X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fln%2Fchannel.rs;h=dffde0be7918f4ebab5f44c6d9d873a8db4666b3;hb=refs%2Fheads%2F2021-10-no-payment-id-leaks;hp=1ae894f7fac86a036600b341ae92522830a7b8af;hpb=d2e6f2ac18159f4d9b3b1cbc30bebd03030f0304;p=rust-lightning

diff --git a/lightning/src/ln/channel.rs b/lightning/src/ln/channel.rs
index 1ae894f7..dffde0be 100644
--- a/lightning/src/ln/channel.rs
+++ b/lightning/src/ln/channel.rs
@@ -1,39 +1,52 @@
-use bitcoin::blockdata::block::BlockHeader;
+// 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::{TxIn, TxOut, Transaction, SigHashType};
-use bitcoin::blockdata::opcodes;
-use bitcoin::util::hash::BitcoinHash;
+use bitcoin::blockdata::transaction::{Transaction, SigHashType};
 use bitcoin::util::bip143;
 use bitcoin::consensus::encode;
 
-use bitcoin::hashes::{Hash, HashEngine};
+use bitcoin::hashes::Hash;
 use bitcoin::hashes::sha256::Hash as Sha256;
-use bitcoin::hash_types::{Txid, BlockHash, WPubkeyHash};
+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, InitFeatures};
 use ln::msgs;
 use ln::msgs::{DecodeError, OptionalField, DataLossProtect};
-use ln::channelmonitor::{ChannelMonitor, ChannelMonitorUpdate, ChannelMonitorUpdateStep, HTLC_FAIL_BACK_BUFFER};
-use ln::channelmanager::{PendingHTLCStatus, HTLCSource, HTLCFailReason, HTLCFailureMsg, PendingHTLCInfo, RAACommitmentOrder, PaymentPreimage, PaymentHash, BREAKDOWN_TIMEOUT, MAX_LOCAL_BREAKDOWN_TIMEOUT};
-use ln::chan_utils::{CounterpartyCommitmentSecrets, LocalCommitmentTransaction, TxCreationKeys, HTLCOutputInCommitment, HTLC_SUCCESS_TX_WEIGHT, HTLC_TIMEOUT_TX_WEIGHT, make_funding_redeemscript, ChannelPublicKeys, PreCalculatedTxCreationKeys};
+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::transaction::OutPoint;
-use chain::keysinterface::{ChannelKeys, KeysInterface};
-use util::transaction_utils;
-use util::ser::{Readable, Writeable, Writer};
+use chain::channelmonitor::{ChannelMonitor, ChannelMonitorUpdate, ChannelMonitorUpdateStep, HTLC_FAIL_BACK_BUFFER};
+use chain::transaction::{OutPoint, TransactionData};
+use chain::keysinterface::{Sign, KeysInterface};
+use util::ser::{Readable, ReadableArgs, Writeable, Writer, VecWriter};
 use util::logger::Logger;
 use util::errors::APIError;
 use util::config::{UserConfig,ChannelConfig};
-
-use std;
-use std::default::Default;
-use std::{cmp,mem,fmt};
-use std::ops::Deref;
+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)]
@@ -44,8 +57,23 @@ pub struct ChannelValueStat {
 	pub pending_outbound_htlcs_amount_msat: u64,
 	pub pending_inbound_htlcs_amount_msat: u64,
 	pub holding_cell_outbound_amount_msat: u64,
-	pub their_max_htlc_value_in_flight_msat: u64, // outgoing
-	pub their_dust_limit_msat: u64,
+	pub counterparty_max_htlc_value_in_flight_msat: u64, // outgoing
+	pub counterparty_dust_limit_msat: u64,
+}
+
+#[derive(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 {
@@ -85,6 +113,7 @@ enum InboundHTLCState {
 	/// 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).
@@ -101,9 +130,9 @@ enum InboundHTLCState {
 	/// 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::would_broadcast_at_height) 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_info will not include this HTLC.
+	/// 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),
 }
 
@@ -224,8 +253,6 @@ enum ChannelState {
 	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.
-	/// TODO: Investigate some kind of timeout mechanism by which point the remote end must provide
-	/// us their shutdown.
 	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.
@@ -234,52 +261,155 @@ enum ChannelState {
 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;
 
-const INITIAL_COMMITMENT_NUMBER: u64 = (1 << 48) - 1;
-
-/// Liveness is called to fluctuate given peer disconnecton/monitor failures/closing.
-/// If channel is public, network should have a liveness view announced by us on a
-/// best-effort, which means we may filter out some status transitions to avoid spam.
-/// See further timer_chan_freshness_every_min.
-#[derive(PartialEq)]
-enum UpdateStatus {
-	/// Status has been gossiped.
-	Fresh,
-	/// Status has been changed.
-	DisabledMarked,
-	/// Status has been marked to be gossiped at next flush
+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,
+}
+
+/// 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(fuzzing)]
+pub const FEE_SPIKE_BUFFER_FEE_INCREASE_MULTIPLE: u64 = 2;
+#[cfg(not(fuzzing))]
+const FEE_SPIKE_BUFFER_FEE_INCREASE_MULTIPLE: u64 = 2;
+
 // 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.
-pub(super) struct Channel<ChanSigner: ChannelKeys> {
+//
+// 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,
-	channel_outbound: bool,
 	secp_ctx: Secp256k1<secp256k1::All>,
 	channel_value_satoshis: u64,
 
 	latest_monitor_update_id: u64,
 
-	#[cfg(not(test))]
-	local_keys: ChanSigner,
-	#[cfg(test)]
-	pub(super) local_keys: ChanSigner,
-	shutdown_pubkey: PublicKey,
+	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_local_commitment_transaction_number: u64,
-	cur_remote_commitment_transaction_number: u64,
+	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>,
@@ -299,99 +429,139 @@ pub(super) struct Channel<ChanSigner: ChannelKeys> {
 	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
-	// For outbound channel, feerate_per_kw is updated with the value from
-	// pending_update_fee when revoke_and_ack is received
+	// pending_update_fee is filled when sending and receiving update_fee.
 	//
-	// For inbound channel, feerate_per_kw is updated when it receives
-	// commitment_signed and revoke_and_ack is generated
-	// The pending value is kept when another pair of update_fee and commitment_signed
-	// is received during AwaitingRemoteRevoke and relieved when the expected
-	// revoke_and_ack is received and new commitment_signed is generated to be
-	// sent to the funder. Otherwise, the pending value is removed when receiving
-	// commitment_signed.
-	pending_update_fee: Option<u32>,
-	// update_fee() during ChannelState::AwaitingRemoteRevoke is hold in
-	// holdina_cell_update_fee then moved to pending_udpate_fee when revoke_and_ack
-	// is received. holding_cell_update_fee is updated when there are additional
-	// update_fee() during ChannelState::AwaitingRemoteRevoke.
+	// 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_local_htlc_id: u64,
-	next_remote_htlc_id: u64,
+	next_holder_htlc_id: u64,
+	next_counterparty_htlc_id: u64,
 	update_time_counter: u32,
 	feerate_per_kw: u32,
 
 	#[cfg(debug_assertions)]
 	/// Max to_local and to_remote outputs in a locally-generated commitment transaction
-	max_commitment_tx_output_local: ::std::sync::Mutex<(u64, u64)>,
+	holder_max_commitment_tx_output: Mutex<(u64, u64)>,
 	#[cfg(debug_assertions)]
 	/// Max to_local and to_remote outputs in a remote-generated commitment transaction
-	max_commitment_tx_output_remote: ::std::sync::Mutex<(u64, u64)>,
+	counterparty_max_commitment_tx_output: Mutex<(u64, u64)>,
 
-	last_sent_closing_fee: Option<(u32, u64, Signature)>, // (feerate, fee, our_sig)
+	last_sent_closing_fee: Option<(u64, Signature)>, // (fee, holder_sig)
+	target_closing_feerate_sats_per_kw: Option<u32>,
 
-	funding_txo: Option<OutPoint>,
+	/// 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 reached our CONF_TARGET. We use this
-	/// to detect unconfirmation after a serialize-unserialize roundtrip where we may not see a full
-	/// series of block_connected/block_disconnected calls. Obviously this is not a guarantee as we
-	/// could miss the funding_tx_confirmed_in block as well, but it serves as a useful fallback.
+	/// 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>,
-	/// Used to deduplicate block_connected callbacks, also used to verify consistency during
-	/// ChannelManager deserialization (hence pub(super))
-	pub(super) last_block_connected: BlockHash,
-	funding_tx_confirmations: u64,
 
-	their_dust_limit_satoshis: u64,
+	counterparty_dust_limit_satoshis: u64,
 	#[cfg(test)]
-	pub(super) our_dust_limit_satoshis: u64,
+	pub(super) holder_dust_limit_satoshis: u64,
 	#[cfg(not(test))]
-	our_dust_limit_satoshis: u64,
+	holder_dust_limit_satoshis: u64,
 	#[cfg(test)]
-	pub(super) their_max_htlc_value_in_flight_msat: u64,
+	pub(super) counterparty_max_htlc_value_in_flight_msat: u64,
 	#[cfg(not(test))]
-	their_max_htlc_value_in_flight_msat: u64,
-	//get_our_max_htlc_value_in_flight_msat(): u64,
+	counterparty_max_htlc_value_in_flight_msat: u64,
+	//get_holder_max_htlc_value_in_flight_msat(): u64,
 	/// minimum channel reserve for self to maintain - set by them.
-	local_channel_reserve_satoshis: u64,
-	// get_remote_channel_reserve_satoshis(channel_value_sats: u64): u64
-	their_htlc_minimum_msat: u64,
-	our_htlc_minimum_msat: u64,
-	their_to_self_delay: u16,
-	our_to_self_delay: u16,
+	counterparty_selected_channel_reserve_satoshis: Option<u64>,
+	// get_holder_selected_channel_reserve_satoshis(channel_value_sats: u64): u64
+	counterparty_htlc_minimum_msat: u64,
+	holder_htlc_minimum_msat: u64,
 	#[cfg(test)]
-	pub their_max_accepted_htlcs: u16,
+	pub counterparty_max_accepted_htlcs: u16,
 	#[cfg(not(test))]
-	their_max_accepted_htlcs: u16,
-	//implied by OUR_MAX_HTLCS: our_max_accepted_htlcs: u16,
-	minimum_depth: u32,
+	counterparty_max_accepted_htlcs: u16,
+	//implied by OUR_MAX_HTLCS: max_accepted_htlcs: u16,
+	minimum_depth: Option<u32>,
 
-	their_pubkeys: Option<ChannelPublicKeys>,
+	counterparty_forwarding_info: Option<CounterpartyForwardingInfo>,
 
-	their_cur_commitment_point: Option<PublicKey>,
+	pub(crate) channel_transaction_parameters: ChannelTransactionParameters,
+	funding_transaction: Option<Transaction>,
 
-	their_prev_commitment_point: Option<PublicKey>,
-	their_node_id: PublicKey,
+	counterparty_cur_commitment_point: Option<PublicKey>,
+	counterparty_prev_commitment_point: Option<PublicKey>,
+	counterparty_node_id: PublicKey,
 
-	their_shutdown_scriptpubkey: Option<Script>,
+	counterparty_shutdown_scriptpubkey: Option<Script>,
 
-	/// Used exclusively to broadcast the latest local state, mostly a historical quirk that this
-	/// is here:
-	channel_monitor: Option<ChannelMonitor<ChanSigner>>,
 	commitment_secrets: CounterpartyCommitmentSecrets,
 
-	network_sync: UpdateStatus,
+	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>,
+}
+
+#[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
-/// Confirmation count threshold at which we close a channel. Ideally we'd keep the channel around
-/// on ice until the funding transaction gets more confirmations, but the LN protocol doesn't
-/// really allow for this, so instead we're stuck closing it out at that point.
-const UNCONF_THRESHOLD: u32 = 6;
-const SPENDING_INPUT_FOR_A_OUTPUT_WEIGHT: u64 = 79; // prevout: 36, nSequence: 4, script len: 1, witness lengths: (3+1)/4, sig: 73/4, if-selector: 1, redeemScript: (6 ops + 2*33 pubkeys + 1*2 delay)/4
-const B_OUTPUT_PLUS_SPENDING_INPUT_WEIGHT: u64 = 104; // prevout: 40, nSequence: 4, script len: 1, witness lengths: 3/4, sig: 73/4, pubkey: 33/4, output: 31 (TODO: Wrong? Useless?)
 
 #[cfg(not(test))]
 const COMMITMENT_TX_BASE_WEIGHT: u64 = 724;
@@ -402,15 +572,37 @@ const COMMITMENT_TX_WEIGHT_PER_HTLC: u64 = 172;
 #[cfg(test)]
 pub const COMMITMENT_TX_WEIGHT_PER_HTLC: u64 = 172;
 
-/// Maximmum `funding_satoshis` value, according to the BOLT #2 specification
+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),
 }
@@ -419,6 +611,7 @@ 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)
 		}
@@ -434,9 +627,9 @@ macro_rules! secp_check {
 	};
 }
 
-impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
+impl<Signer: Sign> Channel<Signer> {
 	// Convert constants + channel value to limits:
-	fn get_our_max_htlc_value_in_flight_msat(channel_value_satoshis: u64) -> u64 {
+	fn get_holder_max_htlc_value_in_flight_msat(channel_value_satoshis: u64) -> u64 {
 		channel_value_satoshis * 1000 / 10 //TODO
 	}
 
@@ -444,22 +637,19 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 	/// required by us.
 	///
 	/// Guaranteed to return a value no larger than channel_value_satoshis
-	pub(crate) fn get_remote_channel_reserve_satoshis(channel_value_satoshis: u64) -> u64 {
+	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
 	}
 
-	fn derive_our_dust_limit_satoshis(at_open_background_feerate: u32) -> u64 {
-		cmp::max(at_open_background_feerate as u64 * B_OUTPUT_PLUS_SPENDING_INPUT_WEIGHT / 1000, 546) //TODO
-	}
-
 	// Constructors:
-	pub fn new_outbound<K: Deref, F: Deref>(fee_estimator: &F, keys_provider: &K, their_node_id: PublicKey, channel_value_satoshis: u64, push_msat: u64, user_id: u64, config: &UserConfig) -> Result<Channel<ChanSigner>, APIError>
-	where K::Target: KeysInterface<ChanKeySigner = ChanSigner>,
+	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) -> Result<Channel<Signer>, APIError>
+	where K::Target: KeysInterface<Signer = Signer>,
 	      F::Target: FeeEstimator,
 	{
-		let our_to_self_delay = config.own_channel_config.our_to_self_delay;
-		let chan_keys = keys_provider.get_channel_keys(false, channel_value_satoshis);
+		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)});
@@ -468,34 +658,46 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		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 our_to_self_delay < BREAKDOWN_TIMEOUT {
-			return Err(APIError::APIMisuseError {err: format!("Configured with an unreasonable our_to_self_delay ({}) putting user funds at risks", our_to_self_delay)});
+		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 background_feerate = fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Background);
-		if Channel::<ChanSigner>::get_remote_channel_reserve_satoshis(channel_value_satoshis) < Channel::<ChanSigner>::derive_our_dust_limit_satoshis(background_feerate) {
-			return Err(APIError::FeeRateTooHigh{err: format!("Not enough reserve above dust limit can be found at current fee rate({})", background_feerate), feerate: background_feerate});
+		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 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: user_id,
+			user_id,
 			config: config.channel_options.clone(),
 
-			channel_id: keys_provider.get_channel_id(),
+			channel_id: keys_provider.get_secure_random_bytes(),
 			channel_state: ChannelState::OurInitSent as u32,
-			channel_outbound: true,
-			secp_ctx: Secp256k1::new(),
-			channel_value_satoshis: channel_value_satoshis,
+			secp_ctx,
+			channel_value_satoshis,
 
 			latest_monitor_update_id: 0,
 
-			local_keys: chan_keys,
-			shutdown_pubkey: keys_provider.get_shutdown_pubkey(),
+			holder_signer,
+			shutdown_scriptpubkey,
 			destination_script: keys_provider.get_destination_script(),
 
-			cur_local_commitment_transaction_number: INITIAL_COMMITMENT_NUMBER,
-			cur_remote_commitment_transaction_number: INITIAL_COMMITMENT_NUMBER,
+			cur_holder_commitment_transaction_number: INITIAL_COMMITMENT_NUMBER,
+			cur_counterparty_commitment_transaction_number: INITIAL_COMMITMENT_NUMBER,
 			value_to_self_msat: channel_value_satoshis * 1000 - push_msat,
 
 			pending_inbound_htlcs: Vec::new(),
@@ -503,8 +705,8 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 			holding_cell_htlc_updates: Vec::new(),
 			pending_update_fee: None,
 			holding_cell_update_fee: None,
-			next_local_htlc_id: 0,
-			next_remote_htlc_id: 0,
+			next_holder_htlc_id: 0,
+			next_counterparty_htlc_id: 0,
 			update_time_counter: 1,
 
 			resend_order: RAACommitmentOrder::CommitmentFirst,
@@ -514,44 +716,65 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 			monitor_pending_commitment_signed: false,
 			monitor_pending_forwards: Vec::new(),
 			monitor_pending_failures: Vec::new(),
+			monitor_pending_finalized_fulfills: Vec::new(),
 
 			#[cfg(debug_assertions)]
-			max_commitment_tx_output_local: ::std::sync::Mutex::new((channel_value_satoshis * 1000 - push_msat, push_msat)),
+			holder_max_commitment_tx_output: Mutex::new((channel_value_satoshis * 1000 - push_msat, push_msat)),
 			#[cfg(debug_assertions)]
-			max_commitment_tx_output_remote: ::std::sync::Mutex::new((channel_value_satoshis * 1000 - push_msat, push_msat)),
+			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_txo: None,
 			funding_tx_confirmed_in: None,
+			funding_tx_confirmation_height: 0,
 			short_channel_id: None,
-			last_block_connected: Default::default(),
-			funding_tx_confirmations: 0,
 
 			feerate_per_kw: feerate,
-			their_dust_limit_satoshis: 0,
-			our_dust_limit_satoshis: Channel::<ChanSigner>::derive_our_dust_limit_satoshis(background_feerate),
-			their_max_htlc_value_in_flight_msat: 0,
-			local_channel_reserve_satoshis: 0,
-			their_htlc_minimum_msat: 0,
-			our_htlc_minimum_msat: if config.own_channel_config.our_htlc_minimum_msat == 0 { 1 } else { config.own_channel_config.our_htlc_minimum_msat },
-			their_to_self_delay: 0,
-			our_to_self_delay,
-			their_max_accepted_htlcs: 0,
-			minimum_depth: 0, // Filled in in accept_channel
-
-			their_pubkeys: None,
-			their_cur_commitment_point: None,
-
-			their_prev_commitment_point: None,
-			their_node_id: their_node_id,
-
-			their_shutdown_scriptpubkey: None,
-
-			channel_monitor: None,
+			counterparty_dust_limit_satoshis: 0,
+			holder_dust_limit_satoshis: MIN_CHAN_DUST_LIMIT_SATOSHIS,
+			counterparty_max_htlc_value_in_flight_msat: 0,
+			counterparty_selected_channel_reserve_satoshis: None, // Filled in in accept_channel
+			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
+			},
+			funding_transaction: None,
+
+			counterparty_cur_commitment_point: None,
+			counterparty_prev_commitment_point: None,
+			counterparty_node_id,
+
+			counterparty_shutdown_scriptpubkey: None,
+
 			commitment_secrets: CounterpartyCommitmentSecrets::new(),
 
-			network_sync: UpdateStatus::Fresh,
+			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(),
 		})
 	}
 
@@ -562,7 +785,12 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		if feerate_per_kw < lower_limit {
 			return Err(ChannelError::Close(format!("Peer's feerate much too low. Actual: {}. Our expected lower limit: {}", feerate_per_kw, lower_limit)));
 		}
-		let upper_limit = fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority) as u64  * 2;
+		// 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)));
 		}
@@ -571,19 +799,19 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 
 	/// 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>(fee_estimator: &F, keys_provider: &K, their_node_id: PublicKey, their_features: InitFeatures, msg: &msgs::OpenChannel, user_id: u64, config: &UserConfig) -> Result<Channel<ChanSigner>, ChannelError>
-		where K::Target: KeysInterface<ChanKeySigner = ChanSigner>,
+	pub fn new_from_req<K: Deref, F: Deref>(fee_estimator: &F, keys_provider: &K, counterparty_node_id: PublicKey, their_features: &InitFeatures, msg: &msgs::OpenChannel, user_id: u64, config: &UserConfig) -> Result<Channel<Signer>, ChannelError>
+		where K::Target: KeysInterface<Signer = Signer>,
           F::Target: FeeEstimator
 	{
-		let mut chan_keys = keys_provider.get_channel_keys(true, msg.funding_satoshis);
-		let their_pubkeys = ChannelPublicKeys {
+		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
 		};
-		chan_keys.on_accept(&their_pubkeys, msg.to_self_delay, config.own_channel_config.our_to_self_delay);
 		let mut local_config = (*config).channel_options.clone();
 
 		if config.own_channel_config.our_to_self_delay < BREAKDOWN_TIMEOUT {
@@ -611,17 +839,17 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		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::<ChanSigner>::check_remote_fee(fee_estimator, msg.feerate_per_kw)?;
+		Channel::<Signer>::check_remote_fee(fee_estimator, msg.feerate_per_kw)?;
 
-		let max_to_self_delay = u16::min(config.peer_channel_config_limits.their_to_self_delay, MAX_LOCAL_BREAKDOWN_TIMEOUT);
-		if msg.to_self_delay > max_to_self_delay {
-			return Err(ChannelError::Close(format!("They wanted our payments to be delayed by a needlessly long period. Upper limit: {}. Actual: {}", max_to_self_delay, msg.to_self_delay)));
+		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 > 483 {
-			return Err(ChannelError::Close(format!("max_accepted_htlcs was {}. It must not be larger than 483", msg.max_accepted_htlcs)));
+		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...
@@ -640,36 +868,35 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		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 < config.peer_channel_config_limits.min_dust_limit_satoshis {
-			return Err(ChannelError::Close(format!("dust_limit_satoshis ({}) is less than the user specified limit ({})", msg.dust_limit_satoshis, config.peer_channel_config_limits.min_dust_limit_satoshis)));
+		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 > config.peer_channel_config_limits.max_dust_limit_satoshis {
-			return Err(ChannelError::Close(format!("dust_limit_satoshis ({}) is greater than the user specified limit ({})", msg.dust_limit_satoshis, config.peer_channel_config_limits.max_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 their_announce = if (msg.channel_flags & 1) == 1 { true } else { false };
+		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 != their_announce {
+			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 = their_announce;
+		local_config.announced_channel = announce;
 
 		let background_feerate = fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Background);
 
