Move ECDSA-specific signers into ecdsa.rs
[rust-lightning] / lightning / src / ln / channel.rs
index d14a868539f68f173fcb79e481e2056aa3f8f090..8a50d47cd20607cc72131d52d5544eb1884f60e0 100644 (file)
@@ -7,9 +7,11 @@
 // You may not use this file except in accordance with one or both of these
 // licenses.
 
-use bitcoin::blockdata::script::{Script,Builder};
-use bitcoin::blockdata::transaction::{Transaction, EcdsaSighashType};
-use bitcoin::util::sighash;
+use bitcoin::blockdata::constants::ChainHash;
+use bitcoin::blockdata::script::{Script, ScriptBuf, Builder};
+use bitcoin::blockdata::transaction::Transaction;
+use bitcoin::sighash;
+use bitcoin::sighash::EcdsaSighashType;
 use bitcoin::consensus::encode;
 
 use bitcoin::hashes::Hash;
@@ -35,10 +37,11 @@ use crate::chain::BestBlock;
 use crate::chain::chaininterface::{FeeEstimator, ConfirmationTarget, LowerBoundedFeeEstimator};
 use crate::chain::channelmonitor::{ChannelMonitor, ChannelMonitorUpdate, ChannelMonitorUpdateStep, LATENCY_GRACE_PERIOD_BLOCKS, CLOSED_CHANNEL_UPDATE_ID};
 use crate::chain::transaction::{OutPoint, TransactionData};
-use crate::sign::{EcdsaChannelSigner, WriteableEcdsaChannelSigner, EntropySource, ChannelSigner, SignerProvider, NodeSigner, Recipient};
+use crate::sign::ecdsa::{EcdsaChannelSigner, WriteableEcdsaChannelSigner};
+use crate::sign::{EntropySource, ChannelSigner, SignerProvider, NodeSigner, Recipient};
 use crate::events::ClosureReason;
 use crate::routing::gossip::NodeId;
-use crate::util::ser::{Readable, ReadableArgs, Writeable, Writer, VecWriter};
+use crate::util::ser::{Readable, ReadableArgs, Writeable, Writer};
 use crate::util::logger::Logger;
 use crate::util::errors::APIError;
 use crate::util::config::{UserConfig, ChannelConfig, LegacyChannelConfig, ChannelHandshakeConfig, ChannelHandshakeLimits, MaxDustHTLCExposure};
@@ -47,12 +50,14 @@ use crate::util::scid_utils::scid_from_parts;
 use crate::io;
 use crate::prelude::*;
 use core::{cmp,mem,fmt};
+use core::convert::TryInto;
 use core::ops::Deref;
 #[cfg(any(test, fuzzing, debug_assertions))]
 use crate::sync::Mutex;
-use bitcoin::hashes::hex::ToHex;
 use crate::sign::type_resolver::ChannelSignerType;
 
+use super::channel_keys::{DelayedPaymentBasepoint, HtlcBasepoint, RevocationBasepoint};
+
 #[cfg(test)]
 pub struct ChannelValueStat {
        pub value_to_self_msat: u64,
@@ -66,6 +71,8 @@ pub struct ChannelValueStat {
 }
 
 pub struct AvailableBalances {
+       /// The amount that would go to us if we close the channel, ignoring any on-chain fees.
+       pub balance_msat: u64,
        /// Total amount available for our counterparty to send to us.
        pub inbound_capacity_msat: u64,
        /// Total amount available for us to send to our counterparty.
@@ -530,6 +537,15 @@ pub(super) struct MonitorRestoreUpdates {
        pub announcement_sigs: Option<msgs::AnnouncementSignatures>,
 }
 
+/// The return value of `signer_maybe_unblocked`
+#[allow(unused)]
+pub(super) struct SignerResumeUpdates {
+       pub commitment_update: Option<msgs::CommitmentUpdate>,
+       pub funding_signed: Option<msgs::FundingSigned>,
+       pub funding_created: Option<msgs::FundingCreated>,
+       pub channel_ready: Option<msgs::ChannelReady>,
+}
+
 /// The return value of `channel_reestablish`
 pub(super) struct ReestablishResponses {
        pub channel_ready: Option<msgs::ChannelReady>,
@@ -540,18 +556,17 @@ pub(super) struct ReestablishResponses {
        pub shutdown_msg: Option<msgs::Shutdown>,
 }
 
-/// The return type of `force_shutdown`
-///
-/// Contains a tuple with the following:
-/// - An optional (counterparty_node_id, funding_txo, [`ChannelMonitorUpdate`]) tuple
-/// - A list of HTLCs to fail back in the form of the (source, payment hash, and this channel's
-/// counterparty_node_id and channel_id).
-/// - An optional transaction id identifying a corresponding batch funding transaction.
-pub(crate) type ShutdownResult = (
-       Option<(PublicKey, OutPoint, ChannelMonitorUpdate)>,
-       Vec<(HTLCSource, PaymentHash, PublicKey, ChannelId)>,
-       Option<Txid>
-);
+/// The result of a shutdown that should be handled.
+#[must_use]
+pub(crate) struct ShutdownResult {
+       /// A channel monitor update to apply.
+       pub(crate) monitor_update: Option<(PublicKey, OutPoint, ChannelMonitorUpdate)>,
+       /// A list of dropped outbound HTLCs that can safely be failed backwards immediately.
+       pub(crate) dropped_outbound_htlcs: Vec<(HTLCSource, PaymentHash, PublicKey, ChannelId)>,
+       /// An unbroadcasted batch funding transaction id. The closure of this channel should be
+       /// propagated to the remainder of the batch.
+       pub(crate) unbroadcasted_batch_funding_txid: Option<Txid>,
+}
 
 /// If the majority of the channels funds are to the fundee and the initiator holds only just
 /// enough funds to cover their reserve value, channels are at risk of getting "stuck". Because the
@@ -633,7 +648,7 @@ pub(super) enum ChannelPhase<SP: Deref> where SP::Target: SignerProvider {
 
 impl<'a, SP: Deref> ChannelPhase<SP> where
        SP::Target: SignerProvider,
-       <SP::Target as SignerProvider>::Signer: ChannelSigner,
+       <SP::Target as SignerProvider>::EcdsaSigner: ChannelSigner,
 {
        pub fn context(&'a self) -> &'a ChannelContext<SP> {
                match self {
@@ -711,9 +726,9 @@ pub(super) struct ChannelContext<SP: Deref> where SP::Target: SignerProvider {
 
        latest_monitor_update_id: u64,
 
-       holder_signer: ChannelSignerType<<SP::Target as SignerProvider>::Signer>,
+       holder_signer: ChannelSignerType<SP>,
        shutdown_scriptpubkey: Option<ShutdownScript>,
-       destination_script: Script,
+       destination_script: ScriptBuf,
 
        // Our commitment numbers start at 2^48-1 and count down, whereas the ones used in transaction
        // generation start at 0 and count up...this simplifies some parts of implementation at the
@@ -721,7 +736,7 @@ pub(super) struct ChannelContext<SP: Deref> where SP::Target: SignerProvider {
 
        cur_holder_commitment_transaction_number: u64,
        cur_counterparty_commitment_transaction_number: u64,
-       value_to_self_msat: u64, // Excluding all pending_htlcs, excluding fees
+       value_to_self_msat: u64, // Excluding all pending_htlcs, fees, and anchor outputs
        pending_inbound_htlcs: Vec<InboundHTLCOutput>,
        pending_outbound_htlcs: Vec<OutboundHTLCOutput>,
        holding_cell_htlc_updates: Vec<HTLCUpdateAwaitingACK>,
@@ -747,6 +762,18 @@ pub(super) struct ChannelContext<SP: Deref> where SP::Target: SignerProvider {
        monitor_pending_failures: Vec<(HTLCSource, PaymentHash, HTLCFailReason)>,
        monitor_pending_finalized_fulfills: Vec<HTLCSource>,
 
+       /// If we went to send a commitment update (ie some messages then [`msgs::CommitmentSigned`])
+       /// but our signer (initially) refused to give us a signature, we should retry at some point in
+       /// the future when the signer indicates it may have a signature for us.
+       ///
+       /// This flag is set in such a case. Note that we don't need to persist this as we'll end up
+       /// setting it again as a side-effect of [`Channel::channel_reestablish`].
+       signer_pending_commitment_update: bool,
+       /// Similar to [`Self::signer_pending_commitment_update`] but we're waiting to send either a
+       /// [`msgs::FundingCreated`] or [`msgs::FundingSigned`] depending on if this channel is
+       /// outbound or inbound.
+       signer_pending_funding: bool,
+
        // pending_update_fee is filled when sending and receiving update_fee.
        //
        // Because it follows the same commitment flow as HTLCs, `FeeUpdateState` is either `Outbound`
@@ -792,6 +819,19 @@ pub(super) struct ChannelContext<SP: Deref> where SP::Target: SignerProvider {
        #[cfg(not(test))]
        closing_fee_limits: Option<(u64, u64)>,
 
+       /// If we remove an HTLC (or fee update), commit, and receive our counterparty's
+       /// `revoke_and_ack`, we remove all knowledge of said HTLC (or fee update). However, the latest
+       /// local commitment transaction that we can broadcast still contains the HTLC (or old fee)
+       /// until we receive a further `commitment_signed`. Thus we are not eligible for initiating the
+       /// `closing_signed` negotiation if we're expecting a counterparty `commitment_signed`.
+       ///
+       /// To ensure we don't send a `closing_signed` too early, we track this state here, waiting
+       /// until we see a `commitment_signed` before doing so.
+       ///
+       /// We don't bother to persist this - we anticipate this state won't last longer than a few
+       /// milliseconds, so any accidental force-closes here should be exceedingly rare.
+       expecting_peer_commitment_signed: bool,
+
        /// The hash of the block in which the funding transaction was included.
        funding_tx_confirmed_in: Option<BlockHash>,
        funding_tx_confirmation_height: u32,
@@ -845,7 +885,7 @@ pub(super) struct ChannelContext<SP: Deref> where SP::Target: SignerProvider {
        counterparty_prev_commitment_point: Option<PublicKey>,
        counterparty_node_id: PublicKey,
 
-       counterparty_shutdown_scriptpubkey: Option<Script>,
+       counterparty_shutdown_scriptpubkey: Option<ScriptBuf>,
 
        commitment_secrets: CounterpartyCommitmentSecrets,
 
@@ -1054,6 +1094,12 @@ impl<SP: Deref> ChannelContext<SP> where SP::Target: SignerProvider  {
                self.outbound_scid_alias
        }
 
+       /// Returns the holder signer for this channel.
+       #[cfg(test)]
+       pub fn get_signer(&self) -> &ChannelSignerType<SP> {
+               return &self.holder_signer
+       }
+
        /// Only allowed immediately after deserialization if get_outbound_scid_alias returns 0,
        /// indicating we were written by LDK prior to 0.0.106 which did not set outbound SCID aliases
        /// or prior to any channel actions during `Channel` initialization.
@@ -1068,6 +1114,16 @@ impl<SP: Deref> ChannelContext<SP> where SP::Target: SignerProvider  {
                self.channel_transaction_parameters.funding_outpoint
        }
 
+       /// Returns the height in which our funding transaction was confirmed.
+       pub fn get_funding_tx_confirmation_height(&self) -> Option<u32> {
+               let conf_height = self.funding_tx_confirmation_height;
+               if conf_height > 0 {
+                       Some(conf_height)
+               } else {
+                       None
+               }
+       }
+
        /// Returns the block hash in which our funding transaction was confirmed.
        pub fn get_funding_tx_confirmed_in(&self) -> Option<BlockHash> {
                self.funding_tx_confirmed_in
@@ -1166,8 +1222,8 @@ impl<SP: Deref> ChannelContext<SP> where SP::Target: SignerProvider  {
                match self.config.options.max_dust_htlc_exposure {
                        MaxDustHTLCExposure::FeeRateMultiplier(multiplier) => {
                                let feerate_per_kw = fee_estimator.bounded_sat_per_1000_weight(
-                                       ConfirmationTarget::HighPriority);
-                               feerate_per_kw as u64 * multiplier
+                                       ConfirmationTarget::OnChainSweep) as u64;
+                               feerate_per_kw.saturating_mul(multiplier)
                        },
                        MaxDustHTLCExposure::FixedLimitMsat(limit) => limit,
                }
@@ -1525,7 +1581,7 @@ impl<SP: Deref> ChannelContext<SP> where SP::Target: SignerProvider  {
        /// Gets the redeemscript for the funding transaction output (ie the funding transaction output
        /// pays to get_funding_redeemscript().to_v0_p2wsh()).
        /// Panics if called before accept_channel/InboundV1Channel::new
-       pub fn get_funding_redeemscript(&self) -> Script {
+       pub fn get_funding_redeemscript(&self) -> ScriptBuf {
                make_funding_redeemscript(&self.get_holder_pubkeys().funding_pubkey, self.counterparty_funding_pubkey())
        }
 
@@ -1655,6 +1711,14 @@ impl<SP: Deref> ChannelContext<SP> where SP::Target: SignerProvider  {
                let inbound_stats = context.get_inbound_pending_htlc_stats(None);
                let outbound_stats = context.get_outbound_pending_htlc_stats(None);
 
+               let mut balance_msat = context.value_to_self_msat;
+               for ref htlc in context.pending_inbound_htlcs.iter() {
+                       if let InboundHTLCState::LocalRemoved(InboundHTLCRemovalReason::Fulfill(_)) = htlc.state {
+                               balance_msat += htlc.amount_msat;
+                       }
+               }
+               balance_msat -= outbound_stats.pending_htlcs_value_msat;
+
                let outbound_capacity_msat = context.value_to_self_msat
                                .saturating_sub(outbound_stats.pending_htlcs_value_msat)
                                .saturating_sub(
@@ -1662,6 +1726,11 @@ impl<SP: Deref> ChannelContext<SP> where SP::Target: SignerProvider  {
 
                let mut available_capacity_msat = outbound_capacity_msat;
 
+               let anchor_outputs_value_msat = if context.get_channel_type().supports_anchors_zero_fee_htlc_tx() {
+                       ANCHOR_OUTPUT_VALUE_SATOSHI * 2 * 1000
+               } else {
+                       0
+               };
                if context.is_outbound() {
                        // We should mind channel commit tx fee when computing how much of the available capacity
                        // can be used in the next htlc. Mirrors the logic in send_htlc.
@@ -1676,14 +1745,19 @@ impl<SP: Deref> ChannelContext<SP> where SP::Target: SignerProvider  {
                        }
 
                        let htlc_above_dust = HTLCCandidate::new(real_dust_limit_timeout_sat * 1000, HTLCInitiator::LocalOffered);
-                       let max_reserved_commit_tx_fee_msat = FEE_SPIKE_BUFFER_FEE_INCREASE_MULTIPLE * context.next_local_commit_tx_fee_msat(htlc_above_dust, Some(()));
+                       let mut max_reserved_commit_tx_fee_msat = context.next_local_commit_tx_fee_msat(htlc_above_dust, Some(()));
                        let htlc_dust = HTLCCandidate::new(real_dust_limit_timeout_sat * 1000 - 1, HTLCInitiator::LocalOffered);
-                       let min_reserved_commit_tx_fee_msat = FEE_SPIKE_BUFFER_FEE_INCREASE_MULTIPLE * context.next_local_commit_tx_fee_msat(htlc_dust, Some(()));
+                       let mut min_reserved_commit_tx_fee_msat = context.next_local_commit_tx_fee_msat(htlc_dust, Some(()));
+                       if !context.get_channel_type().supports_anchors_zero_fee_htlc_tx() {
+                               max_reserved_commit_tx_fee_msat *= FEE_SPIKE_BUFFER_FEE_INCREASE_MULTIPLE;
+                               min_reserved_commit_tx_fee_msat *= FEE_SPIKE_BUFFER_FEE_INCREASE_MULTIPLE;
+                       }
 
                        // We will first subtract the fee as if we were above-dust. Then, if the resulting
                        // value ends up being below dust, we have this fee available again. In that case,
                        // match the value to right-below-dust.
-                       let mut capacity_minus_commitment_fee_msat: i64 = (available_capacity_msat as i64) - (max_reserved_commit_tx_fee_msat as i64);
+                       let mut capacity_minus_commitment_fee_msat: i64 = available_capacity_msat as i64 -
+                               max_reserved_commit_tx_fee_msat as i64 - anchor_outputs_value_msat as i64;
                        if capacity_minus_commitment_fee_msat < (real_dust_limit_timeout_sat as i64) * 1000 {
                                let one_htlc_difference_msat = max_reserved_commit_tx_fee_msat - min_reserved_commit_tx_fee_msat;
                                debug_assert!(one_htlc_difference_msat != 0);
@@ -1708,7 +1782,7 @@ impl<SP: Deref> ChannelContext<SP> where SP::Target: SignerProvider  {
                        let remote_balance_msat = (context.channel_value_satoshis * 1000 - context.value_to_self_msat)
                                .saturating_sub(inbound_stats.pending_htlcs_value_msat);
 
-                       if remote_balance_msat < max_reserved_commit_tx_fee_msat + holder_selected_chan_reserve_msat {
+                       if remote_balance_msat < max_reserved_commit_tx_fee_msat + holder_selected_chan_reserve_msat + anchor_outputs_value_msat {
                                // If another HTLC's fee would reduce the remote's balance below the reserve limit
                                // we've selected for them, we can only send dust HTLCs.
                                available_capacity_msat = cmp::min(available_capacity_msat, real_dust_limit_success_sat * 1000 - 1);
@@ -1733,14 +1807,14 @@ impl<SP: Deref> ChannelContext<SP> where SP::Target: SignerProvider  {
                         context.holder_dust_limit_satoshis       + dust_buffer_feerate * htlc_timeout_tx_weight(context.get_channel_type()) / 1000)
                };
                let on_counterparty_dust_htlc_exposure_msat = inbound_stats.on_counterparty_tx_dust_exposure_msat + outbound_stats.on_counterparty_tx_dust_exposure_msat;
-               if on_counterparty_dust_htlc_exposure_msat as i64 + htlc_success_dust_limit as i64 * 1000 - 1 > max_dust_htlc_exposure_msat as i64 {
+               if on_counterparty_dust_htlc_exposure_msat as i64 + htlc_success_dust_limit as i64 * 1000 - 1 > max_dust_htlc_exposure_msat.try_into().unwrap_or(i64::max_value()) {
                        remaining_msat_below_dust_exposure_limit =
                                Some(max_dust_htlc_exposure_msat.saturating_sub(on_counterparty_dust_htlc_exposure_msat));
                        dust_exposure_dust_limit_msat = cmp::max(dust_exposure_dust_limit_msat, htlc_success_dust_limit * 1000);
                }
 
                let on_holder_dust_htlc_exposure_msat = inbound_stats.on_holder_tx_dust_exposure_msat + outbound_stats.on_holder_tx_dust_exposure_msat;
-               if on_holder_dust_htlc_exposure_msat as i64 + htlc_timeout_dust_limit as i64 * 1000 - 1 > max_dust_htlc_exposure_msat as i64 {
+               if on_holder_dust_htlc_exposure_msat as i64 + htlc_timeout_dust_limit as i64 * 1000 - 1 > max_dust_htlc_exposure_msat.try_into().unwrap_or(i64::max_value()) {
                        remaining_msat_below_dust_exposure_limit = Some(cmp::min(
                                remaining_msat_below_dust_exposure_limit.unwrap_or(u64::max_value()),
                                max_dust_htlc_exposure_msat.saturating_sub(on_holder_dust_htlc_exposure_msat)));
@@ -1771,6 +1845,7 @@ impl<SP: Deref> ChannelContext<SP> where SP::Target: SignerProvider  {
                        outbound_capacity_msat,
                        next_outbound_htlc_limit_msat: available_capacity_msat,
                        next_outbound_htlc_minimum_msat,
+                       balance_msat,
                }
        }
 
