we either got from our peer, or were given by
        /// get_outbound_funding_created.
        pub fn get_funding_txo(&self) -> Option<OutPoint> {
                self.channel_transaction_parameters.funding_outpoint
        }

        fn get_holder_selected_contest_delay(&self) -> u16 {
                self.channel_transaction_parameters.holder_selected_contest_delay
        }

        fn get_holder_pubkeys(&self) -> &ChannelPublicKeys {
                &self.channel_transaction_parameters.holder_pubkeys
        }

        pub fn get_counterparty_selected_contest_delay(&self) -> Option<u16> {
                self.channel_transaction_parameters.counterparty_parameters
                        .as_ref().map(|params| params.selected_contest_delay)
        }

        fn get_counterparty_pubkeys(&self) -> &ChannelPublicKeys {
                &self.channel_transaction_parameters.counterparty_parameters.as_ref().unwrap().pubkeys
        }

        /// Allowed in any state (including after shutdown)
        pub fn get_counterparty_node_id(&self) -> PublicKey {
                self.counterparty_node_id
        }

        /// Allowed in any state (including after shutdown)
        #[cfg(test)]
        pub fn get_holder_htlc_minimum_msat(&self) -> u64 {
                self.holder_htlc_minimum_msat
        }

        /// Allowed in any state (including after shutdown)
        pub fn get_announced_htlc_max_msat(&self) -> u64 {
                return cmp::min(
                        // Upper bound by capacity. We make it a bit less than full capacity to prevent attempts
                        // to use full capacity. This is an effort to reduce routing failures, because in many cases
                        // channel might have been used to route very small values (either by honest users or as DoS).
                        self.channel_value_satoshis * 1000 * 9 / 10,

                        self.holder_max_htlc_value_in_flight_msat
                );
        }

        /// Allowed in any state (including after shutdown)
        pub fn get_counterparty_htlc_minimum_msat(&self) -> u64 {
                self.counterparty_htlc_minimum_msat
        }

        pub fn get_value_satoshis(&self) -> u64 {
                self.channel_value_satoshis
        }

        pub fn get_fee_proportional_millionths(&self) -> u32 {
                self.config.forwarding_fee_proportional_millionths
        }

        pub fn get_cltv_expiry_delta(&self) -> u16 {
                cmp::max(self.config.cltv_expiry_delta, MIN_CLTV_EXPIRY_DELTA)
        }

        pub fn get_max_dust_htlc_exposure_msat(&self) -> u64 {
                self.config.max_dust_htlc_exposure_msat
        }

        pub fn get_feerate(&self) -> u32 {
                self.feerate_per_kw
        }

        pub fn get_dust_buffer_feerate(&self, outbound_feerate_update: Option<u32>) -> u32 {
                // When calculating our exposure to dust HTLCs, we assume that the channel feerate
                // may, at any point, increase by at least 10 sat/vB (i.e 2530 sat/kWU) or 25%,
                // whichever is higher. This ensures that we aren't suddenly exposed to significantly
                // more dust balance if the feerate increases when we have several HTLCs pending
                // which are near the dust limit.
                let mut feerate_per_kw = self.feerate_per_kw;
                // If there's a pending update fee, use it to ensure we aren't under-estimating
                // potential feerate updates coming soon.
                if let Some((feerate, _)) = self.pending_update_fee {
                        feerate_per_kw = cmp::max(feerate_per_kw, feerate);
                }
                if let Some(feerate) = outbound_feerate_update {
                        feerate_per_kw = cmp::max(feerate_per_kw, feerate);
                }
                cmp::max(2530, feerate_per_kw * 1250 / 1000)
        }

        pub fn get_cur_holder_commitment_transaction_number(&self) -> u64 {
                self.cur_holder_commitment_transaction_number + 1
        }

        pub fn get_cur_counterparty_commitment_transaction_number(&self) -> u64 {
                self.cur_counterparty_commitment_transaction_number + 1 - if self.channel_state & (ChannelState::AwaitingRemoteRevoke as u32) != 0 { 1 } else { 0 }
        }

        pub fn get_revoked_counterparty_commitment_transaction_number(&self) -> u64 {
                self.cur_counterparty_commitment_transaction_number + 2
        }

        #[cfg(test)]
        pub fn get_signer(&self) -> &Signer {
                &self.holder_signer
        }

        #[cfg(test)]
        pub fn get_value_stat(&self) -> ChannelValueStat {
                ChannelValueStat {
                        value_to_self_msat: self.value_to_self_msat,
                        channel_value_msat: self.channel_value_satoshis * 1000,
                        channel_reserve_msat: self.counterparty_selected_channel_reserve_satoshis.unwrap() * 1000,
                        pending_outbound_htlcs_amount_msat: self.pending_outbound_htlcs.iter().map(|ref h| h.amount_msat).sum::<u64>(),
                        pending_inbound_htlcs_amount_msat: self.pending_inbound_htlcs.iter().map(|ref h| h.amount_msat).sum::<u64>(),
                        holding_cell_outbound_amount_msat: {
                                let mut res = 0;
                                for h in self.holding_cell_htlc_updates.iter() {
                                        match h {
                                                &HTLCUpdateAwaitingACK::AddHTLC{amount_msat, .. } => {
                                                        res += amount_msat;
                                                }
                                                _ => {}
                                        }
                                }
                                res
                        },
                        counterparty_max_htlc_value_in_flight_msat: self.counterparty_max_htlc_value_in_flight_msat,
                        counterparty_dust_limit_msat: self.counterparty_dust_limit_satoshis * 1000,
                }
        }

        /// Allowed in any state (including after shutdown)
        pub fn get_update_time_counter(&self) -> u32 {
                self.update_time_counter
        }

        pub fn get_latest_monitor_update_id(&self) -> u64 {
                self.latest_monitor_update_id
        }

        pub fn should_announce(&self) -> bool {
                self.config.announced_channel
        }

        pub fn is_outbound(&self) -> bool {
                self.channel_transaction_parameters.is_outbound_from_holder
        }

        /// Gets the fee we'd want to charge for adding an HTLC output to this Channel
        /// Allowed in any state (including after shutdown)
        pub fn get_outbound_forwarding_fee_base_msat(&self) -> u32 {
                self.config.forwarding_fee_base_msat
        }

        /// Returns true if we've ever received a message from the remote end for this Channel
        pub fn have_received_message(&self) -> bool {
                self.channel_state > (ChannelState::OurInitSent as u32)
        }

        /// Returns true if this channel is fully established and not known to be closing.
        /// Allowed in any state (including after shutdown)
        pub fn is_usable(&self) -> bool {
                let mask = ChannelState::ChannelFunded as u32 | BOTH_SIDES_SHUTDOWN_MASK;
                (self.channel_state & mask) == (ChannelState::ChannelFunded as u32)
        }

        /// Returns true if this channel is currently available for use. This is a superset of
        /// is_usable() and considers things like the channel being temporarily disabled.
        /// Allowed in any state (including after shutdown)
        pub fn is_live(&self) -> bool {
                self.is_usable() && (self.channel_state & (ChannelState::PeerDisconnected as u32) == 0)
        }

        /// Returns true if this channel has been marked as awaiting a monitor update to move forward.
        /// Allowed in any state (including after shutdown)
        pub fn is_awaiting_monitor_update(&self) -> bool {
                (self.channel_state & ChannelState::MonitorUpdateFailed as u32) != 0
        }

        /// Returns true if funding_created was sent/received.
        pub fn is_funding_initiated(&self) -> bool {
                self.channel_state >= ChannelState::FundingSent as u32
        }

        /// Returns true if our peer has either initiated or agreed to shut down the channel.
        pub fn received_shutdown(&self) -> bool {
                (self.channel_state & ChannelState::RemoteShutdownSent as u32) != 0
        }

        /// Returns true if we either initiated or agreed to shut down the channel.
        pub fn sent_shutdown(&self) -> bool {
                (self.channel_state & ChannelState::LocalShutdownSent as u32) != 0
        }

        /// Returns true if this channel is fully shut down. True here implies that no further actions
        /// may/will be taken on this channel, and thus this object should be freed. Any future changes
        /// will be handled appropriately by the chain monitor.
        pub fn is_shutdown(&self) -> bool {
                if (self.channel_state & ChannelState::ShutdownComplete as u32) == ChannelState::ShutdownComplete as u32  {
                        assert!(self.channel_state == ChannelState::ShutdownComplete as u32);
                        true
                } else { false }
        }

        pub fn channel_update_status(&self) -> ChannelUpdateStatus {
                self.channel_update_status
        }

        pub fn set_channel_update_status(&mut self, status: ChannelUpdateStatus) {
                self.update_time_counter += 1;
                self.channel_update_status = status;
        }

        fn check_get_funding_locked(&mut self, height: u32) -> Option<msgs::FundingLocked> {
                if self.funding_tx_confirmation_height == 0 {
                        return None;
                }

                let funding_tx_confirmations = height as i64 - self.funding_tx_confirmation_height as i64 + 1;
                if funding_tx_confirmations <= 0 {
                        self.funding_tx_confirmation_height = 0;
                }

                if funding_tx_confirmations < self.minimum_depth.unwrap_or(0) as i64 {
                        return None;
                }

                let non_shutdown_state = self.channel_state & (!MULTI_STATE_FLAGS);
                let need_commitment_update = if non_shutdown_state == ChannelState::FundingSent as u32 {
                        self.channel_state |= ChannelState::OurFundingLocked as u32;
                        true
                } else if non_shutdown_state == (ChannelState::FundingSent as u32 | ChannelState::TheirFundingLocked as u32) {
                        self.channel_state = ChannelState::ChannelFunded as u32 | (self.channel_state & MULTI_STATE_FLAGS);
                        self.update_time_counter += 1;
                        true
                } else if non_shutdown_state == (ChannelState::FundingSent as u32 | ChannelState::OurFundingLocked as u32) {
                        // We got a reorg but not enough to trigger a force close, just ignore.
                        false
                } else if self.channel_state < ChannelState::ChannelFunded as u32 {
                        panic!("Started confirming a channel in a state pre-FundingSent?: {}", self.channel_state);
                } else {
                        // We got a reorg but not enough to trigger a force close, just ignore.
                        false
                };

                if need_commitment_update {
                        if self.channel_state & (ChannelState::MonitorUpdateFailed as u32) == 0 {
                                let next_per_commitment_point = self.holder_signer.get_per_commitment_point(self.cur_holder_commitment_transaction_number, &self.secp_ctx);
                                return Some(msgs::FundingLocked {
                                        channel_id: self.channel_id,
                                        next_per_commitment_point,
                                });
                        } else {
                                self.monitor_pending_funding_locked = true;
                        }
                }
                None
        }

        /// When a transaction is confirmed, we check whether it is or spends the funding transaction
        /// In the first case, we store the confirmation height and calculating the short channel id.
        /// In the second, we simply return an Err indicating we need to be force-closed now.
        pub fn transactions_confirmed<L: Deref>(&mut self, block_hash: &BlockHash, height: u32, txdata: &TransactionData, logger: &L)
        -> Result<Option<msgs::FundingLocked>, ClosureReason> where L::Target: Logger {
                let non_shutdown_state = self.channel_state & (!MULTI_STATE_FLAGS);
                for &(index_in_block, tx) in txdata.iter() {
                        if let Some(funding_txo) = self.get_funding_txo() {
                                // If we haven't yet sent a funding_locked, but are in FundingSent (ignoring
                                // whether they've sent a funding_locked or not), check if we should send one.
                                if non_shutdown_state & !(ChannelState::TheirFundingLocked as u32) == ChannelState::FundingSent as u32 {
                                        if tx.txid() == funding_txo.txid {
                                                let txo_idx = funding_txo.index as usize;
                                                if txo_idx >= tx.output.len() || tx.output[txo_idx].script_pubkey != self.get_funding_redeemscript().to_v0_p2wsh() ||
                                                                tx.output[txo_idx].value != self.channel_value_satoshis {
                                                        if self.is_outbound() {
                                                                // If we generated the funding transaction and it doesn't match what it
                                                                // should, the client is really broken and we should just panic and
                                                                // tell them off. That said, because hash collisions happen with high
                                                                // probability in fuzztarget mode, if we're fuzzing we just close the
                                                                // channel and move on.
                                                                #[cfg(not(feature = "fuzztarget"))]
                                                                panic!("Client called ChannelManager::funding_transaction_generated with bogus transaction!");
                                                        }
                                                        self.update_time_counter += 1;
                                                        let err_reason = "funding tx had wrong script/value or output index";
                                                        return Err(ClosureReason::ProcessingError { err: err_reason.to_owned() });
                                                } else {
                                                        if self.is_outbound() {
                                                                for input in tx.input.iter() {
                                                                        if input.witness.is_empty() {
                                                                                // We generated a malleable funding transaction, implying we've
                                                                                // just exposed ourselves to funds loss to our counterparty.
                                                                                #[cfg(not(feature = "fuzztarget"))]
                                                                                panic!("Client called ChannelManager::funding_transaction_generated with bogus transaction!");
                                                                        }
                                                                }
                                                        }
                                                        self.funding_tx_confirmation_height = height;
                                                        self.funding_tx_confirmed_in = Some(*block_hash);
                                                        self.short_channel_id = match scid_from_parts(height as u64, index_in_block as u64, txo_idx as u64) {
                                                                Ok(scid) => Some(scid),
                                                                Err(_) => panic!("Block was bogus - either height was > 16 million, had > 16 million transactions, or had > 65k outputs"),
                                                        }
                                                }
                                        }
                                        // If we allow 1-conf funding, we may need to check for funding_locked here and
                                        // send it immediately instead of waiting for a best_block_updated call (which
                                        // may have already happened for this block).
                                        if let Some(funding_locked) = self.check_get_funding_locked(height) {
                                                log_info!(logger, "Sending a funding_locked to our peer for channel {}", log_bytes!(self.channel_id));
                                                return Ok(Some(funding_locked));
                                        }
                                }
                                for inp in tx.input.iter() {
                                        if inp.previous_output == funding_txo.into_bitcoin_outpoint() {
                                                log_info!(logger, "Detected channel-closing tx {} spending {}:{}, closing channel {}", tx.txid(), inp.previous_output.txid, inp.previous_output.vout, log_bytes!(self.channel_id()));
                                                return Err(ClosureReason::CommitmentTxConfirmed);
                                        }
                                }
                        }
                }
                Ok(None)
        }

        /// When a new block is connected, we check the height of the block against outbound holding
        /// cell HTLCs in case we need to give up on them prematurely and time them out. Everything
        /// else (e.g. commitment transaction broadcasts, HTLC transaction broadcasting, etc) is
        /// handled by the ChannelMonitor.
        ///
        /// If we return Err, the channel may have been closed, at which point the standard
        /// requirements apply - no calls may be made except those explicitly stated to be allowed
        /// post-shutdown.
        ///
        /// May return some HTLCs (and their payment_hash) which have timed out and should be failed
        /// back.
        pub fn best_block_updated<L: Deref>(&mut self, height: u32, highest_header_time: u32, logger: &L)
        -> Result<(Option<msgs::FundingLocked>, Vec<(HTLCSource, PaymentHash)>), ClosureReason> where L::Target: Logger {
                let mut timed_out_htlcs = Vec::new();
                // This mirrors the check in ChannelManager::decode_update_add_htlc_onion, refusing to
                // forward an HTLC when our counterparty should almost certainly just fail it for expiring
                // ~now.
                let unforwarded_htlc_cltv_limit = height + LATENCY_GRACE_PERIOD_BLOCKS;
                self.holding_cell_htlc_updates.retain(|htlc_update| {
                        match htlc_update {
                                &HTLCUpdateAwaitingACK::AddHTLC { ref payment_hash, ref source, ref cltv_expiry, .. } => {
                                        if *cltv_expiry <= unforwarded_htlc_cltv_limit {
                                                timed_out_htlcs.push((source.clone(), payment_hash.clone()));
                                                false
                                        } else { true }
                                },
                                _ => true
                        }
                });

                self.update_time_counter = cmp::max(self.update_time_counter, highest_header_time);

                if let Some(funding_locked) = self.check_get_funding_locked(height) {
                        log_info!(logger, "Sending a funding_locked to our peer for channel {}", log_bytes!(self.channel_id));
                        return Ok((Some(funding_locked), timed_out_htlcs));
                }

                let non_shutdown_state = self.channel_state & (!MULTI_STATE_FLAGS);
                if non_shutdown_state >= ChannelState::ChannelFunded as u32 ||
                   (non_shutdown_state & ChannelState::OurFundingLocked as u32) == ChannelState::OurFundingLocked as u32 {
                        let mut funding_tx_confirmations = height as i64 - self.funding_tx_confirmation_height as i64 + 1;
                        if self.funding_tx_confirmation_height == 0 {
                                // Note that check_get_funding_locked may reset funding_tx_confirmation_height to
                                // zero if it has been reorged out, however in either case, our state flags
                                // indicate we've already sent a funding_locked
                                funding_tx_confirmations = 0;
                        }

                        // If we've sent funding_locked (or have both sent and received funding_locked), and
                        // the funding transaction's confirmation count has dipped below minimum_depth / 2,
                        // close the channel and hope we can get the latest state on chain (because presumably
                        // the funding transaction is at least still in the mempool of most nodes).
                        if funding_tx_confirmations < self.minimum_depth.unwrap() as i64 / 2 {
                                let err_reason = format!("Funding transaction was un-confirmed. Locked at {} confs, now have {} confs.",
                                        self.minimum_depth.unwrap(), funding_tx_confirmations);
                                return Err(ClosureReason::ProcessingError { err: err_reason });
                        }
                } else if !self.is_outbound() && self.funding_tx_confirmed_in.is_none() &&
                                height >= self.channel_creation_height + FUNDING_CONF_DEADLINE_BLOCKS {
                        log_info!(logger, "Closing channel {} due to funding timeout", log_bytes!(self.channel_id));
                        // If funding_tx_confirmed_in is unset, the channel must not be active
                        assert!(non_shutdown_state <= ChannelState::ChannelFunded as u32);
                        assert_eq!(non_shutdown_state & ChannelState::OurFundingLocked as u32, 0);
                        return Err(ClosureReason::FundingTimedOut);
                }

                Ok((None, timed_out_htlcs))
        }

        /// Indicates the funding transaction is no longer confirmed in the main chain. This may
        /// force-close the channel, but may also indicate a harmless reorganization of a block or two
        /// before the channel has reached funding_locked and we can just wait for more blocks.
        pub fn funding_transaction_unconfirmed<L: Deref>(&mut self, logger: &L) -> Result<(), ClosureReason> where L::Target: Logger {
                if self.funding_tx_confirmation_height != 0 {
                        // We handle the funding disconnection by calling best_block_updated with a height one
                        // below where our funding was connected, implying a reorg back to conf_height - 1.
                        let reorg_height = self.funding_tx_confirmation_height - 1;
                        // We use the time field to bump the current time we set on channel updates if its
                        // larger. If we don't know that time has moved forward, we can just set it to the last
                        // time we saw and it will be ignored.
                        let best_time = self.update_time_counter;
                        match self.best_block_updated(reorg_height, best_time, logger) {
                                Ok((funding_locked, timed_out_htlcs)) => {
                                        assert!(funding_locked.is_none(), "We can't generate a funding with 0 confirmations?");
                                        assert!(timed_out_htlcs.is_empty(), "We can't have accepted HTLCs with a timeout before our funding confirmation?");
                                        Ok(())
                                },
                                Err(e) => Err(e)
                        }
                } else {
                        // We never learned about the funding confirmation anyway, just ignore
                        Ok(())
                }
        }