-		let our_dust_limit_satoshis = Channel::<ChanSigner>::derive_our_dust_limit_satoshis(background_feerate);
-		let remote_channel_reserve_satoshis = Channel::<ChanSigner>::get_remote_channel_reserve_satoshis(msg.funding_satoshis);
-		if remote_channel_reserve_satoshis < our_dust_limit_satoshis {
-			return Err(ChannelError::Close(format!("Suitable channel reserve not found. remote_channel_reserve was ({}). our_dust_limit_satoshis is ({}).", remote_channel_reserve_satoshis, our_dust_limit_satoshis)));
+		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 < our_dust_limit_satoshis {
-			return Err(ChannelError::Close(format!("channel_reserve_satoshis ({}) is smaller than our dust limit ({})", msg.channel_reserve_satoshis, our_dust_limit_satoshis)));
+		if msg.channel_reserve_satoshis < MIN_CHAN_DUST_LIMIT_SATOSHIS {
+			return Err(ChannelError::Close(format!("channel_reserve_satoshis ({}) is smaller than our dust limit ({})", msg.channel_reserve_satoshis, MIN_CHAN_DUST_LIMIT_SATOSHIS)));
 		}
-		if remote_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, remote_channel_reserve_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
@@ -682,22 +909,21 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 
 		let to_local_msat = msg.push_msat;
 		let to_remote_msat = funders_amount_msat - background_feerate as u64 * COMMITMENT_TX_BASE_WEIGHT;
-		if to_local_msat <= msg.channel_reserve_satoshis * 1000 && to_remote_msat <= remote_channel_reserve_satoshis * 1000 {
+		if to_local_msat <= msg.channel_reserve_satoshis * 1000 && to_remote_msat <= holder_selected_channel_reserve_satoshis * 1000 {
 			return Err(ChannelError::Close("Insufficient funding amount for initial commitment".to_owned()));
 		}
 
-		let their_shutdown_scriptpubkey = if their_features.supports_upfront_shutdown_script() {
+		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 provided a non-accepted scriptpubkey format. We enforce it while receiving shutdown msg
-					if script.is_p2pkh() || script.is_p2sh() || script.is_v0_p2wsh() || script.is_v0_p2wpkh() {
-						Some(script.clone())
 					// Peer is signaling upfront_shutdown and has opt-out with a 0-length script. We don't enforce anything
-					} else if script.len() == 0 {
+					if script.len() == 0 {
 						None
-					// Peer is signaling upfront_shutdown and has provided a non-accepted scriptpubkey format. Fail the channel
 					} else {
-						return Err(ChannelError::Close(format!("Peer is signaling upfront_shutdown but has provided a non-accepted scriptpubkey format. script: ({})", script.to_bytes().to_hex())));
+						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
@@ -707,23 +933,35 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 			}
 		} 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: user_id,
+			user_id,
 			config: local_config,
 
 			channel_id: msg.temporary_channel_id,
 			channel_state: (ChannelState::OurInitSent as u32) | (ChannelState::TheirInitSent as u32),
-			channel_outbound: false,
-			secp_ctx: Secp256k1::new(),
+			secp_ctx,
 
 			latest_monitor_update_id: 0,
 
-			local_keys: chan_keys,
-			shutdown_pubkey: keys_provider.get_shutdown_pubkey(),
+			holder_signer,
+			shutdown_scriptpubkey,
 			destination_script: keys_provider.get_destination_script(),
 
-			cur_local_commitment_transaction_number: INITIAL_COMMITMENT_NUMBER,
-			cur_remote_commitment_transaction_number: INITIAL_COMMITMENT_NUMBER,
+			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(),
@@ -731,8 +969,8 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 			holding_cell_htlc_updates: Vec::new(),
 			pending_update_fee: None,
 			holding_cell_update_fee: None,
-			next_local_htlc_id: 0,
-			next_remote_htlc_id: 0,
+			next_holder_htlc_id: 0,
+			next_counterparty_htlc_id: 0,
 			update_time_counter: 1,
 
 			resend_order: RAACommitmentOrder::CommitmentFirst,
@@ -742,71 +980,72 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 			monitor_pending_commitment_signed: false,
 			monitor_pending_forwards: Vec::new(),
 			monitor_pending_failures: Vec::new(),
+			monitor_pending_finalized_fulfills: Vec::new(),
 
 			#[cfg(debug_assertions)]
-			max_commitment_tx_output_local: ::std::sync::Mutex::new((msg.push_msat, msg.funding_satoshis * 1000 - msg.push_msat)),
+			holder_max_commitment_tx_output: Mutex::new((msg.push_msat, msg.funding_satoshis * 1000 - msg.push_msat)),
 			#[cfg(debug_assertions)]
-			max_commitment_tx_output_remote: ::std::sync::Mutex::new((msg.push_msat, msg.funding_satoshis * 1000 - msg.push_msat)),
+			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_txo: None,
 			funding_tx_confirmed_in: None,
+			funding_tx_confirmation_height: 0,
 			short_channel_id: None,
-			last_block_connected: Default::default(),
-			funding_tx_confirmations: 0,
 
 			feerate_per_kw: msg.feerate_per_kw,
 			channel_value_satoshis: msg.funding_satoshis,
-			their_dust_limit_satoshis: msg.dust_limit_satoshis,
-			our_dust_limit_satoshis: our_dust_limit_satoshis,
-			their_max_htlc_value_in_flight_msat: cmp::min(msg.max_htlc_value_in_flight_msat, msg.funding_satoshis * 1000),
-			local_channel_reserve_satoshis: msg.channel_reserve_satoshis,
-			their_htlc_minimum_msat: msg.htlc_minimum_msat,
-			our_htlc_minimum_msat: if config.own_channel_config.our_htlc_minimum_msat == 0 { 1 } else { config.own_channel_config.our_htlc_minimum_msat },
-			their_to_self_delay: msg.to_self_delay,
-			our_to_self_delay: config.own_channel_config.our_to_self_delay,
-			their_max_accepted_htlcs: msg.max_accepted_htlcs,
-			minimum_depth: config.own_channel_config.minimum_depth,
-
-			their_pubkeys: Some(their_pubkeys),
-			their_cur_commitment_point: Some(msg.first_per_commitment_point),
-
-			their_prev_commitment_point: None,
-			their_node_id: their_node_id,
-
-			their_shutdown_scriptpubkey,
-
-			channel_monitor: None,
+			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),
+			counterparty_selected_channel_reserve_satoshis: Some(msg.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
+			},
+			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(),
 
-			network_sync: UpdateStatus::Fresh,
-		};
+			channel_update_status: ChannelUpdateStatus::Enabled,
+			closing_signed_in_flight: false,
 
-		Ok(chan)
-	}
+			announcement_sigs: None,
 
-	// Utilities to build transactions:
+			#[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),
 
-	fn get_commitment_transaction_number_obscure_factor(&self) -> u64 {
-		let mut sha = Sha256::engine();
+			workaround_lnd_bug_4006: None,
 
-		let their_payment_point = &self.their_pubkeys.as_ref().unwrap().payment_point.serialize();
-		if self.channel_outbound {
-			sha.input(&self.local_keys.pubkeys().payment_point.serialize());
-			sha.input(their_payment_point);
-		} else {
-			sha.input(their_payment_point);
-			sha.input(&self.local_keys.pubkeys().payment_point.serialize());
-		}
-		let res = Sha256::from_engine(sha).into_inner();
+			#[cfg(any(test, feature = "fuzztarget"))]
+			historical_inbound_htlc_fulfills: HashSet::new(),
+		};
 
-		((res[26] as u64) << 5*8) |
-		((res[27] as u64) << 4*8) |
-		((res[28] as u64) << 3*8) |
-		((res[29] as u64) << 2*8) |
-		((res[30] as u64) << 1*8) |
-		((res[31] as u64) << 0*8)
+		Ok(chan)
 	}
 
 	/// Transaction nomenclature is somewhat confusing here as there are many different cases - a
@@ -822,34 +1061,38 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 	/// 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.
-	/// Returns (the transaction built, the number of HTLC outputs which were present in the
+	/// Returns (the transaction info, the number of HTLC outputs which were present in the
 	/// transaction, the list of HTLCs which were not ignored when building the transaction).
-	/// Note that below-dust HTLCs are included in the third return value, but not the second, and
-	/// sources are provided only for outbound HTLCs in the third return value.
+	/// Note that below-dust HTLCs are included in the fourth return value, but not the third, and
+	/// sources are provided only for outbound HTLCs in the fourth return value.
 	#[inline]
-	fn build_commitment_transaction<L: Deref>(&self, commitment_number: u64, keys: &TxCreationKeys, local: bool, generated_by_local: bool, feerate_per_kw: u32, logger: &L) -> (Transaction, usize, Vec<(HTLCOutputInCommitment, Option<&HTLCSource>)>) where L::Target: Logger {
-		let obscured_commitment_transaction_number = self.get_commitment_transaction_number_obscure_factor() ^ (INITIAL_COMMITMENT_NUMBER - commitment_number);
-
-		let txins = {
-			let mut ins: Vec<TxIn> = Vec::new();
-			ins.push(TxIn {
-				previous_output: self.funding_txo.unwrap().into_bitcoin_outpoint(),
-				script_sig: Script::new(),
-				sequence: ((0x80 as u32) << 8*3) | ((obscured_commitment_transaction_number >> 3*8) as u32),
-				witness: Vec::new(),
-			});
-			ins
-		};
-
-		let mut txouts: Vec<(TxOut, Option<(HTLCOutputInCommitment, Option<&HTLCSource>)>)> = Vec::with_capacity(self.pending_inbound_htlcs.len() + self.pending_outbound_htlcs.len() + 2);
+	fn build_commitment_transaction<L: Deref>(&self, commitment_number: u64, keys: &TxCreationKeys, local: bool, generated_by_local: bool, logger: &L) -> (CommitmentTransaction, u32, usize, Vec<(HTLCOutputInCommitment, Option<&HTLCSource>)>) 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 dust_limit_satoshis = if local { self.our_dust_limit_satoshis } else { self.their_dust_limit_satoshis };
+		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;
 
-		log_trace!(logger, "Building commitment transaction number {} (really {} xor {}) for {}, generated by {} with fee {}...", commitment_number, (INITIAL_COMMITMENT_NUMBER - commitment_number), self.get_commitment_transaction_number_obscure_factor(), if local { "us" } else { "remote" }, if generated_by_local { "us" } else { "remote" }, feerate_per_kw);
+		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, $offered: expr) => {
@@ -867,24 +1110,18 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 			($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 >= dust_limit_satoshis + (feerate_per_kw as u64 * HTLC_TIMEOUT_TX_WEIGHT / 1000) {
+					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);
-						txouts.push((TxOut {
-							script_pubkey: chan_utils::get_htlc_redeemscript(&htlc_in_tx, &keys).to_v0_p2wsh(),
-							value: $htlc.amount_msat / 1000
-						}, Some((htlc_in_tx, $source))));
+						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 >= dust_limit_satoshis + (feerate_per_kw as u64 * HTLC_SUCCESS_TX_WEIGHT / 1000) {
+					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);
-						txouts.push((TxOut { // "received HTLC output"
-							script_pubkey: chan_utils::get_htlc_redeemscript(&htlc_in_tx, &keys).to_v0_p2wsh(),
-							value: $htlc.amount_msat / 1000
-						}, Some((htlc_in_tx, $source))));
+						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));
@@ -961,168 +1198,155 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		{
 			// 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 max_commitment_tx_output = if generated_by_local {
-				self.max_commitment_tx_output_local.lock().unwrap()
+			let mut broadcaster_max_commitment_tx_output = if generated_by_local {
+				self.holder_max_commitment_tx_output.lock().unwrap()
 			} else {
-				self.max_commitment_tx_output_remote.lock().unwrap()
+				self.counterparty_max_commitment_tx_output.lock().unwrap()
 			};
-			debug_assert!(max_commitment_tx_output.0 <= value_to_self_msat as u64 || value_to_self_msat / 1000 >= self.local_channel_reserve_satoshis as i64);
-			max_commitment_tx_output.0 = cmp::max(max_commitment_tx_output.0, value_to_self_msat as u64);
-			debug_assert!(max_commitment_tx_output.1 <= value_to_remote_msat as u64 || value_to_remote_msat / 1000 >= Channel::<ChanSigner>::get_remote_channel_reserve_satoshis(self.channel_value_satoshis) as i64);
-			max_commitment_tx_output.1 = cmp::max(max_commitment_tx_output.1, value_to_remote_msat as u64);
+			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 >= Channel::<Signer>::get_holder_selected_channel_reserve_satoshis(self.channel_value_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 = feerate_per_kw as u64 * (COMMITMENT_TX_BASE_WEIGHT + (txouts.len() as u64) * COMMITMENT_TX_WEIGHT_PER_HTLC) / 1000;
-		let (value_to_self, value_to_remote) = if self.channel_outbound {
+		let total_fee = feerate_per_kw as u64 * (COMMITMENT_TX_BASE_WEIGHT + (included_non_dust_htlcs.len() as u64) * COMMITMENT_TX_WEIGHT_PER_HTLC) / 1000;
+		let (value_to_self, value_to_remote) = if self.is_outbound() {
 			(value_to_self_msat / 1000 - total_fee as i64, value_to_remote_msat / 1000)
 		} else {
 			(value_to_self_msat / 1000, value_to_remote_msat / 1000 - total_fee as i64)
 		};
 
-		let value_to_a = if local { value_to_self } else { value_to_remote };
-		let value_to_b = if local { value_to_remote } else { value_to_self };
+		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 >= (dust_limit_satoshis as i64) {
+		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);
-			txouts.push((TxOut {
-				script_pubkey: chan_utils::get_revokeable_redeemscript(&keys.revocation_key,
-				                                                       if local { self.their_to_self_delay } else { self.our_to_self_delay },
-				                                                       &keys.a_delayed_payment_key).to_v0_p2wsh(),
-				value: value_to_a as u64
-			}, None));
+		} else {
+			value_to_a = 0;
 		}
 
-		if value_to_b >= (dust_limit_satoshis as i64) {
+		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);
-			let static_payment_pk = if local {
-				self.their_pubkeys.as_ref().unwrap().payment_point
-			} else {
-				self.local_keys.pubkeys().payment_point
-			}.serialize();
-			txouts.push((TxOut {
-				script_pubkey: Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0)
-				                             .push_slice(&WPubkeyHash::hash(&static_payment_pk)[..])
-				                             .into_script(),
-				value: value_to_b as u64
-			}, None));
-		}
-
-		transaction_utils::sort_outputs(&mut txouts, |a, b| {
-			if let &Some(ref a_htlc) = a {
-				if let &Some(ref b_htlc) = b {
-					a_htlc.0.cltv_expiry.cmp(&b_htlc.0.cltv_expiry)
-						// Note that due to hash collisions, we have to have a fallback comparison
-						// here for fuzztarget mode (otherwise at least chanmon_fail_consistency
-						// may fail)!
-						.then(a_htlc.0.payment_hash.0.cmp(&b_htlc.0.payment_hash.0))
-				// For non-HTLC outputs, if they're copying our SPK we don't really care if we
-				// close the channel due to mismatches - they're doing something dumb:
-				} else { cmp::Ordering::Equal }
-			} else { cmp::Ordering::Equal }
-		});
-
-		let mut outputs: Vec<TxOut> = Vec::with_capacity(txouts.len());
-		let mut htlcs_included: Vec<(HTLCOutputInCommitment, Option<&HTLCSource>)> = Vec::with_capacity(txouts.len() + included_dust_htlcs.len());
-		for (idx, mut out) in txouts.drain(..).enumerate() {
-			outputs.push(out.0);
-			if let Some((mut htlc, source_option)) = out.1.take() {
-				htlc.transaction_output_index = Some(idx as u32);
-				htlcs_included.push((htlc, source_option));
-			}
-		}
-		let non_dust_htlc_count = htlcs_included.len();
+		} 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,
+		                                                             false,
+		                                                             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);
 
-		(Transaction {
-			version: 2,
-			lock_time: ((0x20 as u32) << 8*3) | ((obscured_commitment_transaction_number & 0xffffffu64) as u32),
-			input: txins,
-			output: outputs,
-		}, non_dust_htlc_count, htlcs_included)
+		(tx, feerate_per_kw, num_nondust_htlcs, htlcs_included)
 	}
 
 	#[inline]
 	fn get_closing_scriptpubkey(&self) -> Script {
-		let our_channel_close_key_hash = WPubkeyHash::hash(&self.shutdown_pubkey.serialize());
-		Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&our_channel_close_key_hash[..]).into_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(a_scriptpubkey: &Script, b_scriptpubkey: &Script) -> u64 {
-		(4 + 1 + 36 + 4 + 1 + 1 + 2*(8+1) + 4 + a_scriptpubkey.len() as u64 + b_scriptpubkey.len() as u64)*4 + 2 + 1 + 1 + 2*(1 + 72)
+	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) -> (Transaction, u64) {
-		let txins = {
-			let mut ins: Vec<TxIn> = Vec::new();
-			ins.push(TxIn {
-				previous_output: self.funding_txo.unwrap().into_bitcoin_outpoint(),
-				script_sig: Script::new(),
-				sequence: 0xffffffff,
-				witness: Vec::new(),
-			});
-			ins
-		};
-
+	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());
-		let mut txouts: Vec<(TxOut, ())> = Vec::new();
+		assert!(self.pending_update_fee.is_none());
 
 		let mut total_fee_satoshis = proposed_total_fee_satoshis;
-		let value_to_self: i64 = (self.value_to_self_msat as i64) / 1000 - if self.channel_outbound { total_fee_satoshis as i64 } else { 0 };
-		let value_to_remote: i64 = ((self.channel_value_satoshis * 1000 - self.value_to_self_msat) as i64 / 1000) - if self.channel_outbound { 0 } else { total_fee_satoshis as i64 };
+		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_self < 0 {
-			assert!(self.channel_outbound);
-			total_fee_satoshis += (-value_to_self) as u64;
-		} else if value_to_remote < 0 {
-			assert!(!self.channel_outbound);
-			total_fee_satoshis += (-value_to_remote) as u64;
+		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_remote as u64 > self.our_dust_limit_satoshis {
-			txouts.push((TxOut {
-				script_pubkey: self.their_shutdown_scriptpubkey.clone().unwrap(),
-				value: value_to_remote as u64
-			}, ()));
+		if skip_remote_output || value_to_counterparty as u64 <= self.holder_dust_limit_satoshis {
+			value_to_counterparty = 0;
 		}
 
-		if value_to_self as u64 > self.our_dust_limit_satoshis {
-			txouts.push((TxOut {
-				script_pubkey: self.get_closing_scriptpubkey(),
-				value: value_to_self as u64
-			}, ()));
+		if value_to_holder as u64 <= self.holder_dust_limit_satoshis {
+			value_to_holder = 0;
 		}
 
-		transaction_utils::sort_outputs(&mut txouts, |_, _| { cmp::Ordering::Equal }); // Ordering doesnt matter if they used our pubkey...
+		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 mut outputs: Vec<TxOut> = Vec::new();
-		for out in txouts.drain(..) {
-			outputs.push(out.0);
-		}
+		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)
+	}
 
-		(Transaction {
-			version: 2,
-			lock_time: 0,
-			input: txins,
-			output: outputs,
-		}, 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 ownership of (ie a "local" transaction)
+	/// 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_local_transaction_keys(&self, commitment_number: u64) -> Result<TxCreationKeys, ChannelError> {
-		let per_commitment_point = self.local_keys.get_per_commitment_point(commitment_number, &self.secp_ctx);
-		let delayed_payment_base = &self.local_keys.pubkeys().delayed_payment_basepoint;
-		let htlc_basepoint = &self.local_keys.pubkeys().htlc_basepoint;
-		let their_pubkeys = self.their_pubkeys.as_ref().unwrap();
+	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::new(&self.secp_ctx, &per_commitment_point, delayed_payment_base, htlc_basepoint, &their_pubkeys.revocation_basepoint, &their_pubkeys.htlc_basepoint), "Local tx keys generation got bogus keys".to_owned()))
+		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]
@@ -1132,34 +1356,21 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 	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.local_keys.pubkeys().revocation_basepoint;
-		let htlc_basepoint = &self.local_keys.pubkeys().htlc_basepoint;
-		let their_pubkeys = self.their_pubkeys.as_ref().unwrap();
+		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::new(&self.secp_ctx, &self.their_cur_commitment_point.unwrap(), &their_pubkeys.delayed_payment_basepoint, &their_pubkeys.htlc_basepoint, revocation_basepoint, htlc_basepoint), "Remote tx keys generation got bogus keys".to_owned()))
+		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.local_keys.pubkeys().funding_pubkey, self.their_funding_pubkey())
-	}
-
-	/// Builds the htlc-success or htlc-timeout transaction which spends a given HTLC output
-	/// @local is used only to convert relevant internal structures which refer to remote vs local
-	/// to decide value of outputs and direction of HTLCs.
-	fn build_htlc_transaction(&self, prev_hash: &Txid, htlc: &HTLCOutputInCommitment, local: bool, keys: &TxCreationKeys, feerate_per_kw: u32) -> Transaction {
-		chan_utils::build_htlc_transaction(prev_hash, feerate_per_kw, if local { self.their_to_self_delay } else { self.our_to_self_delay }, htlc, &keys.a_delayed_payment_key, &keys.revocation_key)
+		make_funding_redeemscript(&self.get_holder_pubkeys().funding_pubkey, self.counterparty_funding_pubkey())
 	}
 