@@ -2052,7 +2127,80 @@ impl<SP: Deref> ChannelContext<SP> where SP::Target: SignerProvider  {
 
                self.channel_state = ChannelState::ShutdownComplete as u32;
                self.update_time_counter += 1;
-               (monitor_update, dropped_outbound_htlcs, unbroadcasted_batch_funding_txid)
+               ShutdownResult {
+                       monitor_update,
+                       dropped_outbound_htlcs,
+                       unbroadcasted_batch_funding_txid,
+               }
+       }
+
+       /// Only allowed after [`Self::channel_transaction_parameters`] is set.
+       fn get_funding_created_msg<L: Deref>(&mut self, logger: &L) -> Option<msgs::FundingCreated> where L::Target: Logger {
+               let counterparty_keys = self.build_remote_transaction_keys();
+               let counterparty_initial_commitment_tx = self.build_commitment_transaction(self.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, false, logger).tx;
+               let signature = match &self.holder_signer {
+                       // TODO (taproot|arik): move match into calling method for Taproot
+                       ChannelSignerType::Ecdsa(ecdsa) => {
+                               ecdsa.sign_counterparty_commitment(&counterparty_initial_commitment_tx, Vec::new(), &self.secp_ctx)
+                                       .map(|(sig, _)| sig).ok()?
+                       },
+                       // TODO (taproot|arik)
+                       _ => todo!()
+               };
+
+               if self.signer_pending_funding {
+                       log_trace!(logger, "Counterparty commitment signature ready for funding_created message: clearing signer_pending_funding");
+                       self.signer_pending_funding = false;
+               }
+
+               Some(msgs::FundingCreated {
+                       temporary_channel_id: self.temporary_channel_id.unwrap(),
+                       funding_txid: self.channel_transaction_parameters.funding_outpoint.as_ref().unwrap().txid,
+                       funding_output_index: self.channel_transaction_parameters.funding_outpoint.as_ref().unwrap().index,
+                       signature,
+                       #[cfg(taproot)]
+                       partial_signature_with_nonce: None,
+                       #[cfg(taproot)]
+                       next_local_nonce: None,
+               })
+       }
+
+       /// Only allowed after [`Self::channel_transaction_parameters`] is set.
+       fn get_funding_signed_msg<L: Deref>(&mut self, logger: &L) -> (CommitmentTransaction, Option<msgs::FundingSigned>) where L::Target: Logger {
+               let counterparty_keys = self.build_remote_transaction_keys();
+               let counterparty_initial_commitment_tx = self.build_commitment_transaction(self.cur_counterparty_commitment_transaction_number + 1, &counterparty_keys, false, false, logger).tx;
+
+               let counterparty_trusted_tx = counterparty_initial_commitment_tx.trust();
+               let counterparty_initial_bitcoin_tx = counterparty_trusted_tx.built_transaction();
+               log_trace!(logger, "Initial counterparty tx for channel {} is: txid {} tx {}",
+                       &self.channel_id(), counterparty_initial_bitcoin_tx.txid, encode::serialize_hex(&counterparty_initial_bitcoin_tx.transaction));
+
+               match &self.holder_signer {
+                       // TODO (arik): move match into calling method for Taproot
+                       ChannelSignerType::Ecdsa(ecdsa) => {
+                               let funding_signed = ecdsa.sign_counterparty_commitment(&counterparty_initial_commitment_tx, Vec::new(), &self.secp_ctx)
+                                       .map(|(signature, _)| msgs::FundingSigned {
+                                               channel_id: self.channel_id(),
+                                               signature,
+                                               #[cfg(taproot)]
+                                               partial_signature_with_nonce: None,
+                                       })
+                                       .ok();
+
+                               if funding_signed.is_none() {
+                                       log_trace!(logger, "Counterparty commitment signature not available for funding_signed message; setting signer_pending_funding");
+                                       self.signer_pending_funding = true;
+                               } else if self.signer_pending_funding {
+                                       log_trace!(logger, "Counterparty commitment signature available for funding_signed message; clearing signer_pending_funding");
+                                       self.signer_pending_funding = false;
+                               }
+
+                               // We sign "counterparty" commitment transaction, allowing them to broadcast the tx if they wish.
+                               (counterparty_initial_commitment_tx, funding_signed)
+                       },
+                       // TODO (taproot|arik)
+                       _ => todo!()
+               }
        }
 }
 
@@ -2107,7 +2255,7 @@ fn commit_tx_fee_sat(feerate_per_kw: u32, num_htlcs: usize, channel_type_feature
 
 // Get the fee cost in MSATS of a commitment tx with a given number of HTLC outputs.
 // Note that num_htlcs should not include dust HTLCs.
-fn commit_tx_fee_msat(feerate_per_kw: u32, num_htlcs: usize, channel_type_features: &ChannelTypeFeatures) -> u64 {
+pub(crate) fn commit_tx_fee_msat(feerate_per_kw: u32, num_htlcs: usize, channel_type_features: &ChannelTypeFeatures) -> u64 {
        // Note that we need to divide before multiplying to round properly,
        // since the lowest denomination of bitcoin on-chain is the satoshi.
        (commitment_tx_base_weight(channel_type_features) + num_htlcs as u64 * COMMITMENT_TX_WEIGHT_PER_HTLC) * feerate_per_kw as u64 / 1000 * 1000
@@ -2130,42 +2278,20 @@ struct CommitmentTxInfoCached {
 
 impl<SP: Deref> Channel<SP> where
        SP::Target: SignerProvider,
-       <SP::Target as SignerProvider>::Signer: WriteableEcdsaChannelSigner
+       <SP::Target as SignerProvider>::EcdsaSigner: WriteableEcdsaChannelSigner
 {
        fn check_remote_fee<F: Deref, L: Deref>(
                channel_type: &ChannelTypeFeatures, fee_estimator: &LowerBoundedFeeEstimator<F>,
                feerate_per_kw: u32, cur_feerate_per_kw: Option<u32>, logger: &L
        ) -> Result<(), ChannelError> where F::Target: FeeEstimator, L::Target: Logger,
        {
-               // We only bound the fee updates on the upper side to prevent completely absurd feerates,
-               // always accepting up to 25 sat/vByte or 10x our fee estimator's "High Priority" fee.
-               // We generally don't care too much if they set the feerate to something very high, but it
-               // could result in the channel being useless due to everything being dust. This doesn't
-               // apply to channels supporting anchor outputs since HTLC transactions are pre-signed with a
-               // zero fee, so their fee is no longer considered to determine dust limits.
-               if !channel_type.supports_anchors_zero_fee_htlc_tx() {
-                       let upper_limit = cmp::max(250 * 25,
-                               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)));
-                       }
-               }
-
-               // We can afford to use a lower bound with anchors than previously since we can now bump
-               // fees when broadcasting our commitment. However, we must still make sure we meet the
-               // minimum mempool feerate, until package relay is deployed, such that we can ensure the
-               // commitment transaction propagates throughout node mempools on its own.
                let lower_limit_conf_target = if channel_type.supports_anchors_zero_fee_htlc_tx() {
-                       ConfirmationTarget::MempoolMinimum
+                       ConfirmationTarget::MinAllowedAnchorChannelRemoteFee
                } else {
-                       ConfirmationTarget::Background
+                       ConfirmationTarget::MinAllowedNonAnchorChannelRemoteFee
                };
                let lower_limit = fee_estimator.bounded_sat_per_1000_weight(lower_limit_conf_target);
-               // Some fee estimators round up to the next full sat/vbyte (ie 250 sats per kw), causing
-               // occasional issues with feerate disagreements between an initiator that wants a feerate
-               // of 1.1 sat/vbyte and a receiver that wants 1.1 rounded up to 2. Thus, we always add 250
-               // sat/kw before the comparison here.
-               if feerate_per_kw + 250 < lower_limit {
+               if feerate_per_kw < lower_limit {
                        if let Some(cur_feerate) = cur_feerate_per_kw {
                                if feerate_per_kw > cur_feerate {
                                        log_warn!(logger,
@@ -2174,13 +2300,13 @@ impl<SP: Deref> Channel<SP> where
                                        return Ok(());
                                }
                        }
-                       return Err(ChannelError::Close(format!("Peer's feerate much too low. Actual: {}. Our expected lower limit: {} (- 250)", feerate_per_kw, lower_limit)));
+                       return Err(ChannelError::Close(format!("Peer's feerate much too low. Actual: {}. Our expected lower limit: {}", feerate_per_kw, lower_limit)));
                }
                Ok(())
        }
 
        #[inline]
-       fn get_closing_scriptpubkey(&self) -> Script {
+       fn get_closing_scriptpubkey(&self) -> ScriptBuf {
                // The shutdown scriptpubkey is set on channel opening when option_upfront_shutdown_script
                // is signaled. Otherwise, it is set when sending a shutdown message. Calling this method
                // outside of those situations will fail.
@@ -2293,7 +2419,7 @@ impl<SP: Deref> Channel<SP> where
                let mut htlc_value_msat = 0;
                for (idx, htlc) in self.context.pending_inbound_htlcs.iter().enumerate() {
                        if htlc.htlc_id == htlc_id_arg {
-                               debug_assert_eq!(htlc.payment_hash, PaymentHash(Sha256::hash(&payment_preimage_arg.0[..]).into_inner()));
+                               debug_assert_eq!(htlc.payment_hash, PaymentHash(Sha256::hash(&payment_preimage_arg.0[..]).to_byte_array()));
                                log_debug!(logger, "Claiming inbound HTLC id {} with payment hash {} with preimage {}",
                                        htlc.htlc_id, htlc.payment_hash, payment_preimage_arg);
                                match htlc.state {
@@ -2548,7 +2674,7 @@ impl<SP: Deref> Channel<SP> where
        /// 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, signer_provider: &SP, logger: &L
-       ) -> Result<ChannelMonitor<<SP::Target as SignerProvider>::Signer>, ChannelError>
+       ) -> Result<ChannelMonitor<<SP::Target as SignerProvider>::EcdsaSigner>, ChannelError>
        where
                L::Target: Logger
        {
@@ -2650,7 +2776,7 @@ impl<SP: Deref> Channel<SP> where
        /// and the channel is now usable (and public), this may generate an announcement_signatures to
        /// reply with.
        pub fn channel_ready<NS: Deref, L: Deref>(
-               &mut self, msg: &msgs::ChannelReady, node_signer: &NS, genesis_block_hash: BlockHash,
+               &mut self, msg: &msgs::ChannelReady, node_signer: &NS, chain_hash: ChainHash,
                user_config: &UserConfig, best_block: &BestBlock, logger: &L
        ) -> Result<Option<msgs::AnnouncementSignatures>, ChannelError>
        where
@@ -2721,7 +2847,7 @@ impl<SP: Deref> Channel<SP> where
 
                log_info!(logger, "Received channel_ready from peer for channel {}", &self.context.channel_id());
 
-               Ok(self.get_announcement_sigs(node_signer, genesis_block_hash, user_config, best_block.height(), logger))
+               Ok(self.get_announcement_sigs(node_signer, chain_hash, user_config, best_block.height(), logger))
        }
 
        pub fn update_add_htlc<F, FE: Deref, L: Deref>(
@@ -2762,6 +2888,7 @@ impl<SP: Deref> Channel<SP> where
                if inbound_stats.pending_htlcs_value_msat + msg.amount_msat > self.context.holder_max_htlc_value_in_flight_msat {
                        return Err(ChannelError::Close(format!("Remote HTLC add would put them over our max HTLC value ({})", self.context.holder_max_htlc_value_in_flight_msat)));
                }
+
                // Check holder_selected_channel_reserve_satoshis (we're getting paid, so they have to at least meet
                // the reserve_satoshis we told them to always have as direct payment so that they lose
                // something if we punish them for broadcasting an old state).
@@ -2821,30 +2948,40 @@ impl<SP: Deref> Channel<SP> where
 
                // Check that the remote can afford to pay for this HTLC on-chain at the current
                // feerate_per_kw, while maintaining their channel reserve (as required by the spec).
-               let remote_commit_tx_fee_msat = if self.context.is_outbound() { 0 } else {
-                       let htlc_candidate = HTLCCandidate::new(msg.amount_msat, HTLCInitiator::RemoteOffered);
-                       self.context.next_remote_commit_tx_fee_msat(htlc_candidate, None) // Don't include the extra fee spike buffer HTLC in calculations
-               };
-               if pending_remote_value_msat - msg.amount_msat < remote_commit_tx_fee_msat {
-                       return Err(ChannelError::Close("Remote HTLC add would not leave enough to pay for fees".to_owned()));
-               };
-
-               if pending_remote_value_msat - msg.amount_msat - remote_commit_tx_fee_msat < self.context.holder_selected_channel_reserve_satoshis * 1000 {
-                       return Err(ChannelError::Close("Remote HTLC add would put them under remote reserve value".to_owned()));
+               {
+                       let remote_commit_tx_fee_msat = if self.context.is_outbound() { 0 } else {
+                               let htlc_candidate = HTLCCandidate::new(msg.amount_msat, HTLCInitiator::RemoteOffered);
+                               self.context.next_remote_commit_tx_fee_msat(htlc_candidate, None) // Don't include the extra fee spike buffer HTLC in calculations
+                       };
+                       let anchor_outputs_value_msat = if !self.context.is_outbound() && self.context.get_channel_type().supports_anchors_zero_fee_htlc_tx() {
+                               ANCHOR_OUTPUT_VALUE_SATOSHI * 2 * 1000
+                       } else {
+                               0
+                       };
+                       if pending_remote_value_msat.saturating_sub(msg.amount_msat).saturating_sub(anchor_outputs_value_msat) < remote_commit_tx_fee_msat {
+                               return Err(ChannelError::Close("Remote HTLC add would not leave enough to pay for fees".to_owned()));
+                       };
+                       if pending_remote_value_msat.saturating_sub(msg.amount_msat).saturating_sub(remote_commit_tx_fee_msat).saturating_sub(anchor_outputs_value_msat) < self.context.holder_selected_channel_reserve_satoshis * 1000 {
+                               return Err(ChannelError::Close("Remote HTLC add would put them under remote reserve value".to_owned()));
+                       }
                }
 
+               let anchor_outputs_value_msat = if self.context.get_channel_type().supports_anchors_zero_fee_htlc_tx() {
+                       ANCHOR_OUTPUT_VALUE_SATOSHI * 2 * 1000
+               } else {
+                       0
+               };
                if !self.context.is_outbound() {
-                       // `2 *` and `Some(())` is for the fee spike buffer we keep for the remote. This deviates from
-                       // the spec because in the spec, the fee spike buffer requirement doesn't exist on the
-                       // receiver's side, only on the sender's.
-                       // Note that when we eventually remove support for fee updates and switch to anchor output
-                       // fees, we will drop the `2 *`, since we no longer be as sensitive to fee spikes. But, keep
-                       // the extra htlc when calculating the next remote commitment transaction fee as we should
-                       // still be able to afford adding this HTLC plus one more future HTLC, regardless of being
-                       // sensitive to fee spikes.
+                       // `Some(())` is for the fee spike buffer we keep for the remote. This deviates from
+                       // the spec because the fee spike buffer requirement doesn't exist on the receiver's
+                       // side, only on the sender's. Note that with anchor outputs we are no longer as
+                       // sensitive to fee spikes, so we need to account for them.
                        let htlc_candidate = HTLCCandidate::new(msg.amount_msat, HTLCInitiator::RemoteOffered);
-                       let remote_fee_cost_incl_stuck_buffer_msat = 2 * self.context.next_remote_commit_tx_fee_msat(htlc_candidate, Some(()));
-                       if pending_remote_value_msat - msg.amount_msat - self.context.holder_selected_channel_reserve_satoshis * 1000 < remote_fee_cost_incl_stuck_buffer_msat {
+                       let mut remote_fee_cost_incl_stuck_buffer_msat = self.context.next_remote_commit_tx_fee_msat(htlc_candidate, Some(()));
+                       if !self.context.get_channel_type().supports_anchors_zero_fee_htlc_tx() {
+                               remote_fee_cost_incl_stuck_buffer_msat *= FEE_SPIKE_BUFFER_FEE_INCREASE_MULTIPLE;
+                       }
+                       if pending_remote_value_msat.saturating_sub(msg.amount_msat).saturating_sub(self.context.holder_selected_channel_reserve_satoshis * 1000).saturating_sub(anchor_outputs_value_msat) < remote_fee_cost_incl_stuck_buffer_msat {
                                // Note that if the pending_forward_status is not updated here, then it's because we're already failing
                                // the HTLC, i.e. its status is already set to failing.
                                log_info!(logger, "Attempting to fail HTLC due to fee spike buffer violation in channel {}. Rebalancing is required.", &self.context.channel_id());
@@ -2854,7 +2991,7 @@ impl<SP: Deref> Channel<SP> where
                        // Check that they won't violate our local required channel reserve by adding this HTLC.
                        let htlc_candidate = HTLCCandidate::new(msg.amount_msat, HTLCInitiator::RemoteOffered);
                        let local_commit_tx_fee_msat = self.context.next_local_commit_tx_fee_msat(htlc_candidate, None);
-                       if self.context.value_to_self_msat < self.context.counterparty_selected_channel_reserve_satoshis.unwrap() * 1000 + local_commit_tx_fee_msat {
+                       if self.context.value_to_self_msat < self.context.counterparty_selected_channel_reserve_satoshis.unwrap() * 1000 + local_commit_tx_fee_msat + anchor_outputs_value_msat {
                                return Err(ChannelError::Close("Cannot accept HTLC that would put our balance under counterparty-announced channel reserve value".to_owned()));
                        }
                }
@@ -2892,7 +3029,7 @@ impl<SP: Deref> Channel<SP> where
                                let outcome = match check_preimage {
                                        None => fail_reason.into(),
                                        Some(payment_preimage) => {
-                                               let payment_hash = PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner());
+                                               let payment_hash = PaymentHash(Sha256::hash(&payment_preimage.0[..]).to_byte_array());
                                                if payment_hash != htlc.payment_hash {
                                                        return Err(ChannelError::Close(format!("Remote tried to fulfill HTLC ({}) with an incorrect preimage", htlc_id)));
                                                }
@@ -3044,9 +3181,9 @@ impl<SP: Deref> Channel<SP> where
                                let htlc_sighashtype = if self.context.channel_type.supports_anchors_zero_fee_htlc_tx() { 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()),
+                                       log_bytes!(msg.htlc_signatures[idx].serialize_compact()[..]), log_bytes!(keys.countersignatory_htlc_key.to_public_key().serialize()),
                                        encode::serialize_hex(&htlc_tx), log_bytes!(htlc_sighash[..]), encode::serialize_hex(&htlc_redeemscript), &self.context.channel_id());
-                               if let Err(_) = self.context.secp_ctx.verify_ecdsa(&htlc_sighash, &msg.htlc_signatures[idx], &keys.countersignatory_htlc_key) {
+                               if let Err(_) = self.context.secp_ctx.verify_ecdsa(&htlc_sighash, &msg.htlc_signatures[idx], &keys.countersignatory_htlc_key.to_public_key()) {
                                        return Err(ChannelError::Close("Invalid HTLC tx signature from peer".to_owned()));
                                }
                                if !separate_nondust_htlc_sources {
@@ -3128,6 +3265,7 @@ impl<SP: Deref> Channel<SP> where
                };
 
                self.context.cur_holder_commitment_transaction_number -= 1;
+               self.context.expecting_peer_commitment_signed = false;
                // Note that if we need_commitment & !AwaitingRemoteRevoke we'll call
                // build_commitment_no_status_check() next which will reset this to RAAFirst.
                self.context.resend_order = RAACommitmentOrder::CommitmentFirst;
@@ -3138,8 +3276,8 @@ impl<SP: Deref> Channel<SP> where
                        self.context.monitor_pending_revoke_and_ack = true;
                        if need_commitment && (self.context.channel_state & (ChannelState::AwaitingRemoteRevoke as u32)) == 0 {
                                // If we were going to send a commitment_signed after the RAA, go ahead and do all
-                               // the corresponding HTLC status updates so that get_last_commitment_update
-                               // includes the right HTLCs.
+                               // the corresponding HTLC status updates so that
+                               // get_last_commitment_update_for_send includes the right HTLCs.
                                self.context.monitor_pending_commitment_signed = true;
                                let mut additional_update = self.build_commitment_no_status_check(logger);
                                // build_commitment_no_status_check may bump latest_monitor_id but we want them to be
@@ -3352,7 +3490,9 @@ impl<SP: Deref> Channel<SP> where
                                        self.context.cur_counterparty_commitment_transaction_number + 1,
                                        &secret
                                ).map_err(|_| ChannelError::Close("Failed to validate revocation from peer".to_owned()))?;
-                       }
+                       },
+                       // TODO (taproot|arik)
+                       _ => todo!()
                };
 
                self.context.commitment_secrets.provide_secret(self.context.cur_counterparty_commitment_transaction_number + 1, msg.per_commitment_secret)
@@ -3393,6 +3533,7 @@ impl<SP: Deref> Channel<SP> where
                        // Take references explicitly so that we can hold multiple references to self.context.
                        let pending_inbound_htlcs: &mut Vec<_> = &mut self.context.pending_inbound_htlcs;
                        let pending_outbound_htlcs: &mut Vec<_> = &mut self.context.pending_outbound_htlcs;
+                       let expecting_peer_commitment_signed = &mut self.context.expecting_peer_commitment_signed;
 