        // Methods to get unprompted messages to send to the remote end (or where we already returned
        // something in the handler for the message that prompted this message):

        pub fn get_open_channel(&self, chain_hash: BlockHash) -> msgs::OpenChannel {
                if !self.is_outbound() {
                        panic!("Tried to open a channel for an inbound channel?");
                }
                if self.channel_state != ChannelState::OurInitSent as u32 {
                        panic!("Cannot generate an open_channel after we've moved forward");
                }

                if self.cur_holder_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER {
                        panic!("Tried to send an open_channel for a channel that has already advanced");
                }

                let first_per_commitment_point = self.holder_signer.get_per_commitment_point(self.cur_holder_commitment_transaction_number, &self.secp_ctx);
                let keys = self.get_holder_pubkeys();

                msgs::OpenChannel {
                        chain_hash,
                        temporary_channel_id: self.channel_id,
                        funding_satoshis: self.channel_value_satoshis,
                        push_msat: self.channel_value_satoshis * 1000 - self.value_to_self_msat,
                        dust_limit_satoshis: self.holder_dust_limit_satoshis,
                        max_htlc_value_in_flight_msat: self.holder_max_htlc_value_in_flight_msat,
                        channel_reserve_satoshis: self.holder_selected_channel_reserve_satoshis,
                        htlc_minimum_msat: self.holder_htlc_minimum_msat,
                        feerate_per_kw: self.feerate_per_kw as u32,
                        to_self_delay: self.get_holder_selected_contest_delay(),
                        max_accepted_htlcs: OUR_MAX_HTLCS,
                        funding_pubkey: keys.funding_pubkey,
                        revocation_basepoint: keys.revocation_basepoint,
                        payment_point: keys.payment_point,
                        delayed_payment_basepoint: keys.delayed_payment_basepoint,
                        htlc_basepoint: keys.htlc_basepoint,
                        first_per_commitment_point,
                        channel_flags: if self.config.announced_channel {1} else {0},
                        shutdown_scriptpubkey: OptionalField::Present(match &self.shutdown_scriptpubkey {
                                Some(script) => script.clone().into_inner(),
                                None => Builder::new().into_script(),
                        }),
                        channel_type: Some(self.channel_type.clone()),
                }
        }

        pub fn get_accept_channel(&self) -> msgs::AcceptChannel {
                if self.is_outbound() {
                        panic!("Tried to send accept_channel for an outbound channel?");
                }
                if self.channel_state != (ChannelState::OurInitSent as u32) | (ChannelState::TheirInitSent as u32) {
                        panic!("Tried to send accept_channel after channel had moved forward");
                }
                if self.cur_holder_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER {
                        panic!("Tried to send an accept_channel for a channel that has already advanced");
                }

                let first_per_commitment_point = self.holder_signer.get_per_commitment_point(self.cur_holder_commitment_transaction_number, &self.secp_ctx);
                let keys = self.get_holder_pubkeys();

                msgs::AcceptChannel {
                        temporary_channel_id: self.channel_id,
                        dust_limit_satoshis: self.holder_dust_limit_satoshis,
                        max_htlc_value_in_flight_msat: self.holder_max_htlc_value_in_flight_msat,
                        channel_reserve_satoshis: self.holder_selected_channel_reserve_satoshis,
                        htlc_minimum_msat: self.holder_htlc_minimum_msat,
                        minimum_depth: self.minimum_depth.unwrap(),
                        to_self_delay: self.get_holder_selected_contest_delay(),
                        max_accepted_htlcs: OUR_MAX_HTLCS,
                        funding_pubkey: keys.funding_pubkey,
                        revocation_basepoint: keys.revocation_basepoint,
                        payment_point: keys.payment_point,
                        delayed_payment_basepoint: keys.delayed_payment_basepoint,
                        htlc_basepoint: keys.htlc_basepoint,
                        first_per_commitment_point,
                        shutdown_scriptpubkey: OptionalField::Present(match &self.shutdown_scriptpubkey {
                                Some(script) => script.clone().into_inner(),
                                None => Builder::new().into_script(),
                        }),
                }
        }

        /// If an Err is returned, it is a ChannelError::Close (for get_outbound_funding_created)
        fn get_outbound_funding_created_signature<L: Deref>(&mut self, logger: &L) -> Result<Signature, ChannelError> where L::Target: Logger {
                let counterparty_keys = self.build_remote_transaction_keys()?;
                let counterparty_initial_commitment_tx = self.build_commitment_transaction(self.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, false, logger).tx;
                Ok(self.holder_signer.sign_counterparty_commitment(&counterparty_initial_commitment_tx, &self.secp_ctx)
                                .map_err(|_| ChannelError::Close("Failed to get signatures for new commitment_signed".to_owned()))?.0)
        }

        /// Updates channel state with knowledge of the funding transaction's txid/index, and generates
        /// a funding_created message for the remote peer.
        /// Panics if called at some time other than immediately after initial handshake, if called twice,
        /// or if called on an inbound channel.
        /// Note that channel_id changes during this call!
        /// Do NOT broadcast the funding transaction until after a successful funding_signed call!
        /// If an Err is returned, it is a ChannelError::Close.
        pub fn get_outbound_funding_created<L: Deref>(&mut self, funding_transaction: Transaction, funding_txo: OutPoint, logger: &L) -> Result<msgs::FundingCreated, ChannelError> where L::Target: Logger {
                if !self.is_outbound() {
                        panic!("Tried to create outbound funding_created message on an inbound channel!");
                }
                if self.channel_state != (ChannelState::OurInitSent as u32 | ChannelState::TheirInitSent as u32) {
                        panic!("Tried to get a funding_created messsage at a time other than immediately after initial handshake completion (or tried to get funding_created twice)");
                }
                if self.commitment_secrets.get_min_seen_secret() != (1 << 48) ||
                                self.cur_counterparty_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER ||
                                self.cur_holder_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER {
                        panic!("Should not have advanced channel commitment tx numbers prior to funding_created");
                }

                self.channel_transaction_parameters.funding_outpoint = Some(funding_txo);
                self.holder_signer.ready_channel(&self.channel_transaction_parameters);

                let signature = match self.get_outbound_funding_created_signature(logger) {
                        Ok(res) => res,
                        Err(e) => {
                                log_error!(logger, "Got bad signatures: {:?}!", e);
                                self.channel_transaction_parameters.funding_outpoint = None;
                                return Err(e);
                        }
                };

                let temporary_channel_id = self.channel_id;

                // Now that we're past error-generating stuff, update our local state:

                self.channel_state = ChannelState::FundingCreated as u32;
                self.channel_id = funding_txo.to_channel_id();
                self.funding_transaction = Some(funding_transaction);

                Ok(msgs::FundingCreated {
                        temporary_channel_id,
                        funding_txid: funding_txo.txid,
                        funding_output_index: funding_txo.index,
                        signature
                })
        }

        /// Gets an UnsignedChannelAnnouncement, as well as a signature covering it using our
        /// bitcoin_key, if available, for this channel. The channel must be publicly announceable and
        /// available for use (have exchanged FundingLocked messages in both directions). Should be used
        /// for both loose and in response to an AnnouncementSignatures message from the remote peer.
        /// Will only fail if we're not in a state where channel_announcement may be sent (including
        /// closing).
        /// Note that the "channel must be funded" requirement is stricter than BOLT 7 requires - see
        /// https://github.com/lightningnetwork/lightning-rfc/issues/468
        ///
        /// This will only return ChannelError::Ignore upon failure.
        pub fn get_channel_announcement(&self, node_id: PublicKey, chain_hash: BlockHash) -> Result<(msgs::UnsignedChannelAnnouncement, Signature), ChannelError> {
                if !self.config.announced_channel {
                        return Err(ChannelError::Ignore("Channel is not available for public announcements".to_owned()));
                }
                if self.channel_state & (ChannelState::ChannelFunded as u32) == 0 {
                        return Err(ChannelError::Ignore("Cannot get a ChannelAnnouncement until the channel funding has been locked".to_owned()));
                }
                if (self.channel_state & (ChannelState::LocalShutdownSent as u32 | ChannelState::ShutdownComplete as u32)) != 0 {
                        return Err(ChannelError::Ignore("Cannot get a ChannelAnnouncement once the channel is closing".to_owned()));
                }

                let were_node_one = node_id.serialize()[..] < self.counterparty_node_id.serialize()[..];

                let msg = msgs::UnsignedChannelAnnouncement {
                        features: ChannelFeatures::known(),
                        chain_hash,
                        short_channel_id: self.get_short_channel_id().unwrap(),
                        node_id_1: if were_node_one { node_id } else { self.get_counterparty_node_id() },
                        node_id_2: if were_node_one { self.get_counterparty_node_id() } else { node_id },
                        bitcoin_key_1: if were_node_one { self.get_holder_pubkeys().funding_pubkey } else { self.counterparty_funding_pubkey().clone() },
                        bitcoin_key_2: if were_node_one { self.counterparty_funding_pubkey().clone() } else { self.get_holder_pubkeys().funding_pubkey },
                        excess_data: Vec::new(),
                };

                let sig = self.holder_signer.sign_channel_announcement(&msg, &self.secp_ctx)
                        .map_err(|_| ChannelError::Ignore("Signer rejected channel_announcement".to_owned()))?;

                Ok((msg, sig))
        }

        /// Signs the given channel announcement, returning a ChannelError::Ignore if no keys are
        /// available.
        fn sign_channel_announcement(&self, our_node_secret: &SecretKey, our_node_id: PublicKey, msghash: secp256k1::Message, announcement: msgs::UnsignedChannelAnnouncement, our_bitcoin_sig: Signature) -> Result<msgs::ChannelAnnouncement, ChannelError> {
                if let Some((their_node_sig, their_bitcoin_sig)) = self.announcement_sigs {
                        let were_node_one = announcement.node_id_1 == our_node_id;

                        let our_node_sig = self.secp_ctx.sign(&msghash, our_node_secret);
                        Ok(msgs::ChannelAnnouncement {
                                node_signature_1: if were_node_one { our_node_sig } else { their_node_sig },
                                node_signature_2: if were_node_one { their_node_sig } else { our_node_sig },
                                bitcoin_signature_1: if were_node_one { our_bitcoin_sig } else { their_bitcoin_sig },
                                bitcoin_signature_2: if were_node_one { their_bitcoin_sig } else { our_bitcoin_sig },
                                contents: announcement,
                        })
                } else {
                        Err(ChannelError::Ignore("Attempted to sign channel announcement before we'd received announcement_signatures".to_string()))
                }
        }

        /// Processes an incoming announcement_signatures message, providing a fully-signed
        /// channel_announcement message which we can broadcast and storing our counterparty's
        /// signatures for later reconstruction/rebroadcast of the channel_announcement.
        pub fn announcement_signatures(&mut self, our_node_secret: &SecretKey, our_node_id: PublicKey, chain_hash: BlockHash, msg: &msgs::AnnouncementSignatures) -> Result<msgs::ChannelAnnouncement, ChannelError> {
                let (announcement, our_bitcoin_sig) = self.get_channel_announcement(our_node_id.clone(), chain_hash)?;

                let msghash = hash_to_message!(&Sha256d::hash(&announcement.encode()[..])[..]);

                if self.secp_ctx.verify(&msghash, &msg.node_signature, &self.get_counterparty_node_id()).is_err() {
                        return Err(ChannelError::Close(format!(
                                "Bad announcement_signatures. Failed to verify node_signature. UnsignedChannelAnnouncement used for verification is {:?}. their_node_key is {:?}",
                                 &announcement, self.get_counterparty_node_id())));
                }
                if self.secp_ctx.verify(&msghash, &msg.bitcoin_signature, self.counterparty_funding_pubkey()).is_err() {
                        return Err(ChannelError::Close(format!(
                                "Bad announcement_signatures. Failed to verify bitcoin_signature. UnsignedChannelAnnouncement used for verification is {:?}. their_bitcoin_key is ({:?})",
                                &announcement, self.counterparty_funding_pubkey())));
                }

                self.announcement_sigs = Some((msg.node_signature, msg.bitcoin_signature));

                self.sign_channel_announcement(our_node_secret, our_node_id, msghash, announcement, our_bitcoin_sig)
        }

        /// Gets a signed channel_announcement for this channel, if we previously received an
        /// announcement_signatures from our counterparty.
        pub fn get_signed_channel_announcement(&self, our_node_secret: &SecretKey, our_node_id: PublicKey, chain_hash: BlockHash) -> Option<msgs::ChannelAnnouncement> {
                let (announcement, our_bitcoin_sig) = match self.get_channel_announcement(our_node_id.clone(), chain_hash) {
                        Ok(res) => res,
                        Err(_) => return None,
                };
                let msghash = hash_to_message!(&Sha256d::hash(&announcement.encode()[..])[..]);
                match self.sign_channel_announcement(our_node_secret, our_node_id, msghash, announcement, our_bitcoin_sig) {
                        Ok(res) => Some(res),
                        Err(_) => None,
                }
        }

        /// May panic if called on a channel that wasn't immediately-previously
        /// self.remove_uncommitted_htlcs_and_mark_paused()'d
        pub fn get_channel_reestablish<L: Deref>(&self, logger: &L) -> msgs::ChannelReestablish where L::Target: Logger {
                assert_eq!(self.channel_state & ChannelState::PeerDisconnected as u32, ChannelState::PeerDisconnected as u32);
                assert_ne!(self.cur_counterparty_commitment_transaction_number, INITIAL_COMMITMENT_NUMBER);
                // Prior to static_remotekey, my_current_per_commitment_point was critical to claiming
                // current to_remote balances. However, it no longer has any use, and thus is now simply
                // set to a dummy (but valid, as required by the spec) public key.
                // fuzztarget mode marks a subset of pubkeys as invalid so that we can hit "invalid pubkey"
                // branches, but we unwrap it below, so we arbitrarily select a dummy pubkey which is both
                // valid, and valid in fuzztarget mode's arbitrary validity criteria:
                let mut pk = [2; 33]; pk[1] = 0xff;
                let dummy_pubkey = PublicKey::from_slice(&pk).unwrap();
                let data_loss_protect = if self.cur_counterparty_commitment_transaction_number + 1 < INITIAL_COMMITMENT_NUMBER {
                        let remote_last_secret = self.commitment_secrets.get_secret(self.cur_counterparty_commitment_transaction_number + 2).unwrap();
                        log_trace!(logger, "Enough info to generate a Data Loss Protect with per_commitment_secret {} for channel {}", log_bytes!(remote_last_secret), log_bytes!(self.channel_id()));
                        OptionalField::Present(DataLossProtect {
                                your_last_per_commitment_secret: remote_last_secret,
                                my_current_per_commitment_point: dummy_pubkey
                        })
                } else {
                        log_info!(logger, "Sending a data_loss_protect with no previous remote per_commitment_secret for channel {}", log_bytes!(self.channel_id()));
                        OptionalField::Present(DataLossProtect {
                                your_last_per_commitment_secret: [0;32],
                                my_current_per_commitment_point: dummy_pubkey,
                        })
                };
                msgs::ChannelReestablish {
                        channel_id: self.channel_id(),
                        // The protocol has two different commitment number concepts - the "commitment
                        // transaction number", which starts from 0 and counts up, and the "revocation key
                        // index" which starts at INITIAL_COMMITMENT_NUMBER and counts down. We track
                        // commitment transaction numbers by the index which will be used to reveal the
                        // revocation key for that commitment transaction, which means we have to convert them
                        // to protocol-level commitment numbers here...

                        // next_local_commitment_number is the next commitment_signed number we expect to
                        // receive (indicating if they need to resend one that we missed).
                        next_local_commitment_number: INITIAL_COMMITMENT_NUMBER - self.cur_holder_commitment_transaction_number,
                        // We have to set next_remote_commitment_number to the next revoke_and_ack we expect to
                        // receive, however we track it by the next commitment number for a remote transaction
                        // (which is one further, as they always revoke previous commitment transaction, not
                        // the one we send) so we have to decrement by 1. Note that if
                        // cur_counterparty_commitment_transaction_number is INITIAL_COMMITMENT_NUMBER we will have
                        // dropped this channel on disconnect as it hasn't yet reached FundingSent so we can't
                        // overflow here.
                        next_remote_commitment_number: INITIAL_COMMITMENT_NUMBER - self.cur_counterparty_commitment_transaction_number - 1,
                        data_loss_protect,
                }
        }


        // Send stuff to our remote peers:

        /// Adds a pending outbound HTLC to this channel, note that you probably want
        /// send_htlc_and_commit instead cause you'll want both messages at once.
        ///
        /// This returns an optional UpdateAddHTLC as we may be in a state where we cannot add HTLCs on
        /// the wire:
        /// * In cases where we're waiting on the remote peer to send us a revoke_and_ack, we
        ///   wouldn't be able to determine what they actually ACK'ed if we have two sets of updates
        ///   awaiting ACK.
        /// * In cases where we're marked MonitorUpdateFailed, we cannot commit to a new state as we
        ///   may not yet have sent the previous commitment update messages and will need to regenerate
        ///   them.
        ///
        /// You MUST call send_commitment prior to calling any other methods on this Channel!
        ///
        /// If an Err is returned, it's a ChannelError::Ignore!
        pub fn send_htlc<L: Deref>(&mut self, amount_msat: u64, payment_hash: PaymentHash, cltv_expiry: u32, source: HTLCSource, onion_routing_packet: msgs::OnionPacket, logger: &L) -> Result<Option<msgs::UpdateAddHTLC>, ChannelError> where L::Target: Logger {
                if (self.channel_state & (ChannelState::ChannelFunded as u32 | BOTH_SIDES_SHUTDOWN_MASK)) != (ChannelState::ChannelFunded as u32) {
                        return Err(ChannelError::Ignore("Cannot send HTLC until channel is fully established and we haven't started shutting down".to_owned()));
                }
                let channel_total_msat = self.channel_value_satoshis * 1000;
                if amount_msat > channel_total_msat {
                        return Err(ChannelError::Ignore(format!("Cannot send amount {}, because it is more than the total value of the channel {}", amount_msat, channel_total_msat)));
                }

                if amount_msat == 0 {
                        return Err(ChannelError::Ignore("Cannot send 0-msat HTLC".to_owned()));
                }

                if amount_msat < self.counterparty_htlc_minimum_msat {
                        return Err(ChannelError::Ignore(format!("Cannot send less than their minimum HTLC value ({})", self.counterparty_htlc_minimum_msat)));
                }

                if (self.channel_state & (ChannelState::PeerDisconnected as u32)) != 0 {
                        // Note that this should never really happen, if we're !is_live() on receipt of an
                        // incoming HTLC for relay will result in us rejecting the HTLC and we won't allow
                        // the user to send directly into a !is_live() channel. However, if we
                        // disconnected during the time the previous hop was doing the commitment dance we may
                        // end up getting here after the forwarding delay. In any case, returning an
                        // IgnoreError will get ChannelManager to do the right thing and fail backwards now.
                        return Err(ChannelError::Ignore("Cannot send an HTLC while disconnected from channel counterparty".to_owned()));
                }

                let inbound_stats = self.get_inbound_pending_htlc_stats(None);
                let outbound_stats = self.get_outbound_pending_htlc_stats(None);
                if outbound_stats.pending_htlcs + 1 > self.counterparty_max_accepted_htlcs as u32 {
                        return Err(ChannelError::Ignore(format!("Cannot push more than their max accepted HTLCs ({})", self.counterparty_max_accepted_htlcs)));
                }
                // Check their_max_htlc_value_in_flight_msat
                if outbound_stats.pending_htlcs_value_msat + amount_msat > self.counterparty_max_htlc_value_in_flight_msat {
                        return Err(ChannelError::Ignore(format!("Cannot send value that would put us over the max HTLC value in flight our peer will accept ({})", self.counterparty_max_htlc_value_in_flight_msat)));
                }

                let keys = self.build_holder_transaction_keys(self.cur_holder_commitment_transaction_number)?;
                let commitment_stats = self.build_commitment_transaction(self.cur_holder_commitment_transaction_number, &keys, true, true, logger);
                if !self.is_outbound() {
                        // Check that we won't violate the remote channel reserve by adding this HTLC.
                        let htlc_candidate = HTLCCandidate::new(amount_msat, HTLCInitiator::LocalOffered);
                        let counterparty_commit_tx_fee_msat = self.next_remote_commit_tx_fee_msat(htlc_candidate, None);
                        let holder_selected_chan_reserve_msat = self.holder_selected_channel_reserve_satoshis * 1000;
                        if commitment_stats.remote_balance_msat < counterparty_commit_tx_fee_msat + holder_selected_chan_reserve_msat {
                                return Err(ChannelError::Ignore("Cannot send value that would put counterparty balance under holder-announced channel reserve value".to_owned()));
                        }
                }

                let exposure_dust_limit_success_sats = (self.get_dust_buffer_feerate(None) as u64 * HTLC_SUCCESS_TX_WEIGHT / 1000) + self.counterparty_dust_limit_satoshis;
                if amount_msat / 1000 < exposure_dust_limit_success_sats {
                        let on_counterparty_dust_htlc_exposure_msat = inbound_stats.on_counterparty_tx_dust_exposure_msat + outbound_stats.on_counterparty_tx_dust_exposure_msat + amount_msat;
                        if on_counterparty_dust_htlc_exposure_msat > self.get_max_dust_htlc_exposure_msat() {
                                return Err(ChannelError::Ignore(format!("Cannot send value that would put our exposure to dust HTLCs at {} over the limit {} on counterparty commitment tx",
                                        on_counterparty_dust_htlc_exposure_msat, self.get_max_dust_htlc_exposure_msat())));
                        }
                }

                let exposure_dust_limit_timeout_sats = (self.get_dust_buffer_feerate(None) as u64 * HTLC_TIMEOUT_TX_WEIGHT / 1000) + self.holder_dust_limit_satoshis;
                if amount_msat / 1000 <  exposure_dust_limit_timeout_sats {
                        let on_holder_dust_htlc_exposure_msat = inbound_stats.on_holder_tx_dust_exposure_msat + outbound_stats.on_holder_tx_dust_exposure_msat + amount_msat;
                        if on_holder_dust_htlc_exposure_msat > self.get_max_dust_htlc_exposure_msat() {
                                return Err(ChannelError::Ignore(format!("Cannot send value that would put our exposure to dust HTLCs at {} over the limit {} on holder commitment tx",
                                        on_holder_dust_htlc_exposure_msat, self.get_max_dust_htlc_exposure_msat())));
                        }
                }

                let holder_balance_msat = commitment_stats.local_balance_msat - outbound_stats.holding_cell_msat;
                if holder_balance_msat < amount_msat {
                        return Err(ChannelError::Ignore(format!("Cannot send value that would overdraw remaining funds. Amount: {}, pending value to self {}", amount_msat, holder_balance_msat)));
                }

