Mark failed counterparty-is-destination HTLCs retryable
[rust-lightning] / lightning / src / ln / channel.rs
index 8d0f3c5e6d9a051b4aa21230dc9cfbe58c1164d6..624f4d6b688b0e2d81964d39e2deb77e1233af8a 100644 (file)
@@ -8,8 +8,8 @@
 // licenses.
 
 use bitcoin::blockdata::script::{Script,Builder};
-use bitcoin::blockdata::transaction::{Transaction, SigHashType};
-use bitcoin::util::bip143;
+use bitcoin::blockdata::transaction::{Transaction, EcdsaSighashType};
+use bitcoin::util::sighash;
 use bitcoin::consensus::encode;
 
 use bitcoin::hashes::Hash;
@@ -18,8 +18,8 @@ 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::{PublicKey,SecretKey};
+use bitcoin::secp256k1::{Secp256k1,ecdsa::Signature};
 use bitcoin::secp256k1;
 
 use ln::{PaymentPreimage, PaymentHash};
@@ -31,7 +31,7 @@ use ln::channelmanager::{CounterpartyForwardingInfo, PendingHTLCStatus, HTLCSour
 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::chaininterface::{FeeEstimator, ConfirmationTarget, LowerBoundedFeeEstimator};
 use chain::channelmonitor::{ChannelMonitor, ChannelMonitorUpdate, ChannelMonitorUpdateStep, LATENCY_GRACE_PERIOD_BLOCKS};
 use chain::transaction::{OutPoint, TransactionData};
 use chain::keysinterface::{Sign, KeysInterface};
@@ -39,7 +39,7 @@ use util::events::ClosureReason;
 use util::ser::{Readable, ReadableArgs, Writeable, Writer, VecWriter};
 use util::logger::Logger;
 use util::errors::APIError;
-use util::config::{UserConfig, ChannelConfig, ChannelHandshakeLimits};
+use util::config::{UserConfig, ChannelConfig, LegacyChannelConfig, ChannelHandshakeConfig, ChannelHandshakeLimits};
 use util::scid_utils::scid_from_parts;
 
 use io;
@@ -126,7 +126,7 @@ enum InboundHTLCState {
        /// signatures in a commitment_signed message.
        /// Implies AwaitingRemoteRevoke.
        ///
-       /// [BOLT #2]: https://github.com/lightningnetwork/lightning-rfc/blob/master/02-peer-protocol.md
+       /// [BOLT #2]: https://github.com/lightning/bolts/blob/master/02-peer-protocol.md
        AwaitingRemoteRevokeToAnnounce(PendingHTLCStatus),
        /// Included in a received commitment_signed message (implying we've revoke_and_ack'd it).
        /// We have also included this HTLC in our latest commitment_signed and are now just waiting
@@ -243,7 +243,7 @@ enum HTLCUpdateAwaitingACK {
 
 /// There are a few "states" and then a number of flags which can be applied:
 /// We first move through init with OurInitSent -> TheirInitSent -> FundingCreated -> FundingSent.
-/// TheirFundingLocked and OurFundingLocked then get set on FundingSent, and when both are set we
+/// TheirChannelReady and OurChannelReady then get set on FundingSent, and when both are set we
 /// move on to ChannelFunded.
 /// Note that PeerDisconnected can be set on both ChannelFunded and FundingSent.
 /// ChannelFunded can then get all remaining flags set on it, until we finish shutdown, then we
@@ -258,15 +258,15 @@ enum ChannelState {
        /// upon receipt of funding_created, so simply skip this state.
        FundingCreated = 4,
        /// Set when we have received/sent funding_created and funding_signed and are thus now waiting
-       /// on the funding transaction to confirm. The FundingLocked flags are set to indicate when we
+       /// on the funding transaction to confirm. The ChannelReady flags are set to indicate when we
        /// and our counterparty consider the funding transaction confirmed.
        FundingSent = 8,
-       /// Flag which can be set on FundingSent to indicate they sent us a funding_locked message.
-       /// Once both TheirFundingLocked and OurFundingLocked are set, state moves on to ChannelFunded.
-       TheirFundingLocked = 1 << 4,
-       /// Flag which can be set on FundingSent to indicate we sent them a funding_locked message.
-       /// Once both TheirFundingLocked and OurFundingLocked are set, state moves on to ChannelFunded.
-       OurFundingLocked = 1 << 5,
+       /// Flag which can be set on FundingSent to indicate they sent us a channel_ready message.
+       /// Once both TheirChannelReady and OurChannelReady are set, state moves on to ChannelFunded.
+       TheirChannelReady = 1 << 4,
+       /// Flag which can be set on FundingSent to indicate we sent them a channel_ready message.
+       /// Once both TheirChannelReady and OurChannelReady are set, state moves on to ChannelFunded.
+       OurChannelReady = 1 << 5,
        ChannelFunded = 64,
        /// Flag which is set on ChannelFunded and FundingSent indicating remote side is considered
        /// "disconnected" and no updates are allowed until after we've done a channel_reestablish
@@ -429,13 +429,13 @@ pub(super) struct MonitorRestoreUpdates {
        pub failed_htlcs: Vec<(HTLCSource, PaymentHash, HTLCFailReason)>,
        pub finalized_claimed_htlcs: Vec<HTLCSource>,
        pub funding_broadcastable: Option<Transaction>,
-       pub funding_locked: Option<msgs::FundingLocked>,
+       pub channel_ready: Option<msgs::ChannelReady>,
        pub announcement_sigs: Option<msgs::AnnouncementSignatures>,
 }
 
 /// The return value of `channel_reestablish`
 pub(super) struct ReestablishResponses {
-       pub funding_locked: Option<msgs::FundingLocked>,
+       pub channel_ready: Option<msgs::ChannelReady>,
        pub raa: Option<msgs::RevokeAndACK>,
        pub commitment_update: Option<msgs::CommitmentUpdate>,
        pub order: RAACommitmentOrder,
@@ -482,6 +482,16 @@ pub(crate) const CONCURRENT_INBOUND_HTLC_FEE_BUFFER: u32 = 2;
 /// transaction (not counting the value of the HTLCs themselves).
 pub(crate) const MIN_AFFORDABLE_HTLC_COUNT: usize = 4;
 
+/// When a [`Channel`] has its [`ChannelConfig`] updated, its existing one is stashed for up to this
+/// number of ticks to allow forwarding HTLCs by nodes that have yet to receive the new
+/// ChannelUpdate prompted by the config update. This value was determined as follows:
+///
+///   * The expected interval between ticks (1 minute).
+///   * The average convergence delay of updates across the network, i.e., ~300 seconds on average
+///      for a node to see an update as seen on `<https://arxiv.org/pdf/2205.12737.pdf>`.
+///   * `EXPIRE_PREV_CONFIG_TICKS` = convergence_delay / tick_interval
+pub(crate) const EXPIRE_PREV_CONFIG_TICKS: usize = 5;
+
 // 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
@@ -490,10 +500,12 @@ pub(crate) const MIN_AFFORDABLE_HTLC_COUNT: usize = 4;
 // 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,
+       config: LegacyChannelConfig,
+
+       // Track the previous `ChannelConfig` so that we can continue forwarding HTLCs that were
+       // constructed using it. The second element in the tuple corresponds to the number of ticks that
+       // have elapsed since the update occurred.
+       prev_config: Option<(ChannelConfig, usize)>,
 
        inbound_handshake_limits_override: Option<ChannelHandshakeLimits>,
 
@@ -543,7 +555,7 @@ pub(super) struct Channel<Signer: Sign> {
        /// send it first.
        resend_order: RAACommitmentOrder,
 
-       monitor_pending_funding_locked: bool,
+       monitor_pending_channel_ready: bool,
        monitor_pending_revoke_and_ack: bool,
        monitor_pending_commitment_signed: bool,
        monitor_pending_forwards: Vec<(PendingHTLCInfo, u64)>,
@@ -688,12 +700,12 @@ pub(super) struct Channel<Signer: Sign> {
 
        /// 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
+       /// channel_ready *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 channel_ready
        /// message until we receive a channel_reestablish.
        ///
        /// See-also <https://github.com/lightningnetwork/lnd/issues/4006>
-       pub workaround_lnd_bug_4006: Option<msgs::FundingLocked>,
+       pub workaround_lnd_bug_4006: Option<msgs::ChannelReady>,
 
        #[cfg(any(test, fuzzing))]
        // When we receive an HTLC fulfill on an outbound path, we may immediately fulfill the
@@ -710,6 +722,11 @@ pub(super) struct Channel<Signer: Sign> {
        // Our counterparty can offer us SCID aliases which they will map to this channel when routing
        // outbound payments. These can be used in invoice route hints to avoid explicitly revealing
        // the channel's funding UTXO.
+       //
+       // We also use this when sending our peer a channel_update that isn't to be broadcasted
+       // publicly - allowing them to re-use their map of SCID -> channel for channel_update ->
+       // associated channel mapping.
+       //
        // We only bother storing the most recent SCID alias at any time, though our counterparty has
        // to store all of them.
        latest_inbound_scid_alias: Option<u64>,
@@ -745,6 +762,12 @@ pub const COMMITMENT_TX_WEIGHT_PER_HTLC: u64 = 172;
 
 pub const ANCHOR_OUTPUT_VALUE_SATOSHI: u64 = 330;
 
+/// The percentage of the channel value `holder_max_htlc_value_in_flight_msat` used to be set to,
+/// before this was made configurable. The percentage was made configurable in LDK 0.0.107,
+/// although LDK 0.0.104+ enabled serialization of channels with a different value set for
+/// `holder_max_htlc_value_in_flight_msat`.
+pub const MAX_IN_FLIGHT_PERCENT_LEGACY: u8 = 10;
+
 /// Maximum `funding_satoshis` value according to the BOLT #2 specification, if
 /// `option_support_large_channel` (aka wumbo channels) is not supported.
 /// It's 2^24 - 1.
@@ -769,9 +792,12 @@ pub const MAX_CHAN_DUST_LIMIT_SATOSHIS: u64 = MAX_STD_OUTPUT_DUST_LIMIT_SATOSHIS
 /// 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.
+/// See https://github.com/lightning/bolts/issues/905 for more details.
 pub const MIN_CHAN_DUST_LIMIT_SATOSHIS: u64 = 354;
 
+// Just a reasonable implementation-specific safe lower bound, higher than the dust limit.
+pub const MIN_THEIR_CHAN_RESERVE_SATOSHIS: u64 = 1000;
+
 /// 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.
@@ -779,7 +805,6 @@ pub(super) enum ChannelError {
        Ignore(String),
        Warn(String),
        Close(String),
-       CloseDelayBroadcast(String),
 }
 
 impl fmt::Debug for ChannelError {
@@ -788,7 +813,6 @@ impl fmt::Debug for ChannelError {
                        &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)
                }
        }
 }
@@ -803,22 +827,44 @@ macro_rules! secp_check {
 }
 
 impl<Signer: Sign> Channel<Signer> {
-       // Convert constants + channel value to limits:
-       fn get_holder_max_htlc_value_in_flight_msat(channel_value_satoshis: u64) -> u64 {
-               channel_value_satoshis * 1000 / 10 //TODO
+       /// Returns the value to use for `holder_max_htlc_value_in_flight_msat` as a percentage of the
+       /// `channel_value_satoshis` in msat, set through
+       /// [`ChannelHandshakeConfig::max_inbound_htlc_value_in_flight_percent_of_channel`]
+       ///
+       /// The effective percentage is lower bounded by 1% and upper bounded by 100%.
+       ///
+       /// [`ChannelHandshakeConfig::max_inbound_htlc_value_in_flight_percent_of_channel`]: crate::util::config::ChannelHandshakeConfig::max_inbound_htlc_value_in_flight_percent_of_channel
+       fn get_holder_max_htlc_value_in_flight_msat(channel_value_satoshis: u64, config: &ChannelHandshakeConfig) -> u64 {
+               let configured_percent = if config.max_inbound_htlc_value_in_flight_percent_of_channel < 1 {
+                       1
+               } else if config.max_inbound_htlc_value_in_flight_percent_of_channel > 100 {
+                       100
+               } else {
+                       config.max_inbound_htlc_value_in_flight_percent_of_channel as u64
+               };
+               channel_value_satoshis * 10 * configured_percent
        }
 
        /// Returns a minimum channel reserve value the remote needs to maintain,
-       /// required by us.
+       /// required by us according to the configured or default
+       /// [`ChannelHandshakeConfig::their_channel_reserve_proportional_millionths`]
        ///
        /// Guaranteed to return a value no larger than channel_value_satoshis
        ///
-       /// This is used both for new channels and to figure out what reserve value we sent to peers
-       /// for channels serialized before we included our selected reserve value in the serialized
-       /// data explicitly.
-       pub(crate) fn get_holder_selected_channel_reserve_satoshis(channel_value_satoshis: u64) -> u64 {
+       /// This is used both for outbound and inbound channels and has lower bound
+       /// of `MIN_THEIR_CHAN_RESERVE_SATOSHIS`.
+       pub(crate) fn get_holder_selected_channel_reserve_satoshis(channel_value_satoshis: u64, config: &UserConfig) -> u64 {
+               let calculated_reserve = channel_value_satoshis.saturating_mul(config.channel_handshake_config.their_channel_reserve_proportional_millionths as u64) / 1_000_000;
+               cmp::min(channel_value_satoshis, cmp::max(calculated_reserve, MIN_THEIR_CHAN_RESERVE_SATOSHIS))
+       }
+
+       /// This is for legacy reasons, present for forward-compatibility.
+       /// LDK versions older than 0.0.104 don't know how read/handle values other than default
+       /// from storage. Hence, we use this function to not persist default values of
+       /// `holder_selected_channel_reserve_satoshis` for channels into storage.
+       pub(crate) fn get_legacy_default_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
+               cmp::min(channel_value_satoshis, cmp::max(q, 1000))
        }
 
        pub(crate) fn opt_anchors(&self) -> bool {
@@ -831,7 +877,7 @@ impl<Signer: Sign> Channel<Signer> {
                // available. If it's private, we first try `scid_privacy` as it provides better privacy
                // with no other changes, and fall back to `only_static_remotekey`
                let mut ret = ChannelTypeFeatures::only_static_remote_key();
-               if !config.channel_options.announced_channel && config.own_channel_config.negotiate_scid_privacy {
+               if !config.channel_handshake_config.announced_channel && config.channel_handshake_config.negotiate_scid_privacy {
                        ret.set_scid_privacy_required();
                }
                ret
@@ -852,7 +898,7 @@ impl<Signer: Sign> Channel<Signer> {
 
        // Constructors:
        pub fn new_outbound<K: Deref, F: Deref>(
-               fee_estimator: &F, keys_provider: &K, counterparty_node_id: PublicKey, their_features: &InitFeatures,
+               fee_estimator: &LowerBoundedFeeEstimator<F>, keys_provider: &K, counterparty_node_id: PublicKey, their_features: &InitFeatures,
                channel_value_satoshis: u64, push_msat: u64, user_id: u64, config: &UserConfig, current_chain_height: u32,
                outbound_scid_alias: u64
        ) -> Result<Channel<Signer>, APIError>
@@ -861,7 +907,7 @@ impl<Signer: Sign> Channel<Signer> {
        {
                let opt_anchors = false; // TODO - should be based on features
 
-               let holder_selected_contest_delay = config.own_channel_config.our_to_self_delay;
+               let holder_selected_contest_delay = config.channel_handshake_config.our_to_self_delay;
                let holder_signer = keys_provider.get_channel_signer(false, channel_value_satoshis);
                let pubkeys = holder_signer.pubkeys().clone();
 