                        // We really shouldnt have two passes here, but retain gives a non-mutable ref (Rust bug)
                        pending_inbound_htlcs.retain(|htlc| {
@@ -3401,6 +3542,7 @@ impl<SP: Deref> Channel<SP> where
                                        if let &InboundHTLCRemovalReason::Fulfill(_) = reason {
                                                value_to_self_msat_diff += htlc.amount_msat as i64;
                                        }
+                                       *expecting_peer_commitment_signed = true;
                                        false
                                } else { true }
                        });
@@ -3460,6 +3602,7 @@ impl<SP: Deref> Channel<SP> where
                                if let OutboundHTLCState::LocalAnnounced(_) = htlc.state {
                                        log_trace!(logger, " ...promoting outbound LocalAnnounced {} to Committed", &htlc.payment_hash);
                                        htlc.state = OutboundHTLCState::Committed;
+                                       *expecting_peer_commitment_signed = true;
                                }
                                if let &mut OutboundHTLCState::AwaitingRemoteRevokeToRemove(ref mut outcome) = &mut htlc.state {
                                        log_trace!(logger, " ...promoting outbound AwaitingRemoteRevokeToRemove {} to AwaitingRemovedRemoteRevoke", &htlc.payment_hash);
@@ -3480,6 +3623,7 @@ impl<SP: Deref> Channel<SP> where
                                        log_trace!(logger, " ...promoting outbound fee update {} to Committed", feerate);
                                        self.context.feerate_per_kw = feerate;
                                        self.context.pending_update_fee = None;
+                                       self.context.expecting_peer_commitment_signed = true;
                                },
                                FeeUpdateState::RemoteAnnounced => { debug_assert!(!self.context.is_outbound()); },
                                FeeUpdateState::AwaitingRemoteRevokeToAnnounce => {
@@ -3513,9 +3657,10 @@ impl<SP: Deref> Channel<SP> where
                        // cells) while we can't update the monitor, so we just return what we have.
                        if require_commitment {
                                self.context.monitor_pending_commitment_signed = true;
-                               // When the monitor updating is restored we'll call get_last_commitment_update(),
-                               // which does not update state, but we're definitely now awaiting a remote revoke
-                               // before we can step forward any more, so set it here.
+                               // When the monitor updating is restored we'll call
+                               // get_last_commitment_update_for_send(), which does not update state, but we're
+                               // definitely now awaiting a remote revoke before we can step forward any more, so
+                               // set it here.
                                let mut additional_update = self.build_commitment_no_status_check(logger);
                                // build_commitment_no_status_check may bump latest_monitor_id but we want them to be
                                // strictly increasing by one, so decrement it here.
@@ -3755,7 +3900,7 @@ impl<SP: Deref> Channel<SP> where
        /// successfully and we should restore normal operation. Returns messages which should be sent
        /// to the remote side.
        pub fn monitor_updating_restored<L: Deref, NS: Deref>(
-               &mut self, logger: &L, node_signer: &NS, genesis_block_hash: BlockHash,
+               &mut self, logger: &L, node_signer: &NS, chain_hash: ChainHash,
                user_config: &UserConfig, best_block_height: u32
        ) -> MonitorRestoreUpdates
        where
@@ -3796,7 +3941,7 @@ impl<SP: Deref> Channel<SP> where
                        })
                } else { None };
 
-               let announcement_sigs = self.get_announcement_sigs(node_signer, genesis_block_hash, user_config, best_block_height, logger);
+               let announcement_sigs = self.get_announcement_sigs(node_signer, chain_hash, user_config, best_block_height, logger);
 
                let mut accepted_htlcs = Vec::new();
                mem::swap(&mut accepted_htlcs, &mut self.context.monitor_pending_forwards);
@@ -3818,9 +3963,11 @@ impl<SP: Deref> Channel<SP> where
                        Some(self.get_last_revoke_and_ack())
                } else { None };
                let commitment_update = if self.context.monitor_pending_commitment_signed {
-                       self.mark_awaiting_response();
-                       Some(self.get_last_commitment_update(logger))
+                       self.get_last_commitment_update_for_send(logger).ok()
                } else { None };
+               if commitment_update.is_some() {
+                       self.mark_awaiting_response();
+               }
 
                self.context.monitor_pending_revoke_and_ack = false;
                self.context.monitor_pending_commitment_signed = false;
@@ -3844,14 +3991,11 @@ impl<SP: Deref> Channel<SP> where
                        return Err(ChannelError::Close("Peer sent update_fee when we needed a channel_reestablish".to_owned()));
                }
                Channel::<SP>::check_remote_fee(&self.context.channel_type, fee_estimator, msg.feerate_per_kw, Some(self.context.feerate_per_kw), logger)?;
-               let feerate_over_dust_buffer = msg.feerate_per_kw > self.context.get_dust_buffer_feerate(None);
 
                self.context.pending_update_fee = Some((msg.feerate_per_kw, FeeUpdateState::RemoteAnnounced));
                self.context.update_time_counter += 1;
-               // If the feerate has increased over the previous dust buffer (note that
-               // `get_dust_buffer_feerate` considers the `pending_update_fee` status), check that we
-               // won't be pushed over our dust exposure limit by the feerate increase.
-               if feerate_over_dust_buffer {
+               // Check that we won't be pushed over our dust exposure limit by the feerate increase.
+               if !self.context.channel_type.supports_anchors_zero_fee_htlc_tx() {
                        let inbound_stats = self.context.get_inbound_pending_htlc_stats(None);
                        let outbound_stats = self.context.get_outbound_pending_htlc_stats(None);
                        let holder_tx_dust_exposure = inbound_stats.on_holder_tx_dust_exposure_msat + outbound_stats.on_holder_tx_dust_exposure_msat;
@@ -3869,6 +4013,37 @@ impl<SP: Deref> Channel<SP> where
                Ok(())
        }
 
+       /// Indicates that the signer may have some signatures for us, so we should retry if we're
+       /// blocked.
+       #[allow(unused)]
+       pub fn signer_maybe_unblocked<L: Deref>(&mut self, logger: &L) -> SignerResumeUpdates where L::Target: Logger {
+               let commitment_update = if self.context.signer_pending_commitment_update {
+                       self.get_last_commitment_update_for_send(logger).ok()
+               } else { None };
+               let funding_signed = if self.context.signer_pending_funding && !self.context.is_outbound() {
+                       self.context.get_funding_signed_msg(logger).1
+               } else { None };
+               let channel_ready = if funding_signed.is_some() {
+                       self.check_get_channel_ready(0)
+               } else { None };
+               let funding_created = if self.context.signer_pending_funding && self.context.is_outbound() {
+                       self.context.get_funding_created_msg(logger)
+               } else { None };
+
+               log_trace!(logger, "Signer unblocked with {} commitment_update, {} funding_signed, {} funding_created, and {} channel_ready",
+                       if commitment_update.is_some() { "a" } else { "no" },
+                       if funding_signed.is_some() { "a" } else { "no" },
+                       if funding_created.is_some() { "a" } else { "no" },
+                       if channel_ready.is_some() { "a" } else { "no" });
+
+               SignerResumeUpdates {
+                       commitment_update,
+                       funding_signed,
+                       funding_created,
+                       channel_ready,
+               }
+       }
+
        fn get_last_revoke_and_ack(&self) -> msgs::RevokeAndACK {
                let next_per_commitment_point = self.context.holder_signer.as_ref().get_per_commitment_point(self.context.cur_holder_commitment_transaction_number, &self.context.secp_ctx);
                let per_commitment_secret = self.context.holder_signer.as_ref().release_commitment_secret(self.context.cur_holder_commitment_transaction_number + 2);
@@ -3881,7 +4056,8 @@ impl<SP: Deref> Channel<SP> where
                }
        }
 
-       fn get_last_commitment_update<L: Deref>(&self, logger: &L) -> msgs::CommitmentUpdate where L::Target: Logger {
+       /// Gets the last commitment update for immediate sending to our peer.
+       fn get_last_commitment_update_for_send<L: Deref>(&mut self, logger: &L) -> Result<msgs::CommitmentUpdate, ()> where L::Target: Logger {
                let mut update_add_htlcs = Vec::new();
                let mut update_fulfill_htlcs = Vec::new();
                let mut update_fail_htlcs = Vec::new();
@@ -3937,13 +4113,26 @@ impl<SP: Deref> Channel<SP> where
                        })
                } else { None };
 
-               log_trace!(logger, "Regenerated latest commitment update in channel {} with{} {} update_adds, {} update_fulfills, {} update_fails, and {} update_fail_malformeds",
+               log_trace!(logger, "Regenerating latest commitment update in channel {} with{} {} update_adds, {} update_fulfills, {} update_fails, and {} update_fail_malformeds",
                                &self.context.channel_id(), if update_fee.is_some() { " update_fee," } else { "" },
                                update_add_htlcs.len(), update_fulfill_htlcs.len(), update_fail_htlcs.len(), update_fail_malformed_htlcs.len());
-               msgs::CommitmentUpdate {
+               let commitment_signed = if let Ok(update) = self.send_commitment_no_state_update(logger).map(|(cu, _)| cu) {
+                       if self.context.signer_pending_commitment_update {
+                               log_trace!(logger, "Commitment update generated: clearing signer_pending_commitment_update");
+                               self.context.signer_pending_commitment_update = false;
+                       }
+                       update
+               } else {
+                       if !self.context.signer_pending_commitment_update {
+                               log_trace!(logger, "Commitment update awaiting signer: setting signer_pending_commitment_update");
+                               self.context.signer_pending_commitment_update = true;
+                       }
+                       return Err(());
+               };
+               Ok(msgs::CommitmentUpdate {
                        update_add_htlcs, update_fulfill_htlcs, update_fail_htlcs, update_fail_malformed_htlcs, update_fee,
-                       commitment_signed: self.send_commitment_no_state_update(logger).expect("It looks like we failed to re-generate a commitment_signed we had previously sent?").0,
-               }
+                       commitment_signed,
+               })
        }
 
        /// Gets the `Shutdown` message we should send our peer on reconnect, if any.
@@ -3966,7 +4155,7 @@ impl<SP: Deref> Channel<SP> where
        /// [`super::channelmanager::ChannelManager::force_close_all_channels_without_broadcasting_txn`].
        pub fn channel_reestablish<L: Deref, NS: Deref>(
                &mut self, msg: &msgs::ChannelReestablish, logger: &L, node_signer: &NS,
-               genesis_block_hash: BlockHash, user_config: &UserConfig, best_block: &BestBlock
+               chain_hash: ChainHash, user_config: &UserConfig, best_block: &BestBlock
        ) -> Result<ReestablishResponses, ChannelError>
        where
                L::Target: Logger,
@@ -3981,7 +4170,7 @@ impl<SP: Deref> Channel<SP> where
 
                if msg.next_local_commitment_number >= INITIAL_COMMITMENT_NUMBER || msg.next_remote_commitment_number >= INITIAL_COMMITMENT_NUMBER ||
                        msg.next_local_commitment_number == 0 {
-                       return Err(ChannelError::Close("Peer sent a garbage channel_reestablish (usually an lnd node with lost state asking us to force-close for them)".to_owned()));
+                       return Err(ChannelError::Close("Peer sent an invalid channel_reestablish to force close in a non-standard way".to_owned()));
                }
 
                if msg.next_remote_commitment_number > 0 {
@@ -4025,7 +4214,7 @@ impl<SP: Deref> Channel<SP> where
 
                let shutdown_msg = self.get_outbound_shutdown();
 
-               let announcement_sigs = self.get_announcement_sigs(node_signer, genesis_block_hash, user_config, best_block.height(), logger);
+               let announcement_sigs = self.get_announcement_sigs(node_signer, chain_hash, user_config, best_block.height(), logger);
 
                if self.context.channel_state & (ChannelState::FundingSent as u32) == ChannelState::FundingSent as u32 {
                        // If we're waiting on a monitor update, we shouldn't re-send any channel_ready's.
@@ -4123,7 +4312,7 @@ impl<SP: Deref> Channel<SP> where
                                Ok(ReestablishResponses {
                                        channel_ready, shutdown_msg, announcement_sigs,
                                        raa: required_revoke,
-                                       commitment_update: Some(self.get_last_commitment_update(logger)),
+                                       commitment_update: self.get_last_commitment_update_for_send(logger).ok(),
                                        order: self.context.resend_order.clone(),
                                })
                        }
@@ -4144,8 +4333,10 @@ impl<SP: Deref> Channel<SP> where
                // 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.bounded_sat_per_1000_weight(ConfirmationTarget::Background);
-               let normal_feerate = fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Normal);
+               let mut proposed_feerate = fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::ChannelCloseMinimum);
+               // Use NonAnchorChannelFee because this should be an estimate for a channel close
+               // that we don't expect to need fee bumping
+               let normal_feerate = fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::NonAnchorChannelFee);
                let mut proposed_max_feerate = if self.context.is_outbound() { normal_feerate } else { u32::max_value() };
 
                // The spec requires that (when the channel does not have anchors) we only send absolute
@@ -4207,18 +4398,28 @@ impl<SP: Deref> Channel<SP> where
 
        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>
+               -> Result<(Option<msgs::ClosingSigned>, Option<Transaction>, Option<ShutdownResult>), ChannelError>
                where F::Target: FeeEstimator, L::Target: Logger
        {
+               // If we're waiting on a monitor persistence, that implies we're also waiting to send some
+               // message to our counterparty (probably a `revoke_and_ack`). In such a case, we shouldn't
+               // initiate `closing_signed` negotiation until we're clear of all pending messages. Note
+               // that closing_negotiation_ready checks this case (as well as a few others).
                if self.context.last_sent_closing_fee.is_some() || !self.closing_negotiation_ready() {
-                       return Ok((None, None));
+                       return Ok((None, None, None));
                }
 
                if !self.context.is_outbound() {
                        if let Some(msg) = &self.context.pending_counterparty_closing_signed.take() {
                                return self.closing_signed(fee_estimator, &msg);
                        }
-                       return Ok((None, None));
+                       return Ok((None, None, None));
+               }
+
+               // If we're waiting on a counterparty `commitment_signed` to clear some updates from our
+               // local commitment transaction, we can't yet initiate `closing_signed` negotiation.
+               if self.context.expecting_peer_commitment_signed {
+                       return Ok((None, None, None));
                }
 
                let (our_min_fee, our_max_fee) = self.calculate_closing_fee_limits(fee_estimator);
@@ -4243,8 +4444,10 @@ impl<SP: Deref> Channel<SP> where
                                                min_fee_satoshis: our_min_fee,
                                                max_fee_satoshis: our_max_fee,
                                        }),
-                               }), None))
-                       }
+                               }), None, None))
+                       },
+                       // TODO (taproot|arik)
+                       _ => todo!()
                }
        }
 
@@ -4291,12 +4494,12 @@ impl<SP: Deref> Channel<SP> where
                assert_eq!(self.context.channel_state & ChannelState::ShutdownComplete as u32, 0);
 
                if !script::is_bolt2_compliant(&msg.scriptpubkey, their_features) {
-                       return Err(ChannelError::Warn(format!("Got a nonstandard scriptpubkey ({}) from remote peer", msg.scriptpubkey.to_bytes().to_hex())));
+                       return Err(ChannelError::Warn(format!("Got a nonstandard scriptpubkey ({}) from remote peer", msg.scriptpubkey.to_hex_string())));
                }
 
                if self.context.counterparty_shutdown_scriptpubkey.is_some() {
                        if Some(&msg.scriptpubkey) != self.context.counterparty_shutdown_scriptpubkey.as_ref() {
-                               return Err(ChannelError::Warn(format!("Got shutdown request with a scriptpubkey ({}) which did not match their previous scriptpubkey.", msg.scriptpubkey.to_bytes().to_hex())));
+                               return Err(ChannelError::Warn(format!("Got shutdown request with a scriptpubkey ({}) which did not match their previous scriptpubkey.", msg.scriptpubkey.to_hex_string())));
                        }
                } else {
                        self.context.counterparty_shutdown_scriptpubkey = Some(msg.scriptpubkey.clone());
@@ -4392,7 +4595,7 @@ impl<SP: Deref> Channel<SP> where
 
        pub fn closing_signed<F: Deref>(
                &mut self, fee_estimator: &LowerBoundedFeeEstimator<F>, msg: &msgs::ClosingSigned)
-               -> Result<(Option<msgs::ClosingSigned>, Option<Transaction>), ChannelError>
+               -> Result<(Option<msgs::ClosingSigned>, Option<Transaction>, Option<ShutdownResult>), ChannelError>
                where F::Target: FeeEstimator
        {
                if self.context.channel_state & BOTH_SIDES_SHUTDOWN_MASK != BOTH_SIDES_SHUTDOWN_MASK {
@@ -4414,7 +4617,7 @@ impl<SP: Deref> Channel<SP> where
 
                if self.context.channel_state & ChannelState::MonitorUpdateInProgress as u32 != 0 {
                        self.context.pending_counterparty_closing_signed = Some(msg.clone());
-                       return Ok((None, None));
+                       return Ok((None, None, None));
                }
 
                let funding_redeemscript = self.context.get_funding_redeemscript();
@@ -4444,10 +4647,15 @@ impl<SP: Deref> Channel<SP> where
                assert!(self.context.shutdown_scriptpubkey.is_some());
                if let Some((last_fee, sig)) = self.context.last_sent_closing_fee {
                        if last_fee == msg.fee_satoshis {
+                               let shutdown_result = ShutdownResult {
+                                       monitor_update: None,
+                                       dropped_outbound_htlcs: Vec::new(),
+                                       unbroadcasted_batch_funding_txid: self.context.unbroadcasted_batch_funding_txid(),
+                               };
                                let tx = self.build_signed_closing_transaction(&mut closing_tx, &msg.signature, &sig);
                                self.context.channel_state = ChannelState::ShutdownComplete as u32;
                                self.context.update_time_counter += 1;
-                               return Ok((None, Some(tx)));
+                               return Ok((None, Some(tx), Some(shutdown_result)));
                        }
                }
 
@@ -4466,13 +4674,19 @@ impl<SP: Deref> Channel<SP> where
                                                let sig = ecdsa
                                                        .sign_closing_transaction(&closing_tx, &self.context.secp_ctx)
                                                        .map_err(|_| ChannelError::Close("External signer refused to sign closing transaction".to_owned()))?;
-
-                                               let signed_tx = if $new_fee == msg.fee_satoshis {
+                                               let (signed_tx, shutdown_result) = if $new_fee == msg.fee_satoshis {
+                                                       let shutdown_result = ShutdownResult {
+                                                               monitor_update: None,
+                                                               dropped_outbound_htlcs: Vec::new(),
+                                                               unbroadcasted_batch_funding_txid: self.context.unbroadcasted_batch_funding_txid(),
+                                                       };
                                                        self.context.channel_state = ChannelState::ShutdownComplete as u32;
                                                        self.context.update_time_counter += 1;
                                                        let tx = self.build_signed_closing_transaction(&closing_tx, &msg.signature, &sig);
-                                                       Some(tx)
-                                               } else { None };
+                                                       (Some(tx), Some(shutdown_result))
+                                               } else {
+                                                       (None, None)
+                                               };
 
                                                self.context.last_sent_closing_fee = Some((used_fee, sig.clone()));
                                                Ok((Some(msgs::ClosingSigned {
@@ -4483,8 +4697,10 @@ impl<SP: Deref> Channel<SP> where
                                                                min_fee_satoshis: our_min_fee,
                                                                max_fee_satoshis: our_max_fee,
                                                        }),
-                                               }), signed_tx))
-                                       }
+                                               }), signed_tx, shutdown_result))
+                                       },
+                                       // TODO (taproot|arik)
+                                       _ => todo!()
                                }
                        }
                }
@@ -4596,7 +4812,7 @@ impl<SP: Deref> Channel<SP> where
        }
 
        #[cfg(test)]
-       pub fn get_signer(&self) -> &ChannelSignerType<<SP::Target as SignerProvider>::Signer> {
+       pub fn get_signer(&self) -> &ChannelSignerType<SP> {
                &self.context.holder_signer
        }
 
@@ -4751,6 +4967,12 @@ impl<SP: Deref> Channel<SP> where
                        return None;
                }
 