                // `2 *` and extra HTLC are for the fee spike buffer.
                let commit_tx_fee_msat = if self.is_outbound() {
                        let htlc_candidate = HTLCCandidate::new(amount_msat, HTLCInitiator::LocalOffered);
                        FEE_SPIKE_BUFFER_FEE_INCREASE_MULTIPLE * self.next_local_commit_tx_fee_msat(htlc_candidate, Some(()))
                } else { 0 };
                if holder_balance_msat - amount_msat < commit_tx_fee_msat {
                        return Err(ChannelError::Ignore(format!("Cannot send value that would not leave enough to pay for fees. Pending value to self: {}. local_commit_tx_fee {}", holder_balance_msat, commit_tx_fee_msat)));
                }

                // Check self.counterparty_selected_channel_reserve_satoshis (the amount we must keep as
                // reserve for the remote to have something to claim if we misbehave)
                let chan_reserve_msat = self.counterparty_selected_channel_reserve_satoshis.unwrap() * 1000;
                if holder_balance_msat - amount_msat - commit_tx_fee_msat < chan_reserve_msat {
                        return Err(ChannelError::Ignore(format!("Cannot send value that would put our balance under counterparty-announced channel reserve value ({})", chan_reserve_msat)));
                }

                // Now update local state:
                if (self.channel_state & (ChannelState::AwaitingRemoteRevoke as u32 | ChannelState::MonitorUpdateFailed as u32)) != 0 {
                        self.holding_cell_htlc_updates.push(HTLCUpdateAwaitingACK::AddHTLC {
                                amount_msat,
                                payment_hash,
                                cltv_expiry,
                                source,
                                onion_routing_packet,
                        });
                        return Ok(None);
                }

                self.pending_outbound_htlcs.push(OutboundHTLCOutput {
                        htlc_id: self.next_holder_htlc_id,
                        amount_msat,
                        payment_hash: payment_hash.clone(),
                        cltv_expiry,
                        state: OutboundHTLCState::LocalAnnounced(Box::new(onion_routing_packet.clone())),
                        source,
                });

                let res = msgs::UpdateAddHTLC {
                        channel_id: self.channel_id,
                        htlc_id: self.next_holder_htlc_id,
                        amount_msat,
                        payment_hash,
                        cltv_expiry,
                        onion_routing_packet,
                };
                self.next_holder_htlc_id += 1;

                Ok(Some(res))
        }

        /// Creates a signed commitment transaction to send to the remote peer.
        /// Always returns a ChannelError::Close if an immediately-preceding (read: the
        /// last call to this Channel) send_htlc returned Ok(Some(_)) and there is an Err.
        /// May panic if called except immediately after a successful, Ok(Some(_))-returning send_htlc.
        pub fn send_commitment<L: Deref>(&mut self, logger: &L) -> Result<(msgs::CommitmentSigned, ChannelMonitorUpdate), ChannelError> where L::Target: Logger {
                if (self.channel_state & (ChannelState::ChannelFunded as u32)) != (ChannelState::ChannelFunded as u32) {
                        panic!("Cannot create commitment tx until channel is fully established");
                }
                if (self.channel_state & (ChannelState::AwaitingRemoteRevoke as u32)) == (ChannelState::AwaitingRemoteRevoke as u32) {
                        panic!("Cannot create commitment tx until remote revokes their previous commitment");
                }
                if (self.channel_state & (ChannelState::PeerDisconnected as u32)) == (ChannelState::PeerDisconnected as u32) {
                        panic!("Cannot create commitment tx while disconnected, as send_htlc will have returned an Err so a send_commitment precondition has been violated");
                }
                if (self.channel_state & (ChannelState::MonitorUpdateFailed as u32)) == (ChannelState::MonitorUpdateFailed as u32) {
                        panic!("Cannot create commitment tx while awaiting monitor update unfreeze, as send_htlc will have returned an Err so a send_commitment precondition has been violated");
                }
                let mut have_updates = self.is_outbound() && self.pending_update_fee.is_some();
                for htlc in self.pending_outbound_htlcs.iter() {
                        if let OutboundHTLCState::LocalAnnounced(_) = htlc.state {
                                have_updates = true;
                        }
                        if have_updates { break; }
                }
                for htlc in self.pending_inbound_htlcs.iter() {
                        if let InboundHTLCState::LocalRemoved(_) = htlc.state {
                                have_updates = true;
                        }
                        if have_updates { break; }
                }
                if !have_updates {
                        panic!("Cannot create commitment tx until we have some updates to send");
                }
                self.send_commitment_no_status_check(logger)
        }
        /// Only fails in case of bad keys
        fn send_commitment_no_status_check<L: Deref>(&mut self, logger: &L) -> Result<(msgs::CommitmentSigned, ChannelMonitorUpdate), ChannelError> where L::Target: Logger {
                log_trace!(logger, "Updating HTLC state for a newly-sent commitment_signed...");
                // We can upgrade the status of some HTLCs that are waiting on a commitment, even if we
                // fail to generate this, we still are at least at a position where upgrading their status
                // is acceptable.
                for htlc in self.pending_inbound_htlcs.iter_mut() {
                        let new_state = if let &InboundHTLCState::AwaitingRemoteRevokeToAnnounce(ref forward_info) = &htlc.state {
                                Some(InboundHTLCState::AwaitingAnnouncedRemoteRevoke(forward_info.clone()))
                        } else { None };
                        if let Some(state) = new_state {
                                log_trace!(logger, " ...promoting inbound AwaitingRemoteRevokeToAnnounce {} to AwaitingAnnouncedRemoteRevoke", log_bytes!(htlc.payment_hash.0));
                                htlc.state = state;
                        }
                }
                for htlc in self.pending_outbound_htlcs.iter_mut() {
                        if let Some(fail_reason) = if let &mut OutboundHTLCState::AwaitingRemoteRevokeToRemove(ref mut fail_reason) = &mut htlc.state {
                                Some(fail_reason.take())
                        } else { None } {
                                log_trace!(logger, " ...promoting outbound AwaitingRemoteRevokeToRemove {} to AwaitingRemovedRemoteRevoke", log_bytes!(htlc.payment_hash.0));
                                htlc.state = OutboundHTLCState::AwaitingRemovedRemoteRevoke(fail_reason);
                        }
                }
                if let Some((feerate, update_state)) = self.pending_update_fee {
                        if update_state == FeeUpdateState::AwaitingRemoteRevokeToAnnounce {
                                debug_assert!(!self.is_outbound());
                                log_trace!(logger, " ...promoting inbound AwaitingRemoteRevokeToAnnounce fee update {} to Committed", feerate);
                                self.feerate_per_kw = feerate;
                                self.pending_update_fee = None;
                        }
                }
                self.resend_order = RAACommitmentOrder::RevokeAndACKFirst;

                let (res, counterparty_commitment_txid, htlcs) = match self.send_commitment_no_state_update(logger) {
                        Ok((res, (counterparty_commitment_tx, mut htlcs))) => {
                                // Update state now that we've passed all the can-fail calls...
                                let htlcs_no_ref: Vec<(HTLCOutputInCommitment, Option<Box<HTLCSource>>)> =
                                        htlcs.drain(..).map(|(htlc, htlc_source)| (htlc, htlc_source.map(|source_ref| Box::new(source_ref.clone())))).collect();
                                (res, counterparty_commitment_tx, htlcs_no_ref)
                        },
                        Err(e) => return Err(e),
                };

                self.latest_monitor_update_id += 1;
                let monitor_update = ChannelMonitorUpdate {
                        update_id: self.latest_monitor_update_id,
                        updates: vec![ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo {
                                commitment_txid: counterparty_commitment_txid,
                                htlc_outputs: htlcs.clone(),
                                commitment_number: self.cur_counterparty_commitment_transaction_number,
                                their_revocation_point: self.counterparty_cur_commitment_point.unwrap()
                        }]
                };
                self.channel_state |= ChannelState::AwaitingRemoteRevoke as u32;
                Ok((res, monitor_update))
        }

        /// Only fails in case of bad keys. Used for channel_reestablish commitment_signed generation
        /// when we shouldn't change HTLC/channel state.
        fn send_commitment_no_state_update<L: Deref>(&self, logger: &L) -> Result<(msgs::CommitmentSigned, (Txid, Vec<(HTLCOutputInCommitment, Option<&HTLCSource>)>)), ChannelError> where L::Target: Logger {
                let counterparty_keys = self.build_remote_transaction_keys()?;
                let commitment_stats = self.build_commitment_transaction(self.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, true, logger);
                let counterparty_commitment_txid = commitment_stats.tx.trust().txid();
                let (signature, htlc_signatures);

                #[cfg(any(test, feature = "fuzztarget"))]
                {
                        if !self.is_outbound() {
                                let projected_commit_tx_info = self.next_remote_commitment_tx_fee_info_cached.lock().unwrap().take();
                                *self.next_local_commitment_tx_fee_info_cached.lock().unwrap() = None;
                                if let Some(info) = projected_commit_tx_info {
                                        let total_pending_htlcs = self.pending_inbound_htlcs.len() + self.pending_outbound_htlcs.len();
                                        if info.total_pending_htlcs == total_pending_htlcs
                                                && info.next_holder_htlc_id == self.next_holder_htlc_id
                                                && info.next_counterparty_htlc_id == self.next_counterparty_htlc_id
                                                && info.feerate == self.feerate_per_kw {
                                                        let actual_fee = Self::commit_tx_fee_msat(self.feerate_per_kw, commitment_stats.num_nondust_htlcs);
                                                        assert_eq!(actual_fee, info.fee);
                                                }
                                }
                        }
                }

                {
                        let mut htlcs = Vec::with_capacity(commitment_stats.htlcs_included.len());
                        for &(ref htlc, _) in commitment_stats.htlcs_included.iter() {
                                htlcs.push(htlc);
                        }

                        let res = self.holder_signer.sign_counterparty_commitment(&commitment_stats.tx, &self.secp_ctx)
                                .map_err(|_| ChannelError::Close("Failed to get signatures for new commitment_signed".to_owned()))?;
                        signature = res.0;
                        htlc_signatures = res.1;

                        log_trace!(logger, "Signed remote commitment tx {} (txid {}) with redeemscript {} -> {} in channel {}",
                                encode::serialize_hex(&commitment_stats.tx.trust().built_transaction().transaction),
                                &counterparty_commitment_txid, encode::serialize_hex(&self.get_funding_redeemscript()),
                                log_bytes!(signature.serialize_compact()[..]), log_bytes!(self.channel_id()));

                        for (ref htlc_sig, ref htlc) in htlc_signatures.iter().zip(htlcs) {
                                log_trace!(logger, "Signed remote HTLC tx {} with redeemscript {} with pubkey {} -> {} in channel {}",
                                        encode::serialize_hex(&chan_utils::build_htlc_transaction(&counterparty_commitment_txid, commitment_stats.feerate_per_kw, self.get_holder_selected_contest_delay(), htlc, self.opt_anchors(), &counterparty_keys.broadcaster_delayed_payment_key, &counterparty_keys.revocation_key)),
                                        encode::serialize_hex(&chan_utils::get_htlc_redeemscript(&htlc, self.opt_anchors(), &counterparty_keys)),
                                        log_bytes!(counterparty_keys.broadcaster_htlc_key.serialize()),
                                        log_bytes!(htlc_sig.serialize_compact()[..]), log_bytes!(self.channel_id()));
                        }
                }

                Ok((msgs::CommitmentSigned {
                        channel_id: self.channel_id,
                        signature,
                        htlc_signatures,
                }, (counterparty_commitment_txid, commitment_stats.htlcs_included)))
        }

        /// Adds a pending outbound HTLC to this channel, and creates a signed commitment transaction
        /// to send to the remote peer in one go.
        /// Shorthand for calling send_htlc() followed by send_commitment(), see docs on those for
        /// more info.
        pub fn send_htlc_and_commit<L: Deref>(&mut self, amount_msat: u64, payment_hash: PaymentHash, cltv_expiry: u32, source: HTLCSource, onion_routing_packet: msgs::OnionPacket, logger: &L) -> Result<Option<(msgs::UpdateAddHTLC, msgs::CommitmentSigned, ChannelMonitorUpdate)>, ChannelError> where L::Target: Logger {
                match self.send_htlc(amount_msat, payment_hash, cltv_expiry, source, onion_routing_packet, logger)? {
                        Some(update_add_htlc) => {
                                let (commitment_signed, monitor_update) = self.send_commitment_no_status_check(logger)?;
                                Ok(Some((update_add_htlc, commitment_signed, monitor_update)))
                        },
                        None => Ok(None)
                }
        }

        /// Get forwarding information for the counterparty.
        pub fn counterparty_forwarding_info(&self) -> Option<CounterpartyForwardingInfo> {
                self.counterparty_forwarding_info.clone()
        }

        pub fn channel_update(&mut self, msg: &msgs::ChannelUpdate) -> Result<(), ChannelError> {
                if msg.contents.htlc_minimum_msat >= self.channel_value_satoshis * 1000 {
                        return Err(ChannelError::Close("Minimum htlc value is greater than channel value".to_string()));
                }
                self.counterparty_forwarding_info = Some(CounterpartyForwardingInfo {
                        fee_base_msat: msg.contents.fee_base_msat,
                        fee_proportional_millionths: msg.contents.fee_proportional_millionths,
                        cltv_expiry_delta: msg.contents.cltv_expiry_delta
                });

                Ok(())
        }

        /// Begins the shutdown process, getting a message for the remote peer and returning all
        /// holding cell HTLCs for payment failure.
        pub fn get_shutdown<K: Deref>(&mut self, keys_provider: &K, their_features: &InitFeatures, target_feerate_sats_per_kw: Option<u32>)
        -> Result<(msgs::Shutdown, Option<ChannelMonitorUpdate>, Vec<(HTLCSource, PaymentHash)>), APIError>
        where K::Target: KeysInterface<Signer = Signer> {
                for htlc in self.pending_outbound_htlcs.iter() {
                        if let OutboundHTLCState::LocalAnnounced(_) = htlc.state {
                                return Err(APIError::APIMisuseError{err: "Cannot begin shutdown with pending HTLCs. Process pending events first".to_owned()});
                        }
                }
                if self.channel_state & BOTH_SIDES_SHUTDOWN_MASK != 0 {
                        if (self.channel_state & ChannelState::LocalShutdownSent as u32) == ChannelState::LocalShutdownSent as u32 {
                                return Err(APIError::APIMisuseError{err: "Shutdown already in progress".to_owned()});
                        }
                        else if (self.channel_state & ChannelState::RemoteShutdownSent as u32) == ChannelState::RemoteShutdownSent as u32 {
                                return Err(APIError::ChannelUnavailable{err: "Shutdown already in progress by remote".to_owned()});
                        }
                }
                assert_eq!(self.channel_state & ChannelState::ShutdownComplete as u32, 0);
                if self.channel_state & (ChannelState::PeerDisconnected as u32 | ChannelState::MonitorUpdateFailed as u32) != 0 {
                        return Err(APIError::ChannelUnavailable{err: "Cannot begin shutdown while peer is disconnected or we're waiting on a monitor update, maybe force-close instead?".to_owned()});
                }

                let update_shutdown_script = match self.shutdown_scriptpubkey {
                        Some(_) => false,
                        None => {
                                let shutdown_scriptpubkey = keys_provider.get_shutdown_scriptpubkey();
                                if !shutdown_scriptpubkey.is_compatible(their_features) {
                                        return Err(APIError::IncompatibleShutdownScript { script: shutdown_scriptpubkey.clone() });
                                }
                                self.shutdown_scriptpubkey = Some(shutdown_scriptpubkey);
                                true
                        },
                };

                // From here on out, we may not fail!
                self.target_closing_feerate_sats_per_kw = target_feerate_sats_per_kw;
                if self.channel_state < ChannelState::FundingSent as u32 {
                        self.channel_state = ChannelState::ShutdownComplete as u32;
                } else {
                        self.channel_state |= ChannelState::LocalShutdownSent as u32;
                }
                self.update_time_counter += 1;

                let monitor_update = if update_shutdown_script {
                        self.latest_monitor_update_id += 1;
                        Some(ChannelMonitorUpdate {
                                update_id: self.latest_monitor_update_id,
                                updates: vec![ChannelMonitorUpdateStep::ShutdownScript {
                                        scriptpubkey: self.get_closing_scriptpubkey(),
                                }],
                        })
                } else { None };
                let shutdown = msgs::Shutdown {
                        channel_id: self.channel_id,
                        scriptpubkey: self.get_closing_scriptpubkey(),
                };

                // Go ahead and drop holding cell updates as we'd rather fail payments than wait to send
                // our shutdown until we've committed all of the pending changes.
                self.holding_cell_update_fee = None;
                let mut dropped_outbound_htlcs = Vec::with_capacity(self.holding_cell_htlc_updates.len());
                self.holding_cell_htlc_updates.retain(|htlc_update| {
                        match htlc_update {
                                &HTLCUpdateAwaitingACK::AddHTLC { ref payment_hash, ref source, .. } => {
                                        dropped_outbound_htlcs.push((source.clone(), payment_hash.clone()));
                                        false
                                },
                                _ => true
                        }
                });

                Ok((shutdown, monitor_update, dropped_outbound_htlcs))
        }

        /// Gets the latest commitment transaction and any dependent transactions for relay (forcing
        /// shutdown of this channel - no more calls into this Channel may be made afterwards except
        /// those explicitly stated to be allowed after shutdown completes, eg some simple getters).
        /// Also returns the list of payment_hashes for channels which we can safely fail backwards
        /// immediately (others we will have to allow to time out).
        pub fn force_shutdown(&mut self, should_broadcast: bool) -> (Option<(OutPoint, ChannelMonitorUpdate)>, Vec<(HTLCSource, PaymentHash)>) {
                // Note that we MUST only generate a monitor update that indicates force-closure - we're
                // called during initialization prior to the chain_monitor in the encompassing ChannelManager
                // being fully configured in some cases. Thus, its likely any monitor events we generate will
                // be delayed in being processed! See the docs for `ChannelManagerReadArgs` for more.
                assert!(self.channel_state != ChannelState::ShutdownComplete as u32);

