Merge pull request #3086 from alecchendev/2024-05-holder-commitment
authorvalentinewallace <valentinewallace@users.noreply.github.com>
Mon, 10 Jun 2024 22:30:09 +0000 (18:30 -0400)
committerGitHub <noreply@github.com>
Mon, 10 Jun 2024 22:30:09 +0000 (18:30 -0400)
Add `HolderCommitmentPoint` struct to track commitment points

1  2 
lightning/src/ln/channel.rs

index 716eba7cf509e2ab79618a0aad0fb2ede36a458b,b830f9f31e6815842e6aca89aee8543827e195c7..d6ab1876ae0a31af8dfacc5bac01e35ed438e008
@@@ -7,7 -7,6 +7,7 @@@
  // You may not use this file except in accordance with one or both of these
  // licenses.
  
 +use bitcoin::amount::Amount;
  use bitcoin::blockdata::constants::ChainHash;
  use bitcoin::blockdata::script::{Script, ScriptBuf, Builder};
  use bitcoin::blockdata::transaction::Transaction;
@@@ -30,8 -29,7 +30,8 @@@ use crate::ln::features::{ChannelTypeFe
  use crate::ln::msgs;
  use crate::ln::msgs::DecodeError;
  use crate::ln::script::{self, ShutdownScript};
 -use crate::ln::channelmanager::{self, CounterpartyForwardingInfo, PendingHTLCStatus, HTLCSource, SentHTLCId, HTLCFailureMsg, PendingHTLCInfo, RAACommitmentOrder, BREAKDOWN_TIMEOUT, MIN_CLTV_EXPIRY_DELTA, MAX_LOCAL_BREAKDOWN_TIMEOUT, ChannelShutdownState};
 +use crate::ln::channel_state::{ChannelShutdownState, CounterpartyForwardingInfo, InboundHTLCDetails, InboundHTLCStateDetails, OutboundHTLCDetails, OutboundHTLCStateDetails};
 +use crate::ln::channelmanager::{self, PendingHTLCStatus, HTLCSource, SentHTLCId, HTLCFailureMsg, PendingHTLCInfo, RAACommitmentOrder, BREAKDOWN_TIMEOUT, MIN_CLTV_EXPIRY_DELTA, MAX_LOCAL_BREAKDOWN_TIMEOUT};
  use crate::ln::chan_utils::{CounterpartyCommitmentSecrets, TxCreationKeys, HTLCOutputInCommitment, htlc_success_tx_weight, htlc_timeout_tx_weight, make_funding_redeemscript, ChannelPublicKeys, CommitmentTransaction, HolderCommitmentTransaction, ChannelTransactionParameters, CounterpartyChannelTransactionParameters, MAX_HTLCS, get_commitment_transaction_number_obscure_factor, ClosingTransaction};
  use crate::ln::chan_utils;
  use crate::ln::onion_utils::HTLCFailReason;
@@@ -187,6 -185,45 +187,6 @@@ enum InboundHTLCState 
        LocalRemoved(InboundHTLCRemovalReason),
  }
  
 -/// Exposes the state of pending inbound HTLCs.
 -///
 -/// At a high level, an HTLC being forwarded from one Lightning node to another Lightning node goes
 -/// through the following states in the state machine:
 -/// - Announced for addition by the originating node through the update_add_htlc message.
 -/// - Added to the commitment transaction of the receiving node and originating node in turn
 -///   through the exchange of commitment_signed and revoke_and_ack messages.
 -/// - Announced for resolution (fulfillment or failure) by the receiving node through either one of
 -///   the update_fulfill_htlc, update_fail_htlc, and update_fail_malformed_htlc messages.
 -/// - Removed from the commitment transaction of the originating node and receiving node in turn
 -///   through the exchange of commitment_signed and revoke_and_ack messages.
 -///
 -/// This can be used to inspect what next message an HTLC is waiting for to advance its state.
 -#[derive(Clone, Debug, PartialEq)]
 -pub enum InboundHTLCStateDetails {
 -      /// We have added this HTLC in our commitment transaction by receiving commitment_signed and
 -      /// returning revoke_and_ack. We are awaiting the appropriate revoke_and_ack's from the remote
 -      /// before this HTLC is included on the remote commitment transaction.
 -      AwaitingRemoteRevokeToAdd,
 -      /// This HTLC has been included in the commitment_signed and revoke_and_ack messages on both sides
 -      /// and is included in both commitment transactions.
 -      ///
 -      /// This HTLC is now safe to either forward or be claimed as a payment by us. The HTLC will
 -      /// remain in this state until the forwarded upstream HTLC has been resolved and we resolve this
 -      /// HTLC correspondingly, or until we claim it as a payment. If it is part of a multipart
 -      /// payment, it will only be claimed together with other required parts.
 -      Committed,
 -      /// We have received the preimage for this HTLC and it is being removed by fulfilling it with
 -      /// update_fulfill_htlc. This HTLC is still on both commitment transactions, but we are awaiting
 -      /// the appropriate revoke_and_ack's from the remote before this HTLC is removed from the remote
 -      /// commitment transaction after update_fulfill_htlc.
 -      AwaitingRemoteRevokeToRemoveFulfill,
 -      /// The HTLC is being removed by failing it with update_fail_htlc or update_fail_malformed_htlc.
 -      /// This HTLC is still on both commitment transactions, but we are awaiting the appropriate
 -      /// revoke_and_ack's from the remote before this HTLC is removed from the remote commitment
 -      /// transaction.
 -      AwaitingRemoteRevokeToRemoveFail,
 -}
 -
  impl From<&InboundHTLCState> for Option<InboundHTLCStateDetails> {
        fn from(state: &InboundHTLCState) -> Option<InboundHTLCStateDetails> {
                match state {
        }
  }
  