+               // If we're still pending the signature on a funding transaction, then we're not ready to send a
+               // channel_ready yet.
+               if self.context.signer_pending_funding {
+                       return None;
+               }
+
                // Note that we don't include ChannelState::WaitingForBatch as we don't want to send
                // channel_ready until the entire batch is ready.
                let non_shutdown_state = self.context.channel_state & (!MULTI_STATE_FLAGS);
@@ -4802,12 +5024,13 @@ impl<SP: Deref> Channel<SP> where
        /// In the second, we simply return an Err indicating we need to be force-closed now.
        pub fn transactions_confirmed<NS: Deref, L: Deref>(
                &mut self, block_hash: &BlockHash, height: u32, txdata: &TransactionData,
-               genesis_block_hash: BlockHash, node_signer: &NS, user_config: &UserConfig, logger: &L
+               chain_hash: ChainHash, node_signer: &NS, user_config: &UserConfig, logger: &L
        ) -> Result<(Option<msgs::ChannelReady>, Option<msgs::AnnouncementSignatures>), ClosureReason>
        where
                NS::Target: NodeSigner,
                L::Target: Logger
        {
+               let mut msgs = (None, None);
                if let Some(funding_txo) = self.context.get_funding_txo() {
                        for &(index_in_block, tx) in txdata.iter() {
                                // Check if the transaction is the expected funding transaction, and if it is,
@@ -4862,8 +5085,8 @@ impl<SP: Deref> Channel<SP> where
                                        // may have already happened for this block).
                                        if let Some(channel_ready) = self.check_get_channel_ready(height) {
                                                log_info!(logger, "Sending a channel_ready to our peer for channel {}", &self.context.channel_id);
-                                               let announcement_sigs = self.get_announcement_sigs(node_signer, genesis_block_hash, user_config, height, logger);
-                                               return Ok((Some(channel_ready), announcement_sigs));
+                                               let announcement_sigs = self.get_announcement_sigs(node_signer, chain_hash, user_config, height, logger);
+                                               msgs = (Some(channel_ready), announcement_sigs);
                                        }
                                }
                                for inp in tx.input.iter() {
@@ -4874,7 +5097,7 @@ impl<SP: Deref> Channel<SP> where
                                }
                        }
                }
-               Ok((None, None))
+               Ok(msgs)
        }
 
        /// When a new block is connected, we check the height of the block against outbound holding
@@ -4889,19 +5112,19 @@ impl<SP: Deref> Channel<SP> where
        /// May return some HTLCs (and their payment_hash) which have timed out and should be failed
        /// back.
        pub fn best_block_updated<NS: Deref, L: Deref>(
-               &mut self, height: u32, highest_header_time: u32, genesis_block_hash: BlockHash,
+               &mut self, height: u32, highest_header_time: u32, chain_hash: ChainHash,
                node_signer: &NS, user_config: &UserConfig, logger: &L
        ) -> Result<(Option<msgs::ChannelReady>, Vec<(HTLCSource, PaymentHash)>, Option<msgs::AnnouncementSignatures>), ClosureReason>
        where
                NS::Target: NodeSigner,
                L::Target: Logger
        {
-               self.do_best_block_updated(height, highest_header_time, Some((genesis_block_hash, node_signer, user_config)), logger)
+               self.do_best_block_updated(height, highest_header_time, Some((chain_hash, node_signer, user_config)), logger)
        }
 
        fn do_best_block_updated<NS: Deref, L: Deref>(
                &mut self, height: u32, highest_header_time: u32,
-               genesis_node_signer: Option<(BlockHash, &NS, &UserConfig)>, logger: &L
+               chain_node_signer: Option<(ChainHash, &NS, &UserConfig)>, logger: &L
        ) -> Result<(Option<msgs::ChannelReady>, Vec<(HTLCSource, PaymentHash)>, Option<msgs::AnnouncementSignatures>), ClosureReason>
        where
                NS::Target: NodeSigner,
@@ -4927,8 +5150,8 @@ impl<SP: Deref> Channel<SP> where
                self.context.update_time_counter = cmp::max(self.context.update_time_counter, highest_header_time);
 
                if let Some(channel_ready) = self.check_get_channel_ready(height) {
-                       let announcement_sigs = if let Some((genesis_block_hash, node_signer, user_config)) = genesis_node_signer {
-                               self.get_announcement_sigs(node_signer, genesis_block_hash, user_config, height, logger)
+                       let announcement_sigs = if let Some((chain_hash, node_signer, user_config)) = chain_node_signer {
+                               self.get_announcement_sigs(node_signer, chain_hash, user_config, height, logger)
                        } else { None };
                        log_info!(logger, "Sending a channel_ready to our peer for channel {}", &self.context.channel_id);
                        return Ok((Some(channel_ready), timed_out_htlcs, announcement_sigs));
@@ -4968,8 +5191,8 @@ impl<SP: Deref> Channel<SP> where
                        return Err(ClosureReason::FundingTimedOut);
                }
 
-               let announcement_sigs = if let Some((genesis_block_hash, node_signer, user_config)) = genesis_node_signer {
-                       self.get_announcement_sigs(node_signer, genesis_block_hash, user_config, height, logger)
+               let announcement_sigs = if let Some((chain_hash, node_signer, user_config)) = chain_node_signer {
+                       self.get_announcement_sigs(node_signer, chain_hash, user_config, height, logger)
                } else { None };
                Ok((None, timed_out_htlcs, announcement_sigs))
        }
@@ -4986,7 +5209,7 @@ impl<SP: Deref> Channel<SP> where
                        // larger. If we don't know that time has moved forward, we can just set it to the last
                        // time we saw and it will be ignored.
                        let best_time = self.context.update_time_counter;
-                       match self.do_best_block_updated(reorg_height, best_time, None::<(BlockHash, &&NodeSigner, &UserConfig)>, logger) {
+                       match self.do_best_block_updated(reorg_height, best_time, None::<(ChainHash, &&NodeSigner, &UserConfig)>, logger) {
                                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?");
@@ -5016,7 +5239,7 @@ impl<SP: Deref> Channel<SP> where
        ///
        /// [`ChannelReady`]: crate::ln::msgs::ChannelReady
        fn get_channel_announcement<NS: Deref>(
-               &self, node_signer: &NS, chain_hash: BlockHash, user_config: &UserConfig,
+               &self, node_signer: &NS, chain_hash: ChainHash, user_config: &UserConfig,
        ) -> Result<msgs::UnsignedChannelAnnouncement, ChannelError> where NS::Target: NodeSigner {
                if !self.context.config.announced_channel {
                        return Err(ChannelError::Ignore("Channel is not available for public announcements".to_owned()));
@@ -5047,7 +5270,7 @@ impl<SP: Deref> Channel<SP> where
        }
 
        fn get_announcement_sigs<NS: Deref, L: Deref>(
-               &mut self, node_signer: &NS, genesis_block_hash: BlockHash, user_config: &UserConfig,
+               &mut self, node_signer: &NS, chain_hash: ChainHash, user_config: &UserConfig,
                best_block_height: u32, logger: &L
        ) -> Option<msgs::AnnouncementSignatures>
        where
@@ -5072,7 +5295,7 @@ impl<SP: Deref> Channel<SP> where
                }
 
                log_trace!(logger, "Creating an announcement_signatures message for channel {}", &self.context.channel_id());
-               let announcement = match self.get_channel_announcement(node_signer, genesis_block_hash, user_config) {
+               let announcement = match self.get_channel_announcement(node_signer, chain_hash, user_config) {
                        Ok(a) => a,
                        Err(e) => {
                                log_trace!(logger, "{:?}", e);
@@ -5108,7 +5331,9 @@ impl<SP: Deref> Channel<SP> where
                                        node_signature: our_node_sig,
                                        bitcoin_signature: our_bitcoin_sig,
                                })
-                       }
+                       },
+                       // TODO (taproot|arik)
+                       _ => todo!()
                }
        }
 
@@ -5135,7 +5360,9 @@ impl<SP: Deref> Channel<SP> where
                                                bitcoin_signature_2: if were_node_one { their_bitcoin_sig } else { our_bitcoin_sig },
                                                contents: announcement,
                                        })
-                               }
+                               },
+                               // TODO (taproot|arik)
+                               _ => todo!()
                        }
                } else {
                        Err(ChannelError::Ignore("Attempted to sign channel announcement before we'd received announcement_signatures".to_string()))
@@ -5146,7 +5373,7 @@ impl<SP: Deref> Channel<SP> where
        /// channel_announcement message which we can broadcast and storing our counterparty's
        /// signatures for later reconstruction/rebroadcast of the channel_announcement.
        pub fn announcement_signatures<NS: Deref>(
-               &mut self, node_signer: &NS, chain_hash: BlockHash, best_block_height: u32,
+               &mut self, node_signer: &NS, chain_hash: ChainHash, best_block_height: u32,
                msg: &msgs::AnnouncementSignatures, user_config: &UserConfig
        ) -> Result<msgs::ChannelAnnouncement, ChannelError> where NS::Target: NodeSigner {
                let announcement = self.get_channel_announcement(node_signer, chain_hash, user_config)?;
@@ -5176,7 +5403,7 @@ impl<SP: Deref> Channel<SP> where
        /// Gets a signed channel_announcement for this channel, if we previously received an
        /// announcement_signatures from our counterparty.
        pub fn get_signed_channel_announcement<NS: Deref>(
-               &self, node_signer: &NS, chain_hash: BlockHash, best_block_height: u32, user_config: &UserConfig
+               &self, node_signer: &NS, chain_hash: ChainHash, best_block_height: u32, user_config: &UserConfig
        ) -> Option<msgs::ChannelAnnouncement> where NS::Target: NodeSigner {
                if self.context.funding_tx_confirmation_height == 0 || self.context.funding_tx_confirmation_height + 5 > best_block_height {
                        return None;
@@ -5483,7 +5710,7 @@ impl<SP: Deref> Channel<SP> where
                                        }
 
                                        let res = ecdsa.sign_counterparty_commitment(&commitment_stats.tx, commitment_stats.preimages, &self.context.secp_ctx)
-                                               .map_err(|_| ChannelError::Close("Failed to get signatures for new commitment_signed".to_owned()))?;
+                                               .map_err(|_| ChannelError::Ignore("Failed to get signatures for new commitment_signed".to_owned()))?;
                                        signature = res.0;
                                        htlc_signatures = res.1;
 
@@ -5496,7 +5723,7 @@ impl<SP: Deref> Channel<SP> where
                                                log_trace!(logger, "Signed remote HTLC tx {} with redeemscript {} with pubkey {} -> {} in channel {}",
                                                        encode::serialize_hex(&chan_utils::build_htlc_transaction(&counterparty_commitment_txid, commitment_stats.feerate_per_kw, self.context.get_holder_selected_contest_delay(), htlc, &self.context.channel_type, &counterparty_keys.broadcaster_delayed_payment_key, &counterparty_keys.revocation_key)),
                                                        encode::serialize_hex(&chan_utils::get_htlc_redeemscript(&htlc, &self.context.channel_type, &counterparty_keys)),
-                                                       log_bytes!(counterparty_keys.broadcaster_htlc_key.serialize()),
+                                                       log_bytes!(counterparty_keys.broadcaster_htlc_key.to_public_key().serialize()),
                                                        log_bytes!(htlc_sig.serialize_compact()[..]), &self.context.channel_id());
                                        }
                                }
@@ -5508,7 +5735,9 @@ impl<SP: Deref> Channel<SP> where
                                        #[cfg(taproot)]
                                        partial_signature_with_nonce: None,
                                }, (counterparty_commitment_txid, commitment_stats.htlcs_included)))
-                       }
+                       },
+                       // TODO (taproot|arik)
+                       _ => todo!()
                }
        }
 
@@ -5537,17 +5766,20 @@ impl<SP: Deref> Channel<SP> where
                }
        }
 
-       pub fn channel_update(&mut self, msg: &msgs::ChannelUpdate) -> Result<(), ChannelError> {
-               if msg.contents.htlc_minimum_msat >= self.context.channel_value_satoshis * 1000 {
-                       return Err(ChannelError::Close("Minimum htlc value is greater than channel value".to_string()));
-               }
-               self.context.counterparty_forwarding_info = Some(CounterpartyForwardingInfo {
+       /// Applies the `ChannelUpdate` and returns a boolean indicating whether a change actually
+       /// happened.
+       pub fn channel_update(&mut self, msg: &msgs::ChannelUpdate) -> Result<bool, ChannelError> {
+               let new_forwarding_info = Some(CounterpartyForwardingInfo {
                        fee_base_msat: msg.contents.fee_base_msat,
                        fee_proportional_millionths: msg.contents.fee_proportional_millionths,
                        cltv_expiry_delta: msg.contents.cltv_expiry_delta
                });
+               let did_change = self.context.counterparty_forwarding_info != new_forwarding_info;
+               if did_change {
+                       self.context.counterparty_forwarding_info = new_forwarding_info;
+               }
 
-               Ok(())
+               Ok(did_change)
        }
 
        /// Begins the shutdown process, getting a message for the remote peer and returning all
@@ -5557,7 +5789,7 @@ impl<SP: Deref> Channel<SP> where
        /// [`ChannelMonitorUpdate`] will be returned).
        pub fn get_shutdown(&mut self, signer_provider: &SP, their_features: &InitFeatures,
                target_feerate_sats_per_kw: Option<u32>, override_shutdown_script: Option<ShutdownScript>)
-       -> Result<(msgs::Shutdown, Option<ChannelMonitorUpdate>, Vec<(HTLCSource, PaymentHash)>), APIError>
+       -> Result<(msgs::Shutdown, Option<ChannelMonitorUpdate>, Vec<(HTLCSource, PaymentHash)>, Option<ShutdownResult>), APIError>
        {
                for htlc in self.context.pending_outbound_htlcs.iter() {
                        if let OutboundHTLCState::LocalAnnounced(_) = htlc.state {
@@ -5612,11 +5844,18 @@ impl<SP: Deref> Channel<SP> where
 
                // From here on out, we may not fail!
                self.context.target_closing_feerate_sats_per_kw = target_feerate_sats_per_kw;
-               if self.context.channel_state & !STATE_FLAGS < ChannelState::FundingSent as u32 {
+               let shutdown_result = if self.context.channel_state & !STATE_FLAGS < ChannelState::FundingSent as u32 {
+                       let shutdown_result = ShutdownResult {
+                               monitor_update: None,
+                               dropped_outbound_htlcs: Vec::new(),
+                               unbroadcasted_batch_funding_txid: self.context.unbroadcasted_batch_funding_txid(),
+                       };
                        self.context.channel_state = ChannelState::ShutdownComplete as u32;
+                       Some(shutdown_result)
                } else {
                        self.context.channel_state |= ChannelState::LocalShutdownSent as u32;
-               }
+                       None
+               };
                self.context.update_time_counter += 1;
 
                let monitor_update = if update_shutdown_script {
@@ -5652,7 +5891,7 @@ impl<SP: Deref> Channel<SP> where
                debug_assert!(!self.is_shutdown() || monitor_update.is_none(),
                        "we can't both complete shutdown and return a monitor update");
 
-               Ok((shutdown, monitor_update, dropped_outbound_htlcs))
+               Ok((shutdown, monitor_update, dropped_outbound_htlcs, shutdown_result))
        }
 
        pub fn inflight_htlc_sources(&self) -> impl Iterator<Item=(&HTLCSource, &PaymentHash)> {
@@ -5678,7 +5917,7 @@ impl<SP: Deref> OutboundV1Channel<SP> where SP::Target: SignerProvider {
        pub fn new<ES: Deref, F: Deref>(
                fee_estimator: &LowerBoundedFeeEstimator<F>, entropy_source: &ES, signer_provider: &SP, counterparty_node_id: PublicKey, their_features: &InitFeatures,
                channel_value_satoshis: u64, push_msat: u64, user_id: u128, config: &UserConfig, current_chain_height: u32,
-               outbound_scid_alias: u64
+               outbound_scid_alias: u64, temporary_channel_id: Option<ChannelId>
        ) -> Result<OutboundV1Channel<SP>, APIError>
        where ES::Target: EntropySource,
              F::Target: FeeEstimator
@@ -5711,16 +5950,16 @@ impl<SP: Deref> OutboundV1Channel<SP> where SP::Target: SignerProvider {
                let channel_type = Self::get_initial_channel_type(&config, their_features);
                debug_assert!(channel_type.is_subset(&channelmanager::provided_channel_type_features(&config)));
 
-               let commitment_conf_target = if channel_type.supports_anchors_zero_fee_htlc_tx() {
-                       ConfirmationTarget::MempoolMinimum
+               let (commitment_conf_target, anchor_outputs_value_msat)  = if channel_type.supports_anchors_zero_fee_htlc_tx() {
+                       (ConfirmationTarget::AnchorChannelFee, ANCHOR_OUTPUT_VALUE_SATOSHI * 2 * 1000)
                } else {
-                       ConfirmationTarget::Normal
+                       (ConfirmationTarget::NonAnchorChannelFee, 0)
                };
                let commitment_feerate = fee_estimator.bounded_sat_per_1000_weight(commitment_conf_target);
 
                let value_to_self_msat = channel_value_satoshis * 1000 - push_msat;
                let commitment_tx_fee = commit_tx_fee_msat(commitment_feerate, MIN_AFFORDABLE_HTLC_COUNT, &channel_type);
-               if value_to_self_msat < commitment_tx_fee {
+               if value_to_self_msat.saturating_sub(anchor_outputs_value_msat) < commitment_tx_fee {
                        return Err(APIError::APIMisuseError{ err: format!("Funding amount ({}) can't even pay fee for initial commitment transaction fee of {}.", value_to_self_msat / 1000, commitment_tx_fee / 1000) });
                }
 
@@ -5740,12 +5979,12 @@ impl<SP: Deref> OutboundV1Channel<SP> where SP::Target: SignerProvider {
                        }
                }
 
-               let destination_script = match signer_provider.get_destination_script() {
+               let destination_script = match signer_provider.get_destination_script(channel_keys_id) {
                        Ok(script) => script,
                        Err(_) => return Err(APIError::ChannelUnavailable { err: "Failed to get destination script".to_owned()}),
                };
 
-               let temporary_channel_id = ChannelId::temporary_from_entropy_source(entropy_source);
+               let temporary_channel_id = temporary_channel_id.unwrap_or_else(|| ChannelId::temporary_from_entropy_source(entropy_source));
 
                Ok(Self {
                        context: ChannelContext {
@@ -5796,6 +6035,9 @@ impl<SP: Deref> OutboundV1Channel<SP> where SP::Target: SignerProvider {
                                monitor_pending_failures: Vec::new(),
                                monitor_pending_finalized_fulfills: Vec::new(),
 
+                               signer_pending_commitment_update: false,
+                               signer_pending_funding: false,
+
                                #[cfg(debug_assertions)]
                                holder_max_commitment_tx_output: Mutex::new((channel_value_satoshis * 1000 - push_msat, push_msat)),
                                #[cfg(debug_assertions)]
@@ -5803,6 +6045,7 @@ impl<SP: Deref> OutboundV1Channel<SP> where SP::Target: SignerProvider {
 
                                last_sent_closing_fee: None,
                                pending_counterparty_closing_signed: None,
+                               expecting_peer_commitment_signed: false,
                                closing_fee_limits: None,
                                target_closing_feerate_sats_per_kw: None,
 
@@ -5876,19 +6119,6 @@ impl<SP: Deref> OutboundV1Channel<SP> where SP::Target: SignerProvider {
                })
        }
 
-       /// If an Err is returned, it is a ChannelError::Close (for get_funding_created)
-       fn get_funding_created_signature<L: Deref>(&mut self, logger: &L) -> Result<Signature, ChannelError> where L::Target: Logger {
-               let counterparty_keys = self.context.build_remote_transaction_keys();
-               let counterparty_initial_commitment_tx = self.context.build_commitment_transaction(self.context.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, false, logger).tx;
-               match &self.context.holder_signer {
-                       // TODO (taproot|arik): move match into calling method for Taproot
-                       ChannelSignerType::Ecdsa(ecdsa) => {
-                               Ok(ecdsa.sign_counterparty_commitment(&counterparty_initial_commitment_tx, Vec::new(), &self.context.secp_ctx)
-                                       .map_err(|_| ChannelError::Close("Failed to get signatures for new commitment_signed".to_owned()))?.0)
-                       }
-               }
-       }
-
        /// Updates channel state with knowledge of the funding transaction's txid/index, and generates
        /// a funding_created message for the remote peer.
        /// Panics if called at some time other than immediately after initial handshake, if called twice,
@@ -5897,7 +6127,7 @@ impl<SP: Deref> OutboundV1Channel<SP> where SP::Target: SignerProvider {
        /// Do NOT broadcast the funding transaction until after a successful funding_signed call!
        /// If an Err is returned, it is a ChannelError::Close.
        pub fn get_funding_created<L: Deref>(mut self, funding_transaction: Transaction, funding_txo: OutPoint, is_batch_funding: bool, logger: &L)
-       -> Result<(Channel<SP>, msgs::FundingCreated), (Self, ChannelError)> where L::Target: Logger {
+       -> Result<(Channel<SP>, Option<msgs::FundingCreated>), (Self, ChannelError)> where L::Target: Logger {
                if !self.context.is_outbound() {
                        panic!("Tried to create outbound funding_created message on an inbound channel!");
                }
@@ -5913,17 +6143,6 @@ impl<SP: Deref> OutboundV1Channel<SP> where SP::Target: SignerProvider {
                self.context.channel_transaction_parameters.funding_outpoint = Some(funding_txo);
                self.context.holder_signer.as_mut().provide_channel_parameters(&self.context.channel_transaction_parameters);
 