-	/// Per HTLC, only one get_update_fail_htlc or get_update_fulfill_htlc call may be made.
-	/// In such cases we debug_assert!(false) and return a ChannelError::Ignore. Thus, will always
-	/// return Ok(_) if debug assertions are turned on or preconditions are met.
-	///
-	/// Note that it is still possible to hit these assertions in case we find a preimage on-chain
-	/// but then have a reorg which settles on an HTLC-failure on chain.
-	fn get_update_fulfill_htlc<L: Deref>(&mut self, htlc_id_arg: u64, payment_preimage_arg: PaymentPreimage, logger: &L) -> Result<(Option<msgs::UpdateFulfillHTLC>, Option<ChannelMonitorUpdate>), ChannelError> where L::Target: Logger {
+	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,
@@ -1175,7 +1386,8 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		// 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 = std::usize::MAX;
+		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);
@@ -1185,9 +1397,9 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 						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");
 						}
-						debug_assert!(false, "Tried to fulfill an HTLC that was already fail/fulfilled");
-						return Ok((None, None));
+						return UpdateFulfillFetch::DuplicateClaim {};
 					},
 					_ => {
 						debug_assert!(false, "Have an inbound HTLC we tried to claim before it was fully committed to");
@@ -1195,11 +1407,16 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 					}
 				}
 				pending_idx = idx;
+				htlc_value_msat = htlc.amount_msat;
 				break;
 			}
 		}
-		if pending_idx == std::usize::MAX {
-			return Err(ChannelError::Ignore("Unable to find a pending HTLC which matched the given HTLC ID".to_owned()));
+		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:
@@ -1213,7 +1430,6 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 				payment_preimage: payment_preimage_arg.clone(),
 			}],
 		};
-		self.channel_monitor.as_mut().unwrap().update_monitor_ooo(monitor_update.clone(), logger).unwrap();
 
 		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() {
@@ -1222,8 +1438,9 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 						if htlc_id_arg == htlc_id {
 							// Make sure we don't leave latest_monitor_update_id incremented here:
 							self.latest_monitor_update_id -= 1;
-							debug_assert!(false, "Tried to fulfill an HTLC that was already fulfilled");
-							return Ok((None, None));
+							#[cfg(any(test, feature = "fuzztarget"))]
+							debug_assert!(self.historical_inbound_htlc_fulfills.contains(&htlc_id_arg));
+							return UpdateFulfillFetch::DuplicateClaim {};
 						}
 					},
 					&HTLCUpdateAwaitingACK::FailHTLC { htlc_id, .. } => {
@@ -1232,63 +1449,71 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 							// 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 Ok((None, Some(monitor_update)));
+							return UpdateFulfillFetch::NewClaim { monitor_update, htlc_value_msat, msg: None };
 						}
 					},
 					_ => {}
 				}
 			}
-			log_trace!(logger, "Adding HTLC claim to holding_cell! Current state: {}", self.channel_state);
+			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,
 			});
-			return Ok((None, Some(monitor_update)));
+			#[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 Ok((None, Some(monitor_update)));
+				return UpdateFulfillFetch::NewClaim { monitor_update, htlc_value_msat, msg: None };
 			}
-			log_trace!(logger, "Upgrading HTLC {} to LocalRemoved with a Fulfill!", log_bytes!(htlc.payment_hash.0));
+			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()));
 		}
 
-		Ok((Some(msgs::UpdateFulfillHTLC {
-			channel_id: self.channel_id(),
-			htlc_id: htlc_id_arg,
-			payment_preimage: payment_preimage_arg,
-		}), Some(monitor_update)))
+		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<(Option<(msgs::UpdateFulfillHTLC, msgs::CommitmentSigned)>, Option<ChannelMonitorUpdate>), ChannelError> where L::Target: Logger {
-		match self.get_update_fulfill_htlc(htlc_id, payment_preimage, logger)? {
-			(Some(update_fulfill_htlc), Some(mut monitor_update)) => {
-				let (commitment, mut additional_update) = self.send_commitment_no_status_check(logger)?;
+	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((Some((update_fulfill_htlc, commitment)), Some(monitor_update)))
-			},
-			(Some(update_fulfill_htlc), None) => {
-				let (commitment, monitor_update) = self.send_commitment_no_status_check(logger)?;
-				Ok((Some((update_fulfill_htlc, commitment)), Some(monitor_update)))
+				Ok(UpdateFulfillCommitFetch::NewClaim { monitor_update, htlc_value_msat, msgs: Some((update_fulfill_htlc, commitment)) })
 			},
-			(None, Some(monitor_update)) => Ok((None, Some(monitor_update))),
-			(None, None) => Ok((None, None))
+			UpdateFulfillFetch::NewClaim { monitor_update, htlc_value_msat, msg: None } =>
+				Ok(UpdateFulfillCommitFetch::NewClaim { monitor_update, htlc_value_msat, msgs: None }),
+			UpdateFulfillFetch::DuplicateClaim {} => Ok(UpdateFulfillCommitFetch::DuplicateClaim {}),
 		}
 	}
 
-	/// Per HTLC, only one get_update_fail_htlc or get_update_fulfill_htlc call may be made.
-	/// In such cases we debug_assert!(false) and return a ChannelError::Ignore. Thus, will always
-	/// return Ok(_) if debug assertions are turned on or preconditions are met.
-	///
-	/// Note that it is still possible to hit these assertions in case we find a preimage on-chain
-	/// but then have a reorg which settles on an HTLC-failure on chain.
-	pub fn get_update_fail_htlc(&mut self, htlc_id_arg: u64, err_packet: msgs::OnionErrorPacket) -> Result<Option<msgs::UpdateFailHTLC>, ChannelError> {
+	/// 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");
 		}
@@ -1298,13 +1523,16 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		// 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 = std::usize::MAX;
+		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(_) => {
-						debug_assert!(false, "Tried to fail an HTLC that was already fail/fulfilled");
+					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);
 					},
 					_ => {
@@ -1315,8 +1543,12 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 				pending_idx = idx;
 			}
 		}
-		if pending_idx == std::usize::MAX {
-			return Err(ChannelError::Ignore("Unable to find a pending HTLC which matched the given HTLC ID".to_owned()));
+		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:
@@ -1325,8 +1557,9 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 				match pending_update {
 					&HTLCUpdateAwaitingACK::ClaimHTLC { htlc_id, .. } => {
 						if htlc_id_arg == htlc_id {
-							debug_assert!(false, "Tried to fail an HTLC that was already fulfilled");
-							return Err(ChannelError::Ignore("Unable to find a pending HTLC which matched the given HTLC ID".to_owned()));
+							#[cfg(any(test, feature = "fuzztarget"))]
+							debug_assert!(self.historical_inbound_htlc_fulfills.contains(&htlc_id_arg));
+							return Ok(None);
 						}
 					},
 					&HTLCUpdateAwaitingACK::FailHTLC { htlc_id, .. } => {
@@ -1338,6 +1571,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 					_ => {}
 				}
 			}
+			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,
@@ -1345,6 +1579,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 			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()));
@@ -1359,9 +1594,9 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 
 	// Message handlers:
 
-	pub fn accept_channel(&mut self, msg: &msgs::AcceptChannel, config: &UserConfig, their_features: InitFeatures) -> Result<(), ChannelError> {
+	pub fn accept_channel(&mut self, msg: &msgs::AcceptChannel, config: &UserConfig, their_features: &InitFeatures) -> Result<(), ChannelError> {
 		// Check sanity of message fields:
-		if !self.channel_outbound {
+		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 {
@@ -1373,13 +1608,10 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		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 > msg.channel_reserve_satoshis {
-			return Err(ChannelError::Close(format!("Bogus channel_reserve ({}) and dust_limit ({})", msg.channel_reserve_satoshis, msg.dust_limit_satoshis)));
-		}
-		if msg.channel_reserve_satoshis < self.our_dust_limit_satoshis {
-			return Err(ChannelError::Close(format!("Peer never wants payout outputs? channel_reserve_satoshis was ({}). our_dust_limit is ({})", msg.channel_reserve_satoshis, self.our_dust_limit_satoshis)));
+		if msg.channel_reserve_satoshis < self.holder_dust_limit_satoshis {
+			return Err(ChannelError::Close(format!("Peer never wants payout outputs? channel_reserve_satoshis was ({}). dust_limit is ({})", msg.channel_reserve_satoshis, self.holder_dust_limit_satoshis)));
 		}
-		let remote_reserve = Channel::<ChanSigner>::get_remote_channel_reserve_satoshis(self.channel_value_satoshis);
+		let remote_reserve = Channel::<Signer>::get_holder_selected_channel_reserve_satoshis(self.channel_value_satoshis);
 		if msg.dust_limit_satoshis > remote_reserve {
 			return Err(ChannelError::Close(format!("Dust limit ({}) is bigger than our channel reserve ({})", msg.dust_limit_satoshis, remote_reserve)));
 		}
@@ -1394,8 +1626,8 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		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 > 483 {
-			return Err(ChannelError::Close(format!("max_accepted_htlcs was {}. It must not be larger than 483", msg.max_accepted_htlcs)));
+		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...
@@ -1411,28 +1643,33 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		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 < config.peer_channel_config_limits.min_dust_limit_satoshis {
-			return Err(ChannelError::Close(format!("dust_limit_satoshis ({}) is less than the user specified limit ({})", msg.dust_limit_satoshis, config.peer_channel_config_limits.min_dust_limit_satoshis)));
+		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 > config.peer_channel_config_limits.max_dust_limit_satoshis {
-			return Err(ChannelError::Close(format!("dust_limit_satoshis ({}) is greater than the user specified limit ({})", msg.dust_limit_satoshis, config.peer_channel_config_limits.max_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 their_shutdown_scriptpubkey = if their_features.supports_upfront_shutdown_script() {
+		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 provided a non-accepted scriptpubkey format. We enforce it while receiving shutdown msg
-					if script.is_p2pkh() || script.is_p2sh() || script.is_v0_p2wsh() || script.is_v0_p2wpkh() {
-						Some(script.clone())
 					// Peer is signaling upfront_shutdown and has opt-out with a 0-length script. We don't enforce anything
-					} else if script.len() == 0 {
+					if script.len() == 0 {
 						None
-					// Peer is signaling upfront_shutdown and has provided a non-accepted scriptpubkey format. Fail the channel
 					} else {
-						return Err(ChannelError::Close(format!("Peer is signaling upfront_shutdown but has provided a non-accepted scriptpubkey format. scriptpubkey: ({})", script.to_bytes().to_hex())));
+						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
@@ -1442,15 +1679,14 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 			}
 		} else { None };
 
-		self.their_dust_limit_satoshis = msg.dust_limit_satoshis;
-		self.their_max_htlc_value_in_flight_msat = cmp::min(msg.max_htlc_value_in_flight_msat, self.channel_value_satoshis * 1000);
-		self.local_channel_reserve_satoshis = msg.channel_reserve_satoshis;
-		self.their_htlc_minimum_msat = msg.htlc_minimum_msat;
-		self.their_to_self_delay = msg.to_self_delay;
-		self.their_max_accepted_htlcs = msg.max_accepted_htlcs;
-		self.minimum_depth = msg.minimum_depth;
+		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 their_pubkeys = ChannelPublicKeys {
+		let counterparty_pubkeys = ChannelPublicKeys {
 			funding_pubkey: msg.funding_pubkey,
 			revocation_basepoint: msg.revocation_basepoint,
 			payment_point: msg.payment_point,
@@ -1458,46 +1694,57 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 			htlc_basepoint: msg.htlc_basepoint
 		};
 
-		self.local_keys.on_accept(&their_pubkeys, msg.to_self_delay, self.our_to_self_delay);
-		self.their_pubkeys = Some(their_pubkeys);
+		self.channel_transaction_parameters.counterparty_parameters = Some(CounterpartyChannelTransactionParameters {
+			selected_contest_delay: msg.to_self_delay,
+			pubkeys: counterparty_pubkeys,
+		});
 
-		self.their_cur_commitment_point = Some(msg.first_per_commitment_point);
-		self.their_shutdown_scriptpubkey = their_shutdown_scriptpubkey;
+		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<(Transaction, LocalCommitmentTransaction, Signature), ChannelError> where L::Target: Logger {
+	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 local_keys = self.build_local_transaction_keys(self.cur_local_commitment_transaction_number)?;
-		let local_initial_commitment_tx = self.build_commitment_transaction(self.cur_local_commitment_transaction_number, &local_keys, true, false, self.feerate_per_kw, logger).0;
-		let local_sighash = hash_to_message!(&bip143::SighashComponents::new(&local_initial_commitment_tx).sighash_all(&local_initial_commitment_tx.input[0], &funding_script, self.channel_value_satoshis)[..]);
-
-		// They sign the "local" commitment transaction...
-		log_trace!(logger, "Checking funding_created tx signature {} by key {} against tx {} (sighash {}) with redeemscript {}", log_bytes!(sig.serialize_compact()[..]), log_bytes!(self.their_funding_pubkey().serialize()), encode::serialize_hex(&local_initial_commitment_tx), log_bytes!(local_sighash[..]), encode::serialize_hex(&funding_script));
-		secp_check!(self.secp_ctx.verify(&local_sighash, &sig, self.their_funding_pubkey()), "Invalid funding_created signature from peer".to_owned());
-
-		let localtx = LocalCommitmentTransaction::new_missing_local_sig(local_initial_commitment_tx, sig.clone(), &self.local_keys.pubkeys().funding_pubkey, self.their_funding_pubkey(), local_keys, self.feerate_per_kw, Vec::new());
-
-		let remote_keys = self.build_remote_transaction_keys()?;
-		let remote_initial_commitment_tx = self.build_commitment_transaction(self.cur_remote_commitment_transaction_number, &remote_keys, false, false, self.feerate_per_kw, logger).0;
-		let pre_remote_keys = PreCalculatedTxCreationKeys::new(remote_keys);
-		let remote_signature = self.local_keys.sign_remote_commitment(self.feerate_per_kw, &remote_initial_commitment_tx, &pre_remote_keys, &Vec::new(), &self.secp_ctx)
+		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).0;
+		{
+			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).0;
+
+		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 the "remote" commitment transaction, allowing them to broadcast the tx if they wish.
-		Ok((remote_initial_commitment_tx, localtx, remote_signature))
+		// 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 their_funding_pubkey(&self) -> &PublicKey {
-		&self.their_pubkeys.as_ref().expect("their_funding_pubkey() only allowed after accept_channel").funding_pubkey
+	fn counterparty_funding_pubkey(&self) -> &PublicKey {
+		&self.get_counterparty_pubkeys().funding_pubkey
 	}
 
-	pub fn funding_created<L: Deref>(&mut self, msg: &msgs::FundingCreated, logger: &L) -> Result<(msgs::FundingSigned, ChannelMonitor<ChanSigner>), ChannelError> where L::Target: Logger {
-		if self.channel_outbound {
+	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) {
@@ -1507,122 +1754,148 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 			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_remote_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER ||
-				self.cur_local_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER {
+				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.funding_txo = Some(funding_txo.clone());
+		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 (remote_initial_commitment_tx, local_initial_commitment_tx, our_signature) = match self.funding_created_signature(&msg.signature, logger) {
+		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) => {
-				self.funding_txo = None;
-				return 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 their_pubkeys = self.their_pubkeys.as_ref().unwrap();
 		let funding_redeemscript = self.get_funding_redeemscript();
 		let funding_txo_script = funding_redeemscript.to_v0_p2wsh();
-		macro_rules! create_monitor {
-			() => { {
-				let mut channel_monitor = ChannelMonitor::new(self.local_keys.clone(),
-				                                              &self.shutdown_pubkey, self.our_to_self_delay,
-				                                              &self.destination_script, (funding_txo, funding_txo_script.clone()),
-				                                              &their_pubkeys.htlc_basepoint, &their_pubkeys.delayed_payment_basepoint,
-				                                              self.their_to_self_delay, funding_redeemscript.clone(), self.channel_value_satoshis,
-				                                              self.get_commitment_transaction_number_obscure_factor(),
-				                                              local_initial_commitment_tx.clone());
-
-				channel_monitor.provide_latest_remote_commitment_tx_info(&remote_initial_commitment_tx, Vec::new(), self.cur_remote_commitment_transaction_number, self.their_cur_commitment_point.unwrap(), logger);
-				channel_monitor
-			} }
-		}
-
-		self.channel_monitor = Some(create_monitor!());
-		let channel_monitor = create_monitor!();
+		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_remote_commitment_transaction_number -= 1;
-		self.cur_local_commitment_transaction_number -= 1;
+		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: our_signature
+			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, logger: &L) -> Result<ChannelMonitor<ChanSigner>, ChannelError> where L::Target: Logger {
-		if !self.channel_outbound {
+	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_remote_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER ||
-				self.cur_local_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER {
+				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 remote_keys = self.build_remote_transaction_keys()?;
-		let remote_initial_commitment_tx = self.build_commitment_transaction(self.cur_remote_commitment_transaction_number, &remote_keys, false, false, self.feerate_per_kw, logger).0;
-
-		let local_keys = self.build_local_transaction_keys(self.cur_local_commitment_transaction_number)?;
-		let local_initial_commitment_tx = self.build_commitment_transaction(self.cur_local_commitment_transaction_number, &local_keys, true, false, self.feerate_per_kw, logger).0;
-		let local_sighash = hash_to_message!(&bip143::SighashComponents::new(&local_initial_commitment_tx).sighash_all(&local_initial_commitment_tx.input[0], &funding_script, self.channel_value_satoshis)[..]);
+		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).0;
+		let counterparty_trusted_tx = counterparty_initial_commitment_tx.trust();
+		let counterparty_initial_bitcoin_tx = counterparty_trusted_tx.built_transaction();
 
-		let their_funding_pubkey = &self.their_pubkeys.as_ref().unwrap().funding_pubkey;
+		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));
 
-		// They sign the "local" commitment transaction, allowing us to broadcast the tx if we wish.
-		if let Err(_) = self.secp_ctx.verify(&local_sighash, &msg.signature, their_funding_pubkey) {
-			return Err(ChannelError::Close("Invalid funding_signed signature from peer".to_owned()));
+		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).0;
+		{
+			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 their_pubkeys = self.their_pubkeys.as_ref().unwrap();
+		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.funding_txo.as_ref().unwrap();
+		let funding_txo = self.get_funding_txo().unwrap();
 		let funding_txo_script = funding_redeemscript.to_v0_p2wsh();
-		macro_rules! create_monitor {
-			() => { {
-				let local_commitment_tx = LocalCommitmentTransaction::new_missing_local_sig(local_initial_commitment_tx.clone(), msg.signature.clone(), &self.local_keys.pubkeys().funding_pubkey, their_funding_pubkey, local_keys.clone(), self.feerate_per_kw, Vec::new());
-				let mut channel_monitor = ChannelMonitor::new(self.local_keys.clone(),
-				                                              &self.shutdown_pubkey, self.our_to_self_delay,
-				                                              &self.destination_script, (funding_txo.clone(), funding_txo_script.clone()),
-				                                              &their_pubkeys.htlc_basepoint, &their_pubkeys.delayed_payment_basepoint,
-				                                              self.their_to_self_delay, funding_redeemscript.clone(), self.channel_value_satoshis,
-				                                              self.get_commitment_transaction_number_obscure_factor(),
-				                                              local_commitment_tx);
-
-				channel_monitor.provide_latest_remote_commitment_tx_info(&remote_initial_commitment_tx, Vec::new(), self.cur_remote_commitment_transaction_number, self.their_cur_commitment_point.unwrap(), logger);
-
-				channel_monitor
-			} }
-		}
-
-		self.channel_monitor = Some(create_monitor!());
-		let channel_monitor = create_monitor!();
+		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_local_commitment_transaction_number -= 1;
-		self.cur_remote_commitment_transaction_number -= 1;
+		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)
+		Ok((channel_monitor, self.funding_transaction.as_ref().cloned().unwrap()))
 	}
 
-	pub fn funding_locked(&mut self, msg: &msgs::FundingLocked) -> Result<(), ChannelError> {
+	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 {
-			return Err(ChannelError::Close("Peer sent funding_locked when we needed a channel_reestablish".to_owned()));
+			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);
@@ -1634,12 +1907,12 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 			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_local_commitment_transaction_number == INITIAL_COMMITMENT_NUMBER - 1 &&
-				 self.cur_remote_commitment_transaction_number == INITIAL_COMMITMENT_NUMBER - 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.their_cur_commitment_point != Some(msg.next_per_commitment_point) {
+			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
@@ -1648,37 +1921,80 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 			return Err(ChannelError::Close("Peer sent a funding_locked at a strange time".to_owned()));
 		}
 
-		self.their_prev_commitment_point = self.their_cur_commitment_point;
-		self.their_cur_commitment_point = Some(msg.next_per_commitment_point);
+		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 (inbound_htlc_count, htlc_inbound_value_msat)
-	fn get_inbound_pending_htlc_stats(&self) -> (u32, u64) {
-		let mut htlc_inbound_value_msat = 0;
+	/// 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) -> 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,
+		};
+
+		let counterparty_dust_limit_timeout_sat = (self.get_dust_buffer_feerate() as u64 * HTLC_TIMEOUT_TX_WEIGHT / 1000) + self.counterparty_dust_limit_satoshis;
+		let holder_dust_limit_success_sat = (self.get_dust_buffer_feerate() as u64 * HTLC_SUCCESS_TX_WEIGHT / 1000) + self.holder_dust_limit_satoshis;
 		for ref htlc in self.pending_inbound_htlcs.iter() {
-			htlc_inbound_value_msat += htlc.amount_msat;
+			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;
+			}
 		}
-		(self.pending_inbound_htlcs.len() as u32, htlc_inbound_value_msat)
+		stats
 	}
 
-	/// Returns (outbound_htlc_count, htlc_outbound_value_msat) *including* pending adds in our
-	/// holding cell.
-	fn get_outbound_pending_htlc_stats(&self) -> (u32, u64) {
-		let mut htlc_outbound_value_msat = 0;
+	/// Returns a HTLCStats about pending outbound htlcs, *including* pending adds in our holding cell.
+	fn get_outbound_pending_htlc_stats(&self) -> 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,
+		};
+
+		let counterparty_dust_limit_success_sat = (self.get_dust_buffer_feerate() as u64 * HTLC_SUCCESS_TX_WEIGHT / 1000) + self.counterparty_dust_limit_satoshis;
+		let holder_dust_limit_timeout_sat = (self.get_dust_buffer_feerate() as u64 * HTLC_TIMEOUT_TX_WEIGHT / 1000) + self.holder_dust_limit_satoshis;
 		for ref htlc in self.pending_outbound_htlcs.iter() {
-			htlc_outbound_value_msat += htlc.amount_msat;
+			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;
+			}
 		}
 