                // We go ahead and "free" any holding cell HTLCs or HTLCs we haven't yet committed to and
                // return them to fail the payment.
                let mut dropped_outbound_htlcs = Vec::with_capacity(self.holding_cell_htlc_updates.len());
                for htlc_update in self.holding_cell_htlc_updates.drain(..) {
                        match htlc_update {
                                HTLCUpdateAwaitingACK::AddHTLC { source, payment_hash, .. } => {
                                        dropped_outbound_htlcs.push((source, payment_hash));
                                },
                                _ => {}
                        }
                }
                let monitor_update = if let Some(funding_txo) = self.get_funding_txo() {
                        // If we haven't yet exchanged funding signatures (ie channel_state < FundingSent),
                        // returning a channel monitor update here would imply a channel monitor update before
                        // we even registered the channel monitor to begin with, which is invalid.
                        // Thus, if we aren't actually at a point where we could conceivably broadcast the
                        // funding transaction, don't return a funding txo (which prevents providing the
                        // monitor update to the user, even if we return one).
                        // See test_duplicate_chan_id and test_pre_lockin_no_chan_closed_update for more.
                        if self.channel_state & (ChannelState::FundingSent as u32 | ChannelState::ChannelFunded as u32 | ChannelState::ShutdownComplete as u32) != 0 {
                                self.latest_monitor_update_id += 1;
                                Some((funding_txo, ChannelMonitorUpdate {
                                        update_id: self.latest_monitor_update_id,
                                        updates: vec![ChannelMonitorUpdateStep::ChannelForceClosed { should_broadcast }],
                                }))
                        } else { None }
                } else { None };

                self.channel_state = ChannelState::ShutdownComplete as u32;
                self.update_time_counter += 1;
                (monitor_update, dropped_outbound_htlcs)
        }
}

const SERIALIZATION_VERSION: u8 = 2;
const MIN_SERIALIZATION_VERSION: u8 = 1;

impl_writeable_tlv_based_enum!(InboundHTLCRemovalReason,;
        (0, FailRelay),
        (1, FailMalformed),
        (2, Fulfill),
);

impl Writeable for ChannelUpdateStatus {
        fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
                // We only care about writing out the current state as it was announced, ie only either
                // Enabled or Disabled. In the case of DisabledStaged, we most recently announced the
                // channel as enabled, so we write 0. For EnabledStaged, we similarly write a 1.
                match self {
                        ChannelUpdateStatus::Enabled => 0u8.write(writer)?,
                        ChannelUpdateStatus::DisabledStaged => 0u8.write(writer)?,
                        ChannelUpdateStatus::EnabledStaged => 1u8.write(writer)?,
                        ChannelUpdateStatus::Disabled => 1u8.write(writer)?,
                }
                Ok(())
        }
}

impl Readable for ChannelUpdateStatus {
        fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
                Ok(match <u8 as Readable>::read(reader)? {
                        0 => ChannelUpdateStatus::Enabled,
                        1 => ChannelUpdateStatus::Disabled,
                        _ => return Err(DecodeError::InvalidValue),
                })
        }
}

impl<Signer: Sign> Writeable for Channel<Signer> {
        fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
                // Note that we write out as if remove_uncommitted_htlcs_and_mark_paused had just been
                // called.

                write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);

                self.user_id.write(writer)?;

                // Write out the old serialization for the config object. This is read by version-1
                // deserializers, but we will read the version in the TLV at the end instead.
                self.config.forwarding_fee_proportional_millionths.write(writer)?;
                self.config.cltv_expiry_delta.write(writer)?;
                self.config.announced_channel.write(writer)?;
                self.config.commit_upfront_shutdown_pubkey.write(writer)?;

                self.channel_id.write(writer)?;
                (self.channel_state | ChannelState::PeerDisconnected as u32).write(writer)?;
                self.channel_value_satoshis.write(writer)?;

                self.latest_monitor_update_id.write(writer)?;

                let mut key_data = VecWriter(Vec::new());
                self.holder_signer.write(&mut key_data)?;
                assert!(key_data.0.len() < core::usize::MAX);
                assert!(key_data.0.len() < core::u32::MAX as usize);
                (key_data.0.len() as u32).write(writer)?;
                writer.write_all(&key_data.0[..])?;

                // Write out the old serialization for shutdown_pubkey for backwards compatibility, if
                // deserialized from that format.
                match self.shutdown_scriptpubkey.as_ref().and_then(|script| script.as_legacy_pubkey()) {
                        Some(shutdown_pubkey) => shutdown_pubkey.write(writer)?,
                        None => [0u8; PUBLIC_KEY_SIZE].write(writer)?,
                }
                self.destination_script.write(writer)?;

                self.cur_holder_commitment_transaction_number.write(writer)?;
                self.cur_counterparty_commitment_transaction_number.write(writer)?;
                self.value_to_self_msat.write(writer)?;

                let mut dropped_inbound_htlcs = 0;
                for htlc in self.pending_inbound_htlcs.iter() {
                        if let InboundHTLCState::RemoteAnnounced(_) = htlc.state {
                                dropped_inbound_htlcs += 1;
                        }
                }
                (self.pending_inbound_htlcs.len() as u64 - dropped_inbound_htlcs).write(writer)?;
                for htlc in self.pending_inbound_htlcs.iter() {
                        if let &InboundHTLCState::RemoteAnnounced(_) = &htlc.state {
                                continue; // Drop
                        }
                        htlc.htlc_id.write(writer)?;
                        htlc.amount_msat.write(writer)?;
                        htlc.cltv_expiry.write(writer)?;
                        htlc.payment_hash.write(writer)?;
                        match &htlc.state {
                                &InboundHTLCState::RemoteAnnounced(_) => unreachable!(),
                                &InboundHTLCState::AwaitingRemoteRevokeToAnnounce(ref htlc_state) => {
                                        1u8.write(writer)?;
                                        htlc_state.write(writer)?;
                                },
                                &InboundHTLCState::AwaitingAnnouncedRemoteRevoke(ref htlc_state) => {
                                        2u8.write(writer)?;
                                        htlc_state.write(writer)?;
                                },
                                &InboundHTLCState::Committed => {
                                        3u8.write(writer)?;
                                },
                                &InboundHTLCState::LocalRemoved(ref removal_reason) => {
                                        4u8.write(writer)?;
                                        removal_reason.write(writer)?;
                                },
                        }
                }

                (self.pending_outbound_htlcs.len() as u64).write(writer)?;
                for htlc in self.pending_outbound_htlcs.iter() {
                        htlc.htlc_id.write(writer)?;
                        htlc.amount_msat.write(writer)?;
                        htlc.cltv_expiry.write(writer)?;
                        htlc.payment_hash.write(writer)?;
                        htlc.source.write(writer)?;
                        match &htlc.state {
                                &OutboundHTLCState::LocalAnnounced(ref onion_packet) => {
                                        0u8.write(writer)?;
                                        onion_packet.write(writer)?;
                                },
                                &OutboundHTLCState::Committed => {
                                        1u8.write(writer)?;
                                },
                                &OutboundHTLCState::RemoteRemoved(_) => {
                                        // Treat this as a Committed because we haven't received the CS - they'll
                                        // resend the claim/fail on reconnect as we all (hopefully) the missing CS.
                                        1u8.write(writer)?;
                                },
                                &OutboundHTLCState::AwaitingRemoteRevokeToRemove(ref fail_reason) => {
                                        3u8.write(writer)?;
                                        fail_reason.write(writer)?;
                                },
                                &OutboundHTLCState::AwaitingRemovedRemoteRevoke(ref fail_reason) => {
                                        4u8.write(writer)?;
                                        fail_reason.write(writer)?;
                                },
                        }
                }

                (self.holding_cell_htlc_updates.len() as u64).write(writer)?;
                for update in self.holding_cell_htlc_updates.iter() {
                        match update {
                                &HTLCUpdateAwaitingACK::AddHTLC { ref amount_msat, ref cltv_expiry, ref payment_hash, ref source, ref onion_routing_packet } => {
                                        0u8.write(writer)?;
                                        amount_msat.write(writer)?;
                                        cltv_expiry.write(writer)?;
                                        payment_hash.write(writer)?;
                                        source.write(writer)?;
                                        onion_routing_packet.write(writer)?;
                                },
                                &HTLCUpdateAwaitingACK::ClaimHTLC { ref payment_preimage, ref htlc_id } => {
                                        1u8.write(writer)?;
                                        payment_preimage.write(writer)?;
                                        htlc_id.write(writer)?;
                                },
                                &HTLCUpdateAwaitingACK::FailHTLC { ref htlc_id, ref err_packet } => {
                                        2u8.write(writer)?;
                                        htlc_id.write(writer)?;
                                        err_packet.write(writer)?;
                                }
                        }
                }

                match self.resend_order {
                        RAACommitmentOrder::CommitmentFirst => 0u8.write(writer)?,
                        RAACommitmentOrder::RevokeAndACKFirst => 1u8.write(writer)?,
                }

                self.monitor_pending_funding_locked.write(writer)?;
                self.monitor_pending_revoke_and_ack.write(writer)?;
                self.monitor_pending_commitment_signed.write(writer)?;

                (self.monitor_pending_forwards.len() as u64).write(writer)?;
                for &(ref pending_forward, ref htlc_id) in self.monitor_pending_forwards.iter() {
                        pending_forward.write(writer)?;
                        htlc_id.write(writer)?;
                }

                (self.monitor_pending_failures.len() as u64).write(writer)?;
                for &(ref htlc_source, ref payment_hash, ref fail_reason) in self.monitor_pending_failures.iter() {
                        htlc_source.write(writer)?;
                        payment_hash.write(writer)?;
                        fail_reason.write(writer)?;
                }

                if self.is_outbound() {
                        self.pending_update_fee.map(|(a, _)| a).write(writer)?;
                } else if let Some((feerate, FeeUpdateState::AwaitingRemoteRevokeToAnnounce)) = self.pending_update_fee {
                        Some(feerate).write(writer)?;
                } else {
                        // As for inbound HTLCs, if the update was only announced and never committed in a
                        // commitment_signed, drop it.
                        None::<u32>.write(writer)?;
                }
                self.holding_cell_update_fee.write(writer)?;

                self.next_holder_htlc_id.write(writer)?;
                (self.next_counterparty_htlc_id - dropped_inbound_htlcs).write(writer)?;
                self.update_time_counter.write(writer)?;
                self.feerate_per_kw.write(writer)?;

                // Versions prior to 0.0.100 expected to read the fields of `last_sent_closing_fee` here,
                // however we are supposed to restart shutdown fee negotiation on reconnect (and wipe
                // `last_send_closing_fee` in `remove_uncommitted_htlcs_and_mark_paused`) so we should never
                // consider the stale state on reload.
                0u8.write(writer)?;

                self.funding_tx_confirmed_in.write(writer)?;
                self.funding_tx_confirmation_height.write(writer)?;
                self.short_channel_id.write(writer)?;

                self.counterparty_dust_limit_satoshis.write(writer)?;
                self.holder_dust_limit_satoshis.write(writer)?;
                self.counterparty_max_htlc_value_in_flight_msat.write(writer)?;

                // Note that this field is ignored by 0.0.99+ as the TLV Optional variant is used instead.
                self.counterparty_selected_channel_reserve_satoshis.unwrap_or(0).write(writer)?;

                self.counterparty_htlc_minimum_msat.write(writer)?;
                self.holder_htlc_minimum_msat.write(writer)?;
                self.counterparty_max_accepted_htlcs.write(writer)?;

                // Note that this field is ignored by 0.0.99+ as the TLV Optional variant is used instead.
                self.minimum_depth.unwrap_or(0).write(writer)?;

                match &self.counterparty_forwarding_info {
                        Some(info) => {
                                1u8.write(writer)?;
                                info.fee_base_msat.write(writer)?;
                                info.fee_proportional_millionths.write(writer)?;
                                info.cltv_expiry_delta.write(writer)?;
                        },
                        None => 0u8.write(writer)?
                }

                self.channel_transaction_parameters.write(writer)?;
                self.funding_transaction.write(writer)?;

                self.counterparty_cur_commitment_point.write(writer)?;
                self.counterparty_prev_commitment_point.write(writer)?;
                self.counterparty_node_id.write(writer)?;

                self.counterparty_shutdown_scriptpubkey.write(writer)?;

                self.commitment_secrets.write(writer)?;

                self.channel_update_status.write(writer)?;

                #[cfg(any(test, feature = "fuzztarget"))]
                (self.historical_inbound_htlc_fulfills.len() as u64).write(writer)?;
                #[cfg(any(test, feature = "fuzztarget"))]
                for htlc in self.historical_inbound_htlc_fulfills.iter() {
                        htlc.write(writer)?;
                }

                // If the channel type is something other than only-static-remote-key, then we need to have
                // older clients fail to deserialize this channel at all. If the type is
                // only-static-remote-key, we simply consider it "default" and don't write the channel type
                // out at all.
                let chan_type = if self.channel_type != ChannelTypeFeatures::only_static_remote_key() {
                        Some(&self.channel_type) } else { None };

                // The same logic applies for `holder_selected_channel_reserve_satoshis` and
                // `holder_max_htlc_value_in_flight_msat` values other than the defaults.
                let serialized_holder_selected_reserve =
                        if self.holder_selected_channel_reserve_satoshis != Self::get_holder_selected_channel_reserve_satoshis(self.channel_value_satoshis)
                        { Some(self.holder_selected_channel_reserve_satoshis) } else { None };
                let serialized_holder_htlc_max_in_flight =
                        if self.holder_max_htlc_value_in_flight_msat != Self::get_holder_max_htlc_value_in_flight_msat(self.channel_value_satoshis)
                        { Some(self.holder_max_htlc_value_in_flight_msat) } else { None };

                write_tlv_fields!(writer, {
                        (0, self.announcement_sigs, option),
                        // minimum_depth and counterparty_selected_channel_reserve_satoshis used to have a
                        // default value instead of being Option<>al. Thus, to maintain compatibility we write
                        // them twice, once with their original default values above, and once as an option
                        // here. On the read side, old versions will simply ignore the odd-type entries here,
                        // and new versions map the default values to None and allow the TLV entries here to
                        // override that.
                        (1, self.minimum_depth, option),
                        (2, chan_type, option),
                        (3, self.counterparty_selected_channel_reserve_satoshis, option),
                        (4, serialized_holder_selected_reserve, option),
                        (5, self.config, required),
                        (6, serialized_holder_htlc_max_in_flight, option),
                        (7, self.shutdown_scriptpubkey, option),
                        (9, self.target_closing_feerate_sats_per_kw, option),
                        (11, self.monitor_pending_finalized_fulfills, vec_type),
                        (13, self.channel_creation_height, required),
                });

                Ok(())
        }
}

const MAX_ALLOC_SIZE: usize = 64*1024;
impl<'a, Signer: Sign, K: Deref> ReadableArgs<(&'a K, u32)> for Channel<Signer>
                where K::Target: KeysInterface<Signer = Signer> {
        fn read<R : io::Read>(reader: &mut R, args: (&'a K, u32)) -> Result<Self, DecodeError> {
                let (keys_source, serialized_height) = args;
                let ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);

                let user_id = Readable::read(reader)?;

                let mut config = Some(ChannelConfig::default());
                if ver == 1 {
                        // Read the old serialization of the ChannelConfig from version 0.0.98.
                        config.as_mut().unwrap().forwarding_fee_proportional_millionths = Readable::read(reader)?;
                        config.as_mut().unwrap().cltv_expiry_delta = Readable::read(reader)?;
                        config.as_mut().unwrap().announced_channel = Readable::read(reader)?;
                        config.as_mut().unwrap().commit_upfront_shutdown_pubkey = Readable::read(reader)?;
                } else {
                        // Read the 8 bytes of backwards-compatibility ChannelConfig data.
                        let mut _val: u64 = Readable::read(reader)?;
                }

                let channel_id = Readable::read(reader)?;
                let channel_state = Readable::read(reader)?;
                let channel_value_satoshis = Readable::read(reader)?;

                let latest_monitor_update_id = Readable::read(reader)?;

                let keys_len: u32 = Readable::read(reader)?;
                let mut keys_data = Vec::with_capacity(cmp::min(keys_len as usize, MAX_ALLOC_SIZE));
                while keys_data.len() != keys_len as usize {
                        // Read 1KB at a time to avoid accidentally allocating 4GB on corrupted channel keys
                        let mut data = [0; 1024];
                        let read_slice = &mut data[0..cmp::min(1024, keys_len as usize - keys_data.len())];
                        reader.read_exact(read_slice)?;
                        keys_data.extend_from_slice(read_slice);
                }
                let holder_signer = keys_source.read_chan_signer(&keys_data)?;

                // Read the old serialization for shutdown_pubkey, preferring the TLV field later if set.
                let mut shutdown_scriptpubkey = match <PublicKey as Readable>::read(reader) {
                        Ok(pubkey) => Some(ShutdownScript::new_p2wpkh_from_pubkey(pubkey)),
                        Err(_) => None,
                };
                let destination_script = Readable::read(reader)?;

                let cur_holder_commitment_transaction_number = Readable::read(reader)?;
                let cur_counterparty_commitment_transaction_number = Readable::read(reader)?;
                let value_to_self_msat = Readable::read(reader)?;

                let pending_inbound_htlc_count: u64 = Readable::read(reader)?;
                let mut pending_inbound_htlcs = Vec::with_capacity(cmp::min(pending_inbound_htlc_count as usize, OUR_MAX_HTLCS as usize));
                for _ in 0..pending_inbound_htlc_count {
                        pending_inbound_htlcs.push(InboundHTLCOutput {
                                htlc_id: Readable::read(reader)?,
                                amount_msat: Readable::read(reader)?,
                                cltv_expiry: Readable::read(reader)?,
                                payment_hash: Readable::read(reader)?,
                                state: match <u8 as Readable>::read(reader)? {
                                        1 => InboundHTLCState::AwaitingRemoteRevokeToAnnounce(Readable::read(reader)?),
                                        2 => InboundHTLCState::AwaitingAnnouncedRemoteRevoke(Readable::read(reader)?),
                                        3 => InboundHTLCState::Committed,
                                        4 => InboundHTLCState::LocalRemoved(Readable::read(reader)?),
                                        _ => return Err(DecodeError::InvalidValue),
                                },
                        });
                }

                let pending_outbound_htlc_count: u64 = Readable::read(reader)?;
                let mut pending_outbound_htlcs = Vec::with_capacity(cmp::min(pending_outbound_htlc_count as usize, OUR_MAX_HTLCS as usize));
                for _ in 0..pending_outbound_htlc_count {
                        pending_outbound_htlcs.push(OutboundHTLCOutput {
                                htlc_id: Readable::read(reader)?,
                                amount_msat: Readable::read(reader)?,
                                cltv_expiry: Readable::read(reader)?,
                                payment_hash: Readable::read(reader)?,
                                source: Readable::read(reader)?,
                                state: match <u8 as Readable>::read(reader)? {
                                        0 => OutboundHTLCState::LocalAnnounced(Box::new(Readable::read(reader)?)),
                                        1 => OutboundHTLCState::Committed,
                                        2 => OutboundHTLCState::RemoteRemoved(Readable::read(reader)?),
                                        3 => OutboundHTLCState::AwaitingRemoteRevokeToRemove(Readable::read(reader)?),
                                        4 => OutboundHTLCState::AwaitingRemovedRemoteRevoke(Readable::read(reader)?),
                                        _ => return Err(DecodeError::InvalidValue),
                                },
                        });
                }

                let holding_cell_htlc_update_count: u64 = Readable::read(reader)?;
                let mut holding_cell_htlc_updates = Vec::with_capacity(cmp::min(holding_cell_htlc_update_count as usize, OUR_MAX_HTLCS as usize*2));
                for _ in 0..holding_cell_htlc_update_count {
                        holding_cell_htlc_updates.push(match <u8 as Readable>::read(reader)? {
                                0 => HTLCUpdateAwaitingACK::AddHTLC {
                                        amount_msat: Readable::read(reader)?,
                                        cltv_expiry: Readable::read(reader)?,
                                        payment_hash: Readable::read(reader)?,
                                        source: Readable::read(reader)?,
                                        onion_routing_packet: Readable::read(reader)?,
                                },
                                1 => HTLCUpdateAwaitingACK::ClaimHTLC {
                                        payment_preimage: Readable::read(reader)?,
                                        htlc_id: Readable::read(reader)?,
                                },
                                2 => HTLCUpdateAwaitingACK::FailHTLC {
                                        htlc_id: Readable::read(reader)?,
                                        err_packet: Readable::read(reader)?,
                                },
                                _ => return Err(DecodeError::InvalidValue),
                        });
                }

                let resend_order = match <u8 as Readable>::read(reader)? {
                        0 => RAACommitmentOrder::CommitmentFirst,
                        1 => RAACommitmentOrder::RevokeAndACKFirst,
                        _ => return Err(DecodeError::InvalidValue),
                };

                let monitor_pending_funding_locked = Readable::read(reader)?;
                let monitor_pending_revoke_and_ack = Readable::read(reader)?;
                let monitor_pending_commitment_signed = Readable::read(reader)?;

                let monitor_pending_forwards_count: u64 = Readable::read(reader)?;
                let mut monitor_pending_forwards = Vec::with_capacity(cmp::min(monitor_pending_forwards_count as usize, OUR_MAX_HTLCS as usize));
                for _ in 0..monitor_pending_forwards_count {
                        monitor_pending_forwards.push((Readable::read(reader)?, Readable::read(reader)?));
                }

                let monitor_pending_failures_count: u64 = Readable::read(reader)?;
                let mut monitor_pending_failures = Vec::with_capacity(cmp::min(monitor_pending_failures_count as usize, OUR_MAX_HTLCS as usize));
                for _ in 0..monitor_pending_failures_count {
                        monitor_pending_failures.push((Readable::read(reader)?, Readable::read(reader)?, Readable::read(reader)?));
                }

                let pending_update_fee_value: Option<u32> = Readable::read(reader)?;

                let holding_cell_update_fee = Readable::read(reader)?;

                let next_holder_htlc_id = Readable::read(reader)?;
                let next_counterparty_htlc_id = Readable::read(reader)?;
                let update_time_counter = Readable::read(reader)?;
                let feerate_per_kw = Readable::read(reader)?;