@@ -878,12 +924,14 @@ impl<Signer: Sign> Channel<Signer> {
                if holder_selected_contest_delay < BREAKDOWN_TIMEOUT {
                        return Err(APIError::APIMisuseError {err: format!("Configured with an unreasonable our_to_self_delay ({}) putting user funds at risks", holder_selected_contest_delay)});
                }
-               let holder_selected_channel_reserve_satoshis = Channel::<Signer>::get_holder_selected_channel_reserve_satoshis(channel_value_satoshis);
+               let holder_selected_channel_reserve_satoshis = Channel::<Signer>::get_holder_selected_channel_reserve_satoshis(channel_value_satoshis, config);
                if holder_selected_channel_reserve_satoshis < MIN_CHAN_DUST_LIMIT_SATOSHIS {
+                       // Protocol level safety check in place, although it should never happen because
+                       // of `MIN_THEIR_CHAN_RESERVE_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 feerate = fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Normal);
 
                let value_to_self_msat = channel_value_satoshis * 1000 - push_msat;
                let commitment_tx_fee = Self::commit_tx_fee_msat(feerate, MIN_AFFORDABLE_HTLC_COUNT, opt_anchors);
@@ -894,7 +942,7 @@ impl<Signer: Sign> Channel<Signer> {
                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 {
+               let shutdown_scriptpubkey = if config.channel_handshake_config.commit_upfront_shutdown_pubkey {
                        Some(keys_provider.get_shutdown_scriptpubkey())
                } else { None };
 
@@ -906,8 +954,16 @@ impl<Signer: Sign> Channel<Signer> {
 
                Ok(Channel {
                        user_id,
-                       config: config.channel_options.clone(),
-                       inbound_handshake_limits_override: Some(config.peer_channel_config_limits.clone()),
+
+                       config: LegacyChannelConfig {
+                               options: config.channel_config.clone(),
+                               announced_channel: config.channel_handshake_config.announced_channel,
+                               commit_upfront_shutdown_pubkey: config.channel_handshake_config.commit_upfront_shutdown_pubkey,
+                       },
+
+                       prev_config: None,
+
+                       inbound_handshake_limits_override: Some(config.channel_handshake_limits.clone()),
 
                        channel_id: keys_provider.get_secure_random_bytes(),
                        channel_state: ChannelState::OurInitSent as u32,
@@ -936,7 +992,7 @@ impl<Signer: Sign> Channel<Signer> {
 
                        resend_order: RAACommitmentOrder::CommitmentFirst,
 
-                       monitor_pending_funding_locked: false,
+                       monitor_pending_channel_ready: false,
                        monitor_pending_revoke_and_ack: false,
                        monitor_pending_commitment_signed: false,
                        monitor_pending_forwards: Vec::new(),
@@ -964,11 +1020,11 @@ impl<Signer: Sign> Channel<Signer> {
                        counterparty_dust_limit_satoshis: 0,
                        holder_dust_limit_satoshis: MIN_CHAN_DUST_LIMIT_SATOSHIS,
                        counterparty_max_htlc_value_in_flight_msat: 0,
-                       holder_max_htlc_value_in_flight_msat: Self::get_holder_max_htlc_value_in_flight_msat(channel_value_satoshis),
+                       holder_max_htlc_value_in_flight_msat: Self::get_holder_max_htlc_value_in_flight_msat(channel_value_satoshis, &config.channel_handshake_config),
                        counterparty_selected_channel_reserve_satoshis: None, // Filled in in accept_channel
                        holder_selected_channel_reserve_satoshis,
                        counterparty_htlc_minimum_msat: 0,
-                       holder_htlc_minimum_msat: if config.own_channel_config.our_htlc_minimum_msat == 0 { 1 } else { config.own_channel_config.our_htlc_minimum_msat },
+                       holder_htlc_minimum_msat: if config.channel_handshake_config.our_htlc_minimum_msat == 0 { 1 } else { config.channel_handshake_config.our_htlc_minimum_msat },
                        counterparty_max_accepted_htlcs: 0,
                        minimum_depth: None, // Filled in in accept_channel
 
@@ -976,7 +1032,7 @@ impl<Signer: Sign> Channel<Signer> {
 
                        channel_transaction_parameters: ChannelTransactionParameters {
                                holder_pubkeys: pubkeys,
-                               holder_selected_contest_delay: config.own_channel_config.our_to_self_delay,
+                               holder_selected_contest_delay: config.channel_handshake_config.our_to_self_delay,
                                is_outbound_from_holder: true,
                                counterparty_parameters: None,
                                funding_outpoint: None,
@@ -1014,7 +1070,7 @@ impl<Signer: Sign> Channel<Signer> {
                })
        }
 
-       fn check_remote_fee<F: Deref>(fee_estimator: &F, feerate_per_kw: u32) -> Result<(), ChannelError>
+       fn check_remote_fee<F: Deref>(fee_estimator: &LowerBoundedFeeEstimator<F>, feerate_per_kw: u32) -> Result<(), ChannelError>
                where F::Target: FeeEstimator
        {
                // We only bound the fee updates on the upper side to prevent completely absurd feerates,
@@ -1022,11 +1078,11 @@ impl<Signer: Sign> Channel<Signer> {
                // 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);
+                       fee_estimator.bounded_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)));
                }
-               let lower_limit = fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Background);
+               let lower_limit = fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Background);
                // Some fee estimators round up to the next full sat/vbyte (ie 250 sats per kw), causing
                // occasional issues with feerate disagreements between an initiator that wants a feerate
                // of 1.1 sat/vbyte and a receiver that wants 1.1 rounded up to 2. Thus, we always add 250
@@ -1040,7 +1096,7 @@ impl<Signer: Sign> Channel<Signer> {
        /// Creates a new channel from a remote sides' request for one.
        /// Assumes chain_hash has already been checked and corresponds with what we expect!
        pub fn new_from_req<K: Deref, F: Deref, L: Deref>(
-               fee_estimator: &F, keys_provider: &K, counterparty_node_id: PublicKey, their_features: &InitFeatures,
+               fee_estimator: &LowerBoundedFeeEstimator<F>, keys_provider: &K, counterparty_node_id: PublicKey, their_features: &InitFeatures,
                msg: &msgs::OpenChannel, user_id: u64, config: &UserConfig, current_chain_height: u32, logger: &L,
                outbound_scid_alias: u64
        ) -> Result<Channel<Signer>, ChannelError>
@@ -1057,16 +1113,22 @@ impl<Signer: Sign> Channel<Signer> {
                        if channel_type.supports_any_optional_bits() {
                                return Err(ChannelError::Close("Channel Type field contained optional bits - this is not allowed".to_owned()));
                        }
-                       // We currently only allow two channel types, so write it all out here - we allow
-                       // `only_static_remote_key` in all contexts, and further allow
-                       // `static_remote_key|scid_privacy` if the channel is not publicly announced.
-                       let mut allowed_type = ChannelTypeFeatures::only_static_remote_key();
-                       if *channel_type != allowed_type {
-                               allowed_type.set_scid_privacy_required();
-                               if *channel_type != allowed_type {
+
+                       if channel_type.requires_unknown_bits() {
+                               return Err(ChannelError::Close("Channel Type field contains unknown bits".to_owned()));
+                       }
+
+                       // We currently only allow four channel types, so write it all out here - we allow
+                       // `only_static_remote_key` or `static_remote_key | zero_conf` in all contexts, and
+                       // further allow `static_remote_key | scid_privacy` or
+                       // `static_remote_key | scid_privacy | zero_conf`, if the channel is not
+                       // publicly announced.
+                       if *channel_type != ChannelTypeFeatures::only_static_remote_key() {
+                               if !channel_type.requires_scid_privacy() && !channel_type.requires_zero_conf() {
                                        return Err(ChannelError::Close("Channel Type was not understood".to_owned()));
                                }
-                               if announced_channel {
+
+                               if channel_type.requires_scid_privacy() && announced_channel {
                                        return Err(ChannelError::Close("SCID Alias/Privacy Channel Type cannot be set on a public channel".to_owned()));
                                }
                        }
@@ -1087,15 +1149,14 @@ impl<Signer: Sign> Channel<Signer> {
                        delayed_payment_basepoint: msg.delayed_payment_basepoint,
                        htlc_basepoint: msg.htlc_basepoint
                };
-               let mut local_config = (*config).channel_options.clone();
 
-               if config.own_channel_config.our_to_self_delay < BREAKDOWN_TIMEOUT {
-                       return Err(ChannelError::Close(format!("Configured with an unreasonable our_to_self_delay ({}) putting user funds at risks. It must be greater than {}", config.own_channel_config.our_to_self_delay, BREAKDOWN_TIMEOUT)));
+               if config.channel_handshake_config.our_to_self_delay < BREAKDOWN_TIMEOUT {
+                       return Err(ChannelError::Close(format!("Configured with an unreasonable our_to_self_delay ({}) putting user funds at risks. It must be greater than {}", config.channel_handshake_config.our_to_self_delay, BREAKDOWN_TIMEOUT)));
                }
 
                // Check sanity of message fields:
-               if msg.funding_satoshis > config.peer_channel_config_limits.max_funding_satoshis {
-                       return Err(ChannelError::Close(format!("Per our config, funding must be at most {}. It was {}", config.peer_channel_config_limits.max_funding_satoshis, msg.funding_satoshis)));
+               if msg.funding_satoshis > config.channel_handshake_limits.max_funding_satoshis {
+                       return Err(ChannelError::Close(format!("Per our config, funding must be at most {}. It was {}", config.channel_handshake_limits.max_funding_satoshis, msg.funding_satoshis)));
                }
                if msg.funding_satoshis >= TOTAL_BITCOIN_SUPPLY_SATOSHIS {
                        return Err(ChannelError::Close(format!("Funding must be smaller than the total bitcoin supply. It was {}", msg.funding_satoshis)));
@@ -1115,7 +1176,7 @@ impl<Signer: Sign> Channel<Signer> {
                }
                Channel::<Signer>::check_remote_fee(fee_estimator, msg.feerate_per_kw)?;
 
-               let max_counterparty_selected_contest_delay = u16::min(config.peer_channel_config_limits.their_to_self_delay, MAX_LOCAL_BREAKDOWN_TIMEOUT);
+               let max_counterparty_selected_contest_delay = u16::min(config.channel_handshake_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)));
                }
@@ -1127,20 +1188,20 @@ impl<Signer: Sign> Channel<Signer> {
                }
 
                // Now check against optional parameters as set by config...
-               if msg.funding_satoshis < config.peer_channel_config_limits.min_funding_satoshis {
-                       return Err(ChannelError::Close(format!("Funding satoshis ({}) is less than the user specified limit ({})", msg.funding_satoshis, config.peer_channel_config_limits.min_funding_satoshis)));
+               if msg.funding_satoshis < config.channel_handshake_limits.min_funding_satoshis {
+                       return Err(ChannelError::Close(format!("Funding satoshis ({}) is less than the user specified limit ({})", msg.funding_satoshis, config.channel_handshake_limits.min_funding_satoshis)));
                }
-               if msg.htlc_minimum_msat > config.peer_channel_config_limits.max_htlc_minimum_msat {
-                       return Err(ChannelError::Close(format!("htlc_minimum_msat ({}) is higher than the user specified limit ({})", msg.htlc_minimum_msat,  config.peer_channel_config_limits.max_htlc_minimum_msat)));
+               if msg.htlc_minimum_msat > config.channel_handshake_limits.max_htlc_minimum_msat {
+                       return Err(ChannelError::Close(format!("htlc_minimum_msat ({}) is higher than the user specified limit ({})", msg.htlc_minimum_msat,  config.channel_handshake_limits.max_htlc_minimum_msat)));
                }
-               if msg.max_htlc_value_in_flight_msat < config.peer_channel_config_limits.min_max_htlc_value_in_flight_msat {
-                       return Err(ChannelError::Close(format!("max_htlc_value_in_flight_msat ({}) is less than the user specified limit ({})", msg.max_htlc_value_in_flight_msat, config.peer_channel_config_limits.min_max_htlc_value_in_flight_msat)));
+               if msg.max_htlc_value_in_flight_msat < config.channel_handshake_limits.min_max_htlc_value_in_flight_msat {
+                       return Err(ChannelError::Close(format!("max_htlc_value_in_flight_msat ({}) is less than the user specified limit ({})", msg.max_htlc_value_in_flight_msat, config.channel_handshake_limits.min_max_htlc_value_in_flight_msat)));
                }
-               if msg.channel_reserve_satoshis > config.peer_channel_config_limits.max_channel_reserve_satoshis {
-                       return Err(ChannelError::Close(format!("channel_reserve_satoshis ({}) is higher than the user specified limit ({})", msg.channel_reserve_satoshis, config.peer_channel_config_limits.max_channel_reserve_satoshis)));
+               if msg.channel_reserve_satoshis > config.channel_handshake_limits.max_channel_reserve_satoshis {
+                       return Err(ChannelError::Close(format!("channel_reserve_satoshis ({}) is higher than the user specified limit ({})", msg.channel_reserve_satoshis, config.channel_handshake_limits.max_channel_reserve_satoshis)));
                }
-               if msg.max_accepted_htlcs < config.peer_channel_config_limits.min_max_accepted_htlcs {
-                       return Err(ChannelError::Close(format!("max_accepted_htlcs ({}) is less than the user specified limit ({})", msg.max_accepted_htlcs, config.peer_channel_config_limits.min_max_accepted_htlcs)));
+               if msg.max_accepted_htlcs < config.channel_handshake_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.channel_handshake_limits.min_max_accepted_htlcs)));
                }
                if msg.dust_limit_satoshis < MIN_CHAN_DUST_LIMIT_SATOSHIS {
                        return Err(ChannelError::Close(format!("dust_limit_satoshis ({}) is less than the implementation limit ({})", msg.dust_limit_satoshis, MIN_CHAN_DUST_LIMIT_SATOSHIS)));
@@ -1151,20 +1212,20 @@ impl<Signer: Sign> Channel<Signer> {
 
                // Convert things into internal flags and prep our state:
 
-               if config.peer_channel_config_limits.force_announced_channel_preference {
-                       if local_config.announced_channel != announced_channel {
+               if config.channel_handshake_limits.force_announced_channel_preference {
+                       if config.channel_handshake_config.announced_channel != announced_channel {
                                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 = announced_channel;
 
-               let holder_selected_channel_reserve_satoshis = Channel::<Signer>::get_holder_selected_channel_reserve_satoshis(msg.funding_satoshis);
+               let holder_selected_channel_reserve_satoshis = Channel::<Signer>::get_holder_selected_channel_reserve_satoshis(msg.funding_satoshis, config);
                if holder_selected_channel_reserve_satoshis < MIN_CHAN_DUST_LIMIT_SATOSHIS {
+                       // Protocol level safety check in place, although it should never happen because
+                       // of `MIN_THEIR_CHAN_RESERVE_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 holder_selected_channel_reserve_satoshis * 1000 >= full_channel_value_msat {
-                       return Err(ChannelError::Close(format!("Suitable channel reserve not found. remote_channel_reserve was ({}). Channel value is ({} - {}).", holder_selected_channel_reserve_satoshis, full_channel_value_msat, msg.push_msat)));
+                       return Err(ChannelError::Close(format!("Suitable channel reserve not found. remote_channel_reserve was ({})msats. Channel value is ({} - {})msats.", holder_selected_channel_reserve_satoshis * 1000, full_channel_value_msat, msg.push_msat)));
                }
                if msg.channel_reserve_satoshis < MIN_CHAN_DUST_LIMIT_SATOSHIS {
                        log_debug!(logger, "channel_reserve_satoshis ({}) is smaller than our dust limit ({}). We can broadcast stale states without any risk, implying this channel is very insecure for our counterparty.",
@@ -1209,7 +1270,7 @@ impl<Signer: Sign> Channel<Signer> {
                        }
                } else { None };
 