 -impl_writeable_tlv_based_enum_upgradable!(InboundHTLCStateDetails,
 -      (0, AwaitingRemoteRevokeToAdd) => {},
 -      (2, Committed) => {},
 -      (4, AwaitingRemoteRevokeToRemoveFulfill) => {},
 -      (6, AwaitingRemoteRevokeToRemoveFail) => {};
 -);
 -
  struct InboundHTLCOutput {
        htlc_id: u64,
        amount_msat: u64,
        state: InboundHTLCState,
  }
  
 -/// Exposes details around pending inbound HTLCs.
 -#[derive(Clone, Debug, PartialEq)]
 -pub struct InboundHTLCDetails {
 -      /// The HTLC ID.
 -      /// The IDs are incremented by 1 starting from 0 for each offered HTLC.
 -      /// They are unique per channel and inbound/outbound direction, unless an HTLC was only announced
 -      /// and not part of any commitment transaction.
 -      pub htlc_id: u64,
 -      /// The amount in msat.
 -      pub amount_msat: u64,
 -      /// The block height at which this HTLC expires.
 -      pub cltv_expiry: u32,
 -      /// The payment hash.
 -      pub payment_hash: PaymentHash,
 -      /// The state of the HTLC in the state machine.
 -      ///
 -      /// Determines on which commitment transactions the HTLC is included and what message the HTLC is
 -      /// waiting for to advance to the next state.
 -      ///
 -      /// See [`InboundHTLCStateDetails`] for information on the specific states.
 -      ///
 -      /// LDK will always fill this field in, but when downgrading to prior versions of LDK, new
 -      /// states may result in `None` here.
 -      pub state: Option<InboundHTLCStateDetails>,
 -      /// Whether the HTLC has an output below the local dust limit. If so, the output will be trimmed
 -      /// from the local commitment transaction and added to the commitment transaction fee.
 -      /// For non-anchor channels, this takes into account the cost of the second-stage HTLC
 -      /// transactions as well.
 -      ///
 -      /// When the local commitment transaction is broadcasted as part of a unilateral closure,
 -      /// the value of this HTLC will therefore not be claimable but instead burned as a transaction
 -      /// fee.
 -      ///
 -      /// Note that dust limits are specific to each party. An HTLC can be dust for the local
 -      /// commitment transaction but not for the counterparty's commitment transaction and vice versa.
 -      pub is_dust: bool,
 -}
 -
 -impl_writeable_tlv_based!(InboundHTLCDetails, {
 -      (0, htlc_id, required),
 -      (2, amount_msat, required),
 -      (4, cltv_expiry, required),
 -      (6, payment_hash, required),
 -      (7, state, upgradable_option),
 -      (8, is_dust, required),
 -});
 -
  #[cfg_attr(test, derive(Clone, Debug, PartialEq))]
  enum OutboundHTLCState {
        /// Added by us and included in a commitment_signed (if we were AwaitingRemoteRevoke when we
        AwaitingRemovedRemoteRevoke(OutboundHTLCOutcome),
  }
  
 -/// Exposes the state of pending outbound HTLCs.
 -///
 -/// At a high level, an HTLC being forwarded from one Lightning node to another Lightning node goes
 -/// through the following states in the state machine:
 -/// - Announced for addition by the originating node through the update_add_htlc message.
 -/// - Added to the commitment transaction of the receiving node and originating node in turn
 -///   through the exchange of commitment_signed and revoke_and_ack messages.
 -/// - Announced for resolution (fulfillment or failure) by the receiving node through either one of
 -///   the update_fulfill_htlc, update_fail_htlc, and update_fail_malformed_htlc messages.
 -/// - Removed from the commitment transaction of the originating node and receiving node in turn
 -///   through the exchange of commitment_signed and revoke_and_ack messages.
 -///
 -/// This can be used to inspect what next message an HTLC is waiting for to advance its state.
 -#[derive(Clone, Debug, PartialEq)]
 -pub enum OutboundHTLCStateDetails {
 -      /// We are awaiting the appropriate revoke_and_ack's from the remote before the HTLC is added
 -      /// on the remote's commitment transaction after update_add_htlc.
 -      AwaitingRemoteRevokeToAdd,
 -      /// The HTLC has been added to the remote's commitment transaction by sending commitment_signed
 -      /// and receiving revoke_and_ack in return.
 -      ///
 -      /// The HTLC will remain in this state