-               let signature = match self.get_funding_created_signature(logger) {
-                       Ok(res) => res,
-                       Err(e) => {
-                               log_error!(logger, "Got bad signatures: {:?}!", e);
-                               self.context.channel_transaction_parameters.funding_outpoint = None;
-                               return Err((self, e));
-                       }
-               };
-
-               let temporary_channel_id = self.context.channel_id;
-
                // Now that we're past error-generating stuff, update our local state:
 
                self.context.channel_state = ChannelState::FundingCreated as u32;
@@ -5940,20 +6159,19 @@ impl<SP: Deref> OutboundV1Channel<SP> where SP::Target: SignerProvider {
                self.context.funding_transaction = Some(funding_transaction);
                self.context.is_batch_funding = Some(()).filter(|_| is_batch_funding);
 
+               let funding_created = self.context.get_funding_created_msg(logger);
+               if funding_created.is_none() {
+                       if !self.context.signer_pending_funding {
+                               log_trace!(logger, "funding_created awaiting signer; setting signer_pending_funding");
+                               self.context.signer_pending_funding = true;
+                       }
+               }
+
                let channel = Channel {
                        context: self.context,
                };
 
-               Ok((channel, msgs::FundingCreated {
-                       temporary_channel_id,
-                       funding_txid: funding_txo.txid,
-                       funding_output_index: funding_txo.index,
-                       signature,
-                       #[cfg(taproot)]
-                       partial_signature_with_nonce: None,
-                       #[cfg(taproot)]
-                       next_local_nonce: None,
-               }))
+               Ok((channel, funding_created))
        }
 
        fn get_initial_channel_type(config: &UserConfig, their_features: &InitFeatures) -> ChannelTypeFeatures {
@@ -5983,7 +6201,7 @@ impl<SP: Deref> OutboundV1Channel<SP> where SP::Target: SignerProvider {
        /// not of our ability to open any channel at all. Thus, on error, we should first call this
        /// and see if we get a new `OpenChannel` message, otherwise the channel is failed.
        pub(crate) fn maybe_handle_error_without_close<F: Deref>(
-               &mut self, chain_hash: BlockHash, fee_estimator: &LowerBoundedFeeEstimator<F>
+               &mut self, chain_hash: ChainHash, fee_estimator: &LowerBoundedFeeEstimator<F>
        ) -> Result<msgs::OpenChannel, ()>
        where
                F::Target: FeeEstimator
@@ -6004,7 +6222,7 @@ impl<SP: Deref> OutboundV1Channel<SP> where SP::Target: SignerProvider {
                // whatever reason.
                if self.context.channel_type.supports_anchors_zero_fee_htlc_tx() {
                        self.context.channel_type.clear_anchors_zero_fee_htlc_tx();
-                       self.context.feerate_per_kw = fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Normal);
+                       self.context.feerate_per_kw = fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::NonAnchorChannelFee);
                        assert!(!self.context.channel_transaction_parameters.channel_type_features.supports_anchors_nonzero_fee_htlc_tx());
                } else if self.context.channel_type.supports_scid_privacy() {
                        self.context.channel_type.clear_scid_privacy();
@@ -6015,7 +6233,7 @@ impl<SP: Deref> OutboundV1Channel<SP> where SP::Target: SignerProvider {
                Ok(self.get_open_channel(chain_hash))
        }
 
-       pub fn get_open_channel(&self, chain_hash: BlockHash) -> msgs::OpenChannel {
+       pub fn get_open_channel(&self, chain_hash: ChainHash) -> msgs::OpenChannel {
                if !self.context.is_outbound() {
                        panic!("Tried to open a channel for an inbound channel?");
                }
@@ -6043,10 +6261,10 @@ impl<SP: Deref> OutboundV1Channel<SP> where SP::Target: SignerProvider {
                        to_self_delay: self.context.get_holder_selected_contest_delay(),
                        max_accepted_htlcs: self.context.holder_max_accepted_htlcs,
                        funding_pubkey: keys.funding_pubkey,
-                       revocation_basepoint: keys.revocation_basepoint,
+                       revocation_basepoint: keys.revocation_basepoint.to_public_key(),
                        payment_point: keys.payment_point,
-                       delayed_payment_basepoint: keys.delayed_payment_basepoint,
-                       htlc_basepoint: keys.htlc_basepoint,
+                       delayed_payment_basepoint: keys.delayed_payment_basepoint.to_public_key(),
+                       htlc_basepoint: keys.htlc_basepoint.to_public_key(),
                        first_per_commitment_point,
                        channel_flags: if self.context.config.announced_channel {1} else {0},
                        shutdown_scriptpubkey: Some(match &self.context.shutdown_scriptpubkey {
@@ -6168,10 +6386,10 @@ impl<SP: Deref> OutboundV1Channel<SP> where SP::Target: SignerProvider {
 
                let counterparty_pubkeys = ChannelPublicKeys {
                        funding_pubkey: msg.funding_pubkey,
-                       revocation_basepoint: msg.revocation_basepoint,
+                       revocation_basepoint: RevocationBasepoint::from(msg.revocation_basepoint),
                        payment_point: msg.payment_point,
-                       delayed_payment_basepoint: msg.delayed_payment_basepoint,
-                       htlc_basepoint: msg.htlc_basepoint
+                       delayed_payment_basepoint: DelayedPaymentBasepoint::from(msg.delayed_payment_basepoint),
+                       htlc_basepoint: HtlcBasepoint::from(msg.htlc_basepoint)
                };
 
                self.context.channel_transaction_parameters.counterparty_parameters = Some(CounterpartyChannelTransactionParameters {
@@ -6244,10 +6462,10 @@ impl<SP: Deref> InboundV1Channel<SP> where SP::Target: SignerProvider {
                let pubkeys = holder_signer.pubkeys().clone();
                let counterparty_pubkeys = ChannelPublicKeys {
                        funding_pubkey: msg.funding_pubkey,
-                       revocation_basepoint: msg.revocation_basepoint,
+                       revocation_basepoint: RevocationBasepoint::from(msg.revocation_basepoint),
                        payment_point: msg.payment_point,
-                       delayed_payment_basepoint: msg.delayed_payment_basepoint,
-                       htlc_basepoint: msg.htlc_basepoint
+                       delayed_payment_basepoint: DelayedPaymentBasepoint::from(msg.delayed_payment_basepoint),
+                       htlc_basepoint: HtlcBasepoint::from(msg.htlc_basepoint)
                };
 
                if config.channel_handshake_config.our_to_self_delay < BREAKDOWN_TIMEOUT {
@@ -6337,13 +6555,18 @@ impl<SP: Deref> InboundV1Channel<SP> where SP::Target: SignerProvider {
 
                // check if the funder's amount for the initial commitment tx is sufficient
                // for full fee payment plus a few HTLCs to ensure the channel will be useful.
+               let anchor_outputs_value = if channel_type.supports_anchors_zero_fee_htlc_tx() {
+                       ANCHOR_OUTPUT_VALUE_SATOSHI * 2
+               } else {
+                       0
+               };
                let funders_amount_msat = msg.funding_satoshis * 1000 - msg.push_msat;
                let commitment_tx_fee = commit_tx_fee_msat(msg.feerate_per_kw, MIN_AFFORDABLE_HTLC_COUNT, &channel_type) / 1000;
-               if funders_amount_msat / 1000 < commitment_tx_fee {
-                       return Err(ChannelError::Close(format!("Funding amount ({} sats) can't even pay fee for initial commitment transaction fee of {} sats.", funders_amount_msat / 1000, commitment_tx_fee)));
+               if (funders_amount_msat / 1000).saturating_sub(anchor_outputs_value) < commitment_tx_fee {
+                       return Err(ChannelError::Close(format!("Funding amount ({} sats) can't even pay fee for initial commitment transaction fee of {} sats.", (funders_amount_msat / 1000).saturating_sub(anchor_outputs_value), commitment_tx_fee)));
                }
 
-               let to_remote_satoshis = funders_amount_msat / 1000 - commitment_tx_fee;
+               let to_remote_satoshis = funders_amount_msat / 1000 - commitment_tx_fee - anchor_outputs_value;
                // While it's reasonable for us to not meet the channel reserve initially (if they don't
                // want to push much to us), our counterparty should always have more than our reserve.
                if to_remote_satoshis < holder_selected_channel_reserve_satoshis {
@@ -6383,7 +6606,7 @@ impl<SP: Deref> InboundV1Channel<SP> where SP::Target: SignerProvider {
                        }
                }
 
-               let destination_script = match signer_provider.get_destination_script() {
+               let destination_script = match signer_provider.get_destination_script(channel_keys_id) {
                        Ok(script) => script,
                        Err(_) => return Err(ChannelError::Close("Failed to get destination script".to_owned())),
                };
@@ -6445,6 +6668,9 @@ impl<SP: Deref> InboundV1Channel<SP> where SP::Target: SignerProvider {
                                monitor_pending_failures: Vec::new(),
                                monitor_pending_finalized_fulfills: Vec::new(),
 
+                               signer_pending_commitment_update: false,
+                               signer_pending_funding: false,
+
                                #[cfg(debug_assertions)]
                                holder_max_commitment_tx_output: Mutex::new((msg.push_msat, msg.funding_satoshis * 1000 - msg.push_msat)),
                                #[cfg(debug_assertions)]
@@ -6452,6 +6678,7 @@ impl<SP: Deref> InboundV1Channel<SP> where SP::Target: SignerProvider {
 
                                last_sent_closing_fee: None,
                                pending_counterparty_closing_signed: None,
+                               expecting_peer_commitment_signed: false,
                                closing_fee_limits: None,
                                target_closing_feerate_sats_per_kw: None,
 
@@ -6568,10 +6795,10 @@ impl<SP: Deref> InboundV1Channel<SP> where SP::Target: SignerProvider {
                        to_self_delay: self.context.get_holder_selected_contest_delay(),
                        max_accepted_htlcs: self.context.holder_max_accepted_htlcs,
                        funding_pubkey: keys.funding_pubkey,
-                       revocation_basepoint: keys.revocation_basepoint,
+                       revocation_basepoint: keys.revocation_basepoint.to_public_key(),
                        payment_point: keys.payment_point,
-                       delayed_payment_basepoint: keys.delayed_payment_basepoint,
-                       htlc_basepoint: keys.htlc_basepoint,
+                       delayed_payment_basepoint: keys.delayed_payment_basepoint.to_public_key(),
+                       htlc_basepoint: keys.htlc_basepoint.to_public_key(),
                        first_per_commitment_point,
                        shutdown_scriptpubkey: Some(match &self.context.shutdown_scriptpubkey {
                                Some(script) => script.clone().into_inner(),
@@ -6592,46 +6819,27 @@ impl<SP: Deref> InboundV1Channel<SP> where SP::Target: SignerProvider {
                self.generate_accept_channel_message()
        }
 
-       fn funding_created_signature<L: Deref>(&mut self, sig: &Signature, logger: &L) -> Result<(CommitmentTransaction, CommitmentTransaction, Signature), ChannelError> where L::Target: Logger {
+       fn check_funding_created_signature<L: Deref>(&mut self, sig: &Signature, logger: &L) -> Result<CommitmentTransaction, ChannelError> where L::Target: Logger {
                let funding_script = self.context.get_funding_redeemscript();
 
                let keys = self.context.build_holder_transaction_keys(self.context.cur_holder_commitment_transaction_number);
                let initial_commitment_tx = self.context.build_commitment_transaction(self.context.cur_holder_commitment_transaction_number, &keys, true, false, logger).tx;
-               {
-                       let trusted_tx = initial_commitment_tx.trust();
-                       let initial_commitment_bitcoin_tx = trusted_tx.built_transaction();
-                       let sighash = initial_commitment_bitcoin_tx.get_sighash_all(&funding_script, self.context.channel_value_satoshis);
-                       // They sign the holder commitment transaction...
-                       log_trace!(logger, "Checking funding_created tx signature {} by key {} against tx {} (sighash {}) with redeemscript {} for channel {}.",
-                               log_bytes!(sig.serialize_compact()[..]), log_bytes!(self.context.counterparty_funding_pubkey().serialize()),
-                               encode::serialize_hex(&initial_commitment_bitcoin_tx.transaction), log_bytes!(sighash[..]),
-                               encode::serialize_hex(&funding_script), &self.context.channel_id());
-                       secp_check!(self.context.secp_ctx.verify_ecdsa(&sighash, &sig, self.context.counterparty_funding_pubkey()), "Invalid funding_created signature from peer".to_owned());
-               }
+               let trusted_tx = initial_commitment_tx.trust();
+               let initial_commitment_bitcoin_tx = trusted_tx.built_transaction();
+               let sighash = initial_commitment_bitcoin_tx.get_sighash_all(&funding_script, self.context.channel_value_satoshis);
+               // They sign the holder commitment transaction...
+               log_trace!(logger, "Checking funding_created tx signature {} by key {} against tx {} (sighash {}) with redeemscript {} for channel {}.",
+                       log_bytes!(sig.serialize_compact()[..]), log_bytes!(self.context.counterparty_funding_pubkey().serialize()),
+                       encode::serialize_hex(&initial_commitment_bitcoin_tx.transaction), log_bytes!(sighash[..]),
+                       encode::serialize_hex(&funding_script), &self.context.channel_id());
+               secp_check!(self.context.secp_ctx.verify_ecdsa(&sighash, &sig, self.context.counterparty_funding_pubkey()), "Invalid funding_created signature from peer".to_owned());
 
-               let counterparty_keys = self.context.build_remote_transaction_keys();
-               let counterparty_initial_commitment_tx = self.context.build_commitment_transaction(self.context.cur_counterparty_commitment_transaction_number, &counterparty_keys, false, false, logger).tx;
-
-               let counterparty_trusted_tx = counterparty_initial_commitment_tx.trust();
-               let counterparty_initial_bitcoin_tx = counterparty_trusted_tx.built_transaction();
-               log_trace!(logger, "Initial counterparty tx for channel {} is: txid {} tx {}",
-                       &self.context.channel_id(), counterparty_initial_bitcoin_tx.txid, encode::serialize_hex(&counterparty_initial_bitcoin_tx.transaction));
-
-               match &self.context.holder_signer {
-                       // TODO (arik): move match into calling method for Taproot
-                       ChannelSignerType::Ecdsa(ecdsa) => {
-                               let counterparty_signature = ecdsa.sign_counterparty_commitment(&counterparty_initial_commitment_tx, Vec::new(), &self.context.secp_ctx)
-                                       .map_err(|_| ChannelError::Close("Failed to get signatures for new commitment_signed".to_owned()))?.0;
-
-                               // We sign "counterparty" commitment transaction, allowing them to broadcast the tx if they wish.
-                               Ok((counterparty_initial_commitment_tx, initial_commitment_tx, counterparty_signature))
-                       }
-               }
+               Ok(initial_commitment_tx)
        }
 
        pub fn funding_created<L: Deref>(
                mut self, msg: &msgs::FundingCreated, best_block: BestBlock, signer_provider: &SP, logger: &L
-       ) -> Result<(Channel<SP>, msgs::FundingSigned, ChannelMonitor<<SP::Target as SignerProvider>::Signer>), (Self, ChannelError)>
+       ) -> Result<(Channel<SP>, Option<msgs::FundingSigned>, ChannelMonitor<<SP::Target as SignerProvider>::EcdsaSigner>), (Self, ChannelError)>
        where
                L::Target: Logger
        {
@@ -6653,10 +6861,10 @@ impl<SP: Deref> InboundV1Channel<SP> where SP::Target: SignerProvider {
                let funding_txo = OutPoint { txid: msg.funding_txid, index: msg.funding_output_index };
                self.context.channel_transaction_parameters.funding_outpoint = Some(funding_txo);
                // This is an externally observable change before we finish all our checks.  In particular
-               // funding_created_signature may fail.
+               // check_funding_created_signature may fail.
                self.context.holder_signer.as_mut().provide_channel_parameters(&self.context.channel_transaction_parameters);
 
-               let (counterparty_initial_commitment_tx, initial_commitment_tx, signature) = match self.funding_created_signature(&msg.signature, logger) {
+               let initial_commitment_tx = match self.check_funding_created_signature(&msg.signature, logger) {
                        Ok(res) => res,
                        Err(ChannelError::Close(e)) => {
                                self.context.channel_transaction_parameters.funding_outpoint = None;
@@ -6665,7 +6873,7 @@ impl<SP: Deref> InboundV1Channel<SP> where SP::Target: SignerProvider {
                        Err(e) => {
                                // The only error we know how to handle is ChannelError::Close, so we fall over here
                                // to make sure we don't continue with an inconsistent state.
-                               panic!("unexpected error type from funding_created_signature {:?}", e);
+                               panic!("unexpected error type from check_funding_created_signature {:?}", e);
                        }
                };
 
@@ -6683,6 +6891,13 @@ impl<SP: Deref> InboundV1Channel<SP> where SP::Target: SignerProvider {
 
                // Now that we're past error-generating stuff, update our local state:
 
+               self.context.channel_state = ChannelState::FundingSent as u32;
+               self.context.channel_id = funding_txo.to_channel_id();
+               self.context.cur_counterparty_commitment_transaction_number -= 1;
+               self.context.cur_holder_commitment_transaction_number -= 1;
+
+               let (counterparty_initial_commitment_tx, funding_signed) = self.context.get_funding_signed_msg(logger);
+
                let funding_redeemscript = self.context.get_funding_redeemscript();
                let funding_txo_script = funding_redeemscript.to_v0_p2wsh();
                let obscure_factor = get_commitment_transaction_number_obscure_factor(&self.context.get_holder_pubkeys().payment_point, &self.context.get_counterparty_pubkeys().payment_point, self.context.is_outbound());
@@ -6699,38 +6914,28 @@ impl<SP: Deref> InboundV1Channel<SP> where SP::Target: SignerProvider {
 
                channel_monitor.provide_initial_counterparty_commitment_tx(
                        counterparty_initial_commitment_tx.trust().txid(), Vec::new(),
-                       self.context.cur_counterparty_commitment_transaction_number,
+                       self.context.cur_counterparty_commitment_transaction_number + 1,
                        self.context.counterparty_cur_commitment_point.unwrap(), self.context.feerate_per_kw,
                        counterparty_initial_commitment_tx.to_broadcaster_value_sat(),
                        counterparty_initial_commitment_tx.to_countersignatory_value_sat(), logger);
 
-               self.context.channel_state = ChannelState::FundingSent as u32;
-               self.context.channel_id = funding_txo.to_channel_id();
-               self.context.cur_counterparty_commitment_transaction_number -= 1;
-               self.context.cur_holder_commitment_transaction_number -= 1;
-
-               log_info!(logger, "Generated funding_signed for peer for channel {}", &self.context.channel_id());
+               log_info!(logger, "{} funding_signed for peer for channel {}",
+                       if funding_signed.is_some() { "Generated" } else { "Waiting for signature on" }, &self.context.channel_id());
 
                // Promote the channel to a full-fledged one now that we have updated the state and have a
                // `ChannelMonitor`.
                let mut channel = Channel {
                        context: self.context,
                };
-               let channel_id = channel.context.channel_id.clone();
                let need_channel_ready = channel.check_get_channel_ready(0).is_some();
                channel.monitor_updating_paused(false, false, need_channel_ready, Vec::new(), Vec::new(), Vec::new());
 