                // Versions prior to 0.0.100 expected to read the fields of `last_sent_closing_fee` here,
                // however we are supposed to restart shutdown fee negotiation on reconnect (and wipe
                // `last_send_closing_fee` in `remove_uncommitted_htlcs_and_mark_paused`) so we should never
                // consider the stale state on reload.
                match <u8 as Readable>::read(reader)? {
                        0 => {},
                        1 => {
                                let _: u32 = Readable::read(reader)?;
                                let _: u64 = Readable::read(reader)?;
                                let _: Signature = Readable::read(reader)?;
                        },
                        _ => return Err(DecodeError::InvalidValue),
                }

                let funding_tx_confirmed_in = Readable::read(reader)?;
                let funding_tx_confirmation_height = Readable::read(reader)?;
                let short_channel_id = Readable::read(reader)?;

                let counterparty_dust_limit_satoshis = Readable::read(reader)?;
                let holder_dust_limit_satoshis = Readable::read(reader)?;
                let counterparty_max_htlc_value_in_flight_msat = Readable::read(reader)?;
                let mut counterparty_selected_channel_reserve_satoshis = None;
                if ver == 1 {
                        // Read the old serialization from version 0.0.98.
                        counterparty_selected_channel_reserve_satoshis = Some(Readable::read(reader)?);
                } else {
                        // Read the 8 bytes of backwards-compatibility data.
                        let _dummy: u64 = Readable::read(reader)?;
                }
                let counterparty_htlc_minimum_msat = Readable::read(reader)?;
                let holder_htlc_minimum_msat = Readable::read(reader)?;
                let counterparty_max_accepted_htlcs = Readable::read(reader)?;

                let mut minimum_depth = None;
                if ver == 1 {
                        // Read the old serialization from version 0.0.98.
                        minimum_depth = Some(Readable::read(reader)?);
                } else {
                        // Read the 4 bytes of backwards-compatibility data.
                        let _dummy: u32 = Readable::read(reader)?;
                }

                let counterparty_forwarding_info = match <u8 as Readable>::read(reader)? {
                        0 => None,
                        1 => Some(CounterpartyForwardingInfo {
                                fee_base_msat: Readable::read(reader)?,
                                fee_proportional_millionths: Readable::read(reader)?,
                                cltv_expiry_delta: Readable::read(reader)?,
                        }),
                        _ => return Err(DecodeError::InvalidValue),
                };

                let channel_parameters: ChannelTransactionParameters = Readable::read(reader)?;
                let funding_transaction = Readable::read(reader)?;

                let counterparty_cur_commitment_point = Readable::read(reader)?;

                let counterparty_prev_commitment_point = Readable::read(reader)?;
                let counterparty_node_id = Readable::read(reader)?;

                let counterparty_shutdown_scriptpubkey = Readable::read(reader)?;
                let commitment_secrets = Readable::read(reader)?;

                let channel_update_status = Readable::read(reader)?;

                #[cfg(any(test, feature = "fuzztarget"))]
                let mut historical_inbound_htlc_fulfills = HashSet::new();
                #[cfg(any(test, feature = "fuzztarget"))]
                {
                        let htlc_fulfills_len: u64 = Readable::read(reader)?;
                        for _ in 0..htlc_fulfills_len {
                                assert!(historical_inbound_htlc_fulfills.insert(Readable::read(reader)?));
                        }
                }

                let pending_update_fee = if let Some(feerate) = pending_update_fee_value {
                        Some((feerate, if channel_parameters.is_outbound_from_holder {
                                FeeUpdateState::Outbound
                        } else {
                                FeeUpdateState::AwaitingRemoteRevokeToAnnounce
                        }))
                } else {
                        None
                };

                let mut announcement_sigs = None;
                let mut target_closing_feerate_sats_per_kw = None;
                let mut monitor_pending_finalized_fulfills = Some(Vec::new());
                let mut holder_selected_channel_reserve_satoshis = Some(Self::get_holder_selected_channel_reserve_satoshis(channel_value_satoshis));
                let mut holder_max_htlc_value_in_flight_msat = Some(Self::get_holder_max_htlc_value_in_flight_msat(channel_value_satoshis));
                // Prior to supporting channel type negotiation, all of our channels were static_remotekey
                // only, so we default to that if none was written.
                let mut channel_type = Some(ChannelTypeFeatures::only_static_remote_key());
                let mut channel_creation_height = Some(serialized_height);
                read_tlv_fields!(reader, {
                        (0, announcement_sigs, option),
                        (1, minimum_depth, option),
                        (2, channel_type, option),
                        (3, counterparty_selected_channel_reserve_satoshis, option),
                        (4, holder_selected_channel_reserve_satoshis, option),
                        (5, config, option), // Note that if none is provided we will *not* overwrite the existing one.
                        (6, holder_max_htlc_value_in_flight_msat, option),
                        (7, shutdown_scriptpubkey, option),
                        (9, target_closing_feerate_sats_per_kw, option),
                        (11, monitor_pending_finalized_fulfills, vec_type),
                        (13, channel_creation_height, option),
                });

                let chan_features = channel_type.as_ref().unwrap();
                if chan_features.supports_unknown_bits() || chan_features.requires_unknown_bits() {
                        // If the channel was written by a new version and negotiated with features we don't
                        // understand yet, refuse to read it.
                        return Err(DecodeError::UnknownRequiredFeature);
                }

                if channel_parameters.opt_anchors.is_some() {
                        // Relax this check when ChannelTypeFeatures supports anchors.
                        return Err(DecodeError::InvalidValue);
                }

                let mut secp_ctx = Secp256k1::new();
                secp_ctx.seeded_randomize(&keys_source.get_secure_random_bytes());

                Ok(Channel {
                        user_id,

                        config: config.unwrap(),
                        channel_id,
                        channel_state,
                        secp_ctx,
                        channel_value_satoshis,

                        latest_monitor_update_id,

                        holder_signer,
                        shutdown_scriptpubkey,
                        destination_script,

                        cur_holder_commitment_transaction_number,
                        cur_counterparty_commitment_transaction_number,
                        value_to_self_msat,

                        pending_inbound_htlcs,
                        pending_outbound_htlcs,
                        holding_cell_htlc_updates,

                        resend_order,

                        monitor_pending_funding_locked,
                        monitor_pending_revoke_and_ack,
                        monitor_pending_commitment_signed,
                        monitor_pending_forwards,
                        monitor_pending_failures,
                        monitor_pending_finalized_fulfills: monitor_pending_finalized_fulfills.unwrap(),

                        pending_update_fee,
                        holding_cell_update_fee,
                        next_holder_htlc_id,
                        next_counterparty_htlc_id,
                        update_time_counter,
                        feerate_per_kw,

                        #[cfg(debug_assertions)]
                        holder_max_commitment_tx_output: Mutex::new((0, 0)),
                        #[cfg(debug_assertions)]
                        counterparty_max_commitment_tx_output: Mutex::new((0, 0)),

                        last_sent_closing_fee: None,
                        pending_counterparty_closing_signed: None,
                        closing_fee_limits: None,
                        target_closing_feerate_sats_per_kw,

                        funding_tx_confirmed_in,
                        funding_tx_confirmation_height,
                        short_channel_id,
                        channel_creation_height: channel_creation_height.unwrap(),

                        counterparty_dust_limit_satoshis,
                        holder_dust_limit_satoshis,
                        counterparty_max_htlc_value_in_flight_msat,
                        holder_max_htlc_value_in_flight_msat: holder_max_htlc_value_in_flight_msat.unwrap(),
                        counterparty_selected_channel_reserve_satoshis,
                        holder_selected_channel_reserve_satoshis: holder_selected_channel_reserve_satoshis.unwrap(),
                        counterparty_htlc_minimum_msat,
                        holder_htlc_minimum_msat,
                        counterparty_max_accepted_htlcs,
                        minimum_depth,

                        counterparty_forwarding_info,

                        channel_transaction_parameters: channel_parameters,
                        funding_transaction,

                        counterparty_cur_commitment_point,
                        counterparty_prev_commitment_point,
                        counterparty_node_id,

                        counterparty_shutdown_scriptpubkey,

                        commitment_secrets,

                        channel_update_status,
                        closing_signed_in_flight: false,

                        announcement_sigs,

                        #[cfg(any(test, feature = "fuzztarget"))]
                        next_local_commitment_tx_fee_info_cached: Mutex::new(None),
                        #[cfg(any(test, feature = "fuzztarget"))]
                        next_remote_commitment_tx_fee_info_cached: Mutex::new(None),

                        workaround_lnd_bug_4006: None,

                        #[cfg(any(test, feature = "fuzztarget"))]
                        historical_inbound_htlc_fulfills,

                        channel_type: channel_type.unwrap(),
                })
        }
}

#[cfg(test)]
mod tests {
        use bitcoin::util::bip143;
        use bitcoin::consensus::encode::serialize;
        use bitcoin::blockdata::script::{Script, Builder};
        use bitcoin::blockdata::transaction::{Transaction, TxOut, SigHashType};
        use bitcoin::blockdata::constants::genesis_block;
        use bitcoin::blockdata::opcodes;
        use bitcoin::network::constants::Network;
        use bitcoin::hashes::hex::FromHex;
        use hex;
        use ln::{PaymentPreimage, PaymentHash};
        use ln::channelmanager::{HTLCSource, PaymentId};
        use ln::channel::{Channel,InboundHTLCOutput,OutboundHTLCOutput,InboundHTLCState,OutboundHTLCState,HTLCOutputInCommitment,HTLCCandidate,HTLCInitiator,TxCreationKeys};
        use ln::channel::MAX_FUNDING_SATOSHIS;
        use ln::features::InitFeatures;
        use ln::msgs::{ChannelUpdate, DataLossProtect, DecodeError, OptionalField, UnsignedChannelUpdate};
        use ln::script::ShutdownScript;
        use ln::chan_utils;
        use ln::chan_utils::{ChannelPublicKeys, HolderCommitmentTransaction, CounterpartyChannelTransactionParameters, HTLC_SUCCESS_TX_WEIGHT, HTLC_TIMEOUT_TX_WEIGHT};
        use chain::BestBlock;
        use chain::chaininterface::{FeeEstimator,ConfirmationTarget};
        use chain::keysinterface::{InMemorySigner, KeyMaterial, KeysInterface, BaseSign};
        use chain::transaction::OutPoint;
        use util::config::UserConfig;
        use util::enforcing_trait_impls::EnforcingSigner;
        use util::errors::APIError;
        use util::test_utils;
        use util::test_utils::OnGetShutdownScriptpubkey;
        use util::logger::Logger;
        use bitcoin::secp256k1::{Secp256k1, Message, Signature, All};
        use bitcoin::secp256k1::ffi::Signature as FFISignature;
        use bitcoin::secp256k1::key::{SecretKey,PublicKey};
        use bitcoin::secp256k1::recovery::RecoverableSignature;
        use bitcoin::hashes::sha256::Hash as Sha256;
        use bitcoin::hashes::Hash;
        use bitcoin::hash_types::{Txid, WPubkeyHash};
        use core::num::NonZeroU8;
        use sync::Arc;
        use prelude::*;

        struct TestFeeEstimator {
                fee_est: u32
        }
        impl FeeEstimator for TestFeeEstimator {
                fn get_est_sat_per_1000_weight(&self, _: ConfirmationTarget) -> u32 {
                        self.fee_est
                }
        }

        #[test]
        fn test_max_funding_satoshis() {
                assert!(MAX_FUNDING_SATOSHIS <= 21_000_000 * 100_000_000,
                        "MAX_FUNDING_SATOSHIS is greater than all satoshis in existence");
        }

        struct Keys {
                signer: InMemorySigner,
        }
        impl KeysInterface for Keys {
                type Signer = InMemorySigner;

                fn get_node_secret(&self) -> SecretKey { panic!(); }
                fn get_inbound_payment_key_material(&self) -> KeyMaterial { panic!(); }
                fn get_destination_script(&self) -> Script {
                        let secp_ctx = Secp256k1::signing_only();
                        let channel_monitor_claim_key = SecretKey::from_slice(&hex::decode("0fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff").unwrap()[..]).unwrap();
                        let channel_monitor_claim_key_hash = WPubkeyHash::hash(&PublicKey::from_secret_key(&secp_ctx, &channel_monitor_claim_key).serialize());
                        Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&channel_monitor_claim_key_hash[..]).into_script()
                }

                fn get_shutdown_scriptpubkey(&self) -> ShutdownScript {
                        let secp_ctx = Secp256k1::signing_only();
                        let channel_close_key = SecretKey::from_slice(&hex::decode("0fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff").unwrap()[..]).unwrap();
                        ShutdownScript::new_p2wpkh_from_pubkey(PublicKey::from_secret_key(&secp_ctx, &channel_close_key))
                }

                fn get_channel_signer(&self, _inbound: bool, _channel_value_satoshis: u64) -> InMemorySigner {
                        self.signer.clone()
                }
                fn get_secure_random_bytes(&self) -> [u8; 32] { [0; 32] }
                fn read_chan_signer(&self, _data: &[u8]) -> Result<Self::Signer, DecodeError> { panic!(); }
                fn sign_invoice(&self, _invoice_preimage: Vec<u8>) -> Result<RecoverableSignature, ()> { panic!(); }
        }

        fn public_from_secret_hex(secp_ctx: &Secp256k1<All>, hex: &str) -> PublicKey {
                PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&hex::decode(hex).unwrap()[..]).unwrap())
        }

        #[test]
        fn upfront_shutdown_script_incompatibility() {
                let features = InitFeatures::known().clear_shutdown_anysegwit();
                let non_v0_segwit_shutdown_script =
                        ShutdownScript::new_witness_program(NonZeroU8::new(16).unwrap(), &[0, 40]).unwrap();

                let seed = [42; 32];
                let network = Network::Testnet;
                let keys_provider = test_utils::TestKeysInterface::new(&seed, network);
                keys_provider.expect(OnGetShutdownScriptpubkey {
                        returns: non_v0_segwit_shutdown_script.clone(),
                });

                let fee_estimator = TestFeeEstimator { fee_est: 253 };
                let secp_ctx = Secp256k1::new();
                let node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
                let config = UserConfig::default();
                match Channel::<EnforcingSigner>::new_outbound(&&fee_estimator, &&keys_provider, node_id, &features, 10000000, 100000, 42, &config, 0) {
                        Err(APIError::IncompatibleShutdownScript { script }) => {
                                assert_eq!(script.into_inner(), non_v0_segwit_shutdown_script.into_inner());
                        },
                        Err(e) => panic!("Unexpected error: {:?}", e),
                        Ok(_) => panic!("Expected error"),
                }
        }

        // Check that, during channel creation, we use the same feerate in the open channel message
        // as we do in the Channel object creation itself.
        #[test]
        fn test_open_channel_msg_fee() {
                let original_fee = 253;
                let mut fee_est = TestFeeEstimator{fee_est: original_fee };
                let secp_ctx = Secp256k1::new();
                let seed = [42; 32];
                let network = Network::Testnet;
                let keys_provider = test_utils::TestKeysInterface::new(&seed, network);

                let node_a_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
                let config = UserConfig::default();
                let node_a_chan = Channel::<EnforcingSigner>::new_outbound(&&fee_est, &&keys_provider, node_a_node_id, &InitFeatures::known(), 10000000, 100000, 42, &config, 0).unwrap();

                // Now change the fee so we can check that the fee in the open_channel message is the
                // same as the old fee.
                fee_est.fee_est = 500;
                let open_channel_msg = node_a_chan.get_open_channel(genesis_block(network).header.block_hash());
                assert_eq!(open_channel_msg.feerate_per_kw, original_fee);
        }

        #[test]
        fn test_holder_vs_counterparty_dust_limit() {
                // Test that when calculating the local and remote commitment transaction fees, the correct
                // dust limits are used.
                let feeest = TestFeeEstimator{fee_est: 15000};
                let secp_ctx = Secp256k1::new();
                let seed = [42; 32];
                let network = Network::Testnet;
                let keys_provider = test_utils::TestKeysInterface::new(&seed, network);
                let logger = test_utils::TestLogger::new();

                // Go through the flow of opening a channel between two nodes, making sure
                // they have different dust limits.

                // Create Node A's channel pointing to Node B's pubkey
                let node_b_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
                let config = UserConfig::default();
                let mut node_a_chan = Channel::<EnforcingSigner>::new_outbound(&&feeest, &&keys_provider, node_b_node_id, &InitFeatures::known(), 10000000, 100000, 42, &config, 0).unwrap();

                // Create Node B's channel by receiving Node A's open_channel message
                // Make sure A's dust limit is as we expect.
                let open_channel_msg = node_a_chan.get_open_channel(genesis_block(network).header.block_hash());
                let node_b_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[7; 32]).unwrap());
                let node_b_chan = Channel::<EnforcingSigner>::new_from_req(&&feeest, &&keys_provider, node_b_node_id, &InitFeatures::known(), &open_channel_msg, 7, &config, 0, &&logger).unwrap();

                // Node B --> Node A: accept channel, explicitly setting B's dust limit.
                let mut accept_channel_msg = node_b_chan.get_accept_channel();
                accept_channel_msg.dust_limit_satoshis = 546;
                node_a_chan.accept_channel(&accept_channel_msg, &config, &InitFeatures::known()).unwrap();
                node_a_chan.holder_dust_limit_satoshis = 1560;

                // Put some inbound and outbound HTLCs in A's channel.
                let htlc_amount_msat = 11_092_000; // put an amount below A's effective dust limit but above B's.
                node_a_chan.pending_inbound_htlcs.push(InboundHTLCOutput {
                        htlc_id: 0,
                        amount_msat: htlc_amount_msat,
                        payment_hash: PaymentHash(Sha256::hash(&[42; 32]).into_inner()),
                        cltv_expiry: 300000000,
                        state: InboundHTLCState::Committed,
                });

                node_a_chan.pending_outbound_htlcs.push(OutboundHTLCOutput {
                        htlc_id: 1,
                        amount_msat: htlc_amount_msat, // put an amount below A's dust amount but above B's.
                        payment_hash: PaymentHash(Sha256::hash(&[43; 32]).into_inner()),
                        cltv_expiry: 200000000,
                        state: OutboundHTLCState::Committed,
                        source: HTLCSource::OutboundRoute {
                                path: Vec::new(),
                                session_priv: SecretKey::from_slice(&hex::decode("0fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff").unwrap()[..]).unwrap(),
                                first_hop_htlc_msat: 548,
                                payment_id: PaymentId([42; 32]),
                                payment_secret: None,
                                payee: None,
                        }
                });

                // Make sure when Node A calculates their local commitment transaction, none of the HTLCs pass
                // the dust limit check.
                let htlc_candidate = HTLCCandidate::new(htlc_amount_msat, HTLCInitiator::LocalOffered);
                let local_commit_tx_fee = node_a_chan.next_local_commit_tx_fee_msat(htlc_candidate, None);
                let local_commit_fee_0_htlcs = Channel::<EnforcingSigner>::commit_tx_fee_msat(node_a_chan.feerate_per_kw, 0);
                assert_eq!(local_commit_tx_fee, local_commit_fee_0_htlcs);