-		let mut htlc_outbound_count = self.pending_outbound_htlcs.len();
 		for update in self.holding_cell_htlc_updates.iter() {
 			if let &HTLCUpdateAwaitingACK::AddHTLC { ref amount_msat, .. } = update {
-				htlc_outbound_count += 1;
-				htlc_outbound_value_msat += amount_msat;
+				stats.pending_htlcs += 1;
+				stats.pending_htlcs_value_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;
+				}
 			}
 		}
-
-		(htlc_outbound_count as u32, htlc_outbound_value_msat)
+		stats
 	}
 
 	/// Get the available (ie not including pending HTLCs) inbound and outbound balance in msat.
@@ -1687,8 +2003,22 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 	/// corner case properly.
 	pub fn get_inbound_outbound_available_balance_msat(&self) -> (u64, u64) {
 		// Note that we have to handle overflow due to the above case.
-		(cmp::min(self.channel_value_satoshis as i64 * 1000 - self.value_to_self_msat as i64 - self.get_inbound_pending_htlc_stats().1 as i64, 0) as u64,
-		cmp::min(self.value_to_self_msat as i64 - self.get_outbound_pending_htlc_stats().1 as i64, 0) as u64)
+		(
+			cmp::max(self.channel_value_satoshis as i64 * 1000
+				- self.value_to_self_msat as i64
+				- self.get_inbound_pending_htlc_stats().pending_htlcs_value_msat as i64
+				- Self::get_holder_selected_channel_reserve_satoshis(self.channel_value_satoshis) as i64 * 1000,
+			0) as u64,
+			cmp::max(self.value_to_self_msat as i64
+				- self.get_outbound_pending_htlc_stats().pending_htlcs_value_msat as i64
+				- self.counterparty_selected_channel_reserve_satoshis.unwrap_or(0) as i64 * 1000,
+			0) as u64
+		)
+	}
+
+	pub fn get_holder_counterparty_selected_channel_reserve_satoshis(&self) -> (u64, Option<u64>) {
+		(Self::get_holder_selected_channel_reserve_satoshis(self.channel_value_satoshis),
+		self.counterparty_selected_channel_reserve_satoshis)
 	}
 
 	// Get the fee cost of a commitment tx with a given number of HTLC outputs.
@@ -1699,63 +2029,172 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		(COMMITMENT_TX_BASE_WEIGHT + num_htlcs as u64 * COMMITMENT_TX_WEIGHT_PER_HTLC) * self.feerate_per_kw as u64 / 1000 * 1000
 	}
 
-	// Get the commitment tx fee for the local (i.e our) next commitment transaction
-	// based on the number of pending HTLCs that are on track to be in our next
-	// commitment tx. `addl_htcs` is an optional parameter allowing the caller
-	// to add a number of additional HTLCs to the calculation. Note that dust
-	// HTLCs are excluded.
-	fn next_local_commit_tx_fee_msat(&self, addl_htlcs: usize) -> u64 {
-		assert!(self.channel_outbound);
+	// 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;
+		}
 
-		let mut their_acked_htlcs = self.pending_inbound_htlcs.len();
 		for ref htlc in self.pending_outbound_htlcs.iter() {
-			if htlc.amount_msat / 1000 <= self.our_dust_limit_satoshis {
+			if htlc.amount_msat / 1000 < real_dust_limit_timeout_sat {
 				continue
 			}
 			match htlc.state {
-				OutboundHTLCState::Committed => their_acked_htlcs += 1,
-				OutboundHTLCState::RemoteRemoved {..} => their_acked_htlcs += 1,
-				OutboundHTLCState::LocalAnnounced {..} => their_acked_htlcs += 1,
+				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 { .. } => their_acked_htlcs += 1,
-				_ => {},
+				&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.
 			}
 		}
 
-		self.commit_tx_fee_msat(their_acked_htlcs + addl_htlcs)
+		let num_htlcs = included_htlcs + addl_htlcs;
+		let res = self.commit_tx_fee_msat(num_htlcs);
+		#[cfg(any(test, feature = "fuzztarget"))]
+		{
+			let mut fee = res;
+			if fee_spike_buffer_htlc.is_some() {
+				fee = self.commit_tx_fee_msat(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. `addl_htcs` is an optional parameter allowing the caller
-	// to add a number of additional HTLCs to the calculation. Note that dust HTLCs
-	// are excluded.
-	fn next_remote_commit_tx_fee_msat(&self, addl_htlcs: usize) -> u64 {
-		assert!(!self.channel_outbound);
+	// 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;
+		}
 
-		// When calculating the set of HTLCs which will be included in their next
-		// commitment_signed, all inbound HTLCs are included (as all states imply it will be
-		// included) and only committed outbound HTLCs, see below.
-		let mut their_acked_htlcs = self.pending_inbound_htlcs.len();
 		for ref htlc in self.pending_outbound_htlcs.iter() {
-			if htlc.amount_msat / 1000 <= self.their_dust_limit_satoshis {
+			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.
+			// 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 => their_acked_htlcs += 1,
-				OutboundHTLCState::RemoteRemoved {..} => their_acked_htlcs += 1,
+				OutboundHTLCState::Committed => included_htlcs += 1,
+				OutboundHTLCState::RemoteRemoved {..} => included_htlcs += 1,
+				OutboundHTLCState::LocalAnnounced { .. } => included_htlcs += 1,
 				_ => {},
 			}
 		}
 
-		self.commit_tx_fee_msat(their_acked_htlcs + addl_htlcs)
+		let num_htlcs = included_htlcs + addl_htlcs;
+		let res = self.commit_tx_fee_msat(num_htlcs);
+		#[cfg(any(test, feature = "fuzztarget"))]
+		{
+			let mut fee = res;
+			if fee_spike_buffer_htlc.is_some() {
+				fee = self.commit_tx_fee_msat(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>
@@ -1763,7 +2202,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		// 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, 0x1000|20);
+			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);
@@ -1779,19 +2218,20 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		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.our_htlc_minimum_msat {
-			return Err(ChannelError::Close(format!("Remote side tried to send less than our minimum HTLC value. Lower limit: ({}). Actual: ({})", self.our_htlc_minimum_msat, msg.amount_msat)));
+		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_htlc_count, htlc_inbound_value_msat) = self.get_inbound_pending_htlc_stats();
-		if inbound_htlc_count + 1 > OUR_MAX_HTLCS as u32 {
+		let inbound_stats = self.get_inbound_pending_htlc_stats();
+		let outbound_stats = self.get_outbound_pending_htlc_stats();
+		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)));
 		}
-		let our_max_htlc_value_in_flight_msat = Channel::<ChanSigner>::get_our_max_htlc_value_in_flight_msat(self.channel_value_satoshis);
-		if htlc_inbound_value_msat + msg.amount_msat > our_max_htlc_value_in_flight_msat {
-			return Err(ChannelError::Close(format!("Remote HTLC add would put them over our max HTLC value ({})", our_max_htlc_value_in_flight_msat)));
+		let holder_max_htlc_value_in_flight_msat = Channel::<Signer>::get_holder_max_htlc_value_in_flight_msat(self.channel_value_satoshis);
+		if inbound_stats.pending_htlcs_value_msat + msg.amount_msat > holder_max_htlc_value_in_flight_msat {
+			return Err(ChannelError::Close(format!("Remote HTLC add would put them over our max HTLC value ({})", holder_max_htlc_value_in_flight_msat)));
 		}
-		// Check remote_channel_reserve_satoshis (we're getting paid, so they have to at least meet
+		// 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
@@ -1812,8 +2252,28 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 			}
 		}
 
+		let exposure_dust_limit_timeout_sats = (self.get_dust_buffer_feerate() 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() 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 + htlc_inbound_value_msat - removed_outbound_total_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 {
@@ -1822,47 +2282,47 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 
 		// 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.channel_outbound { 0 } else {
-			// +1 for this HTLC.
-			self.next_remote_commit_tx_fee_msat(1)
+		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()));
 		};
 
 		let chan_reserve_msat =
-			Channel::<ChanSigner>::get_remote_channel_reserve_satoshis(self.channel_value_satoshis) * 1000;
+			Channel::<Signer>::get_holder_selected_channel_reserve_satoshis(self.channel_value_satoshis) * 1000;
 		if pending_remote_value_msat - msg.amount_msat - remote_commit_tx_fee_msat < chan_reserve_msat {
 			return Err(ChannelError::Close("Remote HTLC add would put them under remote reserve value".to_owned()));
 		}
 
-		if !self.channel_outbound {
-			// `+1` for this HTLC, `2 *` and `+1` 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 +1
-			// as we should still be able to afford adding this HTLC plus one more future HTLC, regardless of
-			// being sensitive to fee spikes.
-			let remote_fee_cost_incl_stuck_buffer_msat = 2 * self.next_remote_commit_tx_fee_msat(1 + 1);
+		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 - chan_reserve_msat < 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");
+				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.
-
-			// +1 for this HTLC.
-			let local_commit_tx_fee_msat = self.next_local_commit_tx_fee_msat(1);
-			if self.value_to_self_msat < self.local_channel_reserve_satoshis * 1000 + local_commit_tx_fee_msat {
-				return Err(ChannelError::Close("Cannot receive value that would put us under local channel reserve value".to_owned()));
+			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_remote_htlc_id != msg.htlc_id {
-			return Err(ChannelError::Close(format!("Remote skipped HTLC ID (skipped ID: {})", self.next_remote_htlc_id)));
+		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()));
@@ -1875,7 +2335,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		}
 
 		// Now update local state:
-		self.next_remote_htlc_id += 1;
+		self.next_counterparty_htlc_id += 1;
 		self.pending_inbound_htlcs.push(InboundHTLCOutput {
 			htlc_id: msg.htlc_id,
 			amount_msat: msg.amount_msat,
@@ -1888,7 +2348,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 
 	/// 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<&HTLCSource, ChannelError> {
+	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 {
@@ -1907,13 +2367,13 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 					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.source);
+				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, ChannelError> {
+	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()));
 		}
@@ -1922,7 +2382,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		}
 
 		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(|source| source.clone())
+		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> {
@@ -1949,9 +2409,8 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		Ok(())
 	}
 
-	pub fn commitment_signed<F: Deref, L: Deref>(&mut self, msg: &msgs::CommitmentSigned, fee_estimator: &F, logger: &L) -> Result<(msgs::RevokeAndACK, Option<msgs::CommitmentSigned>, Option<msgs::ClosingSigned>, ChannelMonitorUpdate), (Option<ChannelMonitorUpdate>, ChannelError)>
-	where F::Target: FeeEstimator,
-				L::Target: Logger
+	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())));
@@ -1965,114 +2424,140 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 
 		let funding_script = self.get_funding_redeemscript();
 
-		let local_keys = self.build_local_transaction_keys(self.cur_local_commitment_transaction_number).map_err(|e| (None, e))?;
-
-		let mut update_fee = false;
-		let feerate_per_kw = if !self.channel_outbound && self.pending_update_fee.is_some() {
-			update_fee = true;
-			self.pending_update_fee.unwrap()
-		} else {
-			self.feerate_per_kw
-		};
-
-		let mut local_commitment_tx = {
-			let mut commitment_tx = self.build_commitment_transaction(self.cur_local_commitment_transaction_number, &local_keys, true, false, feerate_per_kw, logger);
-			let htlcs_cloned: Vec<_> = commitment_tx.2.drain(..).map(|htlc| (htlc.0, htlc.1.map(|h| h.clone()))).collect();
-			(commitment_tx.0, commitment_tx.1, htlcs_cloned)
+		let keys = self.build_holder_transaction_keys(self.cur_holder_commitment_transaction_number).map_err(|e| (None, e))?;
+
+		let (num_htlcs, mut htlcs_cloned, commitment_tx, commitment_txid, feerate_per_kw) = {
+			let commitment_tx = self.build_commitment_transaction(self.cur_holder_commitment_transaction_number, &keys, true, false, logger);
+			let commitment_txid = {
+				let trusted_tx = commitment_tx.0.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 htlcs_cloned: Vec<_> = commitment_tx.3.iter().map(|htlc| (htlc.0.clone(), htlc.1.map(|h| h.clone()))).collect();
+			(commitment_tx.2, htlcs_cloned, commitment_tx.0, commitment_txid, commitment_tx.1)
 		};
-		let local_commitment_txid = local_commitment_tx.0.txid();
-		let local_sighash = hash_to_message!(&bip143::SighashComponents::new(&local_commitment_tx.0).sighash_all(&local_commitment_tx.0.input[0], &funding_script, self.channel_value_satoshis)[..]);
-		log_trace!(logger, "Checking commitment tx signature {} by key {} against tx {} (sighash {}) with redeemscript {}", log_bytes!(msg.signature.serialize_compact()[..]), log_bytes!(self.their_funding_pubkey().serialize()), encode::serialize_hex(&local_commitment_tx.0), log_bytes!(local_sighash[..]), encode::serialize_hex(&funding_script));
-		if let Err(_) = self.secp_ctx.verify(&local_sighash, &msg.signature, &self.their_funding_pubkey()) {
-			return Err((None, ChannelError::Close("Invalid commitment tx signature from peer".to_owned())));
-		}
 
-		//If channel fee was updated by funder confirm funder can afford the new fee rate when applied to the current local commitment transaction
+		// 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 total_fee = feerate_per_kw as u64 * (COMMITMENT_TX_BASE_WEIGHT + (num_htlcs as u64) * COMMITMENT_TX_WEIGHT_PER_HTLC) / 1000;
 		if update_fee {
-			let num_htlcs = local_commitment_tx.1;
-			let total_fee = feerate_per_kw as u64 * (COMMITMENT_TX_BASE_WEIGHT + (num_htlcs as u64) * COMMITMENT_TX_WEIGHT_PER_HTLC) / 1000;
-
-			let remote_reserve_we_require = Channel::<ChanSigner>::get_remote_channel_reserve_satoshis(self.channel_value_satoshis);
-			if self.channel_value_satoshis - self.value_to_self_msat / 1000 < total_fee + remote_reserve_we_require {
+			let counterparty_reserve_we_require = Channel::<Signer>::get_holder_selected_channel_reserve_satoshis(self.channel_value_satoshis);
+			if self.channel_value_satoshis - self.value_to_self_msat / 1000 < total_fee + counterparty_reserve_we_require {
 				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!(total_fee, info.fee / 1000);
+						}
+				}
+			}
+		}
 
-		if msg.htlc_signatures.len() != local_commitment_tx.1 {
-			return Err((None, ChannelError::Close(format!("Got wrong number of HTLC signatures ({}) from remote. It must be {}", msg.htlc_signatures.len(), local_commitment_tx.1))));
+		if msg.htlc_signatures.len() != num_htlcs {
+			return Err((None, ChannelError::Close(format!("Got wrong number of HTLC signatures ({}) from remote. It must be {}", msg.htlc_signatures.len(), num_htlcs))));
 		}
 
-		// TODO: Merge these two, sadly they are currently both required to be passed separately to
-		// ChannelMonitor:
-		let mut htlcs_without_source = Vec::with_capacity(local_commitment_tx.2.len());
-		let mut htlcs_and_sigs = Vec::with_capacity(local_commitment_tx.2.len());
-		for (idx, (htlc, source)) in local_commitment_tx.2.drain(..).enumerate() {
+		// 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 = self.build_htlc_transaction(&local_commitment_txid, &htlc, true, &local_keys, feerate_per_kw);
-				let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, &local_keys);
-				let htlc_sighash = hash_to_message!(&bip143::SighashComponents::new(&htlc_tx).sighash_all(&htlc_tx.input[0], &htlc_redeemscript, htlc.amount_msat / 1000)[..]);
-				log_trace!(logger, "Checking HTLC tx signature {} by key {} against tx {} (sighash {}) with redeemscript {}", log_bytes!(msg.htlc_signatures[idx].serialize_compact()[..]), log_bytes!(local_keys.b_htlc_key.serialize()), encode::serialize_hex(&htlc_tx), log_bytes!(htlc_sighash[..]), encode::serialize_hex(&htlc_redeemscript));
-				if let Err(_) = self.secp_ctx.verify(&htlc_sighash, &msg.htlc_signatures[idx], &local_keys.b_htlc_key) {
+				let htlc_tx = chan_utils::build_htlc_transaction(&commitment_txid, feerate_per_kw,
+					self.get_counterparty_selected_contest_delay().unwrap(), &htlc,
+					&keys.broadcaster_delayed_payment_key, &keys.revocation_key);
+
+				let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, &keys);
+				let htlc_sighash = hash_to_message!(&bip143::SigHashCache::new(&htlc_tx).signature_hash(0, &htlc_redeemscript, htlc.amount_msat / 1000, SigHashType::All)[..]);
+				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_without_source.push((htlc.clone(), Some(msg.htlc_signatures[idx])));
 				htlcs_and_sigs.push((htlc, Some(msg.htlc_signatures[idx]), source));
 			} else {
-				htlcs_without_source.push((htlc.clone(), None));
 				htlcs_and_sigs.push((htlc, None, source));
 			}
 		}
 
-		let next_per_commitment_point = self.local_keys.get_per_commitment_point(self.cur_local_commitment_transaction_number - 1, &self.secp_ctx);
-		let per_commitment_secret = self.local_keys.release_commitment_secret(self.cur_local_commitment_transaction_number + 1);
+		let holder_commitment_tx = HolderCommitmentTransaction::new(
+			commitment_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_our_commitment = false;
-		if !self.channel_outbound {
-			if let Some(fee_update) = self.pending_update_fee {
-				self.feerate_per_kw = fee_update;
-				// We later use the presence of pending_update_fee to indicate we should generate a
-				// commitment_signed upon receipt of revoke_and_ack, so we can only set it to None
-				// if we're not awaiting a revoke (ie will send a commitment_signed now).
-				if (self.channel_state & ChannelState::AwaitingRemoteRevoke as u32) == 0 {
-					need_our_commitment = true;
-					self.pending_update_fee = None;
-				}
+		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;
 			}
 		}
 
-		let their_funding_pubkey = self.their_pubkeys.as_ref().unwrap().funding_pubkey;
-
 		self.latest_monitor_update_id += 1;
 		let mut monitor_update = ChannelMonitorUpdate {
 			update_id: self.latest_monitor_update_id,
-			updates: vec![ChannelMonitorUpdateStep::LatestLocalCommitmentTXInfo {
-				commitment_tx: LocalCommitmentTransaction::new_missing_local_sig(local_commitment_tx.0, msg.signature.clone(), &self.local_keys.pubkeys().funding_pubkey, &their_funding_pubkey, local_keys, self.feerate_per_kw, htlcs_without_source),
+			updates: vec![ChannelMonitorUpdateStep::LatestHolderCommitmentTXInfo {
+				commitment_tx: holder_commitment_tx,
 				htlc_outputs: htlcs_and_sigs
 			}]
 		};
-		self.channel_monitor.as_mut().unwrap().update_monitor_ooo(monitor_update.clone(), logger).unwrap();
 
 		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_our_commitment = true;
+				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_our_commitment = true;
+				need_commitment = true;
 			}
 		}
 
-		self.cur_local_commitment_transaction_number -= 1;
-		// Note that if we need_our_commitment & !AwaitingRemoteRevoke we'll call
+		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;
 
@@ -2080,7 +2565,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 			// 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_our_commitment && (self.channel_state & (ChannelState::AwaitingRemoteRevoke as u32)) == 0 {
+			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.
@@ -2091,12 +2576,12 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 				self.latest_monitor_update_id = monitor_update.update_id;
 				monitor_update.updates.append(&mut additional_update.updates);
 			}
-			// TODO: Call maybe_propose_first_closing_signed on restoration (or call it here and
-			// re-send the message on restoration)
+			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 (our_commitment_signed, closing_signed) = if need_our_commitment && (self.channel_state & (ChannelState::AwaitingRemoteRevoke as u32)) == 0 {
+		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().
@@ -2105,24 +2590,36 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 			// 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), None)
-		} else if !need_our_commitment {
-			(None, self.maybe_propose_first_closing_signed(fee_estimator))
-		} else { (None, None) };
+			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: per_commitment_secret,
-			next_per_commitment_point: next_per_commitment_point,
-		}, our_commitment_signed, closing_signed, monitor_update))
+			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)>, ChannelError> where L::Target: Logger {
+	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{}", self.holding_cell_htlc_updates.len(), if self.holding_cell_update_fee.is_some() { " and a fee update" } else { "" });
+			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!
@@ -2134,110 +2631,104 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 			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 err = None;
+			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.
-				if err.is_some() { // We're back to AwaitingRemoteRevoke (or are about to fail the channel)
-					self.holding_cell_htlc_updates.push(htlc_update);
-				} else {
-					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()) {
-								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 {}", log_bytes!(payment_hash.0), msg);
-										},
-										_ => {
-											log_info!(logger, "Failed to send HTLC with payment_hash {} resulting in a channel closure during holding_cell freeing", log_bytes!(payment_hash.0));
-										},
-									}
-									err = Some(e);
-								}
-							}
-						},
-						&HTLCUpdateAwaitingACK::ClaimHTLC { ref payment_preimage, htlc_id, .. } => {
-							match self.get_update_fulfill_htlc(htlc_id, *payment_preimage, logger) {
-								Ok((update_fulfill_msg_option, additional_monitor_update_opt)) => {
-									update_fulfill_htlcs.push(update_fulfill_msg_option.unwrap());
-									if let Some(mut additional_monitor_update) = additional_monitor_update_opt {
-										monitor_update.updates.append(&mut additional_monitor_update.updates);
-									}
-								},
-								Err(e) => {
-									if let ChannelError::Ignore(_) = e {}
-									else {
-										panic!("Got a non-IgnoreError action trying to fulfill holding cell HTLC");
-									}
+				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()) {
+							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::FailHTLC { htlc_id, ref err_packet } => {
-							match self.get_update_fail_htlc(htlc_id, err_packet.clone()) {
-								Ok(update_fail_msg_option) => 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");
-									}
+						}
+					},
+					&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 err.is_some() {
-						self.holding_cell_htlc_updates.push(htlc_update);
-						if let Some(ChannelError::Ignore(_)) = err {
-							// If we failed to add the HTLC, but got an Ignore error, we should
-							// still send the new commitment_signed, so reset the err to None.
-							err = None;
 						}
-					}
+					},
 				}
 			}
-			//TODO: Need to examine the type of err - if it's a fee issue or similar we may want to
-			//fail it back the route, if it's a temporary issue we can ignore it...
-			match err {
-				None => {
-					if update_add_htlcs.is_empty() && update_fulfill_htlcs.is_empty() && update_fail_htlcs.is_empty() && self.holding_cell_update_fee.is_none() {
-						// This should never actually happen and indicates we got some Errs back
-						// from update_fulfill_htlc/update_fail_htlc, but we handle it anyway in
-						// case there is some strange way to hit duplicate HTLC removes.
-						return Ok(None);
-					}
-					let update_fee = if let Some(feerate) = self.holding_cell_update_fee {
-							self.pending_update_fee = self.holding_cell_update_fee.take();
-							Some(msgs::UpdateFee {
-								channel_id: self.channel_id,
-								feerate_per_kw: feerate as u32,
-							})
-						} else {
-							None
-						};
+			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() {
+				assert!(self.is_outbound());
+				self.pending_update_fee = Some((feerate, FeeUpdateState::Outbound));
+				Some(msgs::UpdateFee {
+					channel_id: self.channel_id,
+					feerate_per_kw: feerate as u32,
+				})
+			} 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);
+			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);
 