-               let shutdown_scriptpubkey = if config.channel_options.commit_upfront_shutdown_pubkey {
+               let shutdown_scriptpubkey = if config.channel_handshake_config.commit_upfront_shutdown_pubkey {
                        Some(keys_provider.get_shutdown_scriptpubkey())
                } else { None };
 
@@ -1224,7 +1285,15 @@ impl<Signer: Sign> Channel<Signer> {
 
                let chan = Channel {
                        user_id,
-                       config: local_config,
+
+                       config: LegacyChannelConfig {
+                               options: config.channel_config.clone(),
+                               announced_channel,
+                               commit_upfront_shutdown_pubkey: config.channel_handshake_config.commit_upfront_shutdown_pubkey,
+                       },
+
+                       prev_config: None,
+
                        inbound_handshake_limits_override: None,
 
                        channel_id: msg.temporary_channel_id,
@@ -1253,7 +1322,7 @@ impl<Signer: Sign> Channel<Signer> {
 
                        resend_order: RAACommitmentOrder::CommitmentFirst,
 
-                       monitor_pending_funding_locked: false,
+                       monitor_pending_channel_ready: false,
                        monitor_pending_revoke_and_ack: false,
                        monitor_pending_commitment_signed: false,
                        monitor_pending_forwards: Vec::new(),
@@ -1282,19 +1351,19 @@ impl<Signer: Sign> Channel<Signer> {
                        counterparty_dust_limit_satoshis: msg.dust_limit_satoshis,
                        holder_dust_limit_satoshis: MIN_CHAN_DUST_LIMIT_SATOSHIS,
                        counterparty_max_htlc_value_in_flight_msat: cmp::min(msg.max_htlc_value_in_flight_msat, msg.funding_satoshis * 1000),
-                       holder_max_htlc_value_in_flight_msat: Self::get_holder_max_htlc_value_in_flight_msat(msg.funding_satoshis),
+                       holder_max_htlc_value_in_flight_msat: Self::get_holder_max_htlc_value_in_flight_msat(msg.funding_satoshis, &config.channel_handshake_config),
                        counterparty_selected_channel_reserve_satoshis: Some(msg.channel_reserve_satoshis),
                        holder_selected_channel_reserve_satoshis,
                        counterparty_htlc_minimum_msat: msg.htlc_minimum_msat,
-                       holder_htlc_minimum_msat: if config.own_channel_config.our_htlc_minimum_msat == 0 { 1 } else { config.own_channel_config.our_htlc_minimum_msat },
+                       holder_htlc_minimum_msat: if config.channel_handshake_config.our_htlc_minimum_msat == 0 { 1 } else { config.channel_handshake_config.our_htlc_minimum_msat },
                        counterparty_max_accepted_htlcs: msg.max_accepted_htlcs,
-                       minimum_depth: Some(config.own_channel_config.minimum_depth),
+                       minimum_depth: Some(cmp::max(config.channel_handshake_config.minimum_depth, 1)),
 
                        counterparty_forwarding_info: None,
 
                        channel_transaction_parameters: ChannelTransactionParameters {
                                holder_pubkeys: pubkeys,
-                               holder_selected_contest_delay: config.own_channel_config.our_to_self_delay,
+                               holder_selected_contest_delay: config.channel_handshake_config.our_to_self_delay,
                                is_outbound_from_holder: false,
                                counterparty_parameters: Some(CounterpartyChannelTransactionParameters {
                                        selected_contest_delay: msg.to_self_delay,
@@ -1684,6 +1753,28 @@ impl<Signer: Sign> Channel<Signer> {
                make_funding_redeemscript(&self.get_holder_pubkeys().funding_pubkey, self.counterparty_funding_pubkey())
        }
 
+       /// Claims an HTLC while we're disconnected from a peer, dropping the [`ChannelMonitorUpdate`]
+       /// entirely.
+       ///
+       /// The [`ChannelMonitor`] for this channel MUST be updated out-of-band with the preimage
+       /// provided (i.e. without calling [`crate::chain::Watch::update_channel`]).
+       ///
+       /// The HTLC claim will end up in the holding cell (because the caller must ensure the peer is
+       /// disconnected).
+       pub fn claim_htlc_while_disconnected_dropping_mon_update<L: Deref>
+               (&mut self, htlc_id_arg: u64, payment_preimage_arg: PaymentPreimage, logger: &L)
+       where L::Target: Logger {
+               // Assert that we'll add the HTLC claim to the holding cell in `get_update_fulfill_htlc`
+               // (see equivalent if condition there).
+               assert!(self.channel_state & (ChannelState::AwaitingRemoteRevoke as u32 | ChannelState::PeerDisconnected as u32 | ChannelState::MonitorUpdateFailed as u32) != 0);
+               let mon_update_id = self.latest_monitor_update_id; // Forget the ChannelMonitor update
+               let fulfill_resp = self.get_update_fulfill_htlc(htlc_id_arg, payment_preimage_arg, logger);
+               self.latest_monitor_update_id = mon_update_id;
+               if let UpdateFulfillFetch::NewClaim { msg, .. } = fulfill_resp {
+                       assert!(msg.is_none()); // The HTLC must have ended up in the holding cell.
+               }
+       }
+
        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
@@ -1746,6 +1837,10 @@ impl<Signer: Sign> Channel<Signer> {
                };
 
                if (self.channel_state & (ChannelState::AwaitingRemoteRevoke as u32 | ChannelState::PeerDisconnected as u32 | ChannelState::MonitorUpdateFailed as u32)) != 0 {
+                       // Note that this condition is the same as the assertion in
+                       // `claim_htlc_while_disconnected_dropping_mon_update` and must match exactly -
+                       // `claim_htlc_while_disconnected_dropping_mon_update` would not work correctly if we
+                       // do not not get into this branch.
                        for pending_update in self.holding_cell_htlc_updates.iter() {
                                match pending_update {
                                        &HTLCUpdateAwaitingACK::ClaimHTLC { htlc_id, .. } => {
@@ -1927,6 +2022,10 @@ impl<Signer: Sign> Channel<Signer> {
                if msg.dust_limit_satoshis > self.holder_selected_channel_reserve_satoshis {
                        return Err(ChannelError::Close(format!("Dust limit ({}) is bigger than our channel reserve ({})", msg.dust_limit_satoshis, self.holder_selected_channel_reserve_satoshis)));
                }
+               if msg.channel_reserve_satoshis > self.channel_value_satoshis - self.holder_selected_channel_reserve_satoshis {
+                       return Err(ChannelError::Close(format!("Bogus channel_reserve_satoshis ({}). Must not be greater than channel value minus our reserve ({})",
+                               msg.channel_reserve_satoshis, self.channel_value_satoshis - self.holder_selected_channel_reserve_satoshis)));
+               }
                let full_channel_value_msat = (self.channel_value_satoshis - msg.channel_reserve_satoshis) * 1000;
                if msg.htlc_minimum_msat >= full_channel_value_msat {
                        return Err(ChannelError::Close(format!("Minimum htlc value ({}) is full channel value ({})", msg.htlc_minimum_msat, full_channel_value_msat)));
@@ -1964,12 +2063,6 @@ impl<Signer: Sign> Channel<Signer> {
                if msg.minimum_depth > peer_limits.max_minimum_depth {
                        return Err(ChannelError::Close(format!("We consider the minimum depth to be unreasonably large. Expected minimum: ({}). Actual: ({})", peer_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()));
-               }
 
                if let Some(ty) = &msg.channel_type {
                        if *ty != self.channel_type {
@@ -2006,7 +2099,12 @@ impl<Signer: Sign> Channel<Signer> {
                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);
+
+               if peer_limits.trust_own_funding_0conf {
+                       self.minimum_depth = Some(msg.minimum_depth);
+               } else {
+                       self.minimum_depth = Some(cmp::max(1, msg.minimum_depth));
+               }
 
                let counterparty_pubkeys = ChannelPublicKeys {
                        funding_pubkey: msg.funding_pubkey,
@@ -2044,7 +2142,7 @@ impl<Signer: Sign> Channel<Signer> {
                                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());
+                       secp_check!(self.secp_ctx.verify_ecdsa(&sighash, &sig, self.counterparty_funding_pubkey()), "Invalid funding_created signature from peer".to_owned());
                }
 
                let counterparty_keys = self.build_remote_transaction_keys()?;
@@ -2066,7 +2164,7 @@ impl<Signer: Sign> Channel<Signer> {
                &self.get_counterparty_pubkeys().funding_pubkey
        }
 
-       pub fn funding_created<L: Deref>(&mut self, msg: &msgs::FundingCreated, best_block: BestBlock, logger: &L) -> Result<(msgs::FundingSigned, ChannelMonitor<Signer>), ChannelError> where L::Target: Logger {
+       pub fn funding_created<L: Deref>(&mut self, msg: &msgs::FundingCreated, best_block: BestBlock, logger: &L) -> Result<(msgs::FundingSigned, ChannelMonitor<Signer>, Option<msgs::ChannelReady>), ChannelError> where L::Target: Logger {
                if self.is_outbound() {
                        return Err(ChannelError::Close("Received funding_created for an outbound channel?".to_owned()));
                }
@@ -2127,7 +2225,7 @@ impl<Signer: Sign> Channel<Signer> {
                                                          &self.channel_transaction_parameters,
                                                          funding_redeemscript.clone(), self.channel_value_satoshis,
                                                          obscure_factor,
-                                                         holder_commitment_tx, best_block);
+                                                         holder_commitment_tx, best_block, self.counterparty_node_id);
 
                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);
 
@@ -2141,12 +2239,12 @@ impl<Signer: Sign> Channel<Signer> {
                Ok((msgs::FundingSigned {
                        channel_id: self.channel_id,
                        signature
-               }, channel_monitor))
+               }, channel_monitor, self.check_get_channel_ready(0)))
        }
 
        /// Handles a funding_signed message from the remote end.
        /// If this call is successful, broadcast the funding transaction (and not before!)
-       pub fn funding_signed<L: Deref>(&mut self, msg: &msgs::FundingSigned, best_block: BestBlock, logger: &L) -> Result<(ChannelMonitor<Signer>, Transaction), ChannelError> where L::Target: Logger {
+       pub fn funding_signed<L: Deref>(&mut self, msg: &msgs::FundingSigned, best_block: BestBlock, logger: &L) -> Result<(ChannelMonitor<Signer>, Transaction, Option<msgs::ChannelReady>), ChannelError> where L::Target: Logger {
                if !self.is_outbound() {
                        return Err(ChannelError::Close("Received funding_signed for an inbound channel?".to_owned()));
                }
@@ -2176,7 +2274,7 @@ impl<Signer: Sign> Channel<Signer> {
                        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) {
+                       if let Err(_) = self.secp_ctx.verify_ecdsa(&sighash, &msg.signature, &self.get_counterparty_pubkeys().funding_pubkey) {
                                return Err(ChannelError::Close("Invalid funding_signed signature from peer".to_owned()));
                        }
                }
@@ -2204,7 +2302,7 @@ impl<Signer: Sign> Channel<Signer> {
                                                          &self.channel_transaction_parameters,
                                                          funding_redeemscript.clone(), self.channel_value_satoshis,
                                                          obscure_factor,
-                                                         holder_commitment_tx, best_block);
+                                                         holder_commitment_tx, best_block, self.counterparty_node_id);
 
                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);
 
@@ -2215,16 +2313,16 @@ impl<Signer: Sign> Channel<Signer> {
 
                log_info!(logger, "Received funding_signed from peer for channel {}", log_bytes!(self.channel_id()));
 
-               Ok((channel_monitor, self.funding_transaction.as_ref().cloned().unwrap()))
+               Ok((channel_monitor, self.funding_transaction.as_ref().cloned().unwrap(), self.check_get_channel_ready(0)))
        }
 
-       /// Handles a funding_locked message from our peer. If we've already sent our funding_locked
+       /// Handles a channel_ready message from our peer. If we've already sent our channel_ready
        /// and the channel is now usable (and public), this may generate an announcement_signatures to
        /// reply with.
-       pub fn funding_locked<L: Deref>(&mut self, msg: &msgs::FundingLocked, node_pk: PublicKey, genesis_block_hash: BlockHash, best_block: &BestBlock, logger: &L) -> Result<Option<msgs::AnnouncementSignatures>, ChannelError> where L::Target: Logger {
+       pub fn channel_ready<L: Deref>(&mut self, msg: &msgs::ChannelReady, node_pk: PublicKey, genesis_block_hash: BlockHash, best_block: &BestBlock, logger: &L) -> Result<Option<msgs::AnnouncementSignatures>, ChannelError> where L::Target: Logger {
                if self.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 {
                        self.workaround_lnd_bug_4006 = Some(msg.clone());
-                       return Err(ChannelError::Ignore("Peer sent funding_locked when we needed a channel_reestablish. The peer is likely lnd, see https://github.com/lightningnetwork/lnd/issues/4006".to_owned()));
+                       return Err(ChannelError::Ignore("Peer sent channel_ready when we needed a channel_reestablish. The peer is likely lnd, see https://github.com/lightningnetwork/lnd/issues/4006".to_owned()));
                }
 
                if let Some(scid_alias) = msg.short_channel_id_alias {
@@ -2239,16 +2337,16 @@ impl<Signer: Sign> Channel<Signer> {
                let non_shutdown_state = self.channel_state & (!MULTI_STATE_FLAGS);
 
                if non_shutdown_state == ChannelState::FundingSent as u32 {
-                       self.channel_state |= ChannelState::TheirFundingLocked as u32;
-               } else if non_shutdown_state == (ChannelState::FundingSent as u32 | ChannelState::OurFundingLocked as u32) {
+                       self.channel_state |= ChannelState::TheirChannelReady as u32;
+               } else if non_shutdown_state == (ChannelState::FundingSent as u32 | ChannelState::OurChannelReady as u32) {
                        self.channel_state = ChannelState::ChannelFunded as u32 | (self.channel_state & MULTI_STATE_FLAGS);
                        self.update_time_counter += 1;
                } else if self.channel_state & (ChannelState::ChannelFunded as u32) != 0 ||
-                       // 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 we reconnected before sending our `channel_ready` they may still resend theirs:
+                       (self.channel_state & (ChannelState::FundingSent as u32 | ChannelState::TheirChannelReady as u32) ==
+                                             (ChannelState::FundingSent as u32 | ChannelState::TheirChannelReady as u32))
                {
-                       // They probably disconnected/reconnected and re-sent the funding_locked, which is
+                       // They probably disconnected/reconnected and re-sent the channel_ready, which is
                        // required, or they're sending a fresh SCID alias.
                        let expected_point =
                                if self.cur_counterparty_commitment_transaction_number == INITIAL_COMMITMENT_NUMBER - 1 {
@@ -2256,24 +2354,24 @@ impl<Signer: Sign> Channel<Signer> {
                                        // the current one.
                                        self.counterparty_cur_commitment_point
                                } else {
-                                       // If they have sent updated points, funding_locked is always supposed to match
+                                       // If they have sent updated points, channel_ready is always supposed to match
                                        // their "first" point, which we re-derive here.
                                        Some(PublicKey::from_secret_key(&self.secp_ctx, &SecretKey::from_slice(
                                                        &self.commitment_secrets.get_secret(INITIAL_COMMITMENT_NUMBER - 1).expect("We should have all prev secrets available")
                                                ).expect("We already advanced, so previous secret keys should have been validated already")))
                                };
                        if expected_point != Some(msg.next_per_commitment_point) {
-                               return Err(ChannelError::Close("Peer sent a reconnect funding_locked with a different point".to_owned()));
+                               return Err(ChannelError::Close("Peer sent a reconnect channel_ready with a different point".to_owned()));
                        }
                        return Ok(None);
                } else {
-                       return Err(ChannelError::Close("Peer sent a funding_locked at a strange time".to_owned()));
+                       return Err(ChannelError::Close("Peer sent a channel_ready at a strange time".to_owned()));
                }
 
                self.counterparty_prev_commitment_point = self.counterparty_cur_commitment_point;
                self.counterparty_cur_commitment_point = Some(msg.next_per_commitment_point);
 