-               Ok((channel, msgs::FundingSigned {
-                       channel_id,
-                       signature,
-                       #[cfg(taproot)]
-                       partial_signature_with_nonce: None,
-               }, channel_monitor))
+               Ok((channel, funding_signed, channel_monitor))
        }
 }
 
 const SERIALIZATION_VERSION: u8 = 3;
-const MIN_SERIALIZATION_VERSION: u8 = 2;
+const MIN_SERIALIZATION_VERSION: u8 = 3;
 
 impl_writeable_tlv_based_enum!(InboundHTLCRemovalReason,;
        (0, FailRelay),
@@ -6810,14 +7015,6 @@ impl<SP: Deref> Writeable for Channel<SP> where SP::Target: SignerProvider {
 
                self.context.latest_monitor_update_id.write(writer)?;
 
-               let mut key_data = VecWriter(Vec::new());
-               // TODO (taproot|arik): Introduce serialization distinction for non-ECDSA signers.
-               self.context.holder_signer.as_ecdsa().expect("Only ECDSA signers may be serialized").write(&mut key_data)?;
-               assert!(key_data.0.len() < core::usize::MAX);
-               assert!(key_data.0.len() < core::u32::MAX as usize);
-               (key_data.0.len() as u32).write(writer)?;
-               writer.write_all(&key_data.0[..])?;
-
                // Write out the old serialization for shutdown_pubkey for backwards compatibility, if
                // deserialized from that format.
                match self.context.shutdown_scriptpubkey.as_ref().and_then(|script| script.as_legacy_pubkey()) {
@@ -7536,6 +7733,9 @@ impl<'a, 'b, 'c, ES: Deref, SP: Deref> ReadableArgs<(&'a ES, &'b SP, u32, &'c Ch
                                monitor_pending_failures,
                                monitor_pending_finalized_fulfills: monitor_pending_finalized_fulfills.unwrap(),
 
+                               signer_pending_commitment_update: false,
+                               signer_pending_funding: false,
+
                                pending_update_fee,
                                holding_cell_update_fee,
                                next_holder_htlc_id,
@@ -7550,6 +7750,7 @@ impl<'a, 'b, 'c, ES: Deref, SP: Deref> ReadableArgs<(&'a ES, &'b SP, u32, &'c Ch
 
                                last_sent_closing_fee: None,
                                pending_counterparty_closing_signed: None,
+                               expecting_peer_commitment_signed: false,
                                closing_fee_limits: None,
                                target_closing_feerate_sats_per_kw,
 
@@ -7618,22 +7819,21 @@ impl<'a, 'b, 'c, ES: Deref, SP: Deref> ReadableArgs<(&'a ES, &'b SP, u32, &'c Ch
 #[cfg(test)]
 mod tests {
        use std::cmp;
-       use bitcoin::blockdata::script::{Script, Builder};
+       use bitcoin::blockdata::constants::ChainHash;
+       use bitcoin::blockdata::script::{ScriptBuf, Builder};
        use bitcoin::blockdata::transaction::{Transaction, TxOut};
-       use bitcoin::blockdata::constants::genesis_block;
        use bitcoin::blockdata::opcodes;
        use bitcoin::network::constants::Network;
-       use hex;
        use crate::ln::PaymentHash;
-       use crate::ln::channelmanager::{self, HTLCSource, PaymentId};
+       use crate::ln::channel_keys::{RevocationKey, RevocationBasepoint};
+use crate::ln::channelmanager::{self, HTLCSource, PaymentId};
        use crate::ln::channel::InitFeatures;
-       use crate::ln::channel::{Channel, ChannelState, InboundHTLCOutput, OutboundV1Channel, InboundV1Channel, OutboundHTLCOutput, InboundHTLCState, OutboundHTLCState, HTLCCandidate, HTLCInitiator, commit_tx_fee_msat};
+       use crate::ln::channel::{ChannelState, InboundHTLCOutput, OutboundV1Channel, InboundV1Channel, OutboundHTLCOutput, InboundHTLCState, OutboundHTLCState, HTLCCandidate, HTLCInitiator, commit_tx_fee_msat};
        use crate::ln::channel::{MAX_FUNDING_SATOSHIS_NO_WUMBO, TOTAL_BITCOIN_SUPPLY_SATOSHIS, MIN_THEIR_CHAN_RESERVE_SATOSHIS};
        use crate::ln::features::ChannelTypeFeatures;
        use crate::ln::msgs::{ChannelUpdate, DecodeError, UnsignedChannelUpdate, MAX_VALUE_MSAT};
        use crate::ln::script::ShutdownScript;
-       use crate::ln::chan_utils;
-       use crate::ln::chan_utils::{htlc_success_tx_weight, htlc_timeout_tx_weight};
+       use crate::ln::chan_utils::{self, htlc_success_tx_weight, htlc_timeout_tx_weight};
        use crate::chain::BestBlock;
        use crate::chain::chaininterface::{FeeEstimator, LowerBoundedFeeEstimator, ConfirmationTarget};
        use crate::sign::{ChannelSigner, InMemorySigner, EntropySource, SignerProvider};
@@ -7648,9 +7848,10 @@ mod tests {
        use bitcoin::secp256k1::{SecretKey,PublicKey};
        use bitcoin::hashes::sha256::Hash as Sha256;
        use bitcoin::hashes::Hash;
+       use bitcoin::hashes::hex::FromHex;
        use bitcoin::hash_types::WPubkeyHash;
-       use bitcoin::PackedLockTime;
-       use bitcoin::util::address::WitnessVersion;
+       use bitcoin::blockdata::locktime::absolute::LockTime;
+       use bitcoin::address::{WitnessProgram, WitnessVersion};
        use crate::prelude::*;
 
        struct TestFeeEstimator {
@@ -7669,17 +7870,6 @@ mod tests {
                        "MAX_FUNDING_SATOSHIS_NO_WUMBO is greater than all satoshis in existence");
        }
 
-       #[test]
-       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.
-               let fee_est = TestFeeEstimator { fee_est: 42 };
-               let bounded_fee_estimator = LowerBoundedFeeEstimator::new(&fee_est);
-               assert!(Channel::<&TestKeysInterface>::check_remote_fee(
-                       &ChannelTypeFeatures::only_static_remote_key(), &bounded_fee_estimator,
-                       u32::max_value(), None, &&test_utils::TestLogger::new()).is_err());
-       }
-
        struct Keys {
                signer: InMemorySigner,
        }
@@ -7689,42 +7879,45 @@ mod tests {
        }
 
        impl SignerProvider for Keys {
-               type Signer = InMemorySigner;
+               type EcdsaSigner = InMemorySigner;
+               #[cfg(taproot)]
+               type TaprootSigner = InMemorySigner;
 
                fn generate_channel_keys_id(&self, _inbound: bool, _channel_value_satoshis: u64, _user_channel_id: u128) -> [u8; 32] {
                        self.signer.channel_keys_id()
                }
 
-               fn derive_channel_signer(&self, _channel_value_satoshis: u64, _channel_keys_id: [u8; 32]) -> Self::Signer {
+               fn derive_channel_signer(&self, _channel_value_satoshis: u64, _channel_keys_id: [u8; 32]) -> Self::EcdsaSigner {
                        self.signer.clone()
                }
 
-               fn read_chan_signer(&self, _data: &[u8]) -> Result<Self::Signer, DecodeError> { panic!(); }
+               fn read_chan_signer(&self, _data: &[u8]) -> Result<Self::EcdsaSigner, DecodeError> { panic!(); }
 
-               fn get_destination_script(&self) -> Result<Script, ()> {
+               fn get_destination_script(&self, _channel_keys_id: [u8; 32]) -> Result<ScriptBuf, ()> {
                        let secp_ctx = Secp256k1::signing_only();
-                       let channel_monitor_claim_key = SecretKey::from_slice(&hex::decode("0fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff").unwrap()[..]).unwrap();
+                       let channel_monitor_claim_key = SecretKey::from_slice(&<Vec<u8>>::from_hex("0fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff").unwrap()[..]).unwrap();
                        let channel_monitor_claim_key_hash = WPubkeyHash::hash(&PublicKey::from_secret_key(&secp_ctx, &channel_monitor_claim_key).serialize());
-                       Ok(Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&channel_monitor_claim_key_hash[..]).into_script())
+                       Ok(Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(channel_monitor_claim_key_hash).into_script())
                }
 
                fn get_shutdown_scriptpubkey(&self) -> Result<ShutdownScript, ()> {
                        let secp_ctx = Secp256k1::signing_only();
-                       let channel_close_key = SecretKey::from_slice(&hex::decode("0fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff").unwrap()[..]).unwrap();
+                       let channel_close_key = SecretKey::from_slice(&<Vec<u8>>::from_hex("0fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff").unwrap()[..]).unwrap();
                        Ok(ShutdownScript::new_p2wpkh_from_pubkey(PublicKey::from_secret_key(&secp_ctx, &channel_close_key)))
                }
        }
 
        #[cfg(all(feature = "_test_vectors", not(feature = "grind_signatures")))]
        fn public_from_secret_hex(secp_ctx: &Secp256k1<bitcoin::secp256k1::All>, hex: &str) -> PublicKey {
-               PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&hex::decode(hex).unwrap()[..]).unwrap())
+               PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&<Vec<u8>>::from_hex(hex).unwrap()[..]).unwrap())
        }
 
        #[test]
        fn upfront_shutdown_script_incompatibility() {
                let features = channelmanager::provided_init_features(&UserConfig::default()).clear_shutdown_anysegwit();
-               let non_v0_segwit_shutdown_script =
-                       ShutdownScript::new_witness_program(WitnessVersion::V16, &[0, 40]).unwrap();
+               let non_v0_segwit_shutdown_script = ShutdownScript::new_witness_program(
+                       &WitnessProgram::new(WitnessVersion::V16, &[0, 40]).unwrap(),
+               ).unwrap();
 
                let seed = [42; 32];
                let network = Network::Testnet;
@@ -7736,7 +7929,7 @@ mod tests {
                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 OutboundV1Channel::<&TestKeysInterface>::new(&LowerBoundedFeeEstimator::new(&TestFeeEstimator { fee_est: 253 }), &&keys_provider, &&keys_provider, node_id, &features, 10000000, 100000, 42, &config, 0, 42) {
+               match OutboundV1Channel::<&TestKeysInterface>::new(&LowerBoundedFeeEstimator::new(&TestFeeEstimator { fee_est: 253 }), &&keys_provider, &&keys_provider, node_id, &features, 10000000, 100000, 42, &config, 0, 42, None) {
                        Err(APIError::IncompatibleShutdownScript { script }) => {
                                assert_eq!(script.into_inner(), non_v0_segwit_shutdown_script.into_inner());
                        },
@@ -7759,12 +7952,12 @@ 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 = OutboundV1Channel::<&TestKeysInterface>::new(&bounded_fee_estimator, &&keys_provider, &&keys_provider, node_a_node_id, &channelmanager::provided_init_features(&config), 10000000, 100000, 42, &config, 0, 42).unwrap();
+               let node_a_chan = OutboundV1Channel::<&TestKeysInterface>::new(&bounded_fee_estimator, &&keys_provider, &&keys_provider, node_a_node_id, &channelmanager::provided_init_features(&config), 10000000, 100000, 42, &config, 0, 42, None).unwrap();
 
                // Now change the fee so we can check that the fee in the open_channel message is the
                // same as the old fee.
                fee_est.fee_est = 500;
-               let open_channel_msg = node_a_chan.get_open_channel(genesis_block(network).header.block_hash());
+               let open_channel_msg = node_a_chan.get_open_channel(ChainHash::using_genesis_block(network));
                assert_eq!(open_channel_msg.feerate_per_kw, original_fee);
        }
 
@@ -7786,11 +7979,11 @@ 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 = OutboundV1Channel::<&TestKeysInterface>::new(&feeest, &&keys_provider, &&keys_provider, node_b_node_id, &channelmanager::provided_init_features(&config), 10000000, 100000, 42, &config, 0, 42).unwrap();
+               let mut node_a_chan = OutboundV1Channel::<&TestKeysInterface>::new(&feeest, &&keys_provider, &&keys_provider, node_b_node_id, &channelmanager::provided_init_features(&config), 10000000, 100000, 42, &config, 0, 42, None).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 open_channel_msg = node_a_chan.get_open_channel(ChainHash::using_genesis_block(network));
                let node_b_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[7; 32]).unwrap());
                let mut node_b_chan = InboundV1Channel::<&TestKeysInterface>::new(&feeest, &&keys_provider, &&keys_provider, node_b_node_id, &channelmanager::provided_channel_type_features(&config), &channelmanager::provided_init_features(&config), &open_channel_msg, 7, &config, 0, &&logger, /*is_0conf=*/false).unwrap();
 
@@ -7802,22 +7995,22 @@ mod tests {
 
                // Node A --> Node B: funding created
                let output_script = node_a_chan.context.get_funding_redeemscript();
-               let tx = Transaction { version: 1, lock_time: PackedLockTime::ZERO, input: Vec::new(), output: vec![TxOut {
+               let tx = Transaction { version: 1, lock_time: LockTime::ZERO, input: Vec::new(), output: vec![TxOut {
                        value: 10000000, script_pubkey: output_script.clone(),
                }]};
                let funding_outpoint = OutPoint{ txid: tx.txid(), index: 0 };
                let (mut node_a_chan, funding_created_msg) = node_a_chan.get_funding_created(tx.clone(), funding_outpoint, false, &&logger).map_err(|_| ()).unwrap();
-               let (_, funding_signed_msg, _) = node_b_chan.funding_created(&funding_created_msg, best_block, &&keys_provider, &&logger).map_err(|_| ()).unwrap();
+               let (_, funding_signed_msg, _) = node_b_chan.funding_created(&funding_created_msg.unwrap(), best_block, &&keys_provider, &&logger).map_err(|_| ()).unwrap();
 
                // Node B --> Node A: funding signed
-               let _ = node_a_chan.funding_signed(&funding_signed_msg, best_block, &&keys_provider, &&logger).unwrap();
+               let _ = node_a_chan.funding_signed(&funding_signed_msg.unwrap(), best_block, &&keys_provider, &&logger).unwrap();
 
                // Put some inbound and outbound HTLCs in A's channel.
                let htlc_amount_msat = 11_092_000; // put an amount below A's effective dust limit but above B's.
                node_a_chan.context.pending_inbound_htlcs.push(InboundHTLCOutput {
                        htlc_id: 0,
                        amount_msat: htlc_amount_msat,
-                       payment_hash: PaymentHash(Sha256::hash(&[42; 32]).into_inner()),
+                       payment_hash: PaymentHash(Sha256::hash(&[42; 32]).to_byte_array()),
                        cltv_expiry: 300000000,
                        state: InboundHTLCState::Committed,
                });
@@ -7825,12 +8018,12 @@ mod tests {
                node_a_chan.context.pending_outbound_htlcs.push(OutboundHTLCOutput {
                        htlc_id: 1,
                        amount_msat: htlc_amount_msat, // put an amount below A's dust amount but above B's.
-                       payment_hash: PaymentHash(Sha256::hash(&[43; 32]).into_inner()),
+                       payment_hash: PaymentHash(Sha256::hash(&[43; 32]).to_byte_array()),
                        cltv_expiry: 200000000,
                        state: OutboundHTLCState::Committed,
                        source: HTLCSource::OutboundRoute {
                                path: Path { hops: Vec::new(), blinded_tail: None },
-                               session_priv: SecretKey::from_slice(&hex::decode("0fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff").unwrap()[..]).unwrap(),
+                               session_priv: SecretKey::from_slice(&<Vec<u8>>::from_hex("0fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff").unwrap()[..]).unwrap(),
                                first_hop_htlc_msat: 548,
                                payment_id: PaymentId([42; 32]),
                        },
@@ -7867,7 +8060,7 @@ mod tests {
 
                let node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
                let config = UserConfig::default();
-               let mut chan = OutboundV1Channel::<&TestKeysInterface>::new(&fee_est, &&keys_provider, &&keys_provider, node_id, &channelmanager::provided_init_features(&config), 10000000, 100000, 42, &config, 0, 42).unwrap();
+               let mut chan = OutboundV1Channel::<&TestKeysInterface>::new(&fee_est, &&keys_provider, &&keys_provider, node_id, &channelmanager::provided_init_features(&config), 10000000, 100000, 42, &config, 0, 42, None).unwrap();
 
                let commitment_tx_fee_0_htlcs = commit_tx_fee_msat(chan.context.feerate_per_kw, 0, chan.context.get_channel_type());
                let commitment_tx_fee_1_htlc = commit_tx_fee_msat(chan.context.feerate_per_kw, 1, chan.context.get_channel_type());
@@ -7908,7 +8101,7 @@ mod tests {
                let seed = [42; 32];
                let network = Network::Testnet;
                let best_block = BestBlock::from_network(network);
-               let chain_hash = best_block.block_hash();
+               let chain_hash = ChainHash::using_genesis_block(network);
                let keys_provider = test_utils::TestKeysInterface::new(&seed, network);
 
                // Go through the flow of opening a channel between two nodes.
@@ -7916,7 +8109,7 @@ 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 = OutboundV1Channel::<&TestKeysInterface>::new(&feeest, &&keys_provider, &&keys_provider, node_b_node_id, &channelmanager::provided_init_features(&config), 10000000, 100000, 42, &config, 0, 42).unwrap();
+               let mut node_a_chan = OutboundV1Channel::<&TestKeysInterface>::new(&feeest, &&keys_provider, &&keys_provider, node_b_node_id, &channelmanager::provided_init_features(&config), 10000000, 100000, 42, &config, 0, 42, None).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);
@@ -7929,15 +8122,15 @@ mod tests {
 
                // Node A --> Node B: funding created
                let output_script = node_a_chan.context.get_funding_redeemscript();
-               let tx = Transaction { version: 1, lock_time: PackedLockTime::ZERO, input: Vec::new(), output: vec![TxOut {
+               let tx = Transaction { version: 1, lock_time: LockTime::ZERO, input: Vec::new(), output: vec![TxOut {
                        value: 10000000, script_pubkey: output_script.clone(),
                }]};
                let funding_outpoint = OutPoint{ txid: tx.txid(), index: 0 };
                let (mut node_a_chan, funding_created_msg) = node_a_chan.get_funding_created(tx.clone(), funding_outpoint, false, &&logger).map_err(|_| ()).unwrap();
-               let (mut node_b_chan, funding_signed_msg, _) = node_b_chan.funding_created(&funding_created_msg, best_block, &&keys_provider, &&logger).map_err(|_| ()).unwrap();
+               let (mut node_b_chan, funding_signed_msg, _) = node_b_chan.funding_created(&funding_created_msg.unwrap(), best_block, &&keys_provider, &&logger).map_err(|_| ()).unwrap();
 
                // Node B --> Node A: funding signed
-               let _ = node_a_chan.funding_signed(&funding_signed_msg, best_block, &&keys_provider, &&logger).unwrap();
+               let _ = node_a_chan.funding_signed(&funding_signed_msg.unwrap(), best_block, &&keys_provider, &&logger).unwrap();
 
                // Now disconnect the two nodes and check that the commitment point in
                // Node B's channel_reestablish message is sane.
@@ -7979,16 +8172,16 @@ mod tests {
                // Test that `OutboundV1Channel::new` 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 = OutboundV1Channel::<&TestKeysInterface>::new(&feeest, &&keys_provider, &&keys_provider, outbound_node_id, &channelmanager::provided_init_features(&config_2_percent), 10000000, 100000, 42, &config_2_percent, 0, 42).unwrap();
+               let chan_1 = OutboundV1Channel::<&TestKeysInterface>::new(&feeest, &&keys_provider, &&keys_provider, outbound_node_id, &channelmanager::provided_init_features(&config_2_percent), 10000000, 100000, 42, &config_2_percent, 0, 42, None).unwrap();
                let chan_1_value_msat = chan_1.context.channel_value_satoshis * 1000;
                assert_eq!(chan_1.context.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 = OutboundV1Channel::<&TestKeysInterface>::new(&feeest, &&keys_provider, &&keys_provider, outbound_node_id, &channelmanager::provided_init_features(&config_99_percent), 10000000, 100000, 42, &config_99_percent, 0, 42).unwrap();
+               let chan_2 = OutboundV1Channel::<&TestKeysInterface>::new(&feeest, &&keys_provider, &&keys_provider, outbound_node_id, &channelmanager::provided_init_features(&config_99_percent), 10000000, 100000, 42, &config_99_percent, 0, 42, None).unwrap();
                let chan_2_value_msat = chan_2.context.channel_value_satoshis * 1000;
                assert_eq!(chan_2.context.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());
+               let chan_1_open_channel_msg = chan_1.get_open_channel(ChainHash::using_genesis_block(network));
 