-					Ok(Some((msgs::CommitmentUpdate {
-						update_add_htlcs,
-						update_fulfill_htlcs,
-						update_fail_htlcs,
-						update_fail_malformed_htlcs: Vec::new(),
-						update_fee: update_fee,
-						commitment_signed,
-					}, monitor_update)))
-				},
-				Some(e) => Err(e)
-			}
+			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)
+			Ok((None, Vec::new()))
 		}
 	}
 
@@ -2246,9 +2737,8 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 	/// 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<F: Deref, L: Deref>(&mut self, msg: &msgs::RevokeAndACK, fee_estimator: &F, logger: &L) -> Result<(Option<msgs::CommitmentUpdate>, Vec<(PendingHTLCInfo, u64)>, Vec<(HTLCSource, PaymentHash, HTLCFailReason)>, Option<msgs::ClosingSigned>, ChannelMonitorUpdate), ChannelError>
-		where F::Target: FeeEstimator,
-					L::Target: Logger,
+	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()));
@@ -2260,8 +2750,10 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 			return Err(ChannelError::Close("Peer sent revoke_and_ack after we'd started exchanging closing_signeds".to_owned()));
 		}
 
-		if let Some(their_prev_commitment_point) = self.their_prev_commitment_point {
-			if PublicKey::from_secret_key(&self.secp_ctx, &secp_check!(SecretKey::from_slice(&msg.per_commitment_secret), "Peer provided an invalid per_commitment_secret".to_owned())) != their_prev_commitment_point {
+		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()));
 			}
 		}
@@ -2277,30 +2769,41 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 			return Err(ChannelError::Close("Received an unexpected revoke_and_ack".to_owned()));
 		}
 
-		self.commitment_secrets.provide_secret(self.cur_remote_commitment_transaction_number + 1, msg.per_commitment_secret)
+		#[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_remote_commitment_transaction_number + 1,
+				idx: self.cur_counterparty_commitment_transaction_number + 1,
 				secret: msg.per_commitment_secret,
 			}],
 		};
-		self.channel_monitor.as_mut().unwrap().update_monitor_ooo(monitor_update.clone(), logger).unwrap();
 
 		// 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.their_prev_commitment_point = self.their_cur_commitment_point;
-		self.their_cur_commitment_point = Some(msg.next_per_commitment_point);
-		self.cur_remote_commitment_transaction_number -= 1;
+		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...");
+		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;
@@ -2327,6 +2830,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 					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;
 					}
@@ -2335,10 +2839,8 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 			});
 			for htlc in pending_inbound_htlcs.iter_mut() {
 				let swap = if let &InboundHTLCState::AwaitingRemoteRevokeToAnnounce(_) = &htlc.state {
-					log_trace!(logger, " ...promoting inbound AwaitingRemoteRevokeToAnnounce {} to Committed", log_bytes!(htlc.payment_hash.0));
 					true
 				} else if let &InboundHTLCState::AwaitingAnnouncedRemoteRevoke(_) = &htlc.state {
-					log_trace!(logger, " ...promoting inbound AwaitingAnnouncedRemoteRevoke {} to Committed", log_bytes!(htlc.payment_hash.0));
 					true
 				} else { false };
 				if swap {
@@ -2346,11 +2848,13 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 					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) => {
@@ -2364,6 +2868,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 								}
 							},
 							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;
 							}
@@ -2387,21 +2892,22 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		}
 		self.value_to_self_msat = (self.value_to_self_msat as i64 + value_to_self_msat_diff) as u64;
 
-		if self.channel_outbound {
-			if let Some(feerate) = self.pending_update_fee.take() {
-				self.feerate_per_kw = feerate;
-			}
-		} else {
-			if let Some(feerate) = self.pending_update_fee {
-				// Because a node cannot send two commitment_signeds in a row without getting a
-				// revoke_and_ack from us (as it would otherwise not know the per_commitment_point
-				// it should use to create keys with) and because a node can't send a
-				// commitment_signed without changes, checking if the feerate is equal to the
-				// pending feerate update is sufficient to detect require_commitment.
-				if feerate == self.feerate_per_kw {
+		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;
-				}
+				},
 			}
 		}
 
@@ -2421,11 +2927,18 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 			}
 			self.monitor_pending_forwards.append(&mut to_forward_infos);
 			self.monitor_pending_failures.append(&mut revoked_htlcs);
-			return Ok((None, Vec::new(), Vec::new(), None, monitor_update))
+			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)) => {
+			(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);
@@ -2440,9 +2953,16 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 				self.latest_monitor_update_id = monitor_update.update_id;
 				monitor_update.updates.append(&mut additional_update.updates);
 
-				Ok((Some(commitment_update), to_forward_infos, revoked_htlcs, None, monitor_update))
+				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 => {
+			(None, htlcs_to_fail) => {
 				if require_commitment {
 					let (commitment_signed, mut additional_update) = self.send_commitment_no_status_check(logger)?;
 
@@ -2451,27 +2971,39 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 					self.latest_monitor_update_id = monitor_update.update_id;
 					monitor_update.updates.append(&mut additional_update.updates);
 
-					Ok((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
-					}), to_forward_infos, revoked_htlcs, None, monitor_update))
+					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 {
-					Ok((None, to_forward_infos, revoked_htlcs, self.maybe_propose_first_closing_signed(fee_estimator), monitor_update))
+					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.
 	/// You MUST call send_commitment prior to any other calls on this Channel
 	fn send_update_fee(&mut self, feerate_per_kw: u32) -> Option<msgs::UpdateFee> {
-		if !self.channel_outbound {
+		if !self.is_outbound() {
 			panic!("Cannot send fee from inbound channel");
 		}
 		if !self.is_usable() {
@@ -2481,17 +3013,17 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 			panic!("Cannot update fee while peer is disconnected/we're awaiting a monitor update (ChannelManager should have caught this)");
 		}
 
-		if (self.channel_state & (ChannelState::AwaitingRemoteRevoke as u32)) == (ChannelState::AwaitingRemoteRevoke as u32) {
+		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);
+		self.pending_update_fee = Some((feerate_per_kw, FeeUpdateState::Outbound));
 
 		Some(msgs::UpdateFee {
 			channel_id: self.channel_id,
-			feerate_per_kw: feerate_per_kw,
+			feerate_per_kw,
 		})
 	}
 
@@ -2505,23 +3037,22 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		}
 	}
 
-	/// Removes any uncommitted HTLCs, to be used on peer disconnection, including any pending
-	/// HTLCs that we intended to add but haven't as we were waiting on a remote revoke.
-	/// Returns the set of PendingHTLCStatuses from remote uncommitted HTLCs (which we're
-	/// implicitly dropping) and the payment_hashes of HTLCs we tried to add but are dropping.
+	/// 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) -> Vec<(HTLCSource, PaymentHash)> where L::Target: Logger {
-		let mut outbound_drops = Vec::new();
-
+	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 outbound_drops;
+			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| {
@@ -2549,7 +3080,14 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 				},
 			}
 		});
-		self.next_remote_htlc_id -= inbound_drop_count;
+		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 {
@@ -2560,18 +3098,8 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 			}
 		}
 
-		self.holding_cell_htlc_updates.retain(|htlc_update| {
-			match htlc_update {
-				&HTLCUpdateAwaitingACK::AddHTLC { ref payment_hash, ref source, .. } => {
-					outbound_drops.push((source.clone(), payment_hash.clone()));
-					false
-				},
-				&HTLCUpdateAwaitingACK::ClaimHTLC {..} | &HTLCUpdateAwaitingACK::FailHTLC {..} => true,
-			}
-		});
 		self.channel_state |= ChannelState::PeerDisconnected as u32;
-		log_debug!(logger, "Peer disconnection resulted in {} remote-announced HTLC drops and {} waiting-to-locally-announced HTLC drops on channel {}", outbound_drops.len(), inbound_drop_count, log_bytes!(self.channel_id()));
-		outbound_drops
+		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
@@ -2580,51 +3108,59 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 	/// 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)>) {
-		assert_eq!(self.channel_state & ChannelState::MonitorUpdateFailed as u32, 0);
-		self.monitor_pending_revoke_and_ack = resend_raa;
-		self.monitor_pending_commitment_signed = resend_commitment;
-		assert!(self.monitor_pending_forwards.is_empty());
-		mem::swap(&mut pending_forwards, &mut self.monitor_pending_forwards);
-		assert!(self.monitor_pending_failures.is_empty());
-		mem::swap(&mut pending_fails, &mut self.monitor_pending_failures);
+	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) -> (Option<msgs::RevokeAndACK>, Option<msgs::CommitmentUpdate>, RAACommitmentOrder, Vec<(PendingHTLCInfo, u64)>, Vec<(HTLCSource, PaymentHash, HTLCFailReason)>, bool, Option<msgs::FundingLocked>) where L::Target: Logger {
+	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 needs_broadcast_safe = self.channel_state & (ChannelState::FundingSent as u32) != 0 && self.channel_outbound;
+		let funding_broadcastable = if self.channel_state & (ChannelState::FundingSent as u32) != 0 && self.is_outbound() {
+			self.funding_transaction.take()
+		} else { None };
 
-		// Because we will never generate a FundingBroadcastSafe event when we're in
-		// MonitorUpdateFailed, if we assume the user only broadcast the funding transaction when
-		// they received the FundingBroadcastSafe event, 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 even got the funding transaction confirmed before the
-		// monitor was persisted.
+		// 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.channel_outbound, "Funding transaction broadcast without FundingBroadcastSafe!");
+			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.local_keys.get_per_commitment_point(self.cur_local_commitment_transaction_number, &self.secp_ctx);
+			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: next_per_commitment_point,
+				next_per_commitment_point,
 			})
 		} else { None };
 
-		let mut forwards = Vec::new();
-		mem::swap(&mut forwards, &mut self.monitor_pending_forwards);
-		let mut failures = Vec::new();
-		mem::swap(&mut failures, &mut self.monitor_pending_failures);
+		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 (None, None, RAACommitmentOrder::RevokeAndACKFirst, forwards, failures, needs_broadcast_safe, funding_locked);
+			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 {
@@ -2637,32 +3173,52 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		self.monitor_pending_revoke_and_ack = false;
 		self.monitor_pending_commitment_signed = false;
 		let order = self.resend_order.clone();
-		log_trace!(logger, "Restored monitor updating resulting in {}{} commitment update and {} RAA, with {} first",
-			if needs_broadcast_safe { "a funding broadcast safe, " } else { "" },
-			if commitment_update.is_some() { "a" } else { "no" },
-			if raa.is_some() { "an" } else { "no" },
+		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"});
-		(raa, commitment_update, order, forwards, failures, needs_broadcast_safe, funding_locked)
+		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.channel_outbound {
+		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::<ChanSigner>::check_remote_fee(fee_estimator, msg.feerate_per_kw)?;
-		self.pending_update_fee = Some(msg.feerate_per_kw);
+		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();
+
+		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();
+			let outbound_stats = self.get_outbound_pending_htlc_stats();
+			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.local_keys.get_per_commitment_point(self.cur_local_commitment_transaction_number, &self.secp_ctx);
-		let per_commitment_secret = self.local_keys.release_commitment_secret(self.cur_local_commitment_transaction_number + 2);
+		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,
@@ -2718,18 +3274,25 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 			}
 		}
 
-		log_trace!(logger, "Regenerated latest commitment update with {} update_adds, {} update_fulfills, {} update_fails, and {} update_fail_malformeds",
+		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: None,
+			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, Option<msgs::Shutdown>), ChannelError> where L::Target: Logger {
+	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
@@ -2745,13 +3308,13 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		if msg.next_remote_commitment_number > 0 {
 			match msg.data_loss_protect {
 				OptionalField::Present(ref data_loss) => {
-					let expected_point = self.local_keys.get_per_commitment_point(INITIAL_COMMITMENT_NUMBER - msg.next_remote_commitment_number + 1, &self.secp_ctx);
+					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_local_commitment_transaction_number {
+					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()
 						));
@@ -2766,6 +3329,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		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(),
@@ -2780,22 +3344,22 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 					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, shutdown_msg));
+				return Ok((None, None, None, None, RAACommitmentOrder::CommitmentFirst, Vec::new(), shutdown_msg));
 			}
 
 			// We have OurFundingLocked set!
-			let next_per_commitment_point = self.local_keys.get_per_commitment_point(self.cur_local_commitment_transaction_number, &self.secp_ctx);
+			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: next_per_commitment_point,
-			}), None, None, None, RAACommitmentOrder::CommitmentFirst, shutdown_msg));
+				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_local_commitment_transaction_number {
+		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_local_commitment_transaction_number {
+		} 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
@@ -2806,22 +3370,22 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 			return Err(ChannelError::Close("Peer attempted to reestablish channel with a very old local commitment transaction".to_owned()));
 		};
 
-		// We increment cur_remote_commitment_transaction_number only upon receipt of
+		// 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 our_next_remote_commitment_number = INITIAL_COMMITMENT_NUMBER - self.cur_remote_commitment_transaction_number + if (self.channel_state & ChannelState::AwaitingRemoteRevoke as u32) != 0 { 1 } else { 0 };
+		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_local_commitment_transaction_number == 1 {
+		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.local_keys.get_per_commitment_point(self.cur_local_commitment_transaction_number, &self.secp_ctx);
+			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: next_per_commitment_point,
+				next_per_commitment_point,
 			})
 		} else { None };
 
-		if msg.next_local_commitment_number == our_next_remote_commitment_number {
+		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 {
@@ -2835,14 +3399,19 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 				// now!
 				match self.free_holding_cell_htlcs(logger) {
 					Err(ChannelError::Close(msg)) => return Err(ChannelError::Close(msg)),
-					Err(ChannelError::Ignore(_)) | Err(ChannelError::CloseDelayBroadcast(_)) => panic!("Got non-channel-failing result from free_holding_cell_htlcs"),
-					Ok(Some((commitment_update, monitor_update))) => return Ok((resend_funding_locked, required_revoke, Some(commitment_update), Some(monitor_update), self.resend_order.clone(), shutdown_msg)),
-					Ok(None) => return Ok((resend_funding_locked, required_revoke, None, None, self.resend_order.clone(), shutdown_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(), shutdown_msg));
+				return Ok((resend_funding_locked, required_revoke, None, None, self.resend_order.clone(), Vec::new(), shutdown_msg));
 			}
-		} else if msg.next_local_commitment_number == our_next_remote_commitment_number - 1 {
+		} 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 {
@@ -2851,47 +3420,134 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 
 			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(), shutdown_msg));
+				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(), 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()));
 		}
 	}
 
-	fn maybe_propose_first_closing_signed<F: Deref>(&mut self, fee_estimator: &F) -> Option<msgs::ClosingSigned>
+	/// 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 !self.channel_outbound || !self.pending_inbound_htlcs.is_empty() || !self.pending_outbound_htlcs.is_empty() ||
-				self.channel_state & (BOTH_SIDES_SHUTDOWN_MASK | ChannelState::AwaitingRemoteRevoke as u32) != BOTH_SIDES_SHUTDOWN_MASK ||
-				self.last_sent_closing_fee.is_some() || self.pending_update_fee.is_some() {
-			return None;
-		}
+		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);
-		if self.feerate_per_kw > proposed_feerate {
-			proposed_feerate = self.feerate_per_kw;
-		}
-		let tx_weight = Self::get_closing_transaction_weight(&self.get_closing_scriptpubkey(), self.their_shutdown_scriptpubkey.as_ref().unwrap());
+		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);
 
-		let (closing_tx, total_fee_satoshis) = self.build_closing_transaction(proposed_total_fee_satoshis, false);
-		let our_sig = self.local_keys
+		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)
-			.ok();
-		if our_sig.is_none() { return None; }
+			.map_err(|()| ChannelError::Close("Failed to get signature for closing transaction.".to_owned()))?;
 
-		self.last_sent_closing_fee = Some((proposed_feerate, total_fee_satoshis, our_sig.clone().unwrap()));
-		Some(msgs::ClosingSigned {
+		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: our_sig.unwrap(),
-		})
+			signature: sig,
+			fee_range: Some(msgs::ClosingSignedFeeRange {
+				min_fee_satoshis: our_min_fee,
+				max_fee_satoshis: our_max_fee,
+			}),
+		}), None))
 	}
 
-	pub fn shutdown<F: Deref>(&mut self, fee_estimator: &F, msg: &msgs::Shutdown) -> Result<(Option<msgs::Shutdown>, Option<msgs::ClosingSigned>, Vec<(HTLCSource, PaymentHash)>), ChannelError>
-		where F::Target: FeeEstimator
+	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()));
@@ -2909,30 +3565,57 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		}
 		assert_eq!(self.channel_state & ChannelState::ShutdownComplete as u32, 0);
 
-		// BOLT 2 says we must only send a scriptpubkey of certain standard forms, which are up to
-		// 34 bytes in length, so don't let the remote peer feed us some super fee-heavy script.
-		if self.channel_outbound && msg.scriptpubkey.len() > 34 {
-			return Err(ChannelError::Close(format!("Got shutdown_scriptpubkey ({}) of absurd length from remote peer", msg.scriptpubkey.to_bytes().to_hex())));
-		}
-
-		//Check shutdown_scriptpubkey form as BOLT says we must
-		if !msg.scriptpubkey.is_p2pkh() && !msg.scriptpubkey.is_p2sh() && !msg.scriptpubkey.is_v0_p2wpkh() && !msg.scriptpubkey.is_v0_p2wsh() {
+		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.their_shutdown_scriptpubkey.is_some() {
-			if Some(&msg.scriptpubkey) != self.their_shutdown_scriptpubkey.as_ref() {
+		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.their_shutdown_scriptpubkey = Some(msg.scriptpubkey.clone());
+			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.
@@ -2947,45 +3630,32 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 				_ => true
 			}
 		});
-		// If we have any LocalAnnounced updates we'll probably just get back a update_fail_htlc
-		// immediately after the commitment dance, but we can send a Shutdown cause we won't send
-		// any further commitment updates after we set LocalShutdownSent.
-
-		let our_shutdown = if (self.channel_state & ChannelState::LocalShutdownSent as u32) == ChannelState::LocalShutdownSent as u32 {
-			None
-		} else {
-			Some(msgs::Shutdown {
-				channel_id: self.channel_id,
-				scriptpubkey: self.get_closing_scriptpubkey(),
-			})
-		};
 
 		self.channel_state |= ChannelState::LocalShutdownSent as u32;
 		self.update_time_counter += 1;
 
-		Ok((our_shutdown, self.maybe_propose_first_closing_signed(fee_estimator), dropped_outbound_htlcs))
+		Ok((shutdown, monitor_update, dropped_outbound_htlcs))
 	}
 
-	fn build_signed_closing_transaction(&self, tx: &mut Transaction, their_sig: &Signature, our_sig: &Signature) {
-		if tx.input.len() != 1 { panic!("Tried to sign closing transaction that had input count != 1!"); }
-		if tx.input[0].witness.len() != 0 { panic!("Tried to re-sign closing transaction"); }
-		if tx.output.len() > 2 { panic!("Tried to sign bogus closing transaction"); }
+	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 our_funding_key = self.local_keys.pubkeys().funding_pubkey.serialize();
-		let their_funding_key = self.their_funding_pubkey().serialize();
-		if our_funding_key[..] < their_funding_key[..] {
-			tx.input[0].witness.push(our_sig.serialize_der().to_vec());
-			tx.input[0].witness.push(their_sig.serialize_der().to_vec());
+		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(their_sig.serialize_der().to_vec());
-			tx.input[0].witness.push(our_sig.serialize_der().to_vec());
+			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>
@@ -3000,91 +3670,142 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		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 > 21000000 * 10000000 { //this is required to stop potential overflow in build_closing_transaction
+		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 greater than the value they can claim. Fee in message: {}", 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 mut sighash = hash_to_message!(&bip143::SighashComponents::new(&closing_tx).sighash_all(&closing_tx.input[0], &funding_redeemscript, self.channel_value_satoshis)[..]);
-
-		let their_funding_pubkey = &self.their_pubkeys.as_ref().unwrap().funding_pubkey;
+		let sighash = closing_tx.trust().get_sighash_all(&funding_redeemscript, self.channel_value_satoshis);
 
-		match self.secp_ctx.verify(&sighash, &msg.signature, their_funding_pubkey) {
+		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;
-				sighash = hash_to_message!(&bip143::SighashComponents::new(&closing_tx).sighash_all(&closing_tx.input[0], &funding_redeemscript, self.channel_value_satoshis)[..]);
-				secp_check!(self.secp_ctx.verify(&sighash, &msg.signature, self.their_funding_pubkey()), "Invalid closing tx signature from peer".to_owned());
+				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());
 			},
 		};
 
-		if let Some((_, last_fee, our_sig)) = self.last_sent_closing_fee {
+		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 {
-				self.build_signed_closing_transaction(&mut closing_tx, &msg.signature, &our_sig);
+				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(closing_tx)));
+				return Ok((None, Some(tx)));
 			}
 		}
 