-               log_info!(logger, "Received funding_locked from peer for channel {}", log_bytes!(self.channel_id()));
+               log_info!(logger, "Received channel_ready from peer for channel {}", log_bytes!(self.channel_id()));
 
                Ok(self.get_announcement_sigs(node_pk, genesis_block_hash, best_block.height(), logger))
        }
@@ -2814,7 +2912,7 @@ impl<Signer: Sign> Channel<Signer> {
                                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()) {
+                       if let Err(_) = self.secp_ctx.verify_ecdsa(&sighash, &msg.signature, &self.counterparty_funding_pubkey()) {
                                return Err((None, ChannelError::Close("Invalid commitment tx signature from peer".to_owned())));
                        }
                        bitcoin_tx.txid
@@ -2864,12 +2962,12 @@ impl<Signer: Sign> Channel<Signer> {
                                        &keys.broadcaster_delayed_payment_key, &keys.revocation_key);
 
                                let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, self.opt_anchors(), &keys);
-                               let htlc_sighashtype = if self.opt_anchors() { SigHashType::SinglePlusAnyoneCanPay } else { SigHashType::All };
-                               let htlc_sighash = hash_to_message!(&bip143::SigHashCache::new(&htlc_tx).signature_hash(0, &htlc_redeemscript, htlc.amount_msat / 1000, htlc_sighashtype)[..]);
+                               let htlc_sighashtype = if self.opt_anchors() { EcdsaSighashType::SinglePlusAnyoneCanPay } else { EcdsaSighashType::All };
+                               let htlc_sighash = hash_to_message!(&sighash::SighashCache::new(&htlc_tx).segwit_signature_hash(0, &htlc_redeemscript, htlc.amount_msat / 1000, htlc_sighashtype).unwrap()[..]);
                                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) {
+                               if let Err(_) = self.secp_ctx.verify_ecdsa(&htlc_sighash, &msg.htlc_signatures[idx], &keys.countersignatory_htlc_key) {
                                        return Err((None, ChannelError::Close("Invalid HTLC tx signature from peer".to_owned())));
                                }
                                htlcs_and_sigs.push((htlc, Some(msg.htlc_signatures[idx]), source));
@@ -3517,12 +3615,13 @@ impl<Signer: Sign> Channel<Signer> {
        /// 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)>,
+               resend_channel_ready: 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_channel_ready |= resend_channel_ready;
                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);
@@ -3536,20 +3635,31 @@ impl<Signer: Sign> Channel<Signer> {
                assert_eq!(self.channel_state & ChannelState::MonitorUpdateFailed as u32, ChannelState::MonitorUpdateFailed as u32);
                self.channel_state &= !(ChannelState::MonitorUpdateFailed as u32);
 
-               let funding_broadcastable = if self.channel_state & (ChannelState::FundingSent as u32) != 0 && self.is_outbound() {
-                       self.funding_transaction.take()
-               } else { None };
+               // If we're past (or at) the FundingSent stage on an outbound channel, try to
+               // (re-)broadcast the funding transaction as we may have declined to broadcast it when we
+               // first received the funding_signed.
+               let mut funding_broadcastable =
+                       if self.is_outbound() && self.channel_state & !MULTI_STATE_FLAGS >= ChannelState::FundingSent as u32 {
+                               self.funding_transaction.take()
+                       } else { None };
+               // That said, if the funding transaction is already confirmed (ie we're active with a
+               // minimum_depth over 0) don't bother re-broadcasting the confirmed funding tx.
+               if self.channel_state & !MULTI_STATE_FLAGS >= ChannelState::ChannelFunded as u32 && self.minimum_depth != Some(0) {
+                       funding_broadcastable = None;
+               }
 
                // We will never broadcast the funding transaction when we're in MonitorUpdateFailed (and
                // we assume the user never directly broadcasts the funding transaction and waits for us to
-               // do it). Thus, we can only ever hit monitor_pending_funding_locked when we're an inbound
-               // channel which failed to persist the monitor on funding_created, and we got the funding
-               // transaction confirmed before the monitor was persisted.
-               let funding_locked = if self.monitor_pending_funding_locked {
-                       assert!(!self.is_outbound(), "Funding transaction broadcast by the local client before it should have - LDK didn't do it!");
-                       self.monitor_pending_funding_locked = false;
+               // do it). Thus, we can only ever hit monitor_pending_channel_ready when we're
+               // * an inbound channel that failed to persist the monitor on funding_created and we got
+               //   the funding transaction confirmed before the monitor was persisted, or
+               // * a 0-conf channel and intended to send the channel_ready before any broadcast at all.
+               let channel_ready = if self.monitor_pending_channel_ready {
+                       assert!(!self.is_outbound() || self.minimum_depth == Some(0),
+                               "Funding transaction broadcast by the local client before it should have - LDK didn't do it!");
+                       self.monitor_pending_channel_ready = false;
                        let next_per_commitment_point = self.holder_signer.get_per_commitment_point(self.cur_holder_commitment_transaction_number, &self.secp_ctx);
-                       Some(msgs::FundingLocked {
+                       Some(msgs::ChannelReady {
                                channel_id: self.channel_id(),
                                next_per_commitment_point,
                                short_channel_id_alias: Some(self.outbound_scid_alias),
@@ -3570,7 +3680,7 @@ impl<Signer: Sign> Channel<Signer> {
                        self.monitor_pending_commitment_signed = false;
                        return MonitorRestoreUpdates {
                                raa: None, commitment_update: None, order: RAACommitmentOrder::RevokeAndACKFirst,
-                               accepted_htlcs, failed_htlcs, finalized_claimed_htlcs, funding_broadcastable, funding_locked, announcement_sigs
+                               accepted_htlcs, failed_htlcs, finalized_claimed_htlcs, funding_broadcastable, channel_ready, announcement_sigs
                        };
                }
 
@@ -3589,11 +3699,11 @@ impl<Signer: Sign> Channel<Signer> {
                        if commitment_update.is_some() { "a" } else { "no" }, if raa.is_some() { "an" } else { "no" },
                        match order { RAACommitmentOrder::CommitmentFirst => "commitment", RAACommitmentOrder::RevokeAndACKFirst => "RAA"});
                MonitorRestoreUpdates {
-                       raa, commitment_update, order, accepted_htlcs, failed_htlcs, finalized_claimed_htlcs, funding_broadcastable, funding_locked, announcement_sigs
+                       raa, commitment_update, order, accepted_htlcs, failed_htlcs, finalized_claimed_htlcs, funding_broadcastable, channel_ready, announcement_sigs
                }
        }
 
-       pub fn update_fee<F: Deref>(&mut self, fee_estimator: &F, msg: &msgs::UpdateFee) -> Result<(), ChannelError>
+       pub fn update_fee<F: Deref>(&mut self, fee_estimator: &LowerBoundedFeeEstimator<F>, msg: &msgs::UpdateFee) -> Result<(), ChannelError>
                where F::Target: FeeEstimator
        {
                if self.is_outbound() {
@@ -3703,6 +3813,11 @@ impl<Signer: Sign> Channel<Signer> {
 
        /// 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.
+       ///
+       /// Some links printed in log lines are included here to check them during build (when run with
+       /// `cargo doc --document-private-items`):
+       /// [`super::channelmanager::ChannelManager::force_close_without_broadcasting_txn`] and
+       /// [`super::channelmanager::ChannelManager::force_close_all_channels_without_broadcasting_txn`].
        pub fn channel_reestablish<L: Deref>(&mut self, msg: &msgs::ChannelReestablish, logger: &L,
                node_pk: PublicKey, genesis_block_hash: BlockHash, best_block: &BestBlock)
        -> Result<ReestablishResponses, ChannelError> where L::Target: Logger {
@@ -3728,9 +3843,20 @@ impl<Signer: Sign> Channel<Signer> {
                                                return Err(ChannelError::Close("Peer sent a garbage channel_reestablish with secret key not matching the commitment height provided".to_owned()));
                                        }
                                        if msg.next_remote_commitment_number > INITIAL_COMMITMENT_NUMBER - self.cur_holder_commitment_transaction_number {
-                                               return Err(ChannelError::CloseDelayBroadcast(
-                                                       "We have fallen behind - we have received proof that if we broadcast remote is going to claim our funds - we can't do any automated broadcasting".to_owned()
-                                               ));
+                                               macro_rules! log_and_panic {
+                                                       ($err_msg: expr) => {
+                                                               log_error!(logger, $err_msg, log_bytes!(self.channel_id), log_pubkey!(self.counterparty_node_id));
+                                                               panic!($err_msg, log_bytes!(self.channel_id), log_pubkey!(self.counterparty_node_id));
+                                                       }
+                                               }
+                                               log_and_panic!("We have fallen behind - we have received proof that if we broadcast our counterparty is going to claim all our funds.\n\
+                                                       This implies you have restarted with lost ChannelMonitor and ChannelManager state, the first of which is a violation of the LDK chain::Watch requirements.\n\
+                                                       More specifically, this means you have a bug in your implementation that can cause loss of funds, or you are running with an old backup, which is unsafe.\n\
+                                                       If you have restored from an old backup and wish to force-close channels and return to operation, you should start up, call\n\
+                                                       ChannelManager::force_close_without_broadcasting_txn on channel {} with counterparty {} or\n\
+                                                       ChannelManager::force_close_all_channels_without_broadcasting_txn, then reconnect to peer(s).\n\
+                                                       Note that due to a long-standing bug in lnd you may have to reach out to peers running lnd-based nodes to ask them to manually force-close channels\n\
+                                                       See https://github.com/lightningdevkit/rust-lightning/issues/1565 for more info.");
                                        }
                                },
                                OptionalField::Absent => {}
@@ -3761,15 +3887,15 @@ impl<Signer: Sign> Channel<Signer> {
                let announcement_sigs = self.get_announcement_sigs(node_pk, genesis_block_hash, best_block.height(), logger);
 
                if self.channel_state & (ChannelState::FundingSent as u32) == ChannelState::FundingSent as u32 {
-                       // If we're waiting on a monitor update, we shouldn't re-send any funding_locked's.
-                       if self.channel_state & (ChannelState::OurFundingLocked as u32) == 0 ||
+                       // If we're waiting on a monitor update, we shouldn't re-send any channel_ready's.
+                       if self.channel_state & (ChannelState::OurChannelReady as u32) == 0 ||
                                        self.channel_state & (ChannelState::MonitorUpdateFailed as u32) != 0 {
                                if msg.next_remote_commitment_number != 0 {
-                                       return Err(ChannelError::Close("Peer claimed they saw a revoke_and_ack but we haven't sent funding_locked yet".to_owned()));
+                                       return Err(ChannelError::Close("Peer claimed they saw a revoke_and_ack but we haven't sent channel_ready yet".to_owned()));
                                }
                                // Short circuit the whole handler as there is nothing we can resend them
                                return Ok(ReestablishResponses {
-                                       funding_locked: None,
+                                       channel_ready: None,
                                        raa: None, commitment_update: None, mon_update: None,
                                        order: RAACommitmentOrder::CommitmentFirst,
                                        holding_cell_failed_htlcs: Vec::new(),
@@ -3777,10 +3903,10 @@ impl<Signer: Sign> Channel<Signer> {
                                });
                        }
 
-                       // We have OurFundingLocked set!
+                       // We have OurChannelReady set!
                        let next_per_commitment_point = self.holder_signer.get_per_commitment_point(self.cur_holder_commitment_transaction_number, &self.secp_ctx);
                        return Ok(ReestablishResponses {
-                               funding_locked: Some(msgs::FundingLocked {
+                               channel_ready: Some(msgs::ChannelReady {
                                        channel_id: self.channel_id(),
                                        next_per_commitment_point,
                                        short_channel_id_alias: Some(self.outbound_scid_alias),
@@ -3794,7 +3920,7 @@ impl<Signer: Sign> Channel<Signer> {
 
                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.
+                       // Note that if we need to repeat our ChannelReady we'll do that in the next if block.
                        None
                } else if msg.next_remote_commitment_number + 1 == (INITIAL_COMMITMENT_NUMBER - 1) - self.cur_holder_commitment_transaction_number {
                        if self.channel_state & (ChannelState::MonitorUpdateFailed as u32) != 0 {
@@ -3813,10 +3939,10 @@ impl<Signer: Sign> Channel<Signer> {
                // the corresponding revoke_and_ack back yet.
                let next_counterparty_commitment_number = INITIAL_COMMITMENT_NUMBER - self.cur_counterparty_commitment_transaction_number + if (self.channel_state & ChannelState::AwaitingRemoteRevoke as u32) != 0 { 1 } else { 0 };
 