                // Test that `InboundV1Channel::new` creates a channel with the correct value for
                // `holder_max_htlc_value_in_flight_msat`, when configured with a valid percentage value,
@@ -8004,14 +8197,14 @@ mod tests {
 
                // Test that `OutboundV1Channel::new` 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 = OutboundV1Channel::<&TestKeysInterface>::new(&feeest, &&keys_provider, &&keys_provider, outbound_node_id, &channelmanager::provided_init_features(&config_0_percent), 10000000, 100000, 42, &config_0_percent, 0, 42).unwrap();
+               let chan_5 = OutboundV1Channel::<&TestKeysInterface>::new(&feeest, &&keys_provider, &&keys_provider, outbound_node_id, &channelmanager::provided_init_features(&config_0_percent), 10000000, 100000, 42, &config_0_percent, 0, 42, None).unwrap();
                let chan_5_value_msat = chan_5.context.channel_value_satoshis * 1000;
                assert_eq!(chan_5.context.holder_max_htlc_value_in_flight_msat, (chan_5_value_msat as f64 * 0.01) as u64);
 
                // Test that `OutboundV1Channel::new` 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 = OutboundV1Channel::<&TestKeysInterface>::new(&feeest, &&keys_provider, &&keys_provider, outbound_node_id, &channelmanager::provided_init_features(&config_101_percent), 10000000, 100000, 42, &config_101_percent, 0, 42).unwrap();
+               let chan_6 = OutboundV1Channel::<&TestKeysInterface>::new(&feeest, &&keys_provider, &&keys_provider, outbound_node_id, &channelmanager::provided_init_features(&config_101_percent), 10000000, 100000, 42, &config_101_percent, 0, 42, None).unwrap();
                let chan_6_value_msat = chan_6.context.channel_value_satoshis * 1000;
                assert_eq!(chan_6.context.holder_max_htlc_value_in_flight_msat, chan_6_value_msat);
 
@@ -8064,12 +8257,12 @@ mod tests {
 
                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 = OutboundV1Channel::<&TestKeysInterface>::new(&&fee_est, &&keys_provider, &&keys_provider, outbound_node_id, &channelmanager::provided_init_features(&outbound_node_config), channel_value_satoshis, 100_000, 42, &outbound_node_config, 0, 42).unwrap();
+               let chan = OutboundV1Channel::<&TestKeysInterface>::new(&&fee_est, &&keys_provider, &&keys_provider, outbound_node_id, &channelmanager::provided_init_features(&outbound_node_config), channel_value_satoshis, 100_000, 42, &outbound_node_config, 0, 42, None).unwrap();
 
                let expected_outbound_selected_chan_reserve = cmp::max(MIN_THEIR_CHAN_RESERVE_SATOSHIS, (chan.context.channel_value_satoshis as f64 * outbound_selected_channel_reserve_perc) as u64);
                assert_eq!(chan.context.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 chan_open_channel_msg = chan.get_open_channel(ChainHash::using_genesis_block(network));
                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;
 
@@ -8095,17 +8288,17 @@ mod tests {
                let seed = [42; 32];
                let network = Network::Testnet;
                let best_block = BestBlock::from_network(network);
-               let chain_hash = genesis_block(network).header.block_hash();
+               let chain_hash = ChainHash::using_genesis_block(network);
                let keys_provider = test_utils::TestKeysInterface::new(&seed, network);
 
                // 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 = OutboundV1Channel::<&TestKeysInterface>::new(&feeest, &&keys_provider, &&keys_provider, node_b_node_id, &channelmanager::provided_init_features(&config), 10000000, 100000, 42, &config, 0, 42).unwrap();
+               let mut node_a_chan = OutboundV1Channel::<&TestKeysInterface>::new(&feeest, &&keys_provider, &&keys_provider, node_b_node_id, &channelmanager::provided_init_features(&config), 10000000, 100000, 42, &config, 0, 42, None).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 open_channel_msg = node_a_chan.get_open_channel(ChainHash::using_genesis_block(network));
                let node_b_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[7; 32]).unwrap());
                let mut node_b_chan = InboundV1Channel::<&TestKeysInterface>::new(&feeest, &&keys_provider, &&keys_provider, node_b_node_id, &channelmanager::provided_channel_type_features(&config), &channelmanager::provided_init_features(&config), &open_channel_msg, 7, &config, 0, &&logger, /*is_0conf=*/false).unwrap();
 
@@ -8117,15 +8310,15 @@ mod tests {
 
                // Node A --> Node B: funding created
                let output_script = node_a_chan.context.get_funding_redeemscript();
-               let tx = Transaction { version: 1, lock_time: PackedLockTime::ZERO, input: Vec::new(), output: vec![TxOut {
+               let tx = Transaction { version: 1, lock_time: LockTime::ZERO, input: Vec::new(), output: vec![TxOut {
                        value: 10000000, script_pubkey: output_script.clone(),
                }]};
                let funding_outpoint = OutPoint{ txid: tx.txid(), index: 0 };
                let (mut node_a_chan, funding_created_msg) = node_a_chan.get_funding_created(tx.clone(), funding_outpoint, false, &&logger).map_err(|_| ()).unwrap();
-               let (_, funding_signed_msg, _) = node_b_chan.funding_created(&funding_created_msg, best_block, &&keys_provider, &&logger).map_err(|_| ()).unwrap();
+               let (_, funding_signed_msg, _) = node_b_chan.funding_created(&funding_created_msg.unwrap(), best_block, &&keys_provider, &&logger).map_err(|_| ()).unwrap();
 
                // Node B --> Node A: funding signed
-               let _ = node_a_chan.funding_signed(&funding_signed_msg, best_block, &&keys_provider, &&logger).unwrap();
+               let _ = node_a_chan.funding_signed(&funding_signed_msg.unwrap(), best_block, &&keys_provider, &&logger).unwrap();
 
                // Make sure that receiving a channel update will update the Channel as expected.
                let update = ChannelUpdate {
@@ -8143,7 +8336,7 @@ mod tests {
                        },
                        signature: Signature::from(unsafe { FFISignature::new() })
                };
-               node_a_chan.channel_update(&update).unwrap();
+               assert!(node_a_chan.channel_update(&update).unwrap());
 
                // The counterparty can send an update with a higher minimum HTLC, but that shouldn't
                // change our official htlc_minimum_msat.
@@ -8156,23 +8349,28 @@ mod tests {
                        },
                        None => panic!("expected counterparty forwarding info to be Some")
                }
+
+               assert!(!node_a_chan.channel_update(&update).unwrap());
        }
 
        #[cfg(feature = "_test_vectors")]
        #[test]
        fn outbound_commitment_test() {
-               use bitcoin::util::sighash;
+               use bitcoin::sighash;
                use bitcoin::consensus::encode::serialize;
-               use bitcoin::blockdata::transaction::EcdsaSighashType;
+               use bitcoin::sighash::EcdsaSighashType;
                use bitcoin::hashes::hex::FromHex;
                use bitcoin::hash_types::Txid;
                use bitcoin::secp256k1::Message;
-               use crate::sign::EcdsaChannelSigner;
+               use crate::sign::{ChannelDerivationParameters, HTLCDescriptor, ecdsa::EcdsaChannelSigner};
                use crate::ln::PaymentPreimage;
                use crate::ln::channel::{HTLCOutputInCommitment ,TxCreationKeys};
+               use crate::ln::channel_keys::{DelayedPaymentBasepoint, HtlcBasepoint};
                use crate::ln::chan_utils::{ChannelPublicKeys, HolderCommitmentTransaction, CounterpartyChannelTransactionParameters};
                use crate::util::logger::Logger;
                use crate::sync::Arc;
+               use core::str::FromStr;
+               use hex::DisplayHex;
 
                // Test vectors from BOLT 3 Appendices C and F (anchors):
                let feeest = TestFeeEstimator{fee_est: 15000};
@@ -8181,11 +8379,11 @@ mod tests {
 
                let mut signer = InMemorySigner::new(
                        &secp_ctx,
-                       SecretKey::from_slice(&hex::decode("30ff4956bbdd3222d44cc5e8a1261dab1e07957bdac5ae88fe3261ef321f3749").unwrap()[..]).unwrap(),
-                       SecretKey::from_slice(&hex::decode("0fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff").unwrap()[..]).unwrap(),
-                       SecretKey::from_slice(&hex::decode("1111111111111111111111111111111111111111111111111111111111111111").unwrap()[..]).unwrap(),
-                       SecretKey::from_slice(&hex::decode("3333333333333333333333333333333333333333333333333333333333333333").unwrap()[..]).unwrap(),
-                       SecretKey::from_slice(&hex::decode("1111111111111111111111111111111111111111111111111111111111111111").unwrap()[..]).unwrap(),
+                       SecretKey::from_slice(&<Vec<u8>>::from_hex("30ff4956bbdd3222d44cc5e8a1261dab1e07957bdac5ae88fe3261ef321f3749").unwrap()[..]).unwrap(),
+                       SecretKey::from_slice(&<Vec<u8>>::from_hex("0fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff").unwrap()[..]).unwrap(),
+                       SecretKey::from_slice(&<Vec<u8>>::from_hex("1111111111111111111111111111111111111111111111111111111111111111").unwrap()[..]).unwrap(),
+                       SecretKey::from_slice(&<Vec<u8>>::from_hex("3333333333333333333333333333333333333333333333333333333333333333").unwrap()[..]).unwrap(),
+                       SecretKey::from_slice(&<Vec<u8>>::from_hex("1111111111111111111111111111111111111111111111111111111111111111").unwrap()[..]).unwrap(),
 
                        // These aren't set in the test vectors:
                        [0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff],
@@ -8195,24 +8393,24 @@ mod tests {
                );
 
                assert_eq!(signer.pubkeys().funding_pubkey.serialize()[..],
-                               hex::decode("023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb").unwrap()[..]);
+                               <Vec<u8>>::from_hex("023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb").unwrap()[..]);
                let keys_provider = Keys { signer: signer.clone() };
 
                let counterparty_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
                let mut config = UserConfig::default();
                config.channel_handshake_config.announced_channel = false;
-               let mut chan = OutboundV1Channel::<&Keys>::new(&LowerBoundedFeeEstimator::new(&feeest), &&keys_provider, &&keys_provider, counterparty_node_id, &channelmanager::provided_init_features(&config), 10_000_000, 0, 42, &config, 0, 42).unwrap(); // Nothing uses their network key in this test
+               let mut chan = OutboundV1Channel::<&Keys>::new(&LowerBoundedFeeEstimator::new(&feeest), &&keys_provider, &&keys_provider, counterparty_node_id, &channelmanager::provided_init_features(&config), 10_000_000, 0, 42, &config, 0, 42, None).unwrap(); // Nothing uses their network key in this test
                chan.context.holder_dust_limit_satoshis = 546;
                chan.context.counterparty_selected_channel_reserve_satoshis = Some(0); // Filled in in accept_channel
 
-               let funding_info = OutPoint{ txid: Txid::from_hex("8984484a580b825b9972d7adb15050b3ab624ccd731946b3eeddb92f4e7ef6be").unwrap(), index: 0 };
+               let funding_info = OutPoint{ txid: Txid::from_str("8984484a580b825b9972d7adb15050b3ab624ccd731946b3eeddb92f4e7ef6be").unwrap(), index: 0 };
 
                let counterparty_pubkeys = ChannelPublicKeys {
                        funding_pubkey: public_from_secret_hex(&secp_ctx, "1552dfba4f6cf29a62a0af13c8d6981d36d0ef8d61ba10fb0fe90da7634d7e13"),
-                       revocation_basepoint: PublicKey::from_slice(&hex::decode("02466d7fcae563e5cb09a0d1870bb580344804617879a14949cf22285f1bae3f27").unwrap()[..]).unwrap(),
+                       revocation_basepoint: RevocationBasepoint::from(PublicKey::from_slice(&<Vec<u8>>::from_hex("02466d7fcae563e5cb09a0d1870bb580344804617879a14949cf22285f1bae3f27").unwrap()[..]).unwrap()),
                        payment_point: public_from_secret_hex(&secp_ctx, "4444444444444444444444444444444444444444444444444444444444444444"),
-                       delayed_payment_basepoint: public_from_secret_hex(&secp_ctx, "1552dfba4f6cf29a62a0af13c8d6981d36d0ef8d61ba10fb0fe90da7634d7e13"),
-                       htlc_basepoint: public_from_secret_hex(&secp_ctx, "4444444444444444444444444444444444444444444444444444444444444444")
+                       delayed_payment_basepoint: DelayedPaymentBasepoint::from(public_from_secret_hex(&secp_ctx, "1552dfba4f6cf29a62a0af13c8d6981d36d0ef8d61ba10fb0fe90da7634d7e13")),
+                       htlc_basepoint: HtlcBasepoint::from(public_from_secret_hex(&secp_ctx, "4444444444444444444444444444444444444444444444444444444444444444"))
                };
                chan.context.channel_transaction_parameters.counterparty_parameters = Some(
                        CounterpartyChannelTransactionParameters {
@@ -8223,19 +8421,19 @@ mod tests {
                signer.provide_channel_parameters(&chan.context.channel_transaction_parameters);
 
                assert_eq!(counterparty_pubkeys.payment_point.serialize()[..],
-                          hex::decode("032c0b7cf95324a07d05398b240174dc0c2be444d96b159aa6c7f7b1e668680991").unwrap()[..]);
+                          <Vec<u8>>::from_hex("032c0b7cf95324a07d05398b240174dc0c2be444d96b159aa6c7f7b1e668680991").unwrap()[..]);
 
                assert_eq!(counterparty_pubkeys.funding_pubkey.serialize()[..],
-                          hex::decode("030e9f7b623d2ccc7c9bd44d66d5ce21ce504c0acf6385a132cec6d3c39fa711c1").unwrap()[..]);
+                          <Vec<u8>>::from_hex("030e9f7b623d2ccc7c9bd44d66d5ce21ce504c0acf6385a132cec6d3c39fa711c1").unwrap()[..]);
 
-               assert_eq!(counterparty_pubkeys.htlc_basepoint.serialize()[..],
-                          hex::decode("032c0b7cf95324a07d05398b240174dc0c2be444d96b159aa6c7f7b1e668680991").unwrap()[..]);
+               assert_eq!(counterparty_pubkeys.htlc_basepoint.to_public_key().serialize()[..],
+                          <Vec<u8>>::from_hex("032c0b7cf95324a07d05398b240174dc0c2be444d96b159aa6c7f7b1e668680991").unwrap()[..]);
 
                // We can't just use build_holder_transaction_keys here as the per_commitment_secret is not
                // derived from a commitment_seed, so instead we copy it here and call
                // build_commitment_transaction.
                let delayed_payment_base = &chan.context.holder_signer.as_ref().pubkeys().delayed_payment_basepoint;
-               let per_commitment_secret = SecretKey::from_slice(&hex::decode("1f1e1d1c1b1a191817161514131211100f0e0d0c0b0a09080706050403020100").unwrap()[..]).unwrap();
+               let per_commitment_secret = SecretKey::from_slice(&<Vec<u8>>::from_hex("1f1e1d1c1b1a191817161514131211100f0e0d0c0b0a09080706050403020100").unwrap()[..]).unwrap();
                let per_commitment_point = PublicKey::from_secret_key(&secp_ctx, &per_commitment_secret);
                let htlc_basepoint = &chan.context.holder_signer.as_ref().pubkeys().htlc_basepoint;
                let keys = TxCreationKeys::derive_new(&secp_ctx, &per_commitment_point, delayed_payment_base, htlc_basepoint, &counterparty_pubkeys.revocation_basepoint, &counterparty_pubkeys.htlc_basepoint);
@@ -8269,9 +8467,9 @@ mod tests {
                                let trusted_tx = commitment_tx.trust();
                                let unsigned_tx = trusted_tx.built_transaction();
                                let redeemscript = chan.context.get_funding_redeemscript();
-                               let counterparty_signature = Signature::from_der(&hex::decode($counterparty_sig_hex).unwrap()[..]).unwrap();
+                               let counterparty_signature = Signature::from_der(&<Vec<u8>>::from_hex($counterparty_sig_hex).unwrap()[..]).unwrap();
                                let sighash = unsigned_tx.get_sighash_all(&redeemscript, chan.context.channel_value_satoshis);
-                               log_trace!(logger, "unsigned_tx = {}", hex::encode(serialize(&unsigned_tx.transaction)));
+                               log_trace!(logger, "unsigned_tx = {}", serialize(&unsigned_tx.transaction).as_hex());
                                assert!(secp_ctx.verify_ecdsa(&sighash, &counterparty_signature, chan.context.counterparty_funding_pubkey()).is_ok(), "verify counterparty commitment sig");
 
                                let mut per_htlc: Vec<(HTLCOutputInCommitment, Option<Signature>)> = Vec::new();
@@ -8279,7 +8477,7 @@ mod tests {
                                let mut counterparty_htlc_sigs = Vec::new();
                                counterparty_htlc_sigs.clear(); // Don't warn about excess mut for no-HTLC calls
                                $({
-                                       let remote_signature = Signature::from_der(&hex::decode($counterparty_htlc_sig_hex).unwrap()[..]).unwrap();
+                                       let remote_signature = Signature::from_der(&<Vec<u8>>::from_hex($counterparty_htlc_sig_hex).unwrap()[..]).unwrap();
                                        per_htlc.push((htlcs[$htlc_idx].clone(), Some(remote_signature)));
                                        counterparty_htlc_sigs.push(remote_signature);
                                })*
@@ -8292,33 +8490,33 @@ mod tests {
                                        &chan.context.holder_signer.as_ref().pubkeys().funding_pubkey,
                                        chan.context.counterparty_funding_pubkey()
                                );
-                               let (holder_sig, htlc_sigs) = signer.sign_holder_commitment_and_htlcs(&holder_commitment_tx, &secp_ctx).unwrap();
-                               assert_eq!(Signature::from_der(&hex::decode($sig_hex).unwrap()[..]).unwrap(), holder_sig, "holder_sig");
+                               let holder_sig = signer.sign_holder_commitment(&holder_commitment_tx, &secp_ctx).unwrap();
+                               assert_eq!(Signature::from_der(&<Vec<u8>>::from_hex($sig_hex).unwrap()[..]).unwrap(), holder_sig, "holder_sig");
 
                                let funding_redeemscript = chan.context.get_funding_redeemscript();
                                let tx = holder_commitment_tx.add_holder_sig(&funding_redeemscript, holder_sig);
-                               assert_eq!(serialize(&tx)[..], hex::decode($tx_hex).unwrap()[..], "tx");
+                               assert_eq!(serialize(&tx)[..], <Vec<u8>>::from_hex($tx_hex).unwrap()[..], "tx");
 
                                // ((htlc, counterparty_sig), (index, holder_sig))
-                               let mut htlc_sig_iter = holder_commitment_tx.htlcs().iter().zip(&holder_commitment_tx.counterparty_htlc_sigs).zip(htlc_sigs.iter().enumerate());
+                               let mut htlc_counterparty_sig_iter = holder_commitment_tx.counterparty_htlc_sigs.iter();
 
                                $({
                                        log_trace!(logger, "verifying htlc {}", $htlc_idx);
-                                       let remote_signature = Signature::from_der(&hex::decode($counterparty_htlc_sig_hex).unwrap()[..]).unwrap();
+                                       let remote_signature = Signature::from_der(&<Vec<u8>>::from_hex($counterparty_htlc_sig_hex).unwrap()[..]).unwrap();
 
                                        let ref htlc = htlcs[$htlc_idx];
-                                       let htlc_tx = chan_utils::build_htlc_transaction(&unsigned_tx.txid, chan.context.feerate_per_kw,
+                                       let mut htlc_tx = chan_utils::build_htlc_transaction(&unsigned_tx.txid, chan.context.feerate_per_kw,
                                                chan.context.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.supports_anchors_zero_fee_htlc_tx() { 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");
+                                       assert!(secp_ctx.verify_ecdsa(&htlc_sighash, &remote_signature, &keys.countersignatory_htlc_key.to_public_key()).is_ok(), "verify counterparty htlc sig");
 
                                        let mut preimage: Option<PaymentPreimage> = None;
                                        if !htlc.offered {
                                                for i in 0..5 {
-                                                       let out = PaymentHash(Sha256::hash(&[i; 32]).into_inner());
+                                                       let out = PaymentHash(Sha256::hash(&[i; 32]).to_byte_array());
                                                        if out == htlc.payment_hash {
                                                                preimage = Some(PaymentPreimage([i; 32]));
                                                        }
@@ -8327,20 +8525,32 @@ mod tests {
                                                assert!(preimage.is_some());
                                        }
 