-		macro_rules! propose_new_feerate {
-			($new_feerate: expr) => {
-				let closing_tx_max_weight = Self::get_closing_transaction_weight(&self.get_closing_scriptpubkey(), self.their_shutdown_scriptpubkey.as_ref().unwrap());
-				let (closing_tx, used_total_fee) = self.build_closing_transaction($new_feerate as u64 * closing_tx_max_weight / 1000, false);
-				let our_sig = self.local_keys
+		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()))?;
-				self.last_sent_closing_fee = Some(($new_feerate, used_total_fee, our_sig.clone()));
+
+				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_total_fee,
-					signature: our_sig,
-				}), None))
+					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))
 			}
 		}
 
-		let proposed_sat_per_kw = msg.fee_satoshis  * 1000 / closing_tx.get_weight() as u64;
-		if self.channel_outbound {
-			let our_max_feerate = fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Normal);
-			if (proposed_sat_per_kw as u32) > our_max_feerate {
-				if let Some((last_feerate, _, _)) = self.last_sent_closing_fee {
-					if our_max_feerate <= last_feerate {
-						return Err(ChannelError::Close(format!("Unable to come to consensus about closing feerate, remote wanted something higher ({}) than our Normal feerate ({})", last_feerate, our_max_feerate)));
-					}
+		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)));
 				}
-				propose_new_feerate!(our_max_feerate);
+				// The proposed fee is in our acceptable range, accept it and broadcast!
+				propose_fee!(msg.fee_satoshis);
 			}
 		} else {
-			let our_min_feerate = fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Background);
-			if (proposed_sat_per_kw as u32) < our_min_feerate {
-				if let Some((last_feerate, _, _)) = self.last_sent_closing_fee {
-					if our_min_feerate >= last_feerate {
-						return Err(ChannelError::Close(format!("Unable to come to consensus about closing feerate, remote wanted something lower ({}) than our Background feerate ({}).", last_feerate, our_min_feerate)));
+			// 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)));
 					}
 				}
-				propose_new_feerate!(our_min_feerate);
+			} 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);
+				}
 			}
 		}
-
-		let our_sig = self.local_keys
-			.sign_closing_transaction(&closing_tx, &self.secp_ctx)
-			.map_err(|_| ChannelError::Close("External signer refused to sign closing transaction".to_owned()))?;
-		self.build_signed_closing_transaction(&mut closing_tx, &msg.signature, &our_sig);
-
-		self.channel_state = ChannelState::ShutdownComplete as u32;
-		self.update_time_counter += 1;
-
-		Ok((Some(msgs::ClosingSigned {
-			channel_id: self.channel_id,
-			fee_satoshis: msg.fee_satoshis,
-			signature: our_sig,
-		}), Some(closing_tx)))
 	}
 
 	// Public utilities:
@@ -3093,20 +3814,16 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		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
 	}
 
-	/// May only be called after funding has been initiated (ie is_funding_initiated() is true)
-	pub fn channel_monitor(&mut self) -> &mut ChannelMonitor<ChanSigner> {
-		if self.channel_state < ChannelState::FundingSent as u32 {
-			panic!("Can't get a channel monitor until funding has been created");
-		}
-		self.channel_monitor.as_mut().unwrap()
-	}
-
 	/// Guaranteed to be Some after both FundingLocked messages have been exchanged (and, thus,
 	/// is_usable() returns true).
 	/// Allowed in any state (including after shutdown)
@@ -3117,17 +3834,35 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 	/// 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.funding_txo
+		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_their_node_id(&self) -> PublicKey {
-		self.their_node_id
+	pub fn get_counterparty_node_id(&self) -> PublicKey {
+		self.counterparty_node_id
 	}
 
 	/// Allowed in any state (including after shutdown)
-	pub fn get_our_htlc_minimum_msat(&self) -> u64 {
-		self.our_htlc_minimum_msat
+	#[cfg(test)]
+	pub fn get_holder_htlc_minimum_msat(&self) -> u64 {
+		self.holder_htlc_minimum_msat
 	}
 
 	/// Allowed in any state (including after shutdown)
@@ -3136,15 +3871,15 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 			// 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 * 9 / 10,
+			self.channel_value_satoshis * 1000 * 9 / 10,
 
-			Channel::<ChanSigner>::get_our_max_htlc_value_in_flight_msat(self.channel_value_satoshis)
+			Channel::<Signer>::get_holder_max_htlc_value_in_flight_msat(self.channel_value_satoshis)
 		);
 	}
 
 	/// Allowed in any state (including after shutdown)
-	pub fn get_their_htlc_minimum_msat(&self) -> u64 {
-		self.our_htlc_minimum_msat
+	pub fn get_counterparty_htlc_minimum_msat(&self) -> u64 {
+		self.counterparty_htlc_minimum_msat
 	}
 
 	pub fn get_value_satoshis(&self) -> u64 {
@@ -3152,29 +3887,51 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 	}
 
 	pub fn get_fee_proportional_millionths(&self) -> u32 {
-		self.config.fee_proportional_millionths
+		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
 	}
 
-	#[cfg(test)]
 	pub fn get_feerate(&self) -> u32 {
 		self.feerate_per_kw
 	}
 
-	pub fn get_cur_local_commitment_transaction_number(&self) -> u64 {
-		self.cur_local_commitment_transaction_number + 1
+	pub fn get_dust_buffer_feerate(&self) -> 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);
+		}
+		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_remote_commitment_transaction_number(&self) -> u64 {
-		self.cur_remote_commitment_transaction_number + 1 - if self.channel_state & (ChannelState::AwaitingRemoteRevoke as u32) != 0 { 1 } else { 0 }
+	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_remote_commitment_transaction_number(&self) -> u64 {
-		self.cur_remote_commitment_transaction_number + 2
+	pub fn get_revoked_counterparty_commitment_transaction_number(&self) -> u64 {
+		self.cur_counterparty_commitment_transaction_number + 2
 	}
 
 	#[cfg(test)]
-	pub fn get_local_keys(&self) -> &ChanSigner {
-		&self.local_keys
+	pub fn get_signer(&self) -> &Signer {
+		&self.holder_signer
 	}
 
 	#[cfg(test)]
@@ -3182,7 +3939,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		ChannelValueStat {
 			value_to_self_msat: self.value_to_self_msat,
 			channel_value_msat: self.channel_value_satoshis * 1000,
-			channel_reserve_msat: self.local_channel_reserve_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: {
@@ -3197,8 +3954,8 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 				}
 				res
 			},
-			their_max_htlc_value_in_flight_msat: self.their_max_htlc_value_in_flight_msat,
-			their_dust_limit_msat: self.their_dust_limit_satoshis * 1000,
+			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,
 		}
 	}
 
@@ -3216,29 +3973,13 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 	}
 
 	pub fn is_outbound(&self) -> bool {
-		self.channel_outbound
+		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_our_fee_base_msat<F: Deref>(&self, fee_estimator: &F) -> u32
-		where F::Target: FeeEstimator
-	{
-		// For lack of a better metric, we calculate what it would cost to consolidate the new HTLC
-		// output value back into a transaction with the regular channel output:
-
-		// the fee cost of the HTLC-Success/HTLC-Timeout transaction:
-		let mut res = self.feerate_per_kw as u64 * cmp::max(HTLC_TIMEOUT_TX_WEIGHT, HTLC_SUCCESS_TX_WEIGHT) / 1000;
-
-		if self.channel_outbound {
-			// + the marginal fee increase cost to us in the commitment transaction:
-			res += self.feerate_per_kw as u64 * COMMITMENT_TX_WEIGHT_PER_HTLC / 1000;
-		}
-
-		// + the marginal cost of an input which spends the HTLC-Success/HTLC-Timeout output:
-		res += fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Normal) as u64 * SPENDING_INPUT_FOR_A_OUTPUT_WEIGHT / 1000;
-
-		res as u32
+	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
@@ -3257,7 +3998,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 	/// 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 | ChannelState::MonitorUpdateFailed as u32) == 0)
+		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.
@@ -3271,6 +4012,16 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		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.
@@ -3281,46 +4032,149 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		} else { false }
 	}
 
-	pub fn to_disabled_staged(&mut self) {
-		self.network_sync = UpdateStatus::DisabledStaged;
+	pub fn channel_update_status(&self) -> ChannelUpdateStatus {
+		self.channel_update_status
 	}
 
-	pub fn to_disabled_marked(&mut self) {
-		self.network_sync = UpdateStatus::DisabledMarked;
+	pub fn set_channel_update_status(&mut self, status: ChannelUpdateStatus) {
+		self.channel_update_status = status;
 	}
 
-	pub fn to_fresh(&mut self) {
-		self.network_sync = UpdateStatus::Fresh;
-	}
+	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
+		};
 
-	pub fn is_disabled_staged(&self) -> bool {
-		self.network_sync == UpdateStatus::DisabledStaged
+		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
 	}
 
-	pub fn is_disabled_marked(&self) -> bool {
-		self.network_sync == UpdateStatus::DisabledMarked
+	/// 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>, msgs::ErrorMessage> 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;
+							return Err(msgs::ErrorMessage {
+								channel_id: self.channel_id(),
+								data: "funding tx had wrong script/value or output index".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(msgs::ErrorMessage {
+							channel_id: self.channel_id(),
+							data: "Commitment or closing transaction was confirmed on chain.".to_owned()
+						});
+					}
+				}
+			}
+		}
+		Ok(None)
 	}
 
-	/// When we receive a new block, we (a) check whether the block contains the funding
-	/// transaction (which would start us counting blocks until we send the funding_signed), and
-	/// (b) 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, channel closure detection, HTLC transaction broadcasting, etc) is
+	/// 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.
-	/// Only returns an ErrorAction of DisconnectPeer, if Err.
 	///
 	/// May return some HTLCs (and their payment_hash) which have timed out and should be failed
 	/// back.
-	pub fn block_connected(&mut self, header: &BlockHeader, height: u32, txn_matched: &[&Transaction], indexes_of_txn_matched: &[usize]) -> Result<(Option<msgs::FundingLocked>, Vec<(HTLCSource, PaymentHash)>), msgs::ErrorMessage> {
+	pub fn best_block_updated<L: Deref>(&mut self, height: u32, highest_header_time: u32, logger: &L)
+			-> Result<(Option<msgs::FundingLocked>, Vec<(HTLCSource, PaymentHash)>), msgs::ErrorMessage> where L::Target: Logger {
 		let mut timed_out_htlcs = Vec::new();
+		let unforwarded_htlc_cltv_limit = height + HTLC_FAIL_BACK_BUFFER;
 		self.holding_cell_htlc_updates.retain(|htlc_update| {
 			match htlc_update {
 				&HTLCUpdateAwaitingACK::AddHTLC { ref payment_hash, ref source, ref cltv_expiry, .. } => {
-					if *cltv_expiry <= height + HTLC_FAIL_BACK_BUFFER {
+					if *cltv_expiry <= unforwarded_htlc_cltv_limit {
 						timed_out_htlcs.push((source.clone(), payment_hash.clone()));
 						false
 					} else { true }
@@ -3328,206 +4182,151 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 				_ => true
 			}
 		});
-		let non_shutdown_state = self.channel_state & (!MULTI_STATE_FLAGS);
-		if header.bitcoin_hash() != self.last_block_connected {
-			if self.funding_tx_confirmations > 0 {
-				self.funding_tx_confirmations += 1;
-			}
-		}
-		if non_shutdown_state & !(ChannelState::TheirFundingLocked as u32) == ChannelState::FundingSent as u32 {
-			for (ref tx, index_in_block) in txn_matched.iter().zip(indexes_of_txn_matched) {
-				if tx.txid() == self.funding_txo.unwrap().txid {
-					let txo_idx = self.funding_txo.unwrap().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.channel_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.channel_state = ChannelState::ShutdownComplete as u32;
-						self.update_time_counter += 1;
-						return Err(msgs::ErrorMessage {
-							channel_id: self.channel_id(),
-							data: "funding tx had wrong script/value".to_owned()
-						});
-					} else {
-						if self.channel_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!");
-								}
-							}
-						}
-						if height > 0xff_ff_ff || (*index_in_block) > 0xff_ff_ff {
-							panic!("Block was bogus - either height 16 million or had > 16 million transactions");
-						}
-						assert!(txo_idx <= 0xffff); // txo_idx is a (u16 as usize), so this is just listed here for completeness
-						self.funding_tx_confirmations = 1;
-						self.short_channel_id = Some(((height as u64)          << (5*8)) |
-						                             ((*index_in_block as u64) << (2*8)) |
-						                             ((txo_idx as u64)         << (0*8)));
-					}
-				}
-			}
+
+		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));
 		}
-		if header.bitcoin_hash() != self.last_block_connected {
-			self.last_block_connected = header.bitcoin_hash();
-			self.update_time_counter = cmp::max(self.update_time_counter, header.time);
-			if let Some(channel_monitor) = self.channel_monitor.as_mut() {
-				channel_monitor.last_block_hash = self.last_block_connected;
+
+		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 self.funding_tx_confirmations > 0 {
-				if self.funding_tx_confirmations == self.minimum_depth as u64 {
-					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 update
-						// funding_tx_confirmed_in and return.
-						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 update
-						// funding_tx_confirmed_in and return.
-						false
-					};
-					self.funding_tx_confirmed_in = Some(header.bitcoin_hash());
-
-					//TODO: Note that this must be a duplicate of the previous commitment point they sent us,
-					//as otherwise we will have a commitment transaction that they can't revoke (well, kinda,
-					//they can by sending two revoke_and_acks back-to-back, but not really). This appears to be
-					//a protocol oversight, but I assume I'm just missing something.
-					if need_commitment_update {
-						if self.channel_state & (ChannelState::MonitorUpdateFailed as u32) == 0 {
-							let next_per_commitment_point = self.local_keys.get_per_commitment_point(self.cur_local_commitment_transaction_number, &self.secp_ctx);
-							return Ok((Some(msgs::FundingLocked {
-								channel_id: self.channel_id,
-								next_per_commitment_point: next_per_commitment_point,
-							}), timed_out_htlcs));
-						} else {
-							self.monitor_pending_funding_locked = true;
-							return Ok((None, timed_out_htlcs));
-						}
-					}
-				}
+
+			// 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 {
+				return Err(msgs::ErrorMessage {
+					channel_id: self.channel_id(),
+					data: format!("Funding transaction was un-confirmed. Locked at {} confs, now have {} confs.", self.minimum_depth.unwrap(), funding_tx_confirmations),
+				});
 			}
 		}
+
 		Ok((None, timed_out_htlcs))
 	}
 
-	/// Called by channelmanager based on chain blocks being disconnected.
-	/// Returns true if we need to close the channel now due to funding transaction
-	/// unconfirmation/reorg.
-	pub fn block_disconnected(&mut self, header: &BlockHeader) -> bool {
-		if self.funding_tx_confirmations > 0 {
-			self.funding_tx_confirmations -= 1;
-			if self.funding_tx_confirmations == UNCONF_THRESHOLD as u64 {
-				return true;
+	/// 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<(), msgs::ErrorMessage> 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(())
 		}
-		if Some(header.bitcoin_hash()) == self.funding_tx_confirmed_in {
-			self.funding_tx_confirmations = self.minimum_depth as u64 - 1;
-		}
-		self.last_block_connected = header.bitcoin_hash();
-		if let Some(channel_monitor) = self.channel_monitor.as_mut() {
-			channel_monitor.last_block_hash = self.last_block_connected;
-		}
-		false
 	}
 
 	// 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.channel_outbound {
+		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_local_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER {
+		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.local_keys.get_per_commitment_point(self.cur_local_commitment_transaction_number, &self.secp_ctx);
-		let local_keys = self.local_keys.pubkeys();
+		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: chain_hash,
+			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.our_dust_limit_satoshis,
-			max_htlc_value_in_flight_msat: Channel::<ChanSigner>::get_our_max_htlc_value_in_flight_msat(self.channel_value_satoshis),
-			channel_reserve_satoshis: Channel::<ChanSigner>::get_remote_channel_reserve_satoshis(self.channel_value_satoshis),
-			htlc_minimum_msat: self.our_htlc_minimum_msat,
+			dust_limit_satoshis: self.holder_dust_limit_satoshis,
+			max_htlc_value_in_flight_msat: Channel::<Signer>::get_holder_max_htlc_value_in_flight_msat(self.channel_value_satoshis),
+			channel_reserve_satoshis: Channel::<Signer>::get_holder_selected_channel_reserve_satoshis(self.channel_value_satoshis),
+			htlc_minimum_msat: self.holder_htlc_minimum_msat,
 			feerate_per_kw: self.feerate_per_kw as u32,
-			to_self_delay: self.our_to_self_delay,
+			to_self_delay: self.get_holder_selected_contest_delay(),
 			max_accepted_htlcs: OUR_MAX_HTLCS,
-			funding_pubkey: local_keys.funding_pubkey,
-			revocation_basepoint: local_keys.revocation_basepoint,
-			payment_point: local_keys.payment_point,
-			delayed_payment_basepoint: local_keys.delayed_payment_basepoint,
-			htlc_basepoint: local_keys.htlc_basepoint,
+			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(if self.config.commit_upfront_shutdown_pubkey { self.get_closing_scriptpubkey() } else { Builder::new().into_script() })
+			shutdown_scriptpubkey: OptionalField::Present(match &self.shutdown_scriptpubkey {
+				Some(script) => script.clone().into_inner(),
+				None => Builder::new().into_script(),
+			}),
 		}
 	}
 
 	pub fn get_accept_channel(&self) -> msgs::AcceptChannel {
-		if self.channel_outbound {
+		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_local_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER {
+		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.local_keys.get_per_commitment_point(self.cur_local_commitment_transaction_number, &self.secp_ctx);
-		let local_keys = self.local_keys.pubkeys();
+		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.our_dust_limit_satoshis,
-			max_htlc_value_in_flight_msat: Channel::<ChanSigner>::get_our_max_htlc_value_in_flight_msat(self.channel_value_satoshis),
-			channel_reserve_satoshis: Channel::<ChanSigner>::get_remote_channel_reserve_satoshis(self.channel_value_satoshis),
-			htlc_minimum_msat: self.our_htlc_minimum_msat,
-			minimum_depth: self.minimum_depth,
-			to_self_delay: self.our_to_self_delay,
+			dust_limit_satoshis: self.holder_dust_limit_satoshis,
+			max_htlc_value_in_flight_msat: Channel::<Signer>::get_holder_max_htlc_value_in_flight_msat(self.channel_value_satoshis),
+			channel_reserve_satoshis: Channel::<Signer>::get_holder_selected_channel_reserve_satoshis(self.channel_value_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: local_keys.funding_pubkey,
-			revocation_basepoint: local_keys.revocation_basepoint,
-			payment_point: local_keys.payment_point,
-			delayed_payment_basepoint: local_keys.delayed_payment_basepoint,
-			htlc_basepoint: local_keys.htlc_basepoint,
+			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(if self.config.commit_upfront_shutdown_pubkey { self.get_closing_scriptpubkey() } else { Builder::new().into_script() })
+			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 remote_keys = self.build_remote_transaction_keys()?;
-		let remote_initial_commitment_tx = self.build_commitment_transaction(self.cur_remote_commitment_transaction_number, &remote_keys, false, false, self.feerate_per_kw, logger).0;
-		let pre_remote_keys = PreCalculatedTxCreationKeys::new(remote_keys);
-		Ok(self.local_keys.sign_remote_commitment(self.feerate_per_kw, &remote_initial_commitment_tx, &pre_remote_keys, &Vec::new(), &self.secp_ctx)
+		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).0;
+		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)
 	}
 
@@ -3538,25 +4337,27 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 	/// 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_txo: OutPoint, logger: &L) -> Result<msgs::FundingCreated, ChannelError> where L::Target: Logger {
-		if !self.channel_outbound {
+	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_remote_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER ||
-				self.cur_local_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER {
+				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.funding_txo = Some(funding_txo.clone());
-		let our_signature = match self.get_outbound_funding_created_signature(logger) {
+		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.funding_txo = None;
+				self.channel_transaction_parameters.funding_outpoint = None;
 				return Err(e);
 			}
 		};
@@ -3567,12 +4368,13 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 
 		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: our_signature
+			signature
 		})
 	}
 
@@ -3584,7 +4386,9 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 	/// closing).
 	/// Note that the "channel must be funded" requirement is stricter than BOLT 7 requires - see
 	/// https://github.com/lightningnetwork/lightning-rfc/issues/468
-	pub fn get_channel_announcement(&self, our_node_id: PublicKey, chain_hash: BlockHash) -> Result<(msgs::UnsignedChannelAnnouncement, Signature), ChannelError> {
+	///
+	/// 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()));
 		}
@@ -3595,30 +4399,87 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 			return Err(ChannelError::Ignore("Cannot get a ChannelAnnouncement once the channel is closing".to_owned()));
 		}
 
-		let were_node_one = our_node_id.serialize()[..] < self.their_node_id.serialize()[..];
+		let were_node_one = node_id.serialize()[..] < self.counterparty_node_id.serialize()[..];
 
 		let msg = msgs::UnsignedChannelAnnouncement {
 			features: ChannelFeatures::known(),
-			chain_hash: chain_hash,
+			chain_hash,
 			short_channel_id: self.get_short_channel_id().unwrap(),
-			node_id_1: if were_node_one { our_node_id } else { self.get_their_node_id() },
-			node_id_2: if were_node_one { self.get_their_node_id() } else { our_node_id },
-			bitcoin_key_1: if were_node_one { self.local_keys.pubkeys().funding_pubkey } else { self.their_funding_pubkey().clone() },
-			bitcoin_key_2: if were_node_one { self.their_funding_pubkey().clone() } else { self.local_keys.pubkeys().funding_pubkey },
+			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.local_keys.sign_channel_announcement(&msg, &self.secp_ctx)
+		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_remote_commitment_transaction_number, INITIAL_COMMITMENT_NUMBER);
+		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.
@@ -3627,15 +4488,15 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		// 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_remote_commitment_transaction_number + 1 < INITIAL_COMMITMENT_NUMBER {
-			let remote_last_secret = self.commitment_secrets.get_secret(self.cur_remote_commitment_transaction_number + 2).unwrap();
-			log_trace!(logger, "Enough info to generate a Data Loss Protect with per_commitment_secret {}", log_bytes!(remote_last_secret));
+		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");
+			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,
@@ -3652,15 +4513,15 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 
 			// 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_local_commitment_transaction_number,
+			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_remote_commitment_transaction_number is INITIAL_COMMITMENT_NUMBER we will have
+			// 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_remote_commitment_transaction_number - 1,
+			next_remote_commitment_number: INITIAL_COMMITMENT_NUMBER - self.cur_counterparty_commitment_transaction_number - 1,
 			data_loss_protect,
 		}
 	}
@@ -3670,10 +4531,18 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 
 	/// 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 option instead of a pure UpdateAddHTLC as we may be in a state where we are
-	/// waiting on the remote peer to send us a revoke_and_ack during which time we cannot add new
-	/// HTLCs on the wire or we wouldn't be able to determine what they actually ACK'ed.
-	/// You MUST call send_commitment prior to any other calls on this Channel
+	///
+	/// 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(&mut self, amount_msat: u64, payment_hash: PaymentHash, cltv_expiry: u32, source: HTLCSource, onion_routing_packet: msgs::OnionPacket) -> Result<Option<msgs::UpdateAddHTLC>, ChannelError> {
 		if (self.channel_state & (ChannelState::ChannelFunded as u32 | BOTH_SIDES_SHUTDOWN_MASK)) != (ChannelState::ChannelFunded as u32) {
@@ -3688,64 +4557,82 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 			return Err(ChannelError::Ignore("Cannot send 0-msat HTLC".to_owned()));
 		}
 