-               let 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 channel_ready = 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 ChannelReady
                        let next_per_commitment_point = self.holder_signer.get_per_commitment_point(self.cur_holder_commitment_transaction_number, &self.secp_ctx);
-                       Some(msgs::FundingLocked {
+                       Some(msgs::ChannelReady {
                                channel_id: self.channel_id(),
                                next_per_commitment_point,
                                short_channel_id_alias: Some(self.outbound_scid_alias),
@@ -3837,11 +3963,11 @@ impl<Signer: Sign> Channel<Signer> {
                                // now!
                                match self.free_holding_cell_htlcs(logger) {
                                        Err(ChannelError::Close(msg)) => Err(ChannelError::Close(msg)),
-                                       Err(ChannelError::Warn(_)) | Err(ChannelError::Ignore(_)) | Err(ChannelError::CloseDelayBroadcast(_)) =>
+                                       Err(ChannelError::Warn(_)) | Err(ChannelError::Ignore(_)) =>
                                                panic!("Got non-channel-failing result from free_holding_cell_htlcs"),
                                        Ok((Some((commitment_update, monitor_update)), holding_cell_failed_htlcs)) => {
                                                Ok(ReestablishResponses {
-                                                       funding_locked, shutdown_msg, announcement_sigs,
+                                                       channel_ready, shutdown_msg, announcement_sigs,
                                                        raa: required_revoke,
                                                        commitment_update: Some(commitment_update),
                                                        order: self.resend_order.clone(),
@@ -3851,7 +3977,7 @@ impl<Signer: Sign> Channel<Signer> {
                                        },
                                        Ok((None, holding_cell_failed_htlcs)) => {
                                                Ok(ReestablishResponses {
-                                                       funding_locked, shutdown_msg, announcement_sigs,
+                                                       channel_ready, shutdown_msg, announcement_sigs,
                                                        raa: required_revoke,
                                                        commitment_update: None,
                                                        order: self.resend_order.clone(),
@@ -3862,7 +3988,7 @@ impl<Signer: Sign> Channel<Signer> {
                                }
                        } else {
                                Ok(ReestablishResponses {
-                                       funding_locked, shutdown_msg, announcement_sigs,
+                                       channel_ready, shutdown_msg, announcement_sigs,
                                        raa: required_revoke,
                                        commitment_update: None,
                                        order: self.resend_order.clone(),
@@ -3880,14 +4006,14 @@ impl<Signer: Sign> Channel<Signer> {
                        if self.channel_state & (ChannelState::MonitorUpdateFailed as u32) != 0 {
                                self.monitor_pending_commitment_signed = true;
                                Ok(ReestablishResponses {
-                                       funding_locked, shutdown_msg, announcement_sigs,
+                                       channel_ready, shutdown_msg, announcement_sigs,
                                        commitment_update: None, raa: None, mon_update: None,
                                        order: self.resend_order.clone(),
                                        holding_cell_failed_htlcs: Vec::new(),
                                })
                        } else {
                                Ok(ReestablishResponses {
-                                       funding_locked, shutdown_msg, announcement_sigs,
+                                       channel_ready, shutdown_msg, announcement_sigs,
                                        raa: required_revoke,
                                        commitment_update: Some(self.get_last_commitment_update(logger)),
                                        order: self.resend_order.clone(),
@@ -3903,7 +4029,8 @@ impl<Signer: Sign> Channel<Signer> {
        /// 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)
+       fn calculate_closing_fee_limits<F: Deref>(&mut self, fee_estimator: &LowerBoundedFeeEstimator<F>)
+               -> (u64, u64)
                where F::Target: FeeEstimator
        {
                if let Some((min, max)) = self.closing_fee_limits { return (min, max); }
@@ -3911,8 +4038,8 @@ impl<Signer: Sign> Channel<Signer> {
                // Propose a range from our current Background feerate to our Normal feerate plus our
                // force_close_avoidance_max_fee_satoshis.
                // If we fail to come to consensus, we'll have to force-close.
-               let mut proposed_feerate = fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Background);
-               let normal_feerate = fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Normal);
+               let mut proposed_feerate = fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Background);
+               let normal_feerate = fee_estimator.bounded_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
@@ -3940,7 +4067,7 @@ impl<Signer: Sign> Channel<Signer> {
                                // 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,
+                               cmp::max(normal_feerate as u64 * tx_weight / 1000 + self.config.options.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
@@ -3977,7 +4104,8 @@ impl<Signer: Sign> Channel<Signer> {
                Ok(())
        }
 
-       pub fn maybe_propose_closing_signed<F: Deref, L: Deref>(&mut self, fee_estimator: &F, logger: &L)
+       pub fn maybe_propose_closing_signed<F: Deref, L: Deref>(
+               &mut self, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L)
                -> Result<(Option<msgs::ClosingSigned>, Option<Transaction>), ChannelError>
                where F::Target: FeeEstimator, L::Target: Logger
        {
@@ -4115,21 +4243,25 @@ impl<Signer: Sign> Channel<Signer> {
 
                let funding_key = self.get_holder_pubkeys().funding_pubkey.serialize();
                let counterparty_funding_key = self.counterparty_funding_pubkey().serialize();
+               let mut holder_sig = sig.serialize_der().to_vec();
+               holder_sig.push(EcdsaSighashType::All as u8);
+               let mut cp_sig = counterparty_sig.serialize_der().to_vec();
+               cp_sig.push(EcdsaSighashType::All as u8);
                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());
+                       tx.input[0].witness.push(holder_sig);
+                       tx.input[0].witness.push(cp_sig);
                } else {
-                       tx.input[0].witness.push(counterparty_sig.serialize_der().to_vec());
-                       tx.input[0].witness.push(sig.serialize_der().to_vec());
+                       tx.input[0].witness.push(cp_sig);
+                       tx.input[0].witness.push(holder_sig);
                }
-               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>
+       pub fn closing_signed<F: Deref>(
+               &mut self, fee_estimator: &LowerBoundedFeeEstimator<F>, msg: &msgs::ClosingSigned)
+               -> Result<(Option<msgs::ClosingSigned>, Option<Transaction>), ChannelError>
                where F::Target: FeeEstimator
        {
                if self.channel_state & BOTH_SIDES_SHUTDOWN_MASK != BOTH_SIDES_SHUTDOWN_MASK {
@@ -4161,14 +4293,14 @@ impl<Signer: Sign> Channel<Signer> {
                }
                let sighash = closing_tx.trust().get_sighash_all(&funding_redeemscript, self.channel_value_satoshis);
 
-               match self.secp_ctx.verify(&sighash, &msg.signature, &self.get_counterparty_pubkeys().funding_pubkey) {
+               match self.secp_ctx.verify_ecdsa(&sighash, &msg.signature, &self.get_counterparty_pubkeys().funding_pubkey) {
                        Ok(_) => {},
                        Err(_e) => {
                                // The remote end may have decided to revoke their output due to inconsistent dust
                                // limits, so check for that case by re-checking the signature here.
                                closing_tx = self.build_closing_transaction(msg.fee_satoshis, true).0;
                                let sighash = closing_tx.trust().get_sighash_all(&funding_redeemscript, self.channel_value_satoshis);
-                               secp_check!(self.secp_ctx.verify(&sighash, &msg.signature, self.counterparty_funding_pubkey()), "Invalid closing tx signature from peer".to_owned());
+                               secp_check!(self.secp_ctx.verify_ecdsa(&sighash, &msg.signature, self.counterparty_funding_pubkey()), "Invalid closing tx signature from peer".to_owned());
                        },
                };
 
@@ -4300,7 +4432,7 @@ impl<Signer: Sign> Channel<Signer> {
                &self.channel_type
        }
 
-       /// Guaranteed to be Some after both FundingLocked messages have been exchanged (and, thus,
+       /// Guaranteed to be Some after both ChannelReady messages have been exchanged (and, thus,
        /// is_usable() returns true).
        /// Allowed in any state (including after shutdown)
        pub fn get_short_channel_id(&self) -> Option<u64> {
@@ -4369,7 +4501,7 @@ impl<Signer: Sign> Channel<Signer> {
                        // channel might have been used to route very small values (either by honest users or as DoS).
                        self.channel_value_satoshis * 1000 * 9 / 10,
 
-                       self.holder_max_htlc_value_in_flight_msat
+                       self.counterparty_max_htlc_value_in_flight_msat
                );
        }
 
@@ -4398,15 +4530,93 @@ impl<Signer: Sign> Channel<Signer> {
        }
 
        pub fn get_fee_proportional_millionths(&self) -> u32 {
-               self.config.forwarding_fee_proportional_millionths
+               self.config.options.forwarding_fee_proportional_millionths
        }
 
        pub fn get_cltv_expiry_delta(&self) -> u16 {
-               cmp::max(self.config.cltv_expiry_delta, MIN_CLTV_EXPIRY_DELTA)
+               cmp::max(self.config.options.cltv_expiry_delta, MIN_CLTV_EXPIRY_DELTA)
        }
 
        pub fn get_max_dust_htlc_exposure_msat(&self) -> u64 {
-               self.config.max_dust_htlc_exposure_msat
+               self.config.options.max_dust_htlc_exposure_msat
+       }
+
+       /// Returns the previous [`ChannelConfig`] applied to this channel, if any.
+       pub fn prev_config(&self) -> Option<ChannelConfig> {
+               self.prev_config.map(|prev_config| prev_config.0)
+       }
+
+       /// Tracks the number of ticks elapsed since the previous [`ChannelConfig`] was updated. Once
+       /// [`EXPIRE_PREV_CONFIG_TICKS`] is reached, the previous config is considered expired and will
+       /// no longer be considered when forwarding HTLCs.
+       pub fn maybe_expire_prev_config(&mut self) {
+               if self.prev_config.is_none() {
+                       return;
+               }
+               let prev_config = self.prev_config.as_mut().unwrap();
+               prev_config.1 += 1;
+               if prev_config.1 == EXPIRE_PREV_CONFIG_TICKS {
+                       self.prev_config = None;
+               }
+       }
+
+       /// Returns the current [`ChannelConfig`] applied to the channel.
+       pub fn config(&self) -> ChannelConfig {
+               self.config.options
+       }
+
+       /// Updates the channel's config. A bool is returned indicating whether the config update
+       /// applied resulted in a new ChannelUpdate message.
+       pub fn update_config(&mut self, config: &ChannelConfig) -> bool {
+               let did_channel_update =
+                       self.config.options.forwarding_fee_proportional_millionths != config.forwarding_fee_proportional_millionths ||
+                       self.config.options.forwarding_fee_base_msat != config.forwarding_fee_base_msat ||
+                       self.config.options.cltv_expiry_delta != config.cltv_expiry_delta;
+               if did_channel_update {
+                       self.prev_config = Some((self.config.options, 0));
+                       // Update the counter, which backs the ChannelUpdate timestamp, to allow the relay
+                       // policy change to propagate throughout the network.
+                       self.update_time_counter += 1;
+               }
+               self.config.options = *config;
+               did_channel_update
+       }
+
+       fn internal_htlc_satisfies_config(
+               &self, htlc: &msgs::UpdateAddHTLC, amt_to_forward: u64, outgoing_cltv_value: u32, config: &ChannelConfig,
+       ) -> Result<(), (&'static str, u16)> {
+               let fee = amt_to_forward.checked_mul(config.forwarding_fee_proportional_millionths as u64)
+                       .and_then(|prop_fee| (prop_fee / 1000000).checked_add(config.forwarding_fee_base_msat as u64));
+               if fee.is_none() || htlc.amount_msat < fee.unwrap() ||
+                       (htlc.amount_msat - fee.unwrap()) < amt_to_forward {
+                       return Err((
+                               "Prior hop has deviated from specified fees parameters or origin node has obsolete ones",
+                               0x1000 | 12, // fee_insufficient
+                       ));
+               }
+               if (htlc.cltv_expiry as u64) < outgoing_cltv_value as u64 + config.cltv_expiry_delta as u64 {
+                       return Err((
+                               "Forwarding node has tampered with the intended HTLC values or origin node has an obsolete cltv_expiry_delta",
+                               0x1000 | 13, // incorrect_cltv_expiry
+                       ));
+               }
+               Ok(())
+       }
+
+       /// Determines whether the parameters of an incoming HTLC to be forwarded satisfy the channel's
+       /// [`ChannelConfig`]. This first looks at the channel's current [`ChannelConfig`], and if
+       /// unsuccessful, falls back to the previous one if one exists.
+       pub fn htlc_satisfies_config(
+               &self, htlc: &msgs::UpdateAddHTLC, amt_to_forward: u64, outgoing_cltv_value: u32,
+       ) -> Result<(), (&'static str, u16)> {
+               self.internal_htlc_satisfies_config(&htlc, amt_to_forward, outgoing_cltv_value, &self.config())
+                       .or_else(|err| {
+                               if let Some(prev_config) = self.prev_config() {
+                                       self.internal_htlc_satisfies_config(htlc, amt_to_forward, outgoing_cltv_value, &prev_config)
+                               } else {
+                                       Err(err)
+                               }
+                       })
        }
 
        pub fn get_feerate(&self) -> u32 {
@@ -4493,7 +4703,7 @@ impl<Signer: Sign> Channel<Signer> {
        /// Gets the fee we'd want to charge for adding an HTLC output to this Channel
        /// Allowed in any state (including after shutdown)
        pub fn get_outbound_forwarding_fee_base_msat(&self) -> u32 {
-               self.config.forwarding_fee_base_msat
+               self.config.options.forwarding_fee_base_msat
        }
 
        /// Returns true if we've ever received a message from the remote end for this Channel
@@ -4505,7 +4715,7 @@ impl<Signer: Sign> Channel<Signer> {
        /// Allowed in any state (including after shutdown)
        pub fn is_usable(&self) -> bool {
                let mask = ChannelState::ChannelFunded as u32 | BOTH_SIDES_SHUTDOWN_MASK;
-               (self.channel_state & mask) == (ChannelState::ChannelFunded as u32) && !self.monitor_pending_funding_locked
+               (self.channel_state & mask) == (ChannelState::ChannelFunded as u32) && !self.monitor_pending_channel_ready
        }
 
        /// Returns true if this channel is currently available for use. This is a superset of
@@ -4526,6 +4736,11 @@ impl<Signer: Sign> Channel<Signer> {
                self.channel_state >= ChannelState::FundingSent as u32
        }
 
+       /// Returns true if our channel_ready has been sent
+       pub fn is_our_channel_ready(&self) -> bool {
+               (self.channel_state & ChannelState::OurChannelReady as u32) != 0 || self.channel_state >= ChannelState::ChannelFunded 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
@@ -4555,8 +4770,8 @@ impl<Signer: Sign> Channel<Signer> {
                self.channel_update_status = status;
        }
 
-       fn check_get_funding_locked(&mut self, height: u32) -> Option<msgs::FundingLocked> {
-               if self.funding_tx_confirmation_height == 0 {
+       fn check_get_channel_ready(&mut self, height: u32) -> Option<msgs::ChannelReady> {
+               if self.funding_tx_confirmation_height == 0 && self.minimum_depth != Some(0) {
                        return None;
                }
 