                // Finally, make sure that when Node A calculates the remote's commitment transaction fees, all
                // of the HTLCs are seen to be above the dust limit.
                node_a_chan.channel_transaction_parameters.is_outbound_from_holder = false;
                let remote_commit_fee_3_htlcs = Channel::<EnforcingSigner>::commit_tx_fee_msat(node_a_chan.feerate_per_kw, 3);
                let htlc_candidate = HTLCCandidate::new(htlc_amount_msat, HTLCInitiator::LocalOffered);
                let remote_commit_tx_fee = node_a_chan.next_remote_commit_tx_fee_msat(htlc_candidate, None);
                assert_eq!(remote_commit_tx_fee, remote_commit_fee_3_htlcs);
        }

        #[test]
        fn test_timeout_vs_success_htlc_dust_limit() {
                // Make sure that when `next_remote_commit_tx_fee_msat` and `next_local_commit_tx_fee_msat`
                // calculate the real dust limits for HTLCs (i.e. the dust limit given by the counterparty
                // *plus* the fees paid for the HTLC) they don't swap `HTLC_SUCCESS_TX_WEIGHT` for
                // `HTLC_TIMEOUT_TX_WEIGHT`, and vice versa.
                let fee_est = TestFeeEstimator{fee_est: 253 };
                let secp_ctx = Secp256k1::new();
                let seed = [42; 32];
                let network = Network::Testnet;
                let keys_provider = test_utils::TestKeysInterface::new(&seed, network);

                let node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
                let config = UserConfig::default();
                let mut chan = Channel::<EnforcingSigner>::new_outbound(&&fee_est, &&keys_provider, node_id, &InitFeatures::known(), 10000000, 100000, 42, &config, 0).unwrap();

                let commitment_tx_fee_0_htlcs = Channel::<EnforcingSigner>::commit_tx_fee_msat(chan.feerate_per_kw, 0);
                let commitment_tx_fee_1_htlc = Channel::<EnforcingSigner>::commit_tx_fee_msat(chan.feerate_per_kw, 1);

                // If HTLC_SUCCESS_TX_WEIGHT and HTLC_TIMEOUT_TX_WEIGHT were swapped: then this HTLC would be
                // counted as dust when it shouldn't be.
                let htlc_amt_above_timeout = ((253 * HTLC_TIMEOUT_TX_WEIGHT / 1000) + chan.holder_dust_limit_satoshis + 1) * 1000;
                let htlc_candidate = HTLCCandidate::new(htlc_amt_above_timeout, HTLCInitiator::LocalOffered);
                let commitment_tx_fee = chan.next_local_commit_tx_fee_msat(htlc_candidate, None);
                assert_eq!(commitment_tx_fee, commitment_tx_fee_1_htlc);

                // If swapped: this HTLC would be counted as non-dust when it shouldn't be.
                let dust_htlc_amt_below_success = ((253 * HTLC_SUCCESS_TX_WEIGHT / 1000) + chan.holder_dust_limit_satoshis - 1) * 1000;
                let htlc_candidate = HTLCCandidate::new(dust_htlc_amt_below_success, HTLCInitiator::RemoteOffered);
                let commitment_tx_fee = chan.next_local_commit_tx_fee_msat(htlc_candidate, None);
                assert_eq!(commitment_tx_fee, commitment_tx_fee_0_htlcs);

                chan.channel_transaction_parameters.is_outbound_from_holder = false;

                // If swapped: this HTLC would be counted as non-dust when it shouldn't be.
                let dust_htlc_amt_above_timeout = ((253 * HTLC_TIMEOUT_TX_WEIGHT / 1000) + chan.counterparty_dust_limit_satoshis + 1) * 1000;
                let htlc_candidate = HTLCCandidate::new(dust_htlc_amt_above_timeout, HTLCInitiator::LocalOffered);
                let commitment_tx_fee = chan.next_remote_commit_tx_fee_msat(htlc_candidate, None);
                assert_eq!(commitment_tx_fee, commitment_tx_fee_0_htlcs);

                // If swapped: this HTLC would be counted as dust when it shouldn't be.
                let htlc_amt_below_success = ((253 * HTLC_SUCCESS_TX_WEIGHT / 1000) + chan.counterparty_dust_limit_satoshis - 1) * 1000;
                let htlc_candidate = HTLCCandidate::new(htlc_amt_below_success, HTLCInitiator::RemoteOffered);
                let commitment_tx_fee = chan.next_remote_commit_tx_fee_msat(htlc_candidate, None);
                assert_eq!(commitment_tx_fee, commitment_tx_fee_1_htlc);
        }

        #[test]
        fn channel_reestablish_no_updates() {
                let feeest = TestFeeEstimator{fee_est: 15000};
                let logger = test_utils::TestLogger::new();
                let secp_ctx = Secp256k1::new();
                let seed = [42; 32];
                let network = Network::Testnet;
                let best_block = BestBlock::from_genesis(network);
                let chain_hash = best_block.block_hash();
                let keys_provider = test_utils::TestKeysInterface::new(&seed, network);

                // Go through the flow of opening a channel between two nodes.

                // Create Node A's channel pointing to Node B's pubkey
                let node_b_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
                let config = UserConfig::default();
                let mut node_a_chan = Channel::<EnforcingSigner>::new_outbound(&&feeest, &&keys_provider, node_b_node_id, &InitFeatures::known(), 10000000, 100000, 42, &config, 0).unwrap();

                // Create Node B's channel by receiving Node A's open_channel message
                let open_channel_msg = node_a_chan.get_open_channel(chain_hash);
                let node_b_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[7; 32]).unwrap());
                let mut node_b_chan = Channel::<EnforcingSigner>::new_from_req(&&feeest, &&keys_provider, node_b_node_id, &InitFeatures::known(), &open_channel_msg, 7, &config, 0, &&logger).unwrap();

                // Node B --> Node A: accept channel
                let accept_channel_msg = node_b_chan.get_accept_channel();
                node_a_chan.accept_channel(&accept_channel_msg, &config, &InitFeatures::known()).unwrap();

                // Node A --> Node B: funding created
                let output_script = node_a_chan.get_funding_redeemscript();
                let tx = Transaction { version: 1, lock_time: 0, input: Vec::new(), output: vec![TxOut {
                        value: 10000000, script_pubkey: output_script.clone(),
                }]};
                let funding_outpoint = OutPoint{ txid: tx.txid(), index: 0 };
                let funding_created_msg = node_a_chan.get_outbound_funding_created(tx.clone(), funding_outpoint, &&logger).unwrap();
                let (funding_signed_msg, _) = node_b_chan.funding_created(&funding_created_msg, best_block, &&logger).unwrap();

                // Node B --> Node A: funding signed
                let _ = node_a_chan.funding_signed(&funding_signed_msg, best_block, &&logger);

                // Now disconnect the two nodes and check that the commitment point in
                // Node B's channel_reestablish message is sane.
                node_b_chan.remove_uncommitted_htlcs_and_mark_paused(&&logger);
                let msg = node_b_chan.get_channel_reestablish(&&logger);
                assert_eq!(msg.next_local_commitment_number, 1); // now called next_commitment_number
                assert_eq!(msg.next_remote_commitment_number, 0); // now called next_revocation_number
                match msg.data_loss_protect {
                        OptionalField::Present(DataLossProtect { your_last_per_commitment_secret, .. }) => {
                                assert_eq!(your_last_per_commitment_secret, [0; 32]);
                        },
                        _ => panic!()
                }

                // Check that the commitment point in Node A's channel_reestablish message
                // is sane.
                node_a_chan.remove_uncommitted_htlcs_and_mark_paused(&&logger);
                let msg = node_a_chan.get_channel_reestablish(&&logger);
                assert_eq!(msg.next_local_commitment_number, 1); // now called next_commitment_number
                assert_eq!(msg.next_remote_commitment_number, 0); // now called next_revocation_number
                match msg.data_loss_protect {
                        OptionalField::Present(DataLossProtect { your_last_per_commitment_secret, .. }) => {
                                assert_eq!(your_last_per_commitment_secret, [0; 32]);
                        },
                        _ => panic!()
                }
        }

        #[test]
        fn channel_update() {
                let feeest = TestFeeEstimator{fee_est: 15000};
                let secp_ctx = Secp256k1::new();
                let seed = [42; 32];
                let network = Network::Testnet;
                let chain_hash = genesis_block(network).header.block_hash();
                let keys_provider = test_utils::TestKeysInterface::new(&seed, network);

                // Create a channel.
                let node_b_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
                let config = UserConfig::default();
                let mut node_a_chan = Channel::<EnforcingSigner>::new_outbound(&&feeest, &&keys_provider, node_b_node_id, &InitFeatures::known(), 10000000, 100000, 42, &config, 0).unwrap();
                assert!(node_a_chan.counterparty_forwarding_info.is_none());
                assert_eq!(node_a_chan.holder_htlc_minimum_msat, 1); // the default
                assert!(node_a_chan.counterparty_forwarding_info().is_none());

                // Make sure that receiving a channel update will update the Channel as expected.
                let update = ChannelUpdate {
                        contents: UnsignedChannelUpdate {
                                chain_hash,
                                short_channel_id: 0,
                                timestamp: 0,
                                flags: 0,
                                cltv_expiry_delta: 100,
                                htlc_minimum_msat: 5,
                                htlc_maximum_msat: OptionalField::Absent,
                                fee_base_msat: 110,
                                fee_proportional_millionths: 11,
                                excess_data: Vec::new(),
                        },
                        signature: Signature::from(unsafe { FFISignature::new() })
                };
                node_a_chan.channel_update(&update).unwrap();

                // The counterparty can send an update with a higher minimum HTLC, but that shouldn't
                // change our official htlc_minimum_msat.
                assert_eq!(node_a_chan.holder_htlc_minimum_msat, 1);
                match node_a_chan.counterparty_forwarding_info() {
                        Some(info) => {
                                assert_eq!(info.cltv_expiry_delta, 100);
                                assert_eq!(info.fee_base_msat, 110);
                                assert_eq!(info.fee_proportional_millionths, 11);
                        },
                        None => panic!("expected counterparty forwarding info to be Some")
                }
        }

        #[test]
        fn outbound_commitment_test() {
                // Test vectors from BOLT 3 Appendix C:
                let feeest = TestFeeEstimator{fee_est: 15000};
                let logger : Arc<Logger> = Arc::new(test_utils::TestLogger::new());
                let secp_ctx = Secp256k1::new();

                let mut signer = InMemorySigner::new(
                        &secp_ctx,
                        SecretKey::from_slice(&hex::decode("30ff4956bbdd3222d44cc5e8a1261dab1e07957bdac5ae88fe3261ef321f3749").unwrap()[..]).unwrap(),
                        SecretKey::from_slice(&hex::decode("0fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff").unwrap()[..]).unwrap(),
                        SecretKey::from_slice(&hex::decode("1111111111111111111111111111111111111111111111111111111111111111").unwrap()[..]).unwrap(),
                        SecretKey::from_slice(&hex::decode("3333333333333333333333333333333333333333333333333333333333333333").unwrap()[..]).unwrap(),
                        SecretKey::from_slice(&hex::decode("1111111111111111111111111111111111111111111111111111111111111111").unwrap()[..]).unwrap(),

                        // These aren't set in the test vectors:
                        [0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff],
                        10_000_000,
                        [0; 32]
                );

                assert_eq!(signer.pubkeys().funding_pubkey.serialize()[..],
                                hex::decode("023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb").unwrap()[..]);
                let keys_provider = Keys { signer: signer.clone() };

                let counterparty_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
                let mut config = UserConfig::default();
                config.channel_options.announced_channel = false;
                let mut chan = Channel::<InMemorySigner>::new_outbound(&&feeest, &&keys_provider, counterparty_node_id, &InitFeatures::known(), 10_000_000, 100000, 42, &config, 0).unwrap(); // Nothing uses their network key in this test
                chan.holder_dust_limit_satoshis = 546;
                chan.counterparty_selected_channel_reserve_satoshis = Some(0); // Filled in in accept_channel

                let funding_info = OutPoint{ txid: Txid::from_hex("8984484a580b825b9972d7adb15050b3ab624ccd731946b3eeddb92f4e7ef6be").unwrap(), index: 0 };

                let counterparty_pubkeys = ChannelPublicKeys {
                        funding_pubkey: public_from_secret_hex(&secp_ctx, "1552dfba4f6cf29a62a0af13c8d6981d36d0ef8d61ba10fb0fe90da7634d7e13"),
                        revocation_basepoint: PublicKey::from_slice(&hex::decode("02466d7fcae563e5cb09a0d1870bb580344804617879a14949cf22285f1bae3f27").unwrap()[..]).unwrap(),
                        payment_point: public_from_secret_hex(&secp_ctx, "4444444444444444444444444444444444444444444444444444444444444444"),
                        delayed_payment_basepoint: public_from_secret_hex(&secp_ctx, "1552dfba4f6cf29a62a0af13c8d6981d36d0ef8d61ba10fb0fe90da7634d7e13"),
                        htlc_basepoint: public_from_secret_hex(&secp_ctx, "4444444444444444444444444444444444444444444444444444444444444444")
                };
                chan.channel_transaction_parameters.counterparty_parameters = Some(
                        CounterpartyChannelTransactionParameters {
                                pubkeys: counterparty_pubkeys.clone(),
                                selected_contest_delay: 144
                        });
                chan.channel_transaction_parameters.funding_outpoint = Some(funding_info);
                signer.ready_channel(&chan.channel_transaction_parameters);

                assert_eq!(counterparty_pubkeys.payment_point.serialize()[..],
                           hex::decode("032c0b7cf95324a07d05398b240174dc0c2be444d96b159aa6c7f7b1e668680991").unwrap()[..]);

                assert_eq!(counterparty_pubkeys.funding_pubkey.serialize()[..],
                           hex::decode("030e9f7b623d2ccc7c9bd44d66d5ce21ce504c0acf6385a132cec6d3c39fa711c1").unwrap()[..]);

                assert_eq!(counterparty_pubkeys.htlc_basepoint.serialize()[..],
                           hex::decode("032c0b7cf95324a07d05398b240174dc0c2be444d96b159aa6c7f7b1e668680991").unwrap()[..]);

                // We can't just use build_holder_transaction_keys here as the per_commitment_secret is not
                // derived from a commitment_seed, so instead we copy it here and call
                // build_commitment_transaction.
                let delayed_payment_base = &chan.holder_signer.pubkeys().delayed_payment_basepoint;
                let per_commitment_secret = SecretKey::from_slice(&hex::decode("1f1e1d1c1b1a191817161514131211100f0e0d0c0b0a09080706050403020100").unwrap()[..]).unwrap();
                let per_commitment_point = PublicKey::from_secret_key(&secp_ctx, &per_commitment_secret);
                let htlc_basepoint = &chan.holder_signer.pubkeys().htlc_basepoint;
                let keys = TxCreationKeys::derive_new(&secp_ctx, &per_commitment_point, delayed_payment_base, htlc_basepoint, &counterparty_pubkeys.revocation_basepoint, &counterparty_pubkeys.htlc_basepoint).unwrap();

                macro_rules! test_commitment {
                        ( $counterparty_sig_hex: expr, $sig_hex: expr, $tx_hex: expr, {
                                $( { $htlc_idx: expr, $counterparty_htlc_sig_hex: expr, $htlc_sig_hex: expr, $htlc_tx_hex: expr } ), *
                        } ) => { {
                                let (commitment_tx, htlcs): (_, Vec<HTLCOutputInCommitment>) = {
                                        let mut commitment_stats = chan.build_commitment_transaction(0xffffffffffff - 42, &keys, true, false, &logger);

                                        let htlcs = commitment_stats.htlcs_included.drain(..)
                                                .filter_map(|(htlc, _)| if htlc.transaction_output_index.is_some() { Some(htlc) } else { None })
                                                .collect();
                                        (commitment_stats.tx, htlcs)
                                };
                                let trusted_tx = commitment_tx.trust();
                                let unsigned_tx = trusted_tx.built_transaction();
                                let redeemscript = chan.get_funding_redeemscript();
                                let counterparty_signature = Signature::from_der(&hex::decode($counterparty_sig_hex).unwrap()[..]).unwrap();
                                let sighash = unsigned_tx.get_sighash_all(&redeemscript, chan.channel_value_satoshis);
                                secp_ctx.verify(&sighash, &counterparty_signature, chan.counterparty_funding_pubkey()).unwrap();

                                let mut per_htlc: Vec<(HTLCOutputInCommitment, Option<Signature>)> = Vec::new();
                                per_htlc.clear(); // Don't warn about excess mut for no-HTLC calls
                                let mut counterparty_htlc_sigs = Vec::new();
                                counterparty_htlc_sigs.clear(); // Don't warn about excess mut for no-HTLC calls
                                $({
                                        let remote_signature = Signature::from_der(&hex::decode($counterparty_htlc_sig_hex).unwrap()[..]).unwrap();
                                        per_htlc.push((htlcs[$htlc_idx].clone(), Some(remote_signature)));
                                        counterparty_htlc_sigs.push(remote_signature);
                                })*
                                assert_eq!(htlcs.len(), per_htlc.len());

                                let holder_commitment_tx = HolderCommitmentTransaction::new(
                                        commitment_tx.clone(),
                                        counterparty_signature,
                                        counterparty_htlc_sigs,
                                        &chan.holder_signer.pubkeys().funding_pubkey,
                                        chan.counterparty_funding_pubkey()
                                );
                                let (holder_sig, htlc_sigs) = signer.sign_holder_commitment_and_htlcs(&holder_commitment_tx, &secp_ctx).unwrap();
                                assert_eq!(Signature::from_der(&hex::decode($sig_hex).unwrap()[..]).unwrap(), holder_sig, "holder_sig");

                                let funding_redeemscript = chan.get_funding_redeemscript();
                                let tx = holder_commitment_tx.add_holder_sig(&funding_redeemscript, holder_sig);
                                assert_eq!(serialize(&tx)[..], hex::decode($tx_hex).unwrap()[..], "tx");

                                // ((htlc, counterparty_sig), (index, holder_sig))
                                let mut htlc_sig_iter = holder_commitment_tx.htlcs().iter().zip(&holder_commitment_tx.counterparty_htlc_sigs).zip(htlc_sigs.iter().enumerate());

                                $({
                                        let remote_signature = Signature::from_der(&hex::decode($counterparty_htlc_sig_hex).unwrap()[..]).unwrap();

                                        let ref htlc = htlcs[$htlc_idx];
                                        let opt_anchors = false;
                                        let htlc_tx = chan_utils::build_htlc_transaction(&unsigned_tx.txid, chan.feerate_per_kw,
                                                chan.get_counterparty_selected_contest_delay().unwrap(),
                                                &htlc, opt_anchors, &keys.broadcaster_delayed_payment_key, &keys.revocation_key);
                                        let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, opt_anchors, &keys);
                                        let htlc_sighashtype = if opt_anchors { SigHashType::SinglePlusAnyoneCanPay } else { SigHashType::All };
                                        let htlc_sighash = Message::from_slice(&bip143::SigHashCache::new(&htlc_tx).signature_hash(0, &htlc_redeemscript, htlc.amount_msat / 1000, htlc_sighashtype)[..]).unwrap();
                                        secp_ctx.verify(&htlc_sighash, &remote_signature, &keys.countersignatory_htlc_key).unwrap();

                                        let mut preimage: Option<PaymentPreimage> = None;
                                        if !htlc.offered {
                                                for i in 0..5 {
                                                        let out = PaymentHash(Sha256::hash(&[i; 32]).into_inner());
                                                        if out == htlc.payment_hash {
                                                                preimage = Some(PaymentPreimage([i; 32]));
                                                        }
                                                }

                                                assert!(preimage.is_some());
                                        }

                                        let htlc_sig = htlc_sig_iter.next().unwrap();
                                        assert_eq!((htlc_sig.0).0.transaction_output_index, Some($htlc_idx), "output index");

                                        let signature = Signature::from_der(&hex::decode($htlc_sig_hex).unwrap()[..]).unwrap();
                                        assert_eq!(signature, *(htlc_sig.1).1, "htlc sig");
                                        let index = (htlc_sig.1).0;
                                        let channel_parameters = chan.channel_transaction_parameters.as_holder_broadcastable();
                                        let trusted_tx = holder_commitment_tx.trust();
                                        assert_eq!(serialize(&trusted_tx.get_signed_htlc_tx(&channel_parameters, index, &(htlc_sig.0).1, (htlc_sig.1).1, &preimage))[..],
                                                        hex::decode($htlc_tx_hex).unwrap()[..], "htlc tx");
                                })*
                                assert!(htlc_sig_iter.next().is_none());
                        } }
                }