-                                       let htlc_sig = htlc_sig_iter.next().unwrap();
+                                       let htlc_counterparty_sig = htlc_counterparty_sig_iter.next().unwrap();
+                                       let htlc_holder_sig = signer.sign_holder_htlc_transaction(&htlc_tx, 0, &HTLCDescriptor {
+                                               channel_derivation_parameters: ChannelDerivationParameters {
+                                                       value_satoshis: chan.context.channel_value_satoshis,
+                                                       keys_id: chan.context.channel_keys_id,
+                                                       transaction_parameters: chan.context.channel_transaction_parameters.clone(),
+                                               },
+                                               commitment_txid: trusted_tx.txid(),
+                                               per_commitment_number: trusted_tx.commitment_number(),
+                                               per_commitment_point: trusted_tx.per_commitment_point(),
+                                               feerate_per_kw: trusted_tx.feerate_per_kw(),
+                                               htlc: htlc.clone(),
+                                               preimage: preimage.clone(),
+                                               counterparty_sig: *htlc_counterparty_sig,
+                                       }, &secp_ctx).unwrap();
                                        let num_anchors = if $opt_anchors.supports_anchors_zero_fee_htlc_tx() { 2 } else { 0 };
-                                       assert_eq!((htlc_sig.0).0.transaction_output_index, Some($htlc_idx + num_anchors), "output index");
+                                       assert_eq!(htlc.transaction_output_index, Some($htlc_idx + num_anchors), "output index");
 
-                                       let signature = Signature::from_der(&hex::decode($htlc_sig_hex).unwrap()[..]).unwrap();
-                                       assert_eq!(signature, *(htlc_sig.1).1, "htlc sig");
-                                       let index = (htlc_sig.1).0;
-                                       let channel_parameters = chan.context.channel_transaction_parameters.as_holder_broadcastable();
+                                       let signature = Signature::from_der(&<Vec<u8>>::from_hex($htlc_sig_hex).unwrap()[..]).unwrap();
+                                       assert_eq!(signature, htlc_holder_sig, "htlc sig");
                                        let trusted_tx = holder_commitment_tx.trust();
-                                       log_trace!(logger, "htlc_tx = {}", hex::encode(serialize(&trusted_tx.get_signed_htlc_tx(&channel_parameters, index, &(htlc_sig.0).1, (htlc_sig.1).1, &preimage))));
-                                       assert_eq!(serialize(&trusted_tx.get_signed_htlc_tx(&channel_parameters, index, &(htlc_sig.0).1, (htlc_sig.1).1, &preimage))[..],
-                                                       hex::decode($htlc_tx_hex).unwrap()[..], "htlc tx");
+                                       htlc_tx.input[0].witness = trusted_tx.build_htlc_input_witness($htlc_idx, htlc_counterparty_sig, &htlc_holder_sig, &preimage);
+                                       log_trace!(logger, "htlc_tx = {}", serialize(&htlc_tx).as_hex());
+                                       assert_eq!(serialize(&htlc_tx)[..], <Vec<u8>>::from_hex($htlc_tx_hex).unwrap()[..], "htlc tx");
                                })*
-                               assert!(htlc_sig_iter.next().is_none());
+                               assert!(htlc_counterparty_sig_iter.next().is_none());
                        } }
                }
 
@@ -8369,7 +8579,7 @@ mod tests {
                                payment_hash: PaymentHash([0; 32]),
                                state: InboundHTLCState::Committed,
                        };
-                       out.payment_hash.0 = Sha256::hash(&hex::decode("0000000000000000000000000000000000000000000000000000000000000000").unwrap()).into_inner();
+                       out.payment_hash.0 = Sha256::hash(&<Vec<u8>>::from_hex("0000000000000000000000000000000000000000000000000000000000000000").unwrap()).to_byte_array();
                        out
                });
                chan.context.pending_inbound_htlcs.push({
@@ -8380,7 +8590,7 @@ mod tests {
                                payment_hash: PaymentHash([0; 32]),
                                state: InboundHTLCState::Committed,
                        };
-                       out.payment_hash.0 = Sha256::hash(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()).into_inner();
+                       out.payment_hash.0 = Sha256::hash(&<Vec<u8>>::from_hex("0101010101010101010101010101010101010101010101010101010101010101").unwrap()).to_byte_array();
                        out
                });
                chan.context.pending_outbound_htlcs.push({
@@ -8393,7 +8603,7 @@ mod tests {
                                source: HTLCSource::dummy(),
                                skimmed_fee_msat: None,
                        };
-                       out.payment_hash.0 = Sha256::hash(&hex::decode("0202020202020202020202020202020202020202020202020202020202020202").unwrap()).into_inner();
+                       out.payment_hash.0 = Sha256::hash(&<Vec<u8>>::from_hex("0202020202020202020202020202020202020202020202020202020202020202").unwrap()).to_byte_array();
                        out
                });
                chan.context.pending_outbound_htlcs.push({
@@ -8406,7 +8616,7 @@ mod tests {
                                source: HTLCSource::dummy(),
                                skimmed_fee_msat: None,
                        };
-                       out.payment_hash.0 = Sha256::hash(&hex::decode("0303030303030303030303030303030303030303030303030303030303030303").unwrap()).into_inner();
+                       out.payment_hash.0 = Sha256::hash(&<Vec<u8>>::from_hex("0303030303030303030303030303030303030303030303030303030303030303").unwrap()).to_byte_array();
                        out
                });
                chan.context.pending_inbound_htlcs.push({
@@ -8417,7 +8627,7 @@ mod tests {
                                payment_hash: PaymentHash([0; 32]),
                                state: InboundHTLCState::Committed,
                        };
-                       out.payment_hash.0 = Sha256::hash(&hex::decode("0404040404040404040404040404040404040404040404040404040404040404").unwrap()).into_inner();
+                       out.payment_hash.0 = Sha256::hash(&<Vec<u8>>::from_hex("0404040404040404040404040404040404040404040404040404040404040404").unwrap()).to_byte_array();
                        out
                });
 
@@ -8803,7 +9013,7 @@ mod tests {
                                payment_hash: PaymentHash([0; 32]),
                                state: InboundHTLCState::Committed,
                        };
-                       out.payment_hash.0 = Sha256::hash(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()).into_inner();
+                       out.payment_hash.0 = Sha256::hash(&<Vec<u8>>::from_hex("0101010101010101010101010101010101010101010101010101010101010101").unwrap()).to_byte_array();
                        out
                });
                chan.context.pending_outbound_htlcs.clear();
@@ -8817,7 +9027,7 @@ mod tests {
                                source: HTLCSource::dummy(),
                                skimmed_fee_msat: None,
                        };
-                       out.payment_hash.0 = Sha256::hash(&hex::decode("0505050505050505050505050505050505050505050505050505050505050505").unwrap()).into_inner();
+                       out.payment_hash.0 = Sha256::hash(&<Vec<u8>>::from_hex("0505050505050505050505050505050505050505050505050505050505050505").unwrap()).to_byte_array();
                        out
                });
                chan.context.pending_outbound_htlcs.push({
@@ -8830,7 +9040,7 @@ mod tests {
                                source: HTLCSource::dummy(),
                                skimmed_fee_msat: None,
                        };
-                       out.payment_hash.0 = Sha256::hash(&hex::decode("0505050505050505050505050505050505050505050505050505050505050505").unwrap()).into_inner();
+                       out.payment_hash.0 = Sha256::hash(&<Vec<u8>>::from_hex("0505050505050505050505050505050505050505050505050505050505050505").unwrap()).to_byte_array();
                        out
                });
 
@@ -8877,50 +9087,47 @@ mod tests {
                // Test vectors from BOLT 3 Appendix D:
 
                let mut seed = [0; 32];
-               seed[0..32].clone_from_slice(&hex::decode("0000000000000000000000000000000000000000000000000000000000000000").unwrap());
+               seed[0..32].clone_from_slice(&<Vec<u8>>::from_hex("0000000000000000000000000000000000000000000000000000000000000000").unwrap());
                assert_eq!(chan_utils::build_commitment_secret(&seed, 281474976710655),
-                          hex::decode("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap()[..]);
+                          <Vec<u8>>::from_hex("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap()[..]);
 
-               seed[0..32].clone_from_slice(&hex::decode("FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF").unwrap());
+               seed[0..32].clone_from_slice(&<Vec<u8>>::from_hex("FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF").unwrap());
                assert_eq!(chan_utils::build_commitment_secret(&seed, 281474976710655),
-                          hex::decode("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap()[..]);
+                          <Vec<u8>>::from_hex("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap()[..]);
 
                assert_eq!(chan_utils::build_commitment_secret(&seed, 0xaaaaaaaaaaa),
-                          hex::decode("56f4008fb007ca9acf0e15b054d5c9fd12ee06cea347914ddbaed70d1c13a528").unwrap()[..]);
+                          <Vec<u8>>::from_hex("56f4008fb007ca9acf0e15b054d5c9fd12ee06cea347914ddbaed70d1c13a528").unwrap()[..]);
 
                assert_eq!(chan_utils::build_commitment_secret(&seed, 0x555555555555),
-                          hex::decode("9015daaeb06dba4ccc05b91b2f73bd54405f2be9f217fbacd3c5ac2e62327d31").unwrap()[..]);
+                          <Vec<u8>>::from_hex("9015daaeb06dba4ccc05b91b2f73bd54405f2be9f217fbacd3c5ac2e62327d31").unwrap()[..]);
 
-               seed[0..32].clone_from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap());
+               seed[0..32].clone_from_slice(&<Vec<u8>>::from_hex("0101010101010101010101010101010101010101010101010101010101010101").unwrap());
                assert_eq!(chan_utils::build_commitment_secret(&seed, 1),
-                          hex::decode("915c75942a26bb3a433a8ce2cb0427c29ec6c1775cfc78328b57f6ba7bfeaa9c").unwrap()[..]);
+                          <Vec<u8>>::from_hex("915c75942a26bb3a433a8ce2cb0427c29ec6c1775cfc78328b57f6ba7bfeaa9c").unwrap()[..]);
        }
-
+       
        #[test]
        fn test_key_derivation() {
                // Test vectors from BOLT 3 Appendix E:
                let secp_ctx = Secp256k1::new();
 
-               let base_secret = SecretKey::from_slice(&hex::decode("000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f").unwrap()[..]).unwrap();
-               let per_commitment_secret = SecretKey::from_slice(&hex::decode("1f1e1d1c1b1a191817161514131211100f0e0d0c0b0a09080706050403020100").unwrap()[..]).unwrap();
+               let base_secret = SecretKey::from_slice(&<Vec<u8>>::from_hex("000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f").unwrap()[..]).unwrap();
+               let per_commitment_secret = SecretKey::from_slice(&<Vec<u8>>::from_hex("1f1e1d1c1b1a191817161514131211100f0e0d0c0b0a09080706050403020100").unwrap()[..]).unwrap();
 
                let base_point = PublicKey::from_secret_key(&secp_ctx, &base_secret);
-               assert_eq!(base_point.serialize()[..], hex::decode("036d6caac248af96f6afa7f904f550253a0f3ef3f5aa2fe6838a95b216691468e2").unwrap()[..]);
+               assert_eq!(base_point.serialize()[..], <Vec<u8>>::from_hex("036d6caac248af96f6afa7f904f550253a0f3ef3f5aa2fe6838a95b216691468e2").unwrap()[..]);
 
                let per_commitment_point = PublicKey::from_secret_key(&secp_ctx, &per_commitment_secret);
-               assert_eq!(per_commitment_point.serialize()[..], hex::decode("025f7117a78150fe2ef97db7cfc83bd57b2e2c0d0dd25eaf467a4a1c2a45ce1486").unwrap()[..]);
-
-               assert_eq!(chan_utils::derive_public_key(&secp_ctx, &per_commitment_point, &base_point).serialize()[..],
-                               hex::decode("0235f2dbfaa89b57ec7b055afe29849ef7ddfeb1cefdb9ebdc43f5494984db29e5").unwrap()[..]);
+               assert_eq!(per_commitment_point.serialize()[..], <Vec<u8>>::from_hex("025f7117a78150fe2ef97db7cfc83bd57b2e2c0d0dd25eaf467a4a1c2a45ce1486").unwrap()[..]);
 
                assert_eq!(chan_utils::derive_private_key(&secp_ctx, &per_commitment_point, &base_secret),
-                               SecretKey::from_slice(&hex::decode("cbced912d3b21bf196a766651e436aff192362621ce317704ea2f75d87e7be0f").unwrap()[..]).unwrap());
+                               SecretKey::from_slice(&<Vec<u8>>::from_hex("cbced912d3b21bf196a766651e436aff192362621ce317704ea2f75d87e7be0f").unwrap()[..]).unwrap());
 
-               assert_eq!(chan_utils::derive_public_revocation_key(&secp_ctx, &per_commitment_point, &base_point).serialize()[..],
-                               hex::decode("02916e326636d19c33f13e8c0c3a03dd157f332f3e99c317c141dd865eb01f8ff0").unwrap()[..]);
+               assert_eq!(RevocationKey::from_basepoint(&secp_ctx, &RevocationBasepoint::from(base_point), &per_commitment_point).to_public_key().serialize()[..],
+                               <Vec<u8>>::from_hex("02916e326636d19c33f13e8c0c3a03dd157f332f3e99c317c141dd865eb01f8ff0").unwrap()[..]);
 
                assert_eq!(chan_utils::derive_private_revocation_key(&secp_ctx, &per_commitment_secret, &base_secret),
-                               SecretKey::from_slice(&hex::decode("d09ffff62ddb2297ab000cc85bcb4283fdeb6aa052affbc9dddcf33b61078110").unwrap()[..]).unwrap());
+                               SecretKey::from_slice(&<Vec<u8>>::from_hex("d09ffff62ddb2297ab000cc85bcb4283fdeb6aa052affbc9dddcf33b61078110").unwrap()[..]).unwrap());
        }
 
        #[test]
@@ -8935,12 +9142,12 @@ mod tests {
                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 = OutboundV1Channel::<&TestKeysInterface>::new(&feeest, &&keys_provider, &&keys_provider,
-                       node_b_node_id, &channelmanager::provided_init_features(&config), 10000000, 100000, 42, &config, 0, 42).unwrap();
+                       node_b_node_id, &channelmanager::provided_init_features(&config), 10000000, 100000, 42, &config, 0, 42, None).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());
+               let mut open_channel_msg = node_a_chan.get_open_channel(ChainHash::using_genesis_block(network));
                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 = InboundV1Channel::<&TestKeysInterface>::new(&feeest, &&keys_provider, &&keys_provider,
@@ -8970,7 +9177,7 @@ mod tests {
                let channel_a = OutboundV1Channel::<&TestKeysInterface>::new(
                        &fee_estimator, &&keys_provider, &&keys_provider, node_id_b,
                        &channelmanager::provided_init_features(&UserConfig::default()), 10000000, 100000, 42,
-                       &config, 0, 42
+                       &config, 0, 42, None
                ).unwrap();
                assert!(!channel_a.context.channel_type.supports_anchors_zero_fee_htlc_tx());
 
@@ -8980,10 +9187,11 @@ mod tests {
 
                let channel_a = OutboundV1Channel::<&TestKeysInterface>::new(
                        &fee_estimator, &&keys_provider, &&keys_provider, node_id_b,
-                       &channelmanager::provided_init_features(&config), 10000000, 100000, 42, &config, 0, 42
+                       &channelmanager::provided_init_features(&config), 10000000, 100000, 42, &config, 0, 42,
+                       None
                ).unwrap();
 
-               let open_channel_msg = channel_a.get_open_channel(genesis_block(network).header.block_hash());
+               let open_channel_msg = channel_a.get_open_channel(ChainHash::using_genesis_block(network));
                let channel_b = InboundV1Channel::<&TestKeysInterface>::new(
                        &fee_estimator, &&keys_provider, &&keys_provider, node_id_a,
                        &channelmanager::provided_channel_type_features(&config), &channelmanager::provided_init_features(&config),
@@ -9017,11 +9225,12 @@ mod tests {
 
                let channel_a = OutboundV1Channel::<&TestKeysInterface>::new(
                        &fee_estimator, &&keys_provider, &&keys_provider, node_id_b,
-                       &channelmanager::provided_init_features(&config), 10000000, 100000, 42, &config, 0, 42
+                       &channelmanager::provided_init_features(&config), 10000000, 100000, 42, &config, 0, 42,
+                       None
                ).unwrap();
 
                // Set `channel_type` to `None` to force the implicit feature negotiation.
-               let mut open_channel_msg = channel_a.get_open_channel(genesis_block(network).header.block_hash());
+               let mut open_channel_msg = channel_a.get_open_channel(ChainHash::using_genesis_block(network));
                open_channel_msg.channel_type = None;
 
                // Since A supports both `static_remote_key` and `option_anchors`, but B only accepts
@@ -9063,10 +9272,11 @@ mod tests {
                // B as it's not supported by LDK.
                let channel_a = OutboundV1Channel::<&TestKeysInterface>::new(
                        &fee_estimator, &&keys_provider, &&keys_provider, node_id_b,
-                       &channelmanager::provided_init_features(&config), 10000000, 100000, 42, &config, 0, 42
+                       &channelmanager::provided_init_features(&config), 10000000, 100000, 42, &config, 0, 42,
+                       None
                ).unwrap();
 
-               let mut open_channel_msg = channel_a.get_open_channel(genesis_block(network).header.block_hash());
+               let mut open_channel_msg = channel_a.get_open_channel(ChainHash::using_genesis_block(network));
                open_channel_msg.channel_type = Some(simple_anchors_channel_type.clone());
 
                let res = InboundV1Channel::<&TestKeysInterface>::new(
@@ -9082,10 +9292,10 @@ mod tests {
                // LDK.
                let mut channel_a = OutboundV1Channel::<&TestKeysInterface>::new(
                        &fee_estimator, &&keys_provider, &&keys_provider, node_id_b, &simple_anchors_init,
-                       10000000, 100000, 42, &config, 0, 42
+                       10000000, 100000, 42, &config, 0, 42, None
                ).unwrap();
 
-               let open_channel_msg = channel_a.get_open_channel(genesis_block(network).header.block_hash());
+               let open_channel_msg = channel_a.get_open_channel(ChainHash::using_genesis_block(network));
 
                let channel_b = InboundV1Channel::<&TestKeysInterface>::new(
                        &fee_estimator, &&keys_provider, &&keys_provider, node_id_a,
@@ -9110,7 +9320,7 @@ mod tests {
                let seed = [42; 32];
                let network = Network::Testnet;
                let best_block = BestBlock::from_network(network);
-               let chain_hash = genesis_block(network).header.block_hash();
+               let chain_hash = ChainHash::using_genesis_block(network);
                let keys_provider = test_utils::TestKeysInterface::new(&seed, network);
 
                let mut config = UserConfig::default();
@@ -9132,9 +9342,10 @@ mod tests {
                        &config,
                        0,
                        42,
+                       None
                ).unwrap();
 
-               let open_channel_msg = node_a_chan.get_open_channel(genesis_block(network).header.block_hash());
+               let open_channel_msg = node_a_chan.get_open_channel(ChainHash::using_genesis_block(network));
                let node_b_node_id = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[7; 32]).unwrap());
                let mut node_b_chan = InboundV1Channel::<&TestKeysInterface>::new(
                        &feeest,
@@ -9162,7 +9373,7 @@ mod tests {
                let output_script = node_a_chan.context.get_funding_redeemscript();
                let tx = Transaction {
                        version: 1,
-                       lock_time: PackedLockTime::ZERO,
+                       lock_time: LockTime::ZERO,
                        input: Vec::new(),
                        output: vec![
                                TxOut {
@@ -9180,7 +9391,7 @@ mod tests {
                        &&logger,
                ).map_err(|_| ()).unwrap();
                let (mut node_b_chan, funding_signed_msg, _) = node_b_chan.funding_created(
-                       &funding_created_msg,
+                       &funding_created_msg.unwrap(),
                        best_block,
                        &&keys_provider,
                        &&logger,
@@ -9196,7 +9407,7 @@ mod tests {
                // Receive funding_signed, but the channel will be configured to hold sending channel_ready and
                // broadcasting the funding transaction until the batch is ready.
                let _ = node_a_chan.funding_signed(
-                       &funding_signed_msg,
+                       &funding_signed_msg.unwrap(),
                        best_block,
                        &&keys_provider,
                        &&logger,