@@ -4571,18 +4786,26 @@ impl<Signer: Sign> Channel<Signer> {
 
                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;
+                       self.channel_state |= ChannelState::OurChannelReady as u32;
                        true
-               } else if non_shutdown_state == (ChannelState::FundingSent as u32 | ChannelState::TheirFundingLocked as u32) {
+               } else if non_shutdown_state == (ChannelState::FundingSent as u32 | ChannelState::TheirChannelReady 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) {
+               } else if non_shutdown_state == (ChannelState::FundingSent as u32 | ChannelState::OurChannelReady 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 {
+                       if self.channel_state < ChannelState::ChannelFunded as u32 {
+                               // We should never see a funding transaction on-chain until we've received
+                               // funding_signed (if we're an outbound channel), or seen funding_generated (if we're
+                               // an inbound channel - before that we have no known funding TXID). The fuzzer,
+                               // however, may do this and we shouldn't treat it as a bug.
+                               #[cfg(not(fuzzing))]
+                               panic!("Started confirming a channel in a state pre-FundingSent: {}.\n\
+                                       Do NOT broadcast a funding transaction manually - let LDK do it for you!",
+                                       self.channel_state);
+                       }
                        // We got a reorg but not enough to trigger a force close, just ignore.
                        false
                };
@@ -4592,14 +4815,14 @@ impl<Signer: Sign> Channel<Signer> {
                                if self.channel_state & (ChannelState::PeerDisconnected as u32) == 0 {
                                        let next_per_commitment_point =
                                                self.holder_signer.get_per_commitment_point(INITIAL_COMMITMENT_NUMBER - 1, &self.secp_ctx);
-                                       return Some(msgs::FundingLocked {
+                                       return Some(msgs::ChannelReady {
                                                channel_id: self.channel_id,
                                                next_per_commitment_point,
                                                short_channel_id_alias: Some(self.outbound_scid_alias),
                                        });
                                }
                        } else {
-                               self.monitor_pending_funding_locked = true;
+                               self.monitor_pending_channel_ready = true;
                        }
                }
                None
@@ -4610,13 +4833,12 @@ impl<Signer: Sign> Channel<Signer> {
        /// 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, genesis_block_hash: BlockHash, node_pk: PublicKey, logger: &L)
-       -> Result<(Option<msgs::FundingLocked>, Option<msgs::AnnouncementSignatures>), ClosureReason> where L::Target: Logger {
-               let non_shutdown_state = self.channel_state & (!MULTI_STATE_FLAGS);
+       -> Result<(Option<msgs::ChannelReady>, Option<msgs::AnnouncementSignatures>), ClosureReason> where L::Target: Logger {
                if let Some(funding_txo) = self.get_funding_txo() {
                        for &(index_in_block, tx) in txdata.iter() {
-                               // 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 {
+                               // Check if the transaction is the expected funding transaction, and if it is,
+                               // check that it pays the right amount to the right script.
+                               if self.funding_tx_confirmation_height == 0 {
                                        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() ||
@@ -4652,13 +4874,13 @@ impl<Signer: Sign> Channel<Signer> {
                                                        }
                                                }
                                        }
-                                       // If we allow 1-conf funding, we may need to check for funding_locked here and
+                                       // If we allow 1-conf funding, we may need to check for channel_ready 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));
+                                       if let Some(channel_ready) = self.check_get_channel_ready(height) {
+                                               log_info!(logger, "Sending a channel_ready to our peer for channel {}", log_bytes!(self.channel_id));
                                                let announcement_sigs = self.get_announcement_sigs(node_pk, genesis_block_hash, height, logger);
-                                               return Ok((Some(funding_locked), announcement_sigs));
+                                               return Ok((Some(channel_ready), announcement_sigs));
                                        }
                                }
                                for inp in tx.input.iter() {
@@ -4684,12 +4906,12 @@ impl<Signer: Sign> Channel<Signer> {
        /// May return some HTLCs (and their payment_hash) which have timed out and should be failed
        /// back.
        pub fn best_block_updated<L: Deref>(&mut self, height: u32, highest_header_time: u32, genesis_block_hash: BlockHash, node_pk: PublicKey, logger: &L)
-       -> Result<(Option<msgs::FundingLocked>, Vec<(HTLCSource, PaymentHash)>, Option<msgs::AnnouncementSignatures>), ClosureReason> where L::Target: Logger {
+       -> Result<(Option<msgs::ChannelReady>, Vec<(HTLCSource, PaymentHash)>, Option<msgs::AnnouncementSignatures>), ClosureReason> where L::Target: Logger {
                self.do_best_block_updated(height, highest_header_time, Some((genesis_block_hash, node_pk)), logger)
        }
 
        fn do_best_block_updated<L: Deref>(&mut self, height: u32, highest_header_time: u32, genesis_node_pk: Option<(BlockHash, PublicKey)>, logger: &L)
-       -> Result<(Option<msgs::FundingLocked>, Vec<(HTLCSource, PaymentHash)>, Option<msgs::AnnouncementSignatures>), ClosureReason> where L::Target: Logger {
+       -> Result<(Option<msgs::ChannelReady>, Vec<(HTLCSource, PaymentHash)>, Option<msgs::AnnouncementSignatures>), ClosureReason> where L::Target: Logger {
                let mut timed_out_htlcs = Vec::new();
                // This mirrors the check in ChannelManager::decode_update_add_htlc_onion, refusing to
                // forward an HTLC when our counterparty should almost certainly just fail it for expiring
@@ -4709,30 +4931,35 @@ impl<Signer: Sign> Channel<Signer> {
 
                self.update_time_counter = cmp::max(self.update_time_counter, highest_header_time);
 
-               if let Some(funding_locked) = self.check_get_funding_locked(height) {
+               if let Some(channel_ready) = self.check_get_channel_ready(height) {
                        let announcement_sigs = if let Some((genesis_block_hash, node_pk)) = genesis_node_pk {
                                self.get_announcement_sigs(node_pk, genesis_block_hash, height, logger)
                        } else { None };
-                       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, announcement_sigs));
+                       log_info!(logger, "Sending a channel_ready to our peer for channel {}", log_bytes!(self.channel_id));
+                       return Ok((Some(channel_ready), timed_out_htlcs, announcement_sigs));
                }
 
                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 {
+                  (non_shutdown_state & ChannelState::OurChannelReady as u32) == ChannelState::OurChannelReady 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
+                               // Note that check_get_channel_ready 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
+                               // indicate we've already sent a channel_ready
                                funding_tx_confirmations = 0;
                        }
 
-                       // If we've sent funding_locked (or have both sent and received funding_locked), and
-                       // the funding transaction's confirmation count has dipped below minimum_depth / 2,
+                       // If we've sent channel_ready (or have both sent and received channel_ready), and
+                       // the funding transaction has become unconfirmed,
                        // 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 {
+                       //
+                       // Note that ideally we wouldn't force-close if we see *any* reorg on a 1-conf or
+                       // 0-conf channel, but not doing so may lead to the
+                       // `ChannelManager::short_to_chan_info` map  being inconsistent, so we currently have
+                       // to.
+                       if funding_tx_confirmations == 0 && self.funding_tx_confirmed_in.is_some() {
                                let err_reason = format!("Funding transaction was un-confirmed. Locked at {} confs, now have {} confs.",
                                        self.minimum_depth.unwrap(), funding_tx_confirmations);
                                return Err(ClosureReason::ProcessingError { err: err_reason });
@@ -4742,7 +4969,7 @@ impl<Signer: Sign> Channel<Signer> {
                        log_info!(logger, "Closing channel {} due to funding timeout", log_bytes!(self.channel_id));
                        // If funding_tx_confirmed_in is unset, the channel must not be active
                        assert!(non_shutdown_state <= ChannelState::ChannelFunded as u32);
-                       assert_eq!(non_shutdown_state & ChannelState::OurFundingLocked as u32, 0);
+                       assert_eq!(non_shutdown_state & ChannelState::OurChannelReady as u32, 0);
                        return Err(ClosureReason::FundingTimedOut);
                }
 
@@ -4754,7 +4981,7 @@ impl<Signer: Sign> Channel<Signer> {
 
        /// 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.
+       /// before the channel has reached channel_ready and we can just wait for more blocks.
        pub fn funding_transaction_unconfirmed<L: Deref>(&mut self, logger: &L) -> Result<(), ClosureReason> where L::Target: Logger {
                if self.funding_tx_confirmation_height != 0 {
                        // We handle the funding disconnection by calling best_block_updated with a height one
@@ -4765,8 +4992,8 @@ impl<Signer: Sign> Channel<Signer> {
                        // time we saw and it will be ignored.
                        let best_time = self.update_time_counter;
                        match self.do_best_block_updated(reorg_height, best_time, None, logger) {
-                               Ok((funding_locked, timed_out_htlcs, announcement_sigs)) => {
-                                       assert!(funding_locked.is_none(), "We can't generate a funding with 0 confirmations?");
+                               Ok((channel_ready, timed_out_htlcs, announcement_sigs)) => {
+                                       assert!(channel_ready.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?");
                                        assert!(announcement_sigs.is_none(), "We can't generate an announcement_sigs with 0 confirmations?");
                                        Ok(())
@@ -4828,6 +5055,12 @@ impl<Signer: Sign> Channel<Signer> {
                self.inbound_awaiting_accept
        }
 
+       /// Sets this channel to accepting 0conf, must be done before `get_accept_channel`
+       pub fn set_0conf(&mut self) {
+               assert!(self.inbound_awaiting_accept);
+               self.minimum_depth = Some(0);
+       }
+
        /// Marks an inbound channel as accepted and generates a [`msgs::AcceptChannel`] message which
        /// should be sent back to the counterparty node.
        ///
@@ -4950,7 +5183,7 @@ impl<Signer: Sign> Channel<Signer> {
        }
 
        /// Gets an UnsignedChannelAnnouncement for this channel. The channel must be publicly
-       /// announceable and available for use (have exchanged FundingLocked messages in both
+       /// announceable and available for use (have exchanged ChannelReady messages in both
        /// directions). Should be used for both broadcasted announcements and in response to an
        /// AnnouncementSignatures message from the remote peer.
        ///
@@ -5054,12 +5287,12 @@ impl<Signer: Sign> Channel<Signer> {
 
                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() {
+               if self.secp_ctx.verify_ecdsa(&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() {
+               if self.secp_ctx.verify_ecdsa(&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())));
@@ -5371,7 +5604,7 @@ impl<Signer: Sign> Channel<Signer> {
                                commitment_txid: counterparty_commitment_txid,
                                htlc_outputs: htlcs.clone(),
                                commitment_number: self.cur_counterparty_commitment_transaction_number,
-                               their_revocation_point: self.counterparty_cur_commitment_point.unwrap()
+                               their_per_commitment_point: self.counterparty_cur_commitment_point.unwrap()
                        }]
                };
                self.channel_state |= ChannelState::AwaitingRemoteRevoke as u32;
@@ -5548,7 +5781,7 @@ impl<Signer: Sign> Channel<Signer> {
        /// 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, PublicKey, [u8; 32])>) {
                // 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
@@ -5558,10 +5791,11 @@ impl<Signer: Sign> Channel<Signer> {
                // We go ahead and "free" any holding cell HTLCs or HTLCs we haven't yet committed to and
                // return them to fail the payment.
                let mut dropped_outbound_htlcs = Vec::with_capacity(self.holding_cell_htlc_updates.len());
+               let counterparty_node_id = self.get_counterparty_node_id();
                for htlc_update in self.holding_cell_htlc_updates.drain(..) {
                        match htlc_update {
                                HTLCUpdateAwaitingACK::AddHTLC { source, payment_hash, .. } => {
-                                       dropped_outbound_htlcs.push((source, payment_hash));
+                                       dropped_outbound_htlcs.push((source, payment_hash, counterparty_node_id, self.channel_id));
                                },
                                _ => {}
                        }
@@ -5590,7 +5824,7 @@ impl<Signer: Sign> Channel<Signer> {
 }
 
 const SERIALIZATION_VERSION: u8 = 2;
-const MIN_SERIALIZATION_VERSION: u8 = 1;
+const MIN_SERIALIZATION_VERSION: u8 = 2;
 
 impl_writeable_tlv_based_enum!(InboundHTLCRemovalReason,;
        (0, FailRelay),
@@ -5655,12 +5889,10 @@ impl<Signer: Sign> Writeable for Channel<Signer> {
 
                self.user_id.write(writer)?;
 
-               // Write out the old serialization for the config object. This is read by version-1
-               // deserializers, but we will read the version in the TLV at the end instead.
-               self.config.forwarding_fee_proportional_millionths.write(writer)?;
-               self.config.cltv_expiry_delta.write(writer)?;
-               self.config.announced_channel.write(writer)?;
-               self.config.commit_upfront_shutdown_pubkey.write(writer)?;
+               // Version 1 deserializers expected to read parts of the config object here. Version 2
+               // deserializers (0.0.99) now read config through TLVs, and as we now require them for
+               // `minimum_depth` we simply write dummy values here.
+               writer.write_all(&[0; 8])?;
 
                self.channel_id.write(writer)?;
                (self.channel_state | ChannelState::PeerDisconnected as u32).write(writer)?;
@@ -5792,7 +6024,7 @@ impl<Signer: Sign> Writeable for Channel<Signer> {
                        RAACommitmentOrder::RevokeAndACKFirst => 1u8.write(writer)?,
                }
 
-               self.monitor_pending_funding_locked.write(writer)?;
+               self.monitor_pending_channel_ready.write(writer)?;
                self.monitor_pending_revoke_and_ack.write(writer)?;
                self.monitor_pending_commitment_signed.write(writer)?;
 
@@ -5886,13 +6118,18 @@ impl<Signer: Sign> Writeable for Channel<Signer> {
                let chan_type = if self.channel_type != ChannelTypeFeatures::only_static_remote_key() {
                        Some(&self.channel_type) } else { None };
 
-               // The same logic applies for `holder_selected_channel_reserve_satoshis` and
-               // `holder_max_htlc_value_in_flight_msat` values other than the defaults.
+               // The same logic applies for `holder_selected_channel_reserve_satoshis` values other than
+               // the default, and when `holder_max_htlc_value_in_flight_msat` is configured to be set to
+               // a different percentage of the channel value then 10%, which older versions of LDK used
+               // to set it to before the percentage was made configurable.
                let serialized_holder_selected_reserve =
-                       if self.holder_selected_channel_reserve_satoshis != Self::get_holder_selected_channel_reserve_satoshis(self.channel_value_satoshis)
+                       if self.holder_selected_channel_reserve_satoshis != Self::get_legacy_default_holder_selected_channel_reserve_satoshis(self.channel_value_satoshis)
                        { Some(self.holder_selected_channel_reserve_satoshis) } else { None };
+
+               let mut old_max_in_flight_percent_config = UserConfig::default().channel_handshake_config;
+               old_max_in_flight_percent_config.max_inbound_htlc_value_in_flight_percent_of_channel = MAX_IN_FLIGHT_PERCENT_LEGACY;
                let serialized_holder_htlc_max_in_flight =
-                       if self.holder_max_htlc_value_in_flight_msat != Self::get_holder_max_htlc_value_in_flight_msat(self.channel_value_satoshis)
+                       if self.holder_max_htlc_value_in_flight_msat != Self::get_holder_max_htlc_value_in_flight_msat(self.channel_value_satoshis, &old_max_in_flight_percent_config)
                        { Some(self.holder_max_htlc_value_in_flight_msat) } else { None };
 
                write_tlv_fields!(writer, {
@@ -5932,11 +6169,11 @@ impl<'a, Signer: Sign, K: Deref> ReadableArgs<(&'a K, u32)> for Channel<Signer>
 
                let user_id = Readable::read(reader)?;
 
-               let mut config = Some(ChannelConfig::default());
+               let mut config = Some(LegacyChannelConfig::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().options.forwarding_fee_proportional_millionths = Readable::read(reader)?;
+                       config.as_mut().unwrap().options.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 {
@@ -6048,7 +6285,7 @@ impl<'a, Signer: Sign, K: Deref> ReadableArgs<(&'a K, u32)> for Channel<Signer>
                        _ => return Err(DecodeError::InvalidValue),
                };
 
-               let monitor_pending_funding_locked = Readable::read(reader)?;
+               let monitor_pending_channel_ready = Readable::read(reader)?;
                let monitor_pending_revoke_and_ack = Readable::read(reader)?;
                let monitor_pending_commitment_signed = Readable::read(reader)?;
 
@@ -6161,8 +6398,8 @@ impl<'a, Signer: Sign, K: Deref> ReadableArgs<(&'a K, u32)> for Channel<Signer>
                let mut announcement_sigs = None;
                let mut target_closing_feerate_sats_per_kw = None;
                let mut monitor_pending_finalized_fulfills = Some(Vec::new());
-               let mut holder_selected_channel_reserve_satoshis = Some(Self::get_holder_selected_channel_reserve_satoshis(channel_value_satoshis));
-               let mut holder_max_htlc_value_in_flight_msat = Some(Self::get_holder_max_htlc_value_in_flight_msat(channel_value_satoshis));
+               let mut holder_selected_channel_reserve_satoshis = Some(Self::get_legacy_default_holder_selected_channel_reserve_satoshis(channel_value_satoshis));
+               let mut holder_max_htlc_value_in_flight_msat = Some(Self::get_holder_max_htlc_value_in_flight_msat(channel_value_satoshis, &UserConfig::default().channel_handshake_config));
                // Prior to supporting channel type negotiation, all of our channels were static_remotekey
                // only, so we default to that if none was written.
                let mut channel_type = Some(ChannelTypeFeatures::only_static_remote_key());
@@ -6232,6 +6469,8 @@ impl<'a, Signer: Sign, K: Deref> ReadableArgs<(&'a K, u32)> for Channel<Signer>
 