                // simple commitment tx with no HTLCs
                chan.value_to_self_msat = 7000000000;

                test_commitment!("3045022100c3127b33dcc741dd6b05b1e63cbd1a9a7d816f37af9b6756fa2376b056f032370220408b96279808fe57eb7e463710804cdf4f108388bc5cf722d8c848d2c7f9f3b0",
                                                 "30440220616210b2cc4d3afb601013c373bbd8aac54febd9f15400379a8cb65ce7deca60022034236c010991beb7ff770510561ae8dc885b8d38d1947248c38f2ae055647142",
                                                 "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", {});

                chan.pending_inbound_htlcs.push({
                        let mut out = InboundHTLCOutput{
                                htlc_id: 0,
                                amount_msat: 1000000,
                                cltv_expiry: 500,
                                payment_hash: PaymentHash([0; 32]),
                                state: InboundHTLCState::Committed,
                        };
                        out.payment_hash.0 = Sha256::hash(&hex::decode("0000000000000000000000000000000000000000000000000000000000000000").unwrap()).into_inner();
                        out
                });
                chan.pending_inbound_htlcs.push({
                        let mut out = InboundHTLCOutput{
                                htlc_id: 1,
                                amount_msat: 2000000,
                                cltv_expiry: 501,
                                payment_hash: PaymentHash([0; 32]),
                                state: InboundHTLCState::Committed,
                        };
                        out.payment_hash.0 = Sha256::hash(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()).into_inner();
                        out
                });
                chan.pending_outbound_htlcs.push({
                        let mut out = OutboundHTLCOutput{
                                htlc_id: 2,
                                amount_msat: 2000000,
                                cltv_expiry: 502,
                                payment_hash: PaymentHash([0; 32]),
                                state: OutboundHTLCState::Committed,
                                source: HTLCSource::dummy(),
                        };
                        out.payment_hash.0 = Sha256::hash(&hex::decode("0202020202020202020202020202020202020202020202020202020202020202").unwrap()).into_inner();
                        out
                });
                chan.pending_outbound_htlcs.push({
                        let mut out = OutboundHTLCOutput{
                                htlc_id: 3,
                                amount_msat: 3000000,
                                cltv_expiry: 503,
                                payment_hash: PaymentHash([0; 32]),
                                state: OutboundHTLCState::Committed,
                                source: HTLCSource::dummy(),
                        };
                        out.payment_hash.0 = Sha256::hash(&hex::decode("0303030303030303030303030303030303030303030303030303030303030303").unwrap()).into_inner();
                        out
                });
                chan.pending_inbound_htlcs.push({
                        let mut out = InboundHTLCOutput{
                                htlc_id: 4,
                                amount_msat: 4000000,
                                cltv_expiry: 504,
                                payment_hash: PaymentHash([0; 32]),
                                state: InboundHTLCState::Committed,
                        };
                        out.payment_hash.0 = Sha256::hash(&hex::decode("0404040404040404040404040404040404040404040404040404040404040404").unwrap()).into_inner();
                        out
                });

                // commitment tx with all five HTLCs untrimmed (minimum feerate)
                chan.value_to_self_msat = 6993000000; // 7000000000 - 7000000
                chan.feerate_per_kw = 0;

                test_commitment!("3044022009b048187705a8cbc9ad73adbe5af148c3d012e1f067961486c822c7af08158c022006d66f3704cfab3eb2dc49dae24e4aa22a6910fc9b424007583204e3621af2e5",
                                 "304402206fc2d1f10ea59951eefac0b4b7c396a3c3d87b71ff0b019796ef4535beaf36f902201765b0181e514d04f4c8ad75659d7037be26cdb3f8bb6f78fe61decef484c3ea",
                                 "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", {

                                  { 0,
                                  "3045022100d9e29616b8f3959f1d3d7f7ce893ffedcdc407717d0de8e37d808c91d3a7c50d022078c3033f6d00095c8720a4bc943c1b45727818c082e4e3ddbc6d3116435b624b",
                                  "30440220636de5682ef0c5b61f124ec74e8aa2461a69777521d6998295dcea36bc3338110220165285594b23c50b28b82df200234566628a27bcd17f7f14404bd865354eb3ce",
                                  "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" },

                                  { 1,
                                  "30440220649fe8b20e67e46cbb0d09b4acea87dbec001b39b08dee7bdd0b1f03922a8640022037c462dff79df501cecfdb12ea7f4de91f99230bb544726f6e04527b1f896004",
                                  "3045022100803159dee7935dba4a1d36a61055ce8fd62caa528573cc221ae288515405a252022029c59e7cffce374fe860100a4a63787e105c3cf5156d40b12dd53ff55ac8cf3f",
                                  "02000000000101ab84ff284f162cfbfef241f853b47d4368d171f9e2a1445160cd591c4c7d882b01000000000000000001d0070000000000002200204adb4e2f00643db396dd120d4e7dc17625f5f2c11a40d857accc862d6b7dd80e05004730440220649fe8b20e67e46cbb0d09b4acea87dbec001b39b08dee7bdd0b1f03922a8640022037c462dff79df501cecfdb12ea7f4de91f99230bb544726f6e04527b1f89600401483045022100803159dee7935dba4a1d36a61055ce8fd62caa528573cc221ae288515405a252022029c59e7cffce374fe860100a4a63787e105c3cf5156d40b12dd53ff55ac8cf3f01008576a91414011f7254d96b819c76986c277d115efce6f7b58763ac67210394854aa6eab5b2a8122cc726e9dded053a2184d88256816826d6231c068d4a5b7c820120876475527c21030d417a46946384f88d5f3337267c5e579765875dc4daca813e21734b140639e752ae67a914b43e1b38138a41b37f7cd9a1d274bc63e3a9b5d188ac6868f6010000" },

                                  { 2,
                                  "30440220770fc321e97a19f38985f2e7732dd9fe08d16a2efa4bcbc0429400a447faf49102204d40b417f3113e1b0944ae0986f517564ab4acd3d190503faf97a6e420d43352",
                                  "3045022100a437cc2ce77400ecde441b3398fea3c3ad8bdad8132be818227fe3c5b8345989022069d45e7fa0ae551ec37240845e2c561ceb2567eacf3076a6a43a502d05865faa",
                                  "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" },

                                  { 3,
                                  "304402207bcbf4f60a9829b05d2dbab84ed593e0291836be715dc7db6b72a64caf646af802201e489a5a84f7c5cc130398b841d138d031a5137ac8f4c49c770a4959dc3c1363",
                                  "304402203121d9b9c055f354304b016a36662ee99e1110d9501cb271b087ddb6f382c2c80220549882f3f3b78d9c492de47543cb9a697cecc493174726146536c5954dac7487",
                                  "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" },

                                  { 4,
                                  "3044022076dca5cb81ba7e466e349b7128cdba216d4d01659e29b96025b9524aaf0d1899022060de85697b88b21c749702b7d2cfa7dfeaa1f472c8f1d7d9c23f2bf968464b87",
                                  "3045022100d9080f103cc92bac15ec42464a95f070c7fb6925014e673ee2ea1374d36a7f7502200c65294d22eb20d48564954d5afe04a385551919d8b2ddb4ae2459daaeee1d95",
                                  "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" }
                } );

                // commitment tx with seven outputs untrimmed (maximum feerate)
                chan.value_to_self_msat = 6993000000; // 7000000000 - 7000000
                chan.feerate_per_kw = 647;

                test_commitment!("3045022100a135f9e8a5ed25f7277446c67956b00ce6f610ead2bdec2c2f686155b7814772022059f1f6e1a8b336a68efcc1af3fe4d422d4827332b5b067501b099c47b7b5b5ee",
                                 "30450221009ec15c687898bb4da8b3a833e5ab8bfc51ec6e9202aaa8e66611edfd4a85ed1102203d7183e45078b9735c93450bc3415d3e5a8c576141a711ec6ddcb4a893926bb7",
                                 "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", {

                                  { 0,
                                  "30450221008437627f9ad84ac67052e2a414a4367b8556fd1f94d8b02590f89f50525cd33502205b9c21ff6e7fc864f2352746ad8ba59182510819acb644e25b8a12fc37bbf24f",
                                  "30440220344b0deb055230d01703e6c7acd45853c4af2328b49b5d8af4f88a060733406602202ea64f2a43d5751edfe75503cbc35a62e3141b5ed032fa03360faf4ca66f670b",
                                  "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" },

                                  { 1,
                                  "304402205a67f92bf6845cf2892b48d874ac1daf88a36495cf8a06f93d83180d930a6f75022031da1621d95c3f335cc06a3056cf960199dae600b7cf89088f65fc53cdbef28c",
                                  "30450221009e5e3822b0185c6799a95288c597b671d6cc69ab80f43740f00c6c3d0752bdda02206da947a74bd98f3175324dc56fdba86cc783703a120a6f0297537e60632f4c7f",
                                  "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" },

                                  { 2,
                                  "30440220437e21766054a3eef7f65690c5bcfa9920babbc5af92b819f772f6ea96df6c7402207173622024bd97328cfb26c6665e25c2f5d67c319443ccdc60c903217005d8c8",
                                  "3045022100fcfc47e36b712624677626cef3dc1d67f6583bd46926a6398fe6b00b0c9a37760220525788257b187fc775c6370d04eadf34d06f3650a63f8df851cee0ecb47a1673",
                                  "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" },

                                  { 3,
                                  "304402207436e10737e4df499fc051686d3e11a5bb2310e4d1f1e691d287cef66514791202207cb58e71a6b7a42dd001b7e3ae672ea4f71ea3e1cd412b742e9124abb0739c64",
                                  "3045022100e78211b8409afb7255ffe37337da87f38646f1faebbdd61bc1920d69e3ead67a02201a626305adfcd16bfb7e9340928d9b6305464eab4aa4c4a3af6646e9b9f69dee",
                                  "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" },

                                  { 4,
                                  "30450221009acd6a827a76bfee50806178dfe0495cd4e1d9c58279c194c7b01520fe68cb8d022024d439047c368883e570997a7d40f0b430cb5a742f507965e7d3063ae3feccca",
                                  "3044022048762cf546bbfe474f1536365ea7c416e3c0389d60558bc9412cb148fb6ab68202207215d7083b75c96ff9d2b08c59c34e287b66820f530b486a9aa4cdd9c347d5b9",
                                  "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" }
                } );

                // commitment tx with six outputs untrimmed (minimum feerate)
                chan.value_to_self_msat = 6993000000; // 7000000000 - 7000000
                chan.feerate_per_kw = 648;

                test_commitment!("304402203948f900a5506b8de36a4d8502f94f21dd84fd9c2314ab427d52feaa7a0a19f2022059b6a37a4adaa2c5419dc8aea63c6e2a2ec4c4bde46207f6dc1fcd22152fc6e5",
                                 "3045022100b15f72908ba3382a34ca5b32519240a22300cc6015b6f9418635fb41f3d01d8802207adb331b9ed1575383dca0f2355e86c173802feecf8298fbea53b9d4610583e9",
                                 "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", {

                                  { 0,
                                  "3045022100a031202f3be94678f0e998622ee95ebb6ada8da1e9a5110228b5e04a747351e4022010ca6a21e18314ed53cfaae3b1f51998552a61a468e596368829a50ce40110e0",
                                  "304502210097e1873b57267730154595187a34949d3744f52933070c74757005e61ce2112e02204ecfba2aa42d4f14bdf8bad4206bb97217b702e6c433e0e1b0ce6587e6d46ec6",
                                  "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" },

                                  { 1,
                                  "304402202361012a634aee7835c5ecdd6413dcffa8f404b7e77364c792cff984e4ee71e90220715c5e90baa08daa45a7439b1ee4fa4843ed77b19c058240b69406606d384124",
                                  "3044022019de73b00f1d818fb388e83b2c8c31f6bce35ac624e215bc12f88f9dc33edf48022006ff814bb9f700ee6abc3294e146fac3efd4f13f0005236b41c0a946ee00c9ae",
                                  "020000000001010f44041fdfba175987cf4e6135ba2a154e3b7fb96483dc0ed5efc0678e5b6bf10100000000000000000109060000000000002200204adb4e2f00643db396dd120d4e7dc17625f5f2c11a40d857accc862d6b7dd80e050047304402202361012a634aee7835c5ecdd6413dcffa8f404b7e77364c792cff984e4ee71e90220715c5e90baa08daa45a7439b1ee4fa4843ed77b19c058240b69406606d38412401473044022019de73b00f1d818fb388e83b2c8c31f6bce35ac624e215bc12f88f9dc33edf48022006ff814bb9f700ee6abc3294e146fac3efd4f13f0005236b41c0a946ee00c9ae012001010101010101010101010101010101010101010101010101010101010101018a76a91414011f7254d96b819c76986c277d115efce6f7b58763ac67210394854aa6eab5b2a8122cc726e9dded053a2184d88256816826d6231c068d4a5b7c8201208763a9144b6b2e5444c2639cc0fb7bcea5afba3f3cdce23988527c21030d417a46946384f88d5f3337267c5e579765875dc4daca813e21734b140639e752ae677502f501b175ac686800000000" },

                                  { 2,
                                  "304402207e8e82cd71ed4febeb593732c260456836e97d81896153ecd2b3cf320ca6861702202dd4a30f68f98ced7cc56a36369ac1fdd978248c5ff4ed204fc00cc625532989",
                                  "3045022100bd0be6100c4fd8f102ec220e1b053e4c4e2ecca25615490150007b40d314dc3902201a1e0ea266965b43164d9e6576f58fa6726d42883dd1c3996d2925c2e2260796",
                                  "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" },

                                  { 3,
                                  "3044022024cd52e4198c8ae0e414a86d86b5a65ea7450f2eb4e783096736d93395eca5ce022078f0094745b45be4d4b2b04dd5978c9e66ba49109e5704403e84aaf5f387d6be",
                                  "3045022100bbfb9d0a946d420807c86e985d636cceb16e71c3694ed186316251a00cbd807202207773223f9a337e145f64673825be9b30d07ef1542c82188b264bedcf7cda78c6",
                                  "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" }
                } );

                // commitment tx with six outputs untrimmed (maximum feerate)
                chan.value_to_self_msat = 6993000000; // 7000000000 - 7000000
                chan.feerate_per_kw = 2069;

                test_commitment!("304502210090b96a2498ce0c0f2fadbec2aab278fed54c1a7838df793ec4d2c78d96ec096202204fdd439c50f90d483baa7b68feeef4bd33bc277695405447bcd0bfb2ca34d7bc",
                                 "3045022100ad9a9bbbb75d506ca3b716b336ee3cf975dd7834fcf129d7dd188146eb58a8b4022061a759ee417339f7fe2ea1e8deb83abb6a74db31a09b7648a932a639cda23e33",
                                 "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", {

                                  { 0,
                                  "3045022100f33513ee38abf1c582876f921f8fddc06acff48e04515532a32d3938de938ffd02203aa308a2c1863b7d6fdf53159a1465bf2e115c13152546cc5d74483ceaa7f699",
                                  "3045022100a637902a5d4c9ba9e7c472a225337d5aac9e2e3f6744f76e237132e7619ba0400220035c60d784a031c0d9f6df66b7eab8726a5c25397399ee4aa960842059eb3f9d",
                                  "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" },

                                  { 1,
                                  "3045022100ce07682cf4b90093c22dc2d9ab2a77ad6803526b655ef857221cc96af5c9e0bf02200f501cee22e7a268af40b555d15a8237c9f36ad67ef1841daf9f6a0267b1e6df",
                                  "3045022100e57e46234f8782d3ff7aa593b4f7446fb5316c842e693dc63ee324fd49f6a1c302204a2f7b44c48bd26e1554422afae13153eb94b29d3687b733d18930615fb2db61",
                                  "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" },

                                  { 2,
                                  "3045022100e3e35492e55f82ec0bc2f317ffd7a486d1f7024330fe9743c3559fc39f32ef0c02203d1d4db651fc388a91d5ad8ecdd8e83673063bc8eefe27cfd8c189090e3a23e0",
                                  "3044022068613fb1b98eb3aec7f44c5b115b12343c2f066c4277c82b5f873dfe68f37f50022028109b4650f3f528ca4bfe9a467aff2e3e43893b61b5159157119d5d95cf1c18",
                                  "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" },

                                  { 3,
                                  "304402207475aeb0212ef9bf5130b60937817ad88c9a87976988ef1f323f026148cc4a850220739fea17ad3257dcad72e509c73eebe86bee30b178467b9fdab213d631b109df",
                                  "3045022100d315522e09e7d53d2a659a79cb67fef56d6c4bddf3f46df6772d0d20a7beb7c8022070bcc17e288607b6a72be0bd83368bb6d53488db266c1cdb4d72214e4f02ac33",
                                  "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" }
                } );

                // commitment tx with five outputs untrimmed (minimum feerate)
                chan.value_to_self_msat = 6993000000; // 7000000000 - 7000000
                chan.feerate_per_kw = 2070;

                test_commitment!("304402204ca1ba260dee913d318271d86e10ca0f5883026fb5653155cff600fb40895223022037b145204b7054a40e08bb1fefbd826f827b40838d3e501423bcc57924bcb50c",
                                 "3044022001014419b5ba00e083ac4e0a85f19afc848aacac2d483b4b525d15e2ae5adbfe022015ebddad6ee1e72b47cb09f3e78459da5be01ccccd95dceca0e056a00cc773c1",
                                 "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", {

                                  { 0,
                                  "304402205f6b6d12d8d2529fb24f4445630566cf4abbd0f9330ab6c2bdb94222d6a2a0c502202f556258ae6f05b193749e4c541dfcc13b525a5422f6291f073f15617ba8579b",
                                  "30440220150b11069454da70caf2492ded9e0065c9a57f25ac2a4c52657b1d15b6c6ed85022068a38833b603c8892717206383611bad210f1cbb4b1f87ea29c6c65b9e1cb3e5",
                                  "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" },

                                  { 1,
                                  "3045022100f960dfb1c9aee7ce1437efa65b523e399383e8149790e05d8fed27ff6e42fe0002202fe8613e062ffe0b0c518cc4101fba1c6de70f64a5bcc7ae663f2efae43b8546",
                                  "30450221009a6ed18e6873bc3644332a6ee21c152a5b102821865350df7a8c74451a51f9f2022050d801fb4895d7d7fbf452824c0168347f5c0cbe821cf6a97a63af5b8b2563c6",
                                  "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" },

                                  { 2,
                                  "3045022100ae5fc7717ae684bc1fcf9020854e5dbe9842c9e7472879ac06ff95ac2bb10e4e022057728ada4c00083a3e65493fb5d50a232165948a1a0f530ef63185c2c8c56504",
                                  "30440220408ad3009827a8fccf774cb285587686bfb2ed041f89a89453c311ce9c8ee0f902203c7392d9f8306d3a46522a66bd2723a7eb2628cb2d9b34d4c104f1766bf37502",
                                  "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" }
                } );

                // commitment tx with five outputs untrimmed (maximum feerate)
                chan.value_to_self_msat = 6993000000; // 7000000000 - 7000000
                chan.feerate_per_kw = 2194;

                test_commitment!("304402204bb3d6e279d71d9da414c82de42f1f954267c762b2e2eb8b76bc3be4ea07d4b0022014febc009c5edc8c3fc5d94015de163200f780046f1c293bfed8568f08b70fb3",
                                 "3044022072c2e2b1c899b2242656a537dde2892fa3801be0d6df0a87836c550137acde8302201654aa1974d37a829083c3ba15088689f30b56d6a4f6cb14c7bad0ee3116d398",
                                 "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", {

                                  { 0,
                                  "3045022100939726680351a7856c1bc386d4a1f422c7d29bd7b56afc139570f508474e6c40022023175a799ccf44c017fbaadb924c40b2a12115a5b7d0dfd3228df803a2de8450",
                                  "304502210099c98c2edeeee6ec0fb5f3bea8b79bb016a2717afa9b5072370f34382de281d302206f5e2980a995e045cf90a547f0752a7ee99d48547bc135258fe7bc07e0154301",
                                  "02000000000101153cd825fdb3aa624bfe513e8031d5d08c5e582fb3d1d1fe8faf27d3eed410cd0000000000000000000122020000000000002200204adb4e2f00643db396dd120d4e7dc17625f5f2c11a40d857accc862d6b7dd80e0500483045022100939726680351a7856c1bc386d4a1f422c7d29bd7b56afc139570f508474e6c40022023175a799ccf44c017fbaadb924c40b2a12115a5b7d0dfd3228df803a2de84500148304502210099c98c2edeeee6ec0fb5f3bea8b79bb016a2717afa9b5072370f34382de281d302206f5e2980a995e045cf90a547f0752a7ee99d48547bc135258fe7bc07e015430101008576a91414011f7254d96b819c76986c277d115efce6f7b58763ac67210394854aa6eab5b2a8122cc726e9dded053a2184d88256816826d6231c068d4a5b7c820120876475527c21030d417a46946384f88d5f3337267c5e579765875dc4daca813e21734b140639e752ae67a914b43e1b38138a41b37f7cd9a1d274bc63e3a9b5d188ac6868f6010000" },