-		if amount_msat < self.their_htlc_minimum_msat {
-			return Err(ChannelError::Ignore(format!("Cannot send less than their minimum HTLC value ({})", self.their_htlc_minimum_msat)));
+		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 | ChannelState::MonitorUpdateFailed as u32)) != 0 {
+		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/frozen for channel monitor update".to_owned()));
+			return Err(ChannelError::Ignore("Cannot send an HTLC while disconnected from channel counterparty".to_owned()));
 		}
 
-		let (outbound_htlc_count, htlc_outbound_value_msat) = self.get_outbound_pending_htlc_stats();
-		if outbound_htlc_count + 1 > self.their_max_accepted_htlcs as u32 {
-			return Err(ChannelError::Ignore(format!("Cannot push more than their max accepted HTLCs ({})", self.their_max_accepted_htlcs)));
+		let inbound_stats = self.get_inbound_pending_htlc_stats();
+		let outbound_stats = self.get_outbound_pending_htlc_stats();
+		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 htlc_outbound_value_msat + amount_msat > self.their_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.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)));
 		}
 
-		if !self.channel_outbound {
+		if !self.is_outbound() {
 			// Check that we won't violate the remote channel reserve by adding this HTLC.
+			let counterparty_balance_msat = self.channel_value_satoshis * 1000 - self.value_to_self_msat;
+			let holder_selected_chan_reserve_msat = Channel::<Signer>::get_holder_selected_channel_reserve_satoshis(self.channel_value_satoshis) * 1000;
+			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);
+			if counterparty_balance_msat < holder_selected_chan_reserve_msat + counterparty_commit_tx_fee_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() 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 remote_balance_msat = self.channel_value_satoshis * 1000 - self.value_to_self_msat;
-			let remote_chan_reserve_msat = Channel::<ChanSigner>::get_remote_channel_reserve_satoshis(self.channel_value_satoshis);
-			// 1 additional HTLC corresponding to this HTLC.
-			let remote_commit_tx_fee_msat = self.next_remote_commit_tx_fee_msat(1);
-			if remote_balance_msat < remote_chan_reserve_msat + remote_commit_tx_fee_msat {
-				return Err(ChannelError::Ignore("Cannot send value that would put them under remote channel reserve value".to_owned()));
+		let exposure_dust_limit_timeout_sats = (self.get_dust_buffer_feerate() 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 pending_value_to_self_msat = self.value_to_self_msat - htlc_outbound_value_msat;
+		let pending_value_to_self_msat = self.value_to_self_msat - outbound_stats.pending_htlcs_value_msat;
 		if pending_value_to_self_msat < amount_msat {
 			return Err(ChannelError::Ignore(format!("Cannot send value that would overdraw remaining funds. Amount: {}, pending value to self {}", amount_msat, pending_value_to_self_msat)));
 		}
 
-		// The `+1` is for the HTLC currently being added to the commitment tx and
-		// the `2 *` and `+1` are for the fee spike buffer.
-		let local_commit_tx_fee_msat = if self.channel_outbound {
-			2 * self.next_local_commit_tx_fee_msat(1 + 1)
+		// `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 pending_value_to_self_msat - amount_msat < local_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 {}", pending_value_to_self_msat, local_commit_tx_fee_msat)));
+		if pending_value_to_self_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 {}", pending_value_to_self_msat, commit_tx_fee_msat)));
 		}
 
-		// Check self.local_channel_reserve_satoshis (the amount we must keep as
+		// 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.local_channel_reserve_satoshis * 1000;
-		if pending_value_to_self_msat - amount_msat - local_commit_tx_fee_msat < chan_reserve_msat {
-			return Err(ChannelError::Ignore(format!("Cannot send value that would put us under local channel reserve value ({})", chan_reserve_msat)));
+		let chan_reserve_msat = self.counterparty_selected_channel_reserve_satoshis.unwrap() * 1000;
+		if pending_value_to_self_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::AwaitingRemoteRevoke as u32) {
+		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,
@@ -3757,7 +4644,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		}
 
 		self.pending_outbound_htlcs.push(OutboundHTLCOutput {
-			htlc_id: self.next_local_htlc_id,
+			htlc_id: self.next_holder_htlc_id,
 			amount_msat,
 			payment_hash: payment_hash.clone(),
 			cltv_expiry,
@@ -3767,13 +4654,13 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 
 		let res = msgs::UpdateAddHTLC {
 			channel_id: self.channel_id,
-			htlc_id: self.next_local_htlc_id,
+			htlc_id: self.next_holder_htlc_id,
 			amount_msat,
 			payment_hash,
 			cltv_expiry,
 			onion_routing_packet,
 		};
-		self.next_local_htlc_id += 1;
+		self.next_holder_htlc_id += 1;
 
 		Ok(Some(res))
 	}
@@ -3795,7 +4682,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		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.pending_update_fee.is_some();
+		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;
@@ -3815,6 +4702,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 	}
 	/// 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.
@@ -3823,6 +4711,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 				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;
 			}
 		}
@@ -3830,17 +4719,26 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 			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, remote_commitment_tx, htlcs) = match self.send_commitment_no_state_update(logger) {
-			Ok((res, (remote_commitment_tx, mut htlcs))) => {
+		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, remote_commitment_tx, htlcs_no_ref)
+				(res, counterparty_commitment_tx, htlcs_no_ref)
 			},
 			Err(e) => return Err(e),
 		};
@@ -3848,55 +4746,66 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		self.latest_monitor_update_id += 1;
 		let monitor_update = ChannelMonitorUpdate {
 			update_id: self.latest_monitor_update_id,
-			updates: vec![ChannelMonitorUpdateStep::LatestRemoteCommitmentTXInfo {
-				unsigned_commitment_tx: remote_commitment_tx.clone(),
+			updates: vec![ChannelMonitorUpdateStep::LatestCounterpartyCommitmentTXInfo {
+				commitment_txid: counterparty_commitment_txid,
 				htlc_outputs: htlcs.clone(),
-				commitment_number: self.cur_remote_commitment_transaction_number,
-				their_revocation_point: self.their_cur_commitment_point.unwrap()
+				commitment_number: self.cur_counterparty_commitment_transaction_number,
+				their_revocation_point: self.counterparty_cur_commitment_point.unwrap()
 			}]
 		};
-		self.channel_monitor.as_mut().unwrap().update_monitor_ooo(monitor_update.clone(), logger).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, (Transaction, Vec<(HTLCOutputInCommitment, Option<&HTLCSource>)>)), ChannelError> where L::Target: Logger {
-		let mut feerate_per_kw = self.feerate_per_kw;
-		if let Some(feerate) = self.pending_update_fee {
-			if self.channel_outbound {
-				feerate_per_kw = feerate;
+	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 counterparty_commitment_tx = self.build_commitment_transaction(self.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, true, logger);
+		let feerate_per_kw = counterparty_commitment_tx.1;
+		let counterparty_commitment_txid = counterparty_commitment_tx.0.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(counterparty_commitment_tx.2);
+							assert_eq!(actual_fee, info.fee);
+						}
+				}
 			}
 		}
 
-		let remote_keys = self.build_remote_transaction_keys()?;
-		let remote_commitment_tx = self.build_commitment_transaction(self.cur_remote_commitment_transaction_number, &remote_keys, false, true, feerate_per_kw, logger);
-		let (signature, htlc_signatures);
-
 		{
-			let mut htlcs = Vec::with_capacity(remote_commitment_tx.2.len());
-			for &(ref htlc, _) in remote_commitment_tx.2.iter() {
+			let mut htlcs = Vec::with_capacity(counterparty_commitment_tx.3.len());
+			for &(ref htlc, _) in counterparty_commitment_tx.3.iter() {
 				htlcs.push(htlc);
 			}
 
-			let pre_remote_keys = PreCalculatedTxCreationKeys::new(remote_keys.clone());
-			let res = self.local_keys.sign_remote_commitment(feerate_per_kw, &remote_commitment_tx.0, &pre_remote_keys, &htlcs, &self.secp_ctx)
+			let res = self.holder_signer.sign_counterparty_commitment(&counterparty_commitment_tx.0, &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 {} with redeemscript {} -> {}",
-				encode::serialize_hex(&remote_commitment_tx.0),
-				encode::serialize_hex(&self.get_funding_redeemscript()),
-				log_bytes!(signature.serialize_compact()[..]));
+			log_trace!(logger, "Signed remote commitment tx {} (txid {}) with redeemscript {} -> {} in channel {}",
+				encode::serialize_hex(&counterparty_commitment_tx.0.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 {} -> {}",
-					encode::serialize_hex(&chan_utils::build_htlc_transaction(&remote_commitment_tx.0.txid(), feerate_per_kw, self.our_to_self_delay, htlc, &remote_keys.a_delayed_payment_key, &remote_keys.revocation_key)),
-					encode::serialize_hex(&chan_utils::get_htlc_redeemscript(&htlc, &remote_keys)),
-					log_bytes!(remote_keys.a_htlc_key.serialize()),
-					log_bytes!(htlc_sig.serialize_compact()[..]));
+				log_trace!(logger, "Signed remote HTLC tx {} with redeemscript {} with pubkey {} -> {} in channel {}",
+					encode::serialize_hex(&chan_utils::build_htlc_transaction(&counterparty_commitment_txid, feerate_per_kw, self.get_holder_selected_contest_delay(), htlc, &counterparty_keys.broadcaster_delayed_payment_key, &counterparty_keys.revocation_key)),
+					encode::serialize_hex(&chan_utils::get_htlc_redeemscript(&htlc, &counterparty_keys)),
+					log_bytes!(counterparty_keys.broadcaster_htlc_key.serialize()),
+					log_bytes!(htlc_sig.serialize_compact()[..]), log_bytes!(self.channel_id()));
 			}
 		}
 
@@ -3904,7 +4813,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 			channel_id: self.channel_id,
 			signature,
 			htlc_signatures,
-		}, (remote_commitment_tx.0, remote_commitment_tx.2)))
+		}, (counterparty_commitment_txid, counterparty_commitment_tx.3)))
 	}
 
 	/// Adds a pending outbound HTLC to this channel, and creates a signed commitment transaction
@@ -3921,9 +4830,29 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		}
 	}
 
+	/// 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(&mut self) -> Result<(msgs::Shutdown, Vec<(HTLCSource, PaymentHash)>), APIError> {
+	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()});
@@ -3942,9 +4871,20 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 			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 our_closing_script = self.get_closing_scriptpubkey();
+		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 {
@@ -3952,6 +4892,20 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 		}
 		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;
@@ -3966,10 +4920,7 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 			}
 		});
 
-		Ok((msgs::Shutdown {
-			channel_id: self.channel_id,
-			scriptpubkey: our_closing_script,
-		}, dropped_outbound_htlcs))
+		Ok((shutdown, monitor_update, dropped_outbound_htlcs))
 	}
 
 	/// Gets the latest commitment transaction and any dependent transactions for relay (forcing
@@ -3977,7 +4928,11 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 	/// 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)>) {
+	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
@@ -3991,82 +4946,102 @@ impl<ChanSigner: ChannelKeys> Channel<ChanSigner> {
 				_ => {}
 			}
 		}
-
-		for _htlc in self.pending_outbound_htlcs.drain(..) {
-			//TODO: Do something with the remaining HTLCs
-			//(we need to have the ChannelManager monitor them so we can claim the inbound HTLCs
-			//which correspond)
-		}
+		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;
-		self.latest_monitor_update_id += 1;
-		(self.funding_txo.clone(), ChannelMonitorUpdate {
-			update_id: self.latest_monitor_update_id,
-			updates: vec![ChannelMonitorUpdateStep::ChannelForceClosed { should_broadcast }],
-		}, dropped_outbound_htlcs)
+		(monitor_update, dropped_outbound_htlcs)
 	}
 }
 
-const SERIALIZATION_VERSION: u8 = 1;
+const SERIALIZATION_VERSION: u8 = 2;
 const MIN_SERIALIZATION_VERSION: u8 = 1;
 
-impl Writeable for InboundHTLCRemovalReason {
-	fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
+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 {
-			&InboundHTLCRemovalReason::FailRelay(ref error_packet) => {
-				0u8.write(writer)?;
-				error_packet.write(writer)?;
-			},
-			&InboundHTLCRemovalReason::FailMalformed((ref onion_hash, ref err_code)) => {
-				1u8.write(writer)?;
-				onion_hash.write(writer)?;
-				err_code.write(writer)?;
-			},
-			&InboundHTLCRemovalReason::Fulfill(ref payment_preimage) => {
-				2u8.write(writer)?;
-				payment_preimage.write(writer)?;
-			},
+			ChannelUpdateStatus::Enabled => 0u8.write(writer)?,
+			ChannelUpdateStatus::DisabledStaged => 0u8.write(writer)?,
+			ChannelUpdateStatus::EnabledStaged => 1u8.write(writer)?,
+			ChannelUpdateStatus::Disabled => 1u8.write(writer)?,
 		}
 		Ok(())
 	}
 }
 
-impl Readable for InboundHTLCRemovalReason {
-	fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
+impl Readable for ChannelUpdateStatus {
+	fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
 		Ok(match <u8 as Readable>::read(reader)? {
-			0 => InboundHTLCRemovalReason::FailRelay(Readable::read(reader)?),
-			1 => InboundHTLCRemovalReason::FailMalformed((Readable::read(reader)?, Readable::read(reader)?)),
-			2 => InboundHTLCRemovalReason::Fulfill(Readable::read(reader)?),
+			0 => ChannelUpdateStatus::Enabled,
+			1 => ChannelUpdateStatus::Disabled,
 			_ => return Err(DecodeError::InvalidValue),
 		})
 	}
 }
 
-impl<ChanSigner: ChannelKeys + Writeable> Writeable for Channel<ChanSigner> {
-	fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
+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 but include holding cell updates (and obviously we don't modify self).
+		// called.
 
-		writer.write_all(&[SERIALIZATION_VERSION; 1])?;
-		writer.write_all(&[MIN_SERIALIZATION_VERSION; 1])?;
+		write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
 
 		self.user_id.write(writer)?;
-		self.config.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_outbound.write(writer)?;
 		self.channel_value_satoshis.write(writer)?;
 
 		self.latest_monitor_update_id.write(writer)?;
 
-		self.local_keys.write(writer)?;
-		self.shutdown_pubkey.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_local_commitment_transaction_number.write(writer)?;
-		self.cur_remote_commitment_transaction_number.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;
@@ -4119,9 +5094,10 @@ impl<ChanSigner: ChannelKeys + Writeable> Writeable for Channel<ChanSigner> {
 				&OutboundHTLCState::Committed => {
 					1u8.write(writer)?;
 				},
-				&OutboundHTLCState::RemoteRemoved(ref fail_reason) => {
-					2u8.write(writer)?;
-					fail_reason.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)?;
@@ -4180,81 +5156,142 @@ impl<ChanSigner: ChannelKeys + Writeable> Writeable for Channel<ChanSigner> {
 			fail_reason.write(writer)?;
 		}
 
-		self.pending_update_fee.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_local_htlc_id.write(writer)?;
-		(self.next_remote_htlc_id - dropped_inbound_htlcs).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)?;
 
-		match self.last_sent_closing_fee {
-			Some((feerate, fee, sig)) => {
-				1u8.write(writer)?;
-				feerate.write(writer)?;
-				fee.write(writer)?;
-				sig.write(writer)?;
-			},
-			None => 0u8.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_txo.write(writer)?;
 		self.funding_tx_confirmed_in.write(writer)?;
+		self.funding_tx_confirmation_height.write(writer)?;
 		self.short_channel_id.write(writer)?;
 
-		self.last_block_connected.write(writer)?;
-		self.funding_tx_confirmations.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)?;
 
-		self.their_dust_limit_satoshis.write(writer)?;
-		self.our_dust_limit_satoshis.write(writer)?;
-		self.their_max_htlc_value_in_flight_msat.write(writer)?;
-		self.local_channel_reserve_satoshis.write(writer)?;
-		self.their_htlc_minimum_msat.write(writer)?;
-		self.our_htlc_minimum_msat.write(writer)?;
-		self.their_to_self_delay.write(writer)?;
-		self.our_to_self_delay.write(writer)?;
-		self.their_max_accepted_htlcs.write(writer)?;
-		self.minimum_depth.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.their_pubkeys.write(writer)?;
-		self.their_cur_commitment_point.write(writer)?;
+		self.counterparty_htlc_minimum_msat.write(writer)?;
+		self.holder_htlc_minimum_msat.write(writer)?;
+		self.counterparty_max_accepted_htlcs.write(writer)?;
 
-		self.their_prev_commitment_point.write(writer)?;
-		self.their_node_id.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)?;
 
-		self.their_shutdown_scriptpubkey.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_monitor.as_ref().unwrap().write_for_disk(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)?;
+		}
+
+		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),
+			(3, self.counterparty_selected_channel_reserve_satoshis, option),
+			(5, self.config, required),
+			(7, self.shutdown_scriptpubkey, option),
+			(9, self.target_closing_feerate_sats_per_kw, option),
+			(11, self.monitor_pending_finalized_fulfills, vec_type),
+		});
+
 		Ok(())
 	}
 }
 
-impl<ChanSigner: ChannelKeys + Readable> Readable for Channel<ChanSigner> {
-	fn read<R : ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
-		let _ver: u8 = Readable::read(reader)?;
-		let min_ver: u8 = Readable::read(reader)?;
-		if min_ver > SERIALIZATION_VERSION {
-			return Err(DecodeError::UnknownVersion);
-		}
+const MAX_ALLOC_SIZE: usize = 64*1024;
+impl<'a, Signer: Sign, K: Deref> ReadableArgs<&'a K> for Channel<Signer>
+		where K::Target: KeysInterface<Signer = Signer> {
+	fn read<R : io::Read>(reader: &mut R, keys_source: &'a K) -> Result<Self, DecodeError> {
+		let ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
 
 		let user_id = Readable::read(reader)?;
-		let config: ChannelConfig = 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_outbound = Readable::read(reader)?;
 		let channel_value_satoshis = Readable::read(reader)?;
 
 		let latest_monitor_update_id = Readable::read(reader)?;
 
-		let local_keys = Readable::read(reader)?;
-		let shutdown_pubkey = 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_local_commitment_transaction_number = Readable::read(reader)?;
-		let cur_remote_commitment_transaction_number = 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)?;
@@ -4340,72 +5377,133 @@ impl<ChanSigner: ChannelKeys + Readable> Readable for Channel<ChanSigner> {
 			monitor_pending_failures.push((Readable::read(reader)?, Readable::read(reader)?, Readable::read(reader)?));
 		}
 
-		let pending_update_fee = Readable::read(reader)?;
+		let pending_update_fee_value: Option<u32> = Readable::read(reader)?;
+
 		let holding_cell_update_fee = Readable::read(reader)?;
 
-		let next_local_htlc_id = Readable::read(reader)?;
-		let next_remote_htlc_id = 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)?;
 
-		let last_sent_closing_fee = match <u8 as Readable>::read(reader)? {
-			0 => None,
-			1 => Some((Readable::read(reader)?, Readable::read(reader)?, 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_txo = Readable::read(reader)?;
 		let funding_tx_confirmed_in = Readable::read(reader)?;
+		let funding_tx_confirmation_height = Readable::read(reader)?;
 		let short_channel_id = Readable::read(reader)?;
 
-		let last_block_connected = Readable::read(reader)?;
-		let funding_tx_confirmations = 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 their_dust_limit_satoshis = Readable::read(reader)?;
-		let our_dust_limit_satoshis = Readable::read(reader)?;
-		let their_max_htlc_value_in_flight_msat = Readable::read(reader)?;
-		let local_channel_reserve_satoshis = Readable::read(reader)?;
-		let their_htlc_minimum_msat = Readable::read(reader)?;
-		let our_htlc_minimum_msat = Readable::read(reader)?;
-		let their_to_self_delay = Readable::read(reader)?;
-		let our_to_self_delay = Readable::read(reader)?;
-		let their_max_accepted_htlcs = Readable::read(reader)?;
-		let minimum_depth = 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 their_pubkeys = Readable::read(reader)?;
-		let their_cur_commitment_point = 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 their_prev_commitment_point = Readable::read(reader)?;
-		let their_node_id = Readable::read(reader)?;
+		let counterparty_cur_commitment_point = Readable::read(reader)?;
 
-		let their_shutdown_scriptpubkey = 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 (monitor_last_block, channel_monitor) = Readable::read(reader)?;
-		// We drop the ChannelMonitor's last block connected hash cause we don't actually bother
-		// doing full block connection operations on the internal ChannelMonitor copies
-		if monitor_last_block != last_block_connected {
-			return Err(DecodeError::InvalidValue);
+		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());
+		read_tlv_fields!(reader, {
+			(0, announcement_sigs, option),
+			(1, minimum_depth, option),
+			(3, counterparty_selected_channel_reserve_satoshis, option),
+			(5, config, option), // Note that if none is provided we will *not* overwrite the existing one.
+			(7, shutdown_scriptpubkey, option),
+			(9, target_closing_feerate_sats_per_kw, option),
+			(11, monitor_pending_finalized_fulfills, vec_type),
+		});
+
+		let mut secp_ctx = Secp256k1::new();
+		secp_ctx.seeded_randomize(&keys_source.get_secure_random_bytes());
+
 		Ok(Channel {
 			user_id,
 