                        config: config.unwrap(),
 
+                       prev_config: None,
+
                        // Note that we don't care about serializing handshake limits as we only ever serialize
                        // channel data after the handshake has completed.
                        inbound_handshake_limits_override: None,
@@ -6258,7 +6497,7 @@ impl<'a, Signer: Sign, K: Deref> ReadableArgs<(&'a K, u32)> for Channel<Signer>
 
                        resend_order,
 
-                       monitor_pending_funding_locked,
+                       monitor_pending_channel_ready,
                        monitor_pending_revoke_and_ack,
                        monitor_pending_commitment_signed,
                        monitor_pending_forwards,
@@ -6339,6 +6578,7 @@ impl<'a, Signer: Sign, K: Deref> ReadableArgs<(&'a K, u32)> for Channel<Signer>
 
 #[cfg(test)]
 mod tests {
+       use std::cmp;
        use bitcoin::blockdata::script::{Script, Builder};
        use bitcoin::blockdata::transaction::{Transaction, TxOut};
        use bitcoin::blockdata::constants::genesis_block;
@@ -6348,14 +6588,14 @@ mod tests {
        use ln::PaymentHash;
        use ln::channelmanager::{HTLCSource, PaymentId};
        use ln::channel::{Channel, InboundHTLCOutput, OutboundHTLCOutput, InboundHTLCState, OutboundHTLCState, HTLCCandidate, HTLCInitiator};
-       use ln::channel::{MAX_FUNDING_SATOSHIS_NO_WUMBO, TOTAL_BITCOIN_SUPPLY_SATOSHIS};
-       use ln::features::InitFeatures;
-       use ln::msgs::{ChannelUpdate, DataLossProtect, DecodeError, OptionalField, UnsignedChannelUpdate};
+       use ln::channel::{MAX_FUNDING_SATOSHIS_NO_WUMBO, TOTAL_BITCOIN_SUPPLY_SATOSHIS, MIN_THEIR_CHAN_RESERVE_SATOSHIS};
+       use ln::features::{InitFeatures, ChannelTypeFeatures};
+       use ln::msgs::{ChannelUpdate, DataLossProtect, DecodeError, OptionalField, UnsignedChannelUpdate, MAX_VALUE_MSAT};
        use ln::script::ShutdownScript;
        use ln::chan_utils;
        use ln::chan_utils::{htlc_success_tx_weight, htlc_timeout_tx_weight};
        use chain::BestBlock;
-       use chain::chaininterface::{FeeEstimator,ConfirmationTarget};
+       use chain::chaininterface::{FeeEstimator, LowerBoundedFeeEstimator, ConfirmationTarget};
        use chain::keysinterface::{InMemorySigner, Recipient, KeyMaterial, KeysInterface};
        use chain::transaction::OutPoint;
        use util::config::UserConfig;
@@ -6363,15 +6603,17 @@ mod tests {
        use util::errors::APIError;
        use util::test_utils;
        use util::test_utils::OnGetShutdownScriptpubkey;
-       use bitcoin::secp256k1::{Secp256k1, Signature};
+       use bitcoin::secp256k1::{Secp256k1, ecdsa::Signature, Scalar};
        use bitcoin::secp256k1::ffi::Signature as FFISignature;
-       use bitcoin::secp256k1::key::{SecretKey,PublicKey};
-       use bitcoin::secp256k1::recovery::RecoverableSignature;
+       use bitcoin::secp256k1::{SecretKey,PublicKey};
+       use bitcoin::secp256k1::ecdh::SharedSecret;
+       use bitcoin::secp256k1::ecdsa::RecoverableSignature;
        use bitcoin::hashes::sha256::Hash as Sha256;
        use bitcoin::hashes::Hash;
        use bitcoin::hash_types::WPubkeyHash;
-       use core::num::NonZeroU8;
        use bitcoin::bech32::u5;
+       use bitcoin::PackedLockTime;
+       use bitcoin::util::address::WitnessVersion;
        use prelude::*;
 
        struct TestFeeEstimator {
@@ -6394,7 +6636,9 @@ mod tests {
        fn test_no_fee_check_overflow() {
                // Previously, calling `check_remote_fee` with a fee of 0xffffffff would overflow in
                // arithmetic, causing a panic with debug assertions enabled.
-               assert!(Channel::<InMemorySigner>::check_remote_fee(&&TestFeeEstimator { fee_est: 42 }, u32::max_value()).is_err());
+               let fee_est = TestFeeEstimator { fee_est: 42 };
+               let bounded_fee_estimator = LowerBoundedFeeEstimator::new(&fee_est);
+               assert!(Channel::<InMemorySigner>::check_remote_fee(&bounded_fee_estimator, u32::max_value()).is_err());
        }
 
        struct Keys {
@@ -6404,6 +6648,7 @@ mod tests {
                type Signer = InMemorySigner;
 
                fn get_node_secret(&self, _recipient: Recipient) -> Result<SecretKey, ()> { panic!(); }
+               fn ecdh(&self, _recipient: Recipient, _other_key: &PublicKey, _tweak: Option<&Scalar>) -> Result<SharedSecret, ()> { panic!(); }
                fn get_inbound_payment_key_material(&self) -> KeyMaterial { panic!(); }
                fn get_destination_script(&self) -> Script {
                        let secp_ctx = Secp256k1::signing_only();
@@ -6435,7 +6680,7 @@ mod tests {
        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();
+                       ShutdownScript::new_witness_program(WitnessVersion::V16, &[0, 40]).unwrap();
 
                let seed = [42; 32];
                let network = Network::Testnet;
@@ -6444,11 +6689,10 @@ mod tests {
                        returns: non_v0_segwit_shutdown_script.clone(),
                });
 
-               let fee_estimator = TestFeeEstimator { fee_est: 253 };
                let secp_ctx = Secp256k1::new();
                let node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
                let config = UserConfig::default();
-               match Channel::<EnforcingSigner>::new_outbound(&&fee_estimator, &&keys_provider, node_id, &features, 10000000, 100000, 42, &config, 0, 42) {
+               match Channel::<EnforcingSigner>::new_outbound(&LowerBoundedFeeEstimator::new(&TestFeeEstimator { fee_est: 253 }), &&keys_provider, node_id, &features, 10000000, 100000, 42, &config, 0, 42) {
                        Err(APIError::IncompatibleShutdownScript { script }) => {
                                assert_eq!(script.into_inner(), non_v0_segwit_shutdown_script.into_inner());
                        },
@@ -6463,6 +6707,7 @@ mod tests {
        fn test_open_channel_msg_fee() {
                let original_fee = 253;
                let mut fee_est = TestFeeEstimator{fee_est: original_fee };
+               let bounded_fee_estimator = LowerBoundedFeeEstimator::new(&fee_est);
                let secp_ctx = Secp256k1::new();
                let seed = [42; 32];
                let network = Network::Testnet;
@@ -6470,7 +6715,7 @@ 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::<EnforcingSigner>::new_outbound(&&fee_est, &&keys_provider, node_a_node_id, &InitFeatures::known(), 10000000, 100000, 42, &config, 0, 42).unwrap();
+               let node_a_chan = Channel::<EnforcingSigner>::new_outbound(&bounded_fee_estimator, &&keys_provider, node_a_node_id, &InitFeatures::known(), 10000000, 100000, 42, &config, 0, 42).unwrap();
 
                // Now change the fee so we can check that the fee in the open_channel message is the
                // same as the old fee.
@@ -6483,7 +6728,7 @@ mod tests {
        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 feeest = LowerBoundedFeeEstimator::new(&TestFeeEstimator{fee_est: 15000});
                let secp_ctx = Secp256k1::new();
                let seed = [42; 32];
                let network = Network::Testnet;
@@ -6496,18 +6741,18 @@ mod tests {
                // Create Node A's channel pointing to Node B's pubkey
                let node_b_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
                let config = UserConfig::default();
-               let mut node_a_chan = Channel::<EnforcingSigner>::new_outbound(&&feeest, &&keys_provider, node_b_node_id, &InitFeatures::known(), 10000000, 100000, 42, &config, 0, 42).unwrap();
+               let mut node_a_chan = Channel::<EnforcingSigner>::new_outbound(&feeest, &&keys_provider, node_b_node_id, &InitFeatures::known(), 10000000, 100000, 42, &config, 0, 42).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 mut node_b_chan = Channel::<EnforcingSigner>::new_from_req(&&feeest, &&keys_provider, node_b_node_id, &InitFeatures::known(), &open_channel_msg, 7, &config, 0, &&logger, 42).unwrap();
+               let mut node_b_chan = Channel::<EnforcingSigner>::new_from_req(&feeest, &&keys_provider, node_b_node_id, &InitFeatures::known(), &open_channel_msg, 7, &config, 0, &&logger, 42).unwrap();
 
                // Node B --> Node A: accept channel, explicitly setting B's dust limit.
                let mut accept_channel_msg = node_b_chan.accept_inbound_channel(0);
                accept_channel_msg.dust_limit_satoshis = 546;
-               node_a_chan.accept_channel(&accept_channel_msg, &config.peer_channel_config_limits, &InitFeatures::known()).unwrap();
+               node_a_chan.accept_channel(&accept_channel_msg, &config.channel_handshake_limits, &InitFeatures::known()).unwrap();
                node_a_chan.holder_dust_limit_satoshis = 1560;
 
                // Put some inbound and outbound HTLCs in A's channel.
@@ -6558,7 +6803,7 @@ mod tests {
                // 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 fee_est = LowerBoundedFeeEstimator::new(&TestFeeEstimator{fee_est: 253 });
                let secp_ctx = Secp256k1::new();
                let seed = [42; 32];
                let network = Network::Testnet;
@@ -6566,7 +6811,7 @@ mod tests {
 
                let node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
                let config = UserConfig::default();
-               let mut chan = Channel::<EnforcingSigner>::new_outbound(&&fee_est, &&keys_provider, node_id, &InitFeatures::known(), 10000000, 100000, 42, &config, 0, 42).unwrap();
+               let mut chan = Channel::<EnforcingSigner>::new_outbound(&fee_est, &&keys_provider, node_id, &InitFeatures::known(), 10000000, 100000, 42, &config, 0, 42).unwrap();
 
                let commitment_tx_fee_0_htlcs = Channel::<EnforcingSigner>::commit_tx_fee_msat(chan.feerate_per_kw, 0, chan.opt_anchors());
                let commitment_tx_fee_1_htlc = Channel::<EnforcingSigner>::commit_tx_fee_msat(chan.feerate_per_kw, 1, chan.opt_anchors());
@@ -6601,7 +6846,7 @@ mod tests {
 
        #[test]
        fn channel_reestablish_no_updates() {
-               let feeest = TestFeeEstimator{fee_est: 15000};
+               let feeest = LowerBoundedFeeEstimator::new(&TestFeeEstimator{fee_est: 15000});
                let logger = test_utils::TestLogger::new();
                let secp_ctx = Secp256k1::new();
                let seed = [42; 32];
@@ -6615,25 +6860,25 @@ mod tests {
                // Create Node A's channel pointing to Node B's pubkey
                let node_b_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
                let config = UserConfig::default();
-               let mut node_a_chan = Channel::<EnforcingSigner>::new_outbound(&&feeest, &&keys_provider, node_b_node_id, &InitFeatures::known(), 10000000, 100000, 42, &config, 0, 42).unwrap();
+               let mut node_a_chan = Channel::<EnforcingSigner>::new_outbound(&feeest, &&keys_provider, node_b_node_id, &InitFeatures::known(), 10000000, 100000, 42, &config, 0, 42).unwrap();
 
                // Create Node B's channel by receiving Node A's open_channel message
                let open_channel_msg = node_a_chan.get_open_channel(chain_hash);
                let node_b_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[7; 32]).unwrap());
-               let mut node_b_chan = Channel::<EnforcingSigner>::new_from_req(&&feeest, &&keys_provider, node_b_node_id, &InitFeatures::known(), &open_channel_msg, 7, &config, 0, &&logger, 42).unwrap();
+               let mut node_b_chan = Channel::<EnforcingSigner>::new_from_req(&feeest, &&keys_provider, node_b_node_id, &InitFeatures::known(), &open_channel_msg, 7, &config, 0, &&logger, 42).unwrap();
 
                // Node B --> Node A: accept channel
                let accept_channel_msg = node_b_chan.accept_inbound_channel(0);
-               node_a_chan.accept_channel(&accept_channel_msg, &config.peer_channel_config_limits, &InitFeatures::known()).unwrap();
+               node_a_chan.accept_channel(&accept_channel_msg, &config.channel_handshake_limits, &InitFeatures::known()).unwrap();
 
                // Node A --> Node B: funding created
                let output_script = node_a_chan.get_funding_redeemscript();
-               let tx = Transaction { version: 1, lock_time: 0, input: Vec::new(), output: vec![TxOut {
+               let tx = Transaction { version: 1, lock_time: PackedLockTime::ZERO, input: Vec::new(), output: vec![TxOut {
                        value: 10000000, script_pubkey: output_script.clone(),
                }]};
                let funding_outpoint = OutPoint{ txid: tx.txid(), index: 0 };
                let funding_created_msg = node_a_chan.get_outbound_funding_created(tx.clone(), funding_outpoint, &&logger).unwrap();
-               let (funding_signed_msg, _) = node_b_chan.funding_created(&funding_created_msg, best_block, &&logger).unwrap();
+               let (funding_signed_msg, _, _) = node_b_chan.funding_created(&funding_created_msg, best_block, &&logger).unwrap();
 
                // Node B --> Node A: funding signed
                let _ = node_a_chan.funding_signed(&funding_signed_msg, best_block, &&logger);
@@ -6665,9 +6910,140 @@ mod tests {
                }
        }
 