                                  { 1,
                                  "3044022021bb883bf324553d085ba2e821cad80c28ef8b303dbead8f98e548783c02d1600220638f9ef2a9bba25869afc923f4b5dc38be3bb459f9efa5d869392d5f7779a4a0",
                                  "3045022100fd85bd7697b89c08ec12acc8ba89b23090637d83abd26ca37e01ae93e67c367302202b551fe69386116c47f984aab9c8dfd25d864dcde5d3389cfbef2447a85c4b77",
                                  "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" },

                                  { 2,
                                  "3045022100c9e6f0454aa598b905a35e641a70cc9f67b5f38cc4b00843a041238c4a9f1c4a0220260a2822a62da97e44583e837245995ca2e36781769c52f19e498efbdcca262b",
                                  "30450221008a9f2ea24cd455c2b64c1472a5fa83865b0a5f49a62b661801e884cf2849af8302204d44180e50bf6adfcf1c1e581d75af91aba4e28681ce4a5ee5f3cbf65eca10f3",
                                  "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" }
                } );

                // commitment tx with four outputs untrimmed (minimum feerate)
                chan.value_to_self_msat = 6993000000; // 7000000000 - 7000000
                chan.feerate_per_kw = 2195;

                test_commitment!("304402201a8c1b1f9671cd9e46c7323a104d7047cc48d3ee80d40d4512e0c72b8dc65666022066d7f9a2ce18c9eb22d2739ffcce05721c767f9b607622a31b6ea5793ddce403",
                                 "3044022044d592025b610c0d678f65032e87035cdfe89d1598c522cc32524ae8172417c30220749fef9d5b2ae8cdd91ece442ba8809bc891efedae2291e578475f97715d1767",
                                 "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", {

                                  { 0,
                                  "3045022100e57b845066a06ee7c2cbfc29eabffe52daa9bf6f6de760066d04df9f9b250e0002202ffb197f0e6e0a77a75a9aff27014bd3de83b7f748d7efef986abe655e1dd50e",
                                  "3045022100ecc8c6529d0b2316d046f0f0757c1e1c25a636db168ec4f3aa1b9278df685dc0022067ae6b65e936f1337091f7b18a15935b608c5f2cdddb2f892ed0babfdd376d76",
                                  "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" },

                                  { 1,
                                  "3045022100d193b7ecccad8057571620a0b1ffa6c48e9483311723b59cf536043b20bc51550220546d4bd37b3b101ecda14f6c907af46ec391abce1cd9c7ce22b1a62b534f2f2a",
                                  "3044022014d66f11f9cacf923807eba49542076c5fe5cccf252fb08fe98c78ef3ca6ab5402201b290dbe043cc512d9d78de074a5a129b8759bc6a6c546b190d120b690bd6e82",
                                  "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" }
                } );

                // commitment tx with four outputs untrimmed (maximum feerate)
                chan.value_to_self_msat = 6993000000; // 7000000000 - 7000000
                chan.feerate_per_kw = 3702;

                test_commitment!("304502210092a587aeb777f869e7ff0d7898ea619ee26a3dacd1f3672b945eea600be431100220077ee9eae3528d15251f2a52b607b189820e57a6ccfac8d1af502b132ee40169",
                                 "3045022100e5efb73c32d32da2d79702299b6317de6fb24a60476e3855926d78484dd1b3c802203557cb66a42c944ef06e00bcc4da35a5bcb2f185aab0f8e403e519e1d66aaf75",
                                 "02000000000101bef67e4e2fb9ddeeb3461973cd4c62abb35050b1add772995b820b584a488489000000000038b02b8004b80b000000000000220020c20b5d1f8584fd90443e7b7b720136174fa4b9333c261d04dbbd012635c0f419a00f0000000000002200208c48d15160397c9731df9bc3b236656efb6665fbfe92b4a6878e88a499f741c4c0c62d0000000000160014cc1b07838e387deacd0e5232e1e8b49f4c29e4846f916a00000000002200204adb4e2f00643db396dd120d4e7dc17625f5f2c11a40d857accc862d6b7dd80e0400483045022100e5efb73c32d32da2d79702299b6317de6fb24a60476e3855926d78484dd1b3c802203557cb66a42c944ef06e00bcc4da35a5bcb2f185aab0f8e403e519e1d66aaf750148304502210092a587aeb777f869e7ff0d7898ea619ee26a3dacd1f3672b945eea600be431100220077ee9eae3528d15251f2a52b607b189820e57a6ccfac8d1af502b132ee4016901475221023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb21030e9f7b623d2ccc7c9bd44d66d5ce21ce504c0acf6385a132cec6d3c39fa711c152ae3e195220", {

                                  { 0,
                                  "304402206fa54c11f98c3bae1e93df43fc7affeb05b476bf8060c03e29c377c69bc08e8b0220672701cce50d5c379ff45a5d2cfe48ac44973adb066ac32608e21221d869bb89",
                                  "304402206e36c683ebf2cb16bcef3d5439cf8b53cd97280a365ed8acd7abb85a8ba5f21c02206e8621edfc2a5766cbc96eb67fd501127ff163eb6b85518a39f7d4974aef126f",
                                  "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" },

                                  { 1,
                                  "3044022057649739b0eb74d541ead0dfdb3d4b2c15aa192720031044c3434c67812e5ca902201e5ede42d960ae551707f4a6b34b09393cf4dee2418507daa022e3550dbb5817",
                                  "304402207faad26678c8850e01b4a0696d60841f7305e1832b786110ee9075cb92ed14a30220516ef8ee5dfa80824ea28cbcec0dd95f8b847146257c16960db98507db15ffdc",
                                  "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" }
                } );

                // commitment tx with three outputs untrimmed (minimum feerate)
                chan.value_to_self_msat = 6993000000; // 7000000000 - 7000000
                chan.feerate_per_kw = 3703;

                test_commitment!("3045022100b495d239772a237ff2cf354b1b11be152fd852704cb184e7356d13f2fb1e5e430220723db5cdb9cbd6ead7bfd3deb419cf41053a932418cbb22a67b581f40bc1f13e",
                                 "304402201b736d1773a124c745586217a75bed5f66c05716fbe8c7db4fdb3c3069741cdd02205083f39c321c1bcadfc8d97e3c791a66273d936abac0c6a2fde2ed46019508e1",
                                 "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", {

                                  { 0,
                                  "3045022100c34c61735f93f2e324cc873c3b248111ccf8f6db15d5969583757010d4ad2b4602207867bb919b2ddd6387873e425345c9b7fd18d1d66aba41f3607bc2896ef3c30a",
                                  "3045022100988c143e2110067117d2321bdd4bd16ca1734c98b29290d129384af0962b634e02206c1b02478878c5f547018b833986578f90c3e9be669fe5788ad0072a55acbb05",
                                  "0200000000010120060e4a29579d429f0f27c17ee5f1ee282f20d706d6f90b63d35946d8f3029a0000000000000000000175050000000000002200204adb4e2f00643db396dd120d4e7dc17625f5f2c11a40d857accc862d6b7dd80e0500483045022100c34c61735f93f2e324cc873c3b248111ccf8f6db15d5969583757010d4ad2b4602207867bb919b2ddd6387873e425345c9b7fd18d1d66aba41f3607bc2896ef3c30a01483045022100988c143e2110067117d2321bdd4bd16ca1734c98b29290d129384af0962b634e02206c1b02478878c5f547018b833986578f90c3e9be669fe5788ad0072a55acbb05012004040404040404040404040404040404040404040404040404040404040404048a76a91414011f7254d96b819c76986c277d115efce6f7b58763ac67210394854aa6eab5b2a8122cc726e9dded053a2184d88256816826d6231c068d4a5b7c8201208763a91418bc1a114ccf9c052d3d23e28d3b0a9d1227434288527c21030d417a46946384f88d5f3337267c5e579765875dc4daca813e21734b140639e752ae677502f801b175ac686800000000" }
                } );

                // commitment tx with three outputs untrimmed (maximum feerate)
                chan.value_to_self_msat = 6993000000; // 7000000000 - 7000000
                chan.feerate_per_kw = 4914;

                test_commitment!("3045022100b4b16d5f8cc9fc4c1aff48831e832a0d8990e133978a66e302c133550954a44d022073573ce127e2200d316f6b612803a5c0c97b8d20e1e44dbe2ac0dd2fb8c95244",
                                 "3045022100d72638bc6308b88bb6d45861aae83e5b9ff6e10986546e13bce769c70036e2620220320be7c6d66d22f30b9fcd52af66531505b1310ca3b848c19285b38d8a1a8c19",
                                 "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", {

                                  { 0,
                                  "3045022100f43591c156038ba217756006bb3c55f7d113a325cdd7d9303c82115372858d68022016355b5aadf222bc8d12e426c75f4a03423917b2443a103eb2a498a3a2234374",
                                  "30440220585dee80fafa264beac535c3c0bb5838ac348b156fdc982f86adc08dfc9bfd250220130abb82f9f295cc9ef423dcfef772fde2acd85d9df48cc538981d26a10a9c10",
                                  "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" }
                } );

                // commitment tx with two outputs untrimmed (minimum feerate)
                chan.value_to_self_msat = 6993000000; // 7000000000 - 7000000
                chan.feerate_per_kw = 4915;

                test_commitment!("304402203a286936e74870ca1459c700c71202af0381910a6bfab687ef494ef1bc3e02c902202506c362d0e3bee15e802aa729bf378e051644648253513f1c085b264cc2a720",
                                 "30450221008a953551f4d67cb4df3037207fc082ddaf6be84d417b0bd14c80aab66f1b01a402207508796dc75034b2dee876fe01dc05a08b019f3e5d689ac8842ade2f1befccf5",
                                 "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", {});

                // commitment tx with two outputs untrimmed (maximum feerate)
                chan.value_to_self_msat = 6993000000; // 7000000000 - 7000000
                chan.feerate_per_kw = 9651180;

                test_commitment!("304402200a8544eba1d216f5c5e530597665fa9bec56943c0f66d98fc3d028df52d84f7002201e45fa5c6bc3a506cc2553e7d1c0043a9811313fc39c954692c0d47cfce2bbd3",
                                 "3045022100e11b638c05c650c2f63a421d36ef8756c5ce82f2184278643520311cdf50aa200220259565fb9c8e4a87ccaf17f27a3b9ca4f20625754a0920d9c6c239d8156a11de",
                                 "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", {});

                // commitment tx with one output untrimmed (minimum feerate)
                chan.value_to_self_msat = 6993000000; // 7000000000 - 7000000
                chan.feerate_per_kw = 9651181;

                test_commitment!("304402202ade0142008309eb376736575ad58d03e5b115499709c6db0b46e36ff394b492022037b63d78d66404d6504d4c4ac13be346f3d1802928a6d3ad95a6a944227161a2",
                                 "304402207e8d51e0c570a5868a78414f4e0cbfaed1106b171b9581542c30718ee4eb95ba02203af84194c97adf98898c9afe2f2ed4a7f8dba05a2dfab28ac9d9c604aa49a379",
                                 "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", {});

                // commitment tx with fee greater than funder amount
                chan.value_to_self_msat = 6993000000; // 7000000000 - 7000000
                chan.feerate_per_kw = 9651936;

                test_commitment!("304402202ade0142008309eb376736575ad58d03e5b115499709c6db0b46e36ff394b492022037b63d78d66404d6504d4c4ac13be346f3d1802928a6d3ad95a6a944227161a2",
                                 "304402207e8d51e0c570a5868a78414f4e0cbfaed1106b171b9581542c30718ee4eb95ba02203af84194c97adf98898c9afe2f2ed4a7f8dba05a2dfab28ac9d9c604aa49a379",
                                 "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", {});

                // commitment tx with 3 htlc outputs, 2 offered having the same amount and preimage
                chan.value_to_self_msat = 7_000_000_000 - 2_000_000;
                chan.feerate_per_kw = 253;
                chan.pending_inbound_htlcs.clear();
                chan.pending_inbound_htlcs.push({
                        let mut out = InboundHTLCOutput{
                                htlc_id: 1,
                                amount_msat: 2000000,
                                cltv_expiry: 501,
                                payment_hash: PaymentHash([0; 32]),
                                state: InboundHTLCState::Committed,
                        };
                        out.payment_hash.0 = Sha256::hash(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()).into_inner();
                        out
                });
                chan.pending_outbound_htlcs.clear();
                chan.pending_outbound_htlcs.push({
                        let mut out = OutboundHTLCOutput{
                                htlc_id: 6,
                                amount_msat: 5000000,
                                cltv_expiry: 506,
                                payment_hash: PaymentHash([0; 32]),
                                state: OutboundHTLCState::Committed,
                                source: HTLCSource::dummy(),
                        };
                        out.payment_hash.0 = Sha256::hash(&hex::decode("0505050505050505050505050505050505050505050505050505050505050505").unwrap()).into_inner();
                        out
                });
                chan.pending_outbound_htlcs.push({
                        let mut out = OutboundHTLCOutput{
                                htlc_id: 5,
                                amount_msat: 5000000,
                                cltv_expiry: 505,
                                payment_hash: PaymentHash([0; 32]),
                                state: OutboundHTLCState::Committed,
                                source: HTLCSource::dummy(),
                        };
                        out.payment_hash.0 = Sha256::hash(&hex::decode("0505050505050505050505050505050505050505050505050505050505050505").unwrap()).into_inner();
                        out
                });

                test_commitment!("30440220048705bec5288d28b3f29344b8d124853b1af423a568664d2c6f02c8ea886525022060f998a461052a2476b912db426ea2a06700953a241135c7957f2e79bc222df9",
                                 "3045022100c4f1d60b6fca9febc8b39de1a31e84c5f7c4b41c97239ef05f4350aa484c6b5e02200c5134ac8b20eb7a29d0dd4a501f6aa8fefb8489171f4cb408bd2a32324ab03f",
                                 "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", {

                                  { 0,
                                  "304502210081cbb94121761d34c189cd4e6a281feea6f585060ad0ba2632e8d6b3c6bb8a6c02201007981bbd16539d63df2805b5568f1f5688cd2a885d04706f50db9b77ba13c6",
                                  "304502210090ed76aeb21b53236a598968abc66e2024691d07b62f53ddbeca8f93144af9c602205f873af5a0c10e62690e9aba09740550f194a9dc455ba4c1c23f6cde7704674c",
                                  "0200000000010189a326e23addc28323dbadcb4e71c2c17088b6e8fa184103e552f44075dddc34000000000000000000011f070000000000002200204adb4e2f00643db396dd120d4e7dc17625f5f2c11a40d857accc862d6b7dd80e050048304502210081cbb94121761d34c189cd4e6a281feea6f585060ad0ba2632e8d6b3c6bb8a6c02201007981bbd16539d63df2805b5568f1f5688cd2a885d04706f50db9b77ba13c60148304502210090ed76aeb21b53236a598968abc66e2024691d07b62f53ddbeca8f93144af9c602205f873af5a0c10e62690e9aba09740550f194a9dc455ba4c1c23f6cde7704674c012001010101010101010101010101010101010101010101010101010101010101018a76a91414011f7254d96b819c76986c277d115efce6f7b58763ac67210394854aa6eab5b2a8122cc726e9dded053a2184d88256816826d6231c068d4a5b7c8201208763a9144b6b2e5444c2639cc0fb7bcea5afba3f3cdce23988527c21030d417a46946384f88d5f3337267c5e579765875dc4daca813e21734b140639e752ae677502f501b175ac686800000000" },
                                  { 1,
                                  "304402201d0f09d2bf7bc245a4f17980e1e9164290df16c70c6a2ff1592f5030d6108581022061e744a7dc151b36bf0aff7a4f1812ba90b8b03633bb979a270d19858fd960c5",
                                  "30450221009aef000d2e843a4202c1b1a2bf554abc9a7902bf49b2cb0759bc507456b7ebad02204e7c3d193ede2fd2b4cd6b39f51a920e581e35575e357e44d7b699c40ce61d39",
                                  "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" },
                                  { 2,
                                  "30440220010bf035d5823596e50dce2076a4d9f942d8d28031c9c428b901a02b6b8140de02203250e8e4a08bc5b4ecdca4d0eedf98223e02e3ac1c0206b3a7ffdb374aa21e5f",
                                  "30440220073de0067b88e425b3018b30366bfeda0ccb703118ccd3d02ead08c0f53511d002203fac50ac0e4cf8a3af0b4b1b12e801650591f748f8ddf1e089c160f10b69e511",
                                  "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" }
                } );
        }

        #[test]
        fn test_per_commitment_secret_gen() {
                // Test vectors from BOLT 3 Appendix D:

                let mut seed = [0; 32];
                seed[0..32].clone_from_slice(&hex::decode("0000000000000000000000000000000000000000000000000000000000000000").unwrap());
                assert_eq!(chan_utils::build_commitment_secret(&seed, 281474976710655),
                           hex::decode("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap()[..]);

                seed[0..32].clone_from_slice(&hex::decode("FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF").unwrap());
                assert_eq!(chan_utils::build_commitment_secret(&seed, 281474976710655),
                           hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap()[..]);

                assert_eq!(chan_utils::build_commitment_secret(&seed, 0xaaaaaaaaaaa),
                           hex::decode("56f4008fb007ca9acf0e15b054d5c9fd12ee06cea347914ddbaed70d1c13a528").unwrap()[..]);

                assert_eq!(chan_utils::build_commitment_secret(&seed, 0x555555555555),
                           hex::decode("9015daaeb06dba4ccc05b91b2f73bd54405f2be9f217fbacd3c5ac2e62327d31").unwrap()[..]);

                seed[0..32].clone_from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap());
                assert_eq!(chan_utils::build_commitment_secret(&seed, 1),
                           hex::decode("915c75942a26bb3a433a8ce2cb0427c29ec6c1775cfc78328b57f6ba7bfeaa9c").unwrap()[..]);
        }

        #[test]
        fn test_key_derivation() {
                // Test vectors from BOLT 3 Appendix E:
                let secp_ctx = Secp256k1::new();

                let base_secret = SecretKey::from_slice(&hex::decode("000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f").unwrap()[..]).unwrap();
                let per_commitment_secret = SecretKey::from_slice(&hex::decode("1f1e1d1c1b1a191817161514131211100f0e0d0c0b0a09080706050403020100").unwrap()[..]).unwrap();

                let base_point = PublicKey::from_secret_key(&secp_ctx, &base_secret);
                assert_eq!(base_point.serialize()[..], hex::decode("036d6caac248af96f6afa7f904f550253a0f3ef3f5aa2fe6838a95b216691468e2").unwrap()[..]);

                let per_commitment_point = PublicKey::from_secret_key(&secp_ctx, &per_commitment_secret);
                assert_eq!(per_commitment_point.serialize()[..], hex::decode("025f7117a78150fe2ef97db7cfc83bd57b2e2c0d0dd25eaf467a4a1c2a45ce1486").unwrap()[..]);

                assert_eq!(chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &base_point).unwrap().serialize()[..],
                                hex::decode("0235f2dbfaa89b57ec7b055afe29849ef7ddfeb1cefdb9ebdc43f5494984db29e5").unwrap()[..]);

                assert_eq!(chan_utils::derive_private_key(&secp_ctx, &per_commitment_point, &base_secret).unwrap(),
                                SecretKey::from_slice(&hex::decode("cbced912d3b21bf196a766651e436aff192362621ce317704ea2f75d87e7be0f").unwrap()[..]).unwrap());

                assert_eq!(chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &base_point).unwrap().serialize()[..],
                                hex::decode("02916e326636d19c33f13e8c0c3a03dd157f332f3e99c317c141dd865eb01f8ff0").unwrap()[..]);

                assert_eq!(chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_secret, &base_secret).unwrap(),
                                SecretKey::from_slice(&hex::decode("d09ffff62ddb2297ab000cc85bcb4283fdeb6aa052affbc9dddcf33b61078110").unwrap()[..]).unwrap());
        }
}