-			config,
+			config: config.unwrap(),
 			channel_id,
 			channel_state,
-			channel_outbound,
-			secp_ctx: Secp256k1::new(),
+			secp_ctx,
 			channel_value_satoshis,
 
 			latest_monitor_update_id,
 
-			local_keys,
-			shutdown_pubkey,
+			holder_signer,
+			shutdown_scriptpubkey,
 			destination_script,
 
-			cur_local_commitment_transaction_number,
-			cur_remote_commitment_transaction_number,
+			cur_holder_commitment_transaction_number,
+			cur_counterparty_commitment_transaction_number,
 			value_to_self_msat,
 
 			pending_inbound_htlcs,
@@ -4419,86 +5517,109 @@ impl<ChanSigner: ChannelKeys + Readable> Readable for Channel<ChanSigner> {
 			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_local_htlc_id,
-			next_remote_htlc_id,
+			next_holder_htlc_id,
+			next_counterparty_htlc_id,
 			update_time_counter,
 			feerate_per_kw,
 
 			#[cfg(debug_assertions)]
-			max_commitment_tx_output_local: ::std::sync::Mutex::new((0, 0)),
+			holder_max_commitment_tx_output: Mutex::new((0, 0)),
 			#[cfg(debug_assertions)]
-			max_commitment_tx_output_remote: ::std::sync::Mutex::new((0, 0)),
+			counterparty_max_commitment_tx_output: Mutex::new((0, 0)),
 
-			last_sent_closing_fee,
+			last_sent_closing_fee: None,
+			pending_counterparty_closing_signed: None,
+			closing_fee_limits: None,
+			target_closing_feerate_sats_per_kw,
 
-			funding_txo,
 			funding_tx_confirmed_in,
+			funding_tx_confirmation_height,
 			short_channel_id,
-			last_block_connected,
-			funding_tx_confirmations,
-
-			their_dust_limit_satoshis,
-			our_dust_limit_satoshis,
-			their_max_htlc_value_in_flight_msat,
-			local_channel_reserve_satoshis,
-			their_htlc_minimum_msat,
-			our_htlc_minimum_msat,
-			their_to_self_delay,
-			our_to_self_delay,
-			their_max_accepted_htlcs,
+
+			counterparty_dust_limit_satoshis,
+			holder_dust_limit_satoshis,
+			counterparty_max_htlc_value_in_flight_msat,
+			counterparty_selected_channel_reserve_satoshis,
+			counterparty_htlc_minimum_msat,
+			holder_htlc_minimum_msat,
+			counterparty_max_accepted_htlcs,
 			minimum_depth,
 
-			their_pubkeys,
-			their_cur_commitment_point,
+			counterparty_forwarding_info,
+
+			channel_transaction_parameters: channel_parameters,
+			funding_transaction,
 
-			their_prev_commitment_point,
-			their_node_id,
+			counterparty_cur_commitment_point,
+			counterparty_prev_commitment_point,
+			counterparty_node_id,
 
-			their_shutdown_scriptpubkey,
+			counterparty_shutdown_scriptpubkey,
 
-			channel_monitor: Some(channel_monitor),
 			commitment_secrets,
 
-			network_sync: UpdateStatus::Fresh,
+			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,
 		})
 	}
 }
 
 #[cfg(test)]
 mod tests {
-	use bitcoin::BitcoinHash;
 	use bitcoin::util::bip143;
 	use bitcoin::consensus::encode::serialize;
 	use bitcoin::blockdata::script::{Script, Builder};
-	use bitcoin::blockdata::transaction::{Transaction, TxOut};
+	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::channelmanager::{HTLCSource, PaymentPreimage, PaymentHash};
-	use ln::channel::{Channel,ChannelKeys,InboundHTLCOutput,OutboundHTLCOutput,InboundHTLCState,OutboundHTLCState,HTLCOutputInCommitment,TxCreationKeys};
+	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::{OptionalField, DataLossProtect};
+	use ln::msgs::{ChannelUpdate, DataLossProtect, DecodeError, OptionalField, UnsignedChannelUpdate};
+	use ln::script::ShutdownScript;
 	use ln::chan_utils;
-	use ln::chan_utils::{LocalCommitmentTransaction, ChannelPublicKeys};
+	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::{InMemoryChannelKeys, KeysInterface};
+	use chain::keysinterface::{InMemorySigner, KeysInterface, BaseSign};
 	use chain::transaction::OutPoint;
 	use util::config::UserConfig;
-	use util::enforcing_trait_impls::EnforcingChannelKeys;
+	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 std::sync::Arc;
+	use core::num::NonZeroU8;
+	use sync::Arc;
+	use prelude::*;
 
 	struct TestFeeEstimator {
 		fee_est: u32
@@ -4516,36 +5637,63 @@ mod tests {
 	}
 
 	struct Keys {
-		chan_keys: InMemoryChannelKeys,
+		signer: InMemorySigner,
 	}
 	impl KeysInterface for Keys {
-		type ChanKeySigner = InMemoryChannelKeys;
+		type Signer = InMemorySigner;
 
 		fn get_node_secret(&self) -> SecretKey { 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 our_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(&our_channel_monitor_claim_key_hash[..]).into_script()
+			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_pubkey(&self) -> PublicKey {
+		fn get_shutdown_scriptpubkey(&self) -> ShutdownScript {
 			let secp_ctx = Secp256k1::signing_only();
 			let channel_close_key = SecretKey::from_slice(&hex::decode("0fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff").unwrap()[..]).unwrap();
-			PublicKey::from_secret_key(&secp_ctx, &channel_close_key)
+			ShutdownScript::new_p2wpkh_from_pubkey(PublicKey::from_secret_key(&secp_ctx, &channel_close_key))
 		}
 
-		fn get_channel_keys(&self, _inbound: bool, _channel_value_satoshis: u64) -> InMemoryChannelKeys {
-			self.chan_keys.clone()
+		fn get_channel_signer(&self, _inbound: bool, _channel_value_satoshis: u64) -> InMemorySigner {
+			self.signer.clone()
 		}
-		fn get_onion_rand(&self) -> (SecretKey, [u8; 32]) { panic!(); }
-		fn get_channel_id(&self) -> [u8; 32] { [0; 32] }
+		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) {
+			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]
@@ -4559,15 +5707,134 @@ mod tests {
 
 		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::<EnforcingChannelKeys>::new_outbound(&&fee_est, &&keys_provider, node_a_node_id, 10000000, 100000, 42, &config).unwrap();
+		let node_a_chan = Channel::<EnforcingSigner>::new_outbound(&&fee_est, &&keys_provider, node_a_node_id, &InitFeatures::known(), 10000000, 100000, 42, &config).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.bitcoin_hash());
+		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);
+
+		// 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).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).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 = node_a_chan.commit_tx_fee_msat(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 = node_a_chan.commit_tx_fee_msat(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).unwrap();
+
+		let commitment_tx_fee_0_htlcs = chan.commit_tx_fee_msat(0);
+		let commitment_tx_fee_1_htlc = chan.commit_tx_fee_msat(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};
@@ -4575,23 +5842,25 @@ mod tests {
 		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
-		let node_a_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
+		// 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::<EnforcingChannelKeys>::new_outbound(&&feeest, &&keys_provider, node_a_node_id, 10000000, 100000, 42, &config).unwrap();
+		let mut node_a_chan = Channel::<EnforcingSigner>::new_outbound(&&feeest, &&keys_provider, node_b_node_id, &InitFeatures::known(), 10000000, 100000, 42, &config).unwrap();
 
 		// Create Node B's channel by receiving Node A's open_channel message
-		let open_channel_msg = node_a_chan.get_open_channel(genesis_block(network).header.bitcoin_hash());
+		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::<EnforcingChannelKeys>::new_from_req(&&feeest, &&keys_provider, node_b_node_id, InitFeatures::known(), &open_channel_msg, 7, &config).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).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_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();
@@ -4599,11 +5868,11 @@ mod tests {
 			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(funding_outpoint, &&logger).unwrap();
-		let (funding_signed_msg, _) = node_b_chan.funding_created(&funding_created_msg, &&logger).unwrap();
+		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, &&logger);
+		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.
@@ -4632,6 +5901,54 @@ mod tests {
 		}
 	}
 
+	#[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).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:
@@ -4639,7 +5956,7 @@ mod tests {
 		let logger : Arc<Logger> = Arc::new(test_utils::TestLogger::new());
 		let secp_ctx = Secp256k1::new();
 
-		let mut chan_keys = InMemoryChannelKeys::new(
+		let mut signer = InMemorySigner::new(
 			&secp_ctx,
 			SecretKey::from_slice(&hex::decode("30ff4956bbdd3222d44cc5e8a1261dab1e07957bdac5ae88fe3261ef321f3749").unwrap()[..]).unwrap(),
 			SecretKey::from_slice(&hex::decode("0fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff").unwrap()[..]).unwrap(),
@@ -4650,97 +5967,112 @@ mod tests {
 			// 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, 0)
+			[0; 32]
 		);
 
-		assert_eq!(chan_keys.pubkeys().funding_pubkey.serialize()[..],
+		assert_eq!(signer.pubkeys().funding_pubkey.serialize()[..],
 				hex::decode("023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb").unwrap()[..]);
-		let keys_provider = Keys { chan_keys: chan_keys.clone() };
+		let keys_provider = Keys { signer: signer.clone() };
 
-		let their_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
+		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::<InMemoryChannelKeys>::new_outbound(&&feeest, &&keys_provider, their_node_id, 10_000_000, 100000, 42, &config).unwrap(); // Nothing uses their network key in this test
-		chan.their_to_self_delay = 144;
-		chan.our_dust_limit_satoshis = 546;
+		let mut chan = Channel::<InMemorySigner>::new_outbound(&&feeest, &&keys_provider, counterparty_node_id, &InitFeatures::known(), 10_000_000, 100000, 42, &config).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 };
-		chan.funding_txo = Some(funding_info);
 
-		let their_pubkeys = ChannelPublicKeys {
+		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_keys.on_accept(&their_pubkeys, chan.their_to_self_delay, chan.our_to_self_delay);
+		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!(their_pubkeys.payment_point.serialize()[..],
+		assert_eq!(counterparty_pubkeys.payment_point.serialize()[..],
 		           hex::decode("032c0b7cf95324a07d05398b240174dc0c2be444d96b159aa6c7f7b1e668680991").unwrap()[..]);
 
-		assert_eq!(their_pubkeys.funding_pubkey.serialize()[..],
+		assert_eq!(counterparty_pubkeys.funding_pubkey.serialize()[..],
 		           hex::decode("030e9f7b623d2ccc7c9bd44d66d5ce21ce504c0acf6385a132cec6d3c39fa711c1").unwrap()[..]);
 
-		assert_eq!(their_pubkeys.htlc_basepoint.serialize()[..],
+		assert_eq!(counterparty_pubkeys.htlc_basepoint.serialize()[..],
 		           hex::decode("032c0b7cf95324a07d05398b240174dc0c2be444d96b159aa6c7f7b1e668680991").unwrap()[..]);
 
-		// We can't just use build_local_transaction_keys here as the per_commitment_secret is not
+		// 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.local_keys.pubkeys().delayed_payment_basepoint;
+		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.local_keys.pubkeys().htlc_basepoint;
-		let keys = TxCreationKeys::new(&secp_ctx, &per_commitment_point, delayed_payment_base, htlc_basepoint, &their_pubkeys.revocation_basepoint, &their_pubkeys.htlc_basepoint).unwrap();
-
-		chan.their_pubkeys = Some(their_pubkeys);
-
-		let mut unsigned_tx: (Transaction, Vec<HTLCOutputInCommitment>);
+		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();
 
-		let mut localtx;
 		macro_rules! test_commitment {
-			( $their_sig_hex: expr, $our_sig_hex: expr, $tx_hex: expr, {
-				$( { $htlc_idx: expr, $their_htlc_sig_hex: expr, $our_htlc_sig_hex: expr, $htlc_tx_hex: expr } ), *
+			( $counterparty_sig_hex: expr, $sig_hex: expr, $tx_hex: expr, {
+				$( { $htlc_idx: expr, $counterparty_htlc_sig_hex: expr, $htlc_sig_hex: expr, $htlc_tx_hex: expr } ), *
 			} ) => { {
-				unsigned_tx = {
-					let mut res = chan.build_commitment_transaction(0xffffffffffff - 42, &keys, true, false, chan.feerate_per_kw, &logger);
-					let htlcs = res.2.drain(..)
+				let (commitment_tx, htlcs): (_, Vec<HTLCOutputInCommitment>) = {
+					let mut res = chan.build_commitment_transaction(0xffffffffffff - 42, &keys, true, false, &logger);
+
+					let htlcs = res.3.drain(..)
 						.filter_map(|(htlc, _)| if htlc.transaction_output_index.is_some() { Some(htlc) } else { None })
 						.collect();
 					(res.0, htlcs)
 				};
+				let trusted_tx = commitment_tx.trust();
+				let unsigned_tx = trusted_tx.built_transaction();
 				let redeemscript = chan.get_funding_redeemscript();
-				let their_signature = Signature::from_der(&hex::decode($their_sig_hex).unwrap()[..]).unwrap();
-				let sighash = Message::from_slice(&bip143::SighashComponents::new(&unsigned_tx.0).sighash_all(&unsigned_tx.0.input[0], &redeemscript, chan.channel_value_satoshis)[..]).unwrap();
-				secp_ctx.verify(&sighash, &their_signature, chan.their_funding_pubkey()).unwrap();
+				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::new();
+				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
 				$({
-					let remote_signature = Signature::from_der(&hex::decode($their_htlc_sig_hex).unwrap()[..]).unwrap();
-					per_htlc.push((unsigned_tx.1[$htlc_idx].clone(), Some(remote_signature)));
+					let remote_signature = Signature::from_der(&hex::decode($counterparty_htlc_sig_hex).unwrap()[..]).unwrap();
+					per_htlc.push((htlcs[$htlc_idx].clone(), Some(remote_signature)));
+					counterparty_htlc_sigs.push(remote_signature);
 				})*
-				assert_eq!(unsigned_tx.1.len(), per_htlc.len());
+				assert_eq!(htlcs.len(), per_htlc.len());
 
-				localtx = LocalCommitmentTransaction::new_missing_local_sig(unsigned_tx.0.clone(), their_signature.clone(), &chan_keys.pubkeys().funding_pubkey, chan.their_funding_pubkey(), keys.clone(), chan.feerate_per_kw, per_htlc);
-				let local_sig = chan_keys.sign_local_commitment(&localtx, &chan.secp_ctx).unwrap();
-				assert_eq!(Signature::from_der(&hex::decode($our_sig_hex).unwrap()[..]).unwrap(), local_sig);
+				let holder_commitment_tx = HolderCommitmentTransaction::new(
+					commitment_tx.clone(),
+					counterparty_signature,
+					counterparty_htlc_sigs,
+					&chan.holder_signer.pubkeys().funding_pubkey,
+					chan.counterparty_funding_pubkey()
+				);
+				let (holder_sig, htlc_sigs) = signer.sign_holder_commitment_and_htlcs(&holder_commitment_tx, &secp_ctx).unwrap();
+				assert_eq!(Signature::from_der(&hex::decode($sig_hex).unwrap()[..]).unwrap(), holder_sig, "holder_sig");
 
-				assert_eq!(serialize(&localtx.add_local_sig(&redeemscript, local_sig))[..],
-						hex::decode($tx_hex).unwrap()[..]);
+				let funding_redeemscript = chan.get_funding_redeemscript();
+				let tx = holder_commitment_tx.add_holder_sig(&funding_redeemscript, holder_sig);
+				assert_eq!(serialize(&tx)[..], hex::decode($tx_hex).unwrap()[..], "tx");
 
-				let htlc_sigs = chan_keys.sign_local_commitment_htlc_transactions(&localtx, &chan.secp_ctx).unwrap();
-				let mut htlc_sig_iter = localtx.per_htlc.iter().zip(htlc_sigs.iter().enumerate());
+				// ((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());
 
 				$({
-					let remote_signature = Signature::from_der(&hex::decode($their_htlc_sig_hex).unwrap()[..]).unwrap();
+					let remote_signature = Signature::from_der(&hex::decode($counterparty_htlc_sig_hex).unwrap()[..]).unwrap();
 
-					let ref htlc = unsigned_tx.1[$htlc_idx];
-					let htlc_tx = chan.build_htlc_transaction(&unsigned_tx.0.txid(), &htlc, true, &keys, chan.feerate_per_kw);
+					let ref htlc = htlcs[$htlc_idx];
+					let htlc_tx = chan_utils::build_htlc_transaction(&unsigned_tx.txid, chan.feerate_per_kw,
+						chan.get_counterparty_selected_contest_delay().unwrap(),
+						&htlc, &keys.broadcaster_delayed_payment_key, &keys.revocation_key);
 					let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, &keys);
-					let htlc_sighash = Message::from_slice(&bip143::SighashComponents::new(&htlc_tx).sighash_all(&htlc_tx.input[0], &htlc_redeemscript, htlc.amount_msat / 1000)[..]).unwrap();
-					secp_ctx.verify(&htlc_sighash, &remote_signature, &keys.b_htlc_key).unwrap();
+					let htlc_sighash = Message::from_slice(&bip143::SigHashCache::new(&htlc_tx).signature_hash(0, &htlc_redeemscript, htlc.amount_msat / 1000, SigHashType::All)[..]).unwrap();
+					secp_ctx.verify(&htlc_sighash, &remote_signature, &keys.countersignatory_htlc_key).unwrap();
 
 					let mut preimage: Option<PaymentPreimage> = None;
 					if !htlc.offered {
@@ -4754,20 +6086,18 @@ mod tests {
 						assert!(preimage.is_some());
 					}
 
-					let mut htlc_sig = htlc_sig_iter.next().unwrap();
-					while (htlc_sig.1).1.is_none() { htlc_sig = htlc_sig_iter.next().unwrap(); }
-					assert_eq!((htlc_sig.0).0.transaction_output_index, Some($htlc_idx));
+					let htlc_sig = htlc_sig_iter.next().unwrap();
+					assert_eq!((htlc_sig.0).0.transaction_output_index, Some($htlc_idx), "output index");
 
-					let our_signature = Signature::from_der(&hex::decode($our_htlc_sig_hex).unwrap()[..]).unwrap();
-					assert_eq!(Some(our_signature), *(htlc_sig.1).1);
-					assert_eq!(serialize(&localtx.get_signed_htlc_tx((htlc_sig.1).0, &(htlc_sig.1).1.unwrap(), &preimage, chan.their_to_self_delay))[..],
-							hex::decode($htlc_tx_hex).unwrap()[..]);
+					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");
 				})*
-				loop {
-					let htlc_sig = htlc_sig_iter.next();
-					if htlc_sig.is_none() { break; }
-					assert!((htlc_sig.unwrap().1).1.is_none());
-				}
+				assert!(htlc_sig_iter.next().is_none());
 			} }
 		}
 
@@ -5107,6 +6437,65 @@ mod tests {
 		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",
+		                 "02000000000101bef67e4e2fb9ddeeb3461973cd4c62abb35050b1add772995b820b584a488489000000000038b02b8005d007000000000000220020748eba944fedc8827f6b06bc44678f93c0f9e6078b35c6331ed31e75f8ce0c2d8813000000000000220020305c12e1a0bc21e283c131cea1c66d68857d28b7b2fce0a6fbc40c164852121b8813000000000000220020305c12e1a0bc21e283c131cea1c66d68857d28b7b2fce0a6fbc40c164852121bc0c62d0000000000160014cc1b07838e387deacd0e5232e1e8b49f4c29e484a79f6a00000000002200204adb4e2f00643db396dd120d4e7dc17625f5f2c11a40d857accc862d6b7dd80e0400483045022100c4f1d60b6fca9febc8b39de1a31e84c5f7c4b41c97239ef05f4350aa484c6b5e02200c5134ac8b20eb7a29d0dd4a501f6aa8fefb8489171f4cb408bd2a32324ab03f014730440220048705bec5288d28b3f29344b8d124853b1af423a568664d2c6f02c8ea886525022060f998a461052a2476b912db426ea2a06700953a241135c7957f2e79bc222df901475221023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb21030e9f7b623d2ccc7c9bd44d66d5ce21ce504c0acf6385a132cec6d3c39fa711c152ae3e195220", {
+
+		                  { 0,
+		                  "304502210081cbb94121761d34c189cd4e6a281feea6f585060ad0ba2632e8d6b3c6bb8a6c02201007981bbd16539d63df2805b5568f1f5688cd2a885d04706f50db9b77ba13c6",
+		                  "304502210090ed76aeb21b53236a598968abc66e2024691d07b62f53ddbeca8f93144af9c602205f873af5a0c10e62690e9aba09740550f194a9dc455ba4c1c23f6cde7704674c",
+		                  "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" },
+		                  { 1,
+		                  "304402201d0f09d2bf7bc245a4f17980e1e9164290df16c70c6a2ff1592f5030d6108581022061e744a7dc151b36bf0aff7a4f1812ba90b8b03633bb979a270d19858fd960c5",
+		                  "30450221009aef000d2e843a4202c1b1a2bf554abc9a7902bf49b2cb0759bc507456b7ebad02204e7c3d193ede2fd2b4cd6b39f51a920e581e35575e357e44d7b699c40ce61d39",
+		                  "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" },
+		                  { 2,
+		                  "30440220010bf035d5823596e50dce2076a4d9f942d8d28031c9c428b901a02b6b8140de02203250e8e4a08bc5b4ecdca4d0eedf98223e02e3ac1c0206b3a7ffdb374aa21e5f",
+		                  "30440220073de0067b88e425b3018b30366bfeda0ccb703118ccd3d02ead08c0f53511d002203fac50ac0e4cf8a3af0b4b1b12e801650591f748f8ddf1e089c160f10b69e511",
+		                  "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" }
+		} );
 	}
 
 	#[test]