+       #[test]
+       fn test_configured_holder_max_htlc_value_in_flight() {
+               let feeest = LowerBoundedFeeEstimator::new(&TestFeeEstimator{fee_est: 15000});
+               let logger = test_utils::TestLogger::new();
+               let secp_ctx = Secp256k1::new();
+               let seed = [42; 32];
+               let network = Network::Testnet;
+               let keys_provider = test_utils::TestKeysInterface::new(&seed, network);
+               let outbound_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
+               let inbound_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[7; 32]).unwrap());
+
+               let mut config_2_percent = UserConfig::default();
+               config_2_percent.channel_handshake_config.max_inbound_htlc_value_in_flight_percent_of_channel = 2;
+               let mut config_99_percent = UserConfig::default();
+               config_99_percent.channel_handshake_config.max_inbound_htlc_value_in_flight_percent_of_channel = 99;
+               let mut config_0_percent = UserConfig::default();
+               config_0_percent.channel_handshake_config.max_inbound_htlc_value_in_flight_percent_of_channel = 0;
+               let mut config_101_percent = UserConfig::default();
+               config_101_percent.channel_handshake_config.max_inbound_htlc_value_in_flight_percent_of_channel = 101;
+
+               // Test that `new_outbound` creates a channel with the correct value for
+               // `holder_max_htlc_value_in_flight_msat`, when configured with a valid percentage value,
+               // which is set to the lower bound + 1 (2%) of the `channel_value`.
+               let chan_1 = Channel::<EnforcingSigner>::new_outbound(&feeest, &&keys_provider, outbound_node_id, &InitFeatures::known(), 10000000, 100000, 42, &config_2_percent, 0, 42).unwrap();
+               let chan_1_value_msat = chan_1.channel_value_satoshis * 1000;
+               assert_eq!(chan_1.holder_max_htlc_value_in_flight_msat, (chan_1_value_msat as f64 * 0.02) as u64);
+
+               // Test with the upper bound - 1 of valid values (99%).
+               let chan_2 = Channel::<EnforcingSigner>::new_outbound(&feeest, &&keys_provider, outbound_node_id, &InitFeatures::known(), 10000000, 100000, 42, &config_99_percent, 0, 42).unwrap();
+               let chan_2_value_msat = chan_2.channel_value_satoshis * 1000;
+               assert_eq!(chan_2.holder_max_htlc_value_in_flight_msat, (chan_2_value_msat as f64 * 0.99) as u64);
+
+               let chan_1_open_channel_msg = chan_1.get_open_channel(genesis_block(network).header.block_hash());
+
+               // Test that `new_from_req` creates a channel with the correct value for
+               // `holder_max_htlc_value_in_flight_msat`, when configured with a valid percentage value,
+               // which is set to the lower bound - 1 (2%) of the `channel_value`.
+               let chan_3 = Channel::<EnforcingSigner>::new_from_req(&feeest, &&keys_provider, inbound_node_id, &InitFeatures::known(), &chan_1_open_channel_msg, 7, &config_2_percent, 0, &&logger, 42).unwrap();
+               let chan_3_value_msat = chan_3.channel_value_satoshis * 1000;
+               assert_eq!(chan_3.holder_max_htlc_value_in_flight_msat, (chan_3_value_msat as f64 * 0.02) as u64);
+
+               // Test with the upper bound - 1 of valid values (99%).
+               let chan_4 = Channel::<EnforcingSigner>::new_from_req(&feeest, &&keys_provider, inbound_node_id, &InitFeatures::known(), &chan_1_open_channel_msg, 7, &config_99_percent, 0, &&logger, 42).unwrap();
+               let chan_4_value_msat = chan_4.channel_value_satoshis * 1000;
+               assert_eq!(chan_4.holder_max_htlc_value_in_flight_msat, (chan_4_value_msat as f64 * 0.99) as u64);
+
+               // Test that `new_outbound` uses the lower bound of the configurable percentage values (1%)
+               // if `max_inbound_htlc_value_in_flight_percent_of_channel` is set to a value less than 1.
+               let chan_5 = Channel::<EnforcingSigner>::new_outbound(&feeest, &&keys_provider, outbound_node_id, &InitFeatures::known(), 10000000, 100000, 42, &config_0_percent, 0, 42).unwrap();
+               let chan_5_value_msat = chan_5.channel_value_satoshis * 1000;
+               assert_eq!(chan_5.holder_max_htlc_value_in_flight_msat, (chan_5_value_msat as f64 * 0.01) as u64);
+
+               // Test that `new_outbound` uses the upper bound of the configurable percentage values
+               // (100%) if `max_inbound_htlc_value_in_flight_percent_of_channel` is set to a larger value
+               // than 100.
+               let chan_6 = Channel::<EnforcingSigner>::new_outbound(&feeest, &&keys_provider, outbound_node_id, &InitFeatures::known(), 10000000, 100000, 42, &config_101_percent, 0, 42).unwrap();
+               let chan_6_value_msat = chan_6.channel_value_satoshis * 1000;
+               assert_eq!(chan_6.holder_max_htlc_value_in_flight_msat, chan_6_value_msat);
+
+               // Test that `new_from_req` uses the lower bound of the configurable percentage values (1%)
+               // if `max_inbound_htlc_value_in_flight_percent_of_channel` is set to a value less than 1.
+               let chan_7 = Channel::<EnforcingSigner>::new_from_req(&feeest, &&keys_provider, inbound_node_id, &InitFeatures::known(), &chan_1_open_channel_msg, 7, &config_0_percent, 0, &&logger, 42).unwrap();
+               let chan_7_value_msat = chan_7.channel_value_satoshis * 1000;
+               assert_eq!(chan_7.holder_max_htlc_value_in_flight_msat, (chan_7_value_msat as f64 * 0.01) as u64);
+
+               // Test that `new_from_req` uses the upper bound of the configurable percentage values
+               // (100%) if `max_inbound_htlc_value_in_flight_percent_of_channel` is set to a larger value
+               // than 100.
+               let chan_8 = Channel::<EnforcingSigner>::new_from_req(&feeest, &&keys_provider, inbound_node_id, &InitFeatures::known(), &chan_1_open_channel_msg, 7, &config_101_percent, 0, &&logger, 42).unwrap();
+               let chan_8_value_msat = chan_8.channel_value_satoshis * 1000;
+               assert_eq!(chan_8.holder_max_htlc_value_in_flight_msat, chan_8_value_msat);
+       }
+
+       #[test]
+       fn test_configured_holder_selected_channel_reserve_satoshis() {
+
+               // Test that `new_outbound` and `new_from_req` create a channel with the correct
+               // channel reserves, when `their_channel_reserve_proportional_millionths` is configured.
+               test_self_and_counterparty_channel_reserve(10_000_000, 0.02, 0.02);
+
+               // Test with valid but unreasonably high channel reserves
+               // Requesting and accepting parties have requested for 49%-49% and 60%-30% channel reserve
+               test_self_and_counterparty_channel_reserve(10_000_000, 0.49, 0.49);
+               test_self_and_counterparty_channel_reserve(10_000_000, 0.60, 0.30);
+
+               // Test with calculated channel reserve less than lower bound
+               // i.e `MIN_THEIR_CHAN_RESERVE_SATOSHIS`
+               test_self_and_counterparty_channel_reserve(100_000, 0.00002, 0.30);
+
+               // Test with invalid channel reserves since sum of both is greater than or equal
+               // to channel value
+               test_self_and_counterparty_channel_reserve(10_000_000, 0.50, 0.50);
+               test_self_and_counterparty_channel_reserve(10_000_000, 0.60, 0.50);
+       }
+
+       fn test_self_and_counterparty_channel_reserve(channel_value_satoshis: u64, outbound_selected_channel_reserve_perc: f64, inbound_selected_channel_reserve_perc: f64) {
+               let fee_est = LowerBoundedFeeEstimator::new(&TestFeeEstimator { fee_est: 15_000 });
+               let logger = test_utils::TestLogger::new();
+               let secp_ctx = Secp256k1::new();
+               let seed = [42; 32];
+               let network = Network::Testnet;
+               let keys_provider = test_utils::TestKeysInterface::new(&seed, network);
+               let outbound_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
+               let inbound_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[7; 32]).unwrap());
+
+
+               let mut outbound_node_config = UserConfig::default();
+               outbound_node_config.channel_handshake_config.their_channel_reserve_proportional_millionths = (outbound_selected_channel_reserve_perc * 1_000_000.0) as u32;
+               let chan = Channel::<EnforcingSigner>::new_outbound(&&fee_est, &&keys_provider, outbound_node_id, &InitFeatures::known(), channel_value_satoshis, 100_000, 42, &outbound_node_config, 0, 42).unwrap();
+
+               let expected_outbound_selected_chan_reserve = cmp::max(MIN_THEIR_CHAN_RESERVE_SATOSHIS, (chan.channel_value_satoshis as f64 * outbound_selected_channel_reserve_perc) as u64);
+               assert_eq!(chan.holder_selected_channel_reserve_satoshis, expected_outbound_selected_chan_reserve);
+
+               let chan_open_channel_msg = chan.get_open_channel(genesis_block(network).header.block_hash());
+               let mut inbound_node_config = UserConfig::default();
+               inbound_node_config.channel_handshake_config.their_channel_reserve_proportional_millionths = (inbound_selected_channel_reserve_perc * 1_000_000.0) as u32;
+
+               if outbound_selected_channel_reserve_perc + inbound_selected_channel_reserve_perc < 1.0 {
+                       let chan_inbound_node = Channel::<EnforcingSigner>::new_from_req(&&fee_est, &&keys_provider, inbound_node_id, &InitFeatures::known(), &chan_open_channel_msg, 7, &inbound_node_config, 0, &&logger, 42).unwrap();
+
+                       let expected_inbound_selected_chan_reserve = cmp::max(MIN_THEIR_CHAN_RESERVE_SATOSHIS, (chan.channel_value_satoshis as f64 * inbound_selected_channel_reserve_perc) as u64);
+
+                       assert_eq!(chan_inbound_node.holder_selected_channel_reserve_satoshis, expected_inbound_selected_chan_reserve);
+                       assert_eq!(chan_inbound_node.counterparty_selected_channel_reserve_satoshis.unwrap(), expected_outbound_selected_chan_reserve);
+               } else {
+                       // Channel Negotiations failed
+                       let result = Channel::<EnforcingSigner>::new_from_req(&&fee_est, &&keys_provider, inbound_node_id, &InitFeatures::known(), &chan_open_channel_msg, 7, &inbound_node_config, 0, &&logger, 42);
+                       assert!(result.is_err());
+               }
+       }
+
        #[test]
        fn channel_update() {
-               let feeest = TestFeeEstimator{fee_est: 15000};
+               let feeest = LowerBoundedFeeEstimator::new(&TestFeeEstimator{fee_est: 15000});
                let secp_ctx = Secp256k1::new();
                let seed = [42; 32];
                let network = Network::Testnet;
@@ -6677,7 +7053,7 @@ mod tests {
                // Create a channel.
                let node_b_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
                let config = UserConfig::default();
-               let mut node_a_chan = Channel::<EnforcingSigner>::new_outbound(&&feeest, &&keys_provider, node_b_node_id, &InitFeatures::known(), 10000000, 100000, 42, &config, 0, 42).unwrap();
+               let mut node_a_chan = Channel::<EnforcingSigner>::new_outbound(&feeest, &&keys_provider, node_b_node_id, &InitFeatures::known(), 10000000, 100000, 42, &config, 0, 42).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());
@@ -6691,7 +7067,7 @@ mod tests {
                                flags: 0,
                                cltv_expiry_delta: 100,
                                htlc_minimum_msat: 5,
-                               htlc_maximum_msat: OptionalField::Absent,
+                               htlc_maximum_msat: MAX_VALUE_MSAT,
                                fee_base_msat: 110,
                                fee_proportional_millionths: 11,
                                excess_data: Vec::new(),
@@ -6716,9 +7092,9 @@ mod tests {
        #[cfg(not(feature = "grind_signatures"))]
        #[test]
        fn outbound_commitment_test() {
-               use bitcoin::util::bip143;
+               use bitcoin::util::sighash;
                use bitcoin::consensus::encode::serialize;
-               use bitcoin::blockdata::transaction::SigHashType;
+               use bitcoin::blockdata::transaction::EcdsaSighashType;
                use bitcoin::hashes::hex::FromHex;
                use bitcoin::hash_types::Txid;
                use bitcoin::secp256k1::Message;
@@ -6755,8 +7131,8 @@ mod tests {
 
                let counterparty_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
                let mut config = UserConfig::default();
-               config.channel_options.announced_channel = false;
-               let mut chan = Channel::<InMemorySigner>::new_outbound(&&feeest, &&keys_provider, counterparty_node_id, &InitFeatures::known(), 10_000_000, 100000, 42, &config, 0, 42).unwrap(); // Nothing uses their network key in this test
+               config.channel_handshake_config.announced_channel = false;
+               let mut chan = Channel::<InMemorySigner>::new_outbound(&LowerBoundedFeeEstimator::new(&feeest), &&keys_provider, counterparty_node_id, &InitFeatures::known(), 10_000_000, 100000, 42, &config, 0, 42).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
 
@@ -6827,7 +7203,7 @@ mod tests {
                                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);
                                log_trace!(logger, "unsigned_tx = {}", hex::encode(serialize(&unsigned_tx.transaction)));
-                               assert!(secp_ctx.verify(&sighash, &counterparty_signature, chan.counterparty_funding_pubkey()).is_ok(), "verify counterparty commitment sig");
+                               assert!(secp_ctx.verify_ecdsa(&sighash, &counterparty_signature, chan.counterparty_funding_pubkey()).is_ok(), "verify counterparty commitment sig");
 
                                let mut per_htlc: Vec<(HTLCOutputInCommitment, Option<Signature>)> = Vec::new();
                                per_htlc.clear(); // Don't warn about excess mut for no-HTLC calls
@@ -6866,9 +7242,9 @@ mod tests {
                                                chan.get_counterparty_selected_contest_delay().unwrap(),
                                                &htlc, $opt_anchors, &keys.broadcaster_delayed_payment_key, &keys.revocation_key);
                                        let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, $opt_anchors, &keys);
-                                       let htlc_sighashtype = if $opt_anchors { SigHashType::SinglePlusAnyoneCanPay } else { SigHashType::All };
-                                       let htlc_sighash = Message::from_slice(&bip143::SigHashCache::new(&htlc_tx).signature_hash(0, &htlc_redeemscript, htlc.amount_msat / 1000, htlc_sighashtype)[..]).unwrap();
-                                       assert!(secp_ctx.verify(&htlc_sighash, &remote_signature, &keys.countersignatory_htlc_key).is_ok(), "verify counterparty htlc sig");
+                                       let htlc_sighashtype = if $opt_anchors { EcdsaSighashType::SinglePlusAnyoneCanPay } else { EcdsaSighashType::All };
+                                       let htlc_sighash = Message::from_slice(&sighash::SighashCache::new(&htlc_tx).segwit_signature_hash(0, &htlc_redeemscript, htlc.amount_msat / 1000, htlc_sighashtype).unwrap()[..]).unwrap();
+                                       assert!(secp_ctx.verify_ecdsa(&htlc_sighash, &remote_signature, &keys.countersignatory_htlc_key).is_ok(), "verify counterparty htlc sig");
 
                                        let mut preimage: Option<PaymentPreimage> = None;
                                        if !htlc.offered {
@@ -7591,4 +7967,29 @@ mod tests {
                assert_eq!(chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_secret, &base_secret).unwrap(),
                                SecretKey::from_slice(&hex::decode("d09ffff62ddb2297ab000cc85bcb4283fdeb6aa052affbc9dddcf33b61078110").unwrap()[..]).unwrap());
        }
+
+       #[test]
+       fn test_zero_conf_channel_type_support() {
+               let feeest = LowerBoundedFeeEstimator::new(&TestFeeEstimator{fee_est: 15000});
+               let secp_ctx = Secp256k1::new();
+               let seed = [42; 32];
+               let network = Network::Testnet;
+               let keys_provider = test_utils::TestKeysInterface::new(&seed, network);
+               let logger = test_utils::TestLogger::new();
+
+               let node_b_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
+               let config = UserConfig::default();
+               let node_a_chan = Channel::<EnforcingSigner>::new_outbound(&feeest, &&keys_provider,
+                       node_b_node_id, &InitFeatures::known(), 10000000, 100000, 42, &config, 0, 42).unwrap();
+
+               let mut channel_type_features = ChannelTypeFeatures::only_static_remote_key();
+               channel_type_features.set_zero_conf_required();
+
+               let mut open_channel_msg = node_a_chan.get_open_channel(genesis_block(network).header.block_hash());
+               open_channel_msg.channel_type = Some(channel_type_features);
+               let node_b_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[7; 32]).unwrap());
+               let res = Channel::<EnforcingSigner>::new_from_req(&feeest, &&keys_provider,
+                       node_b_node_id, &InitFeatures::known(), &open_channel_msg, 7, &config, 0, &&logger, 42);
+               assert!(res.is_ok());
+       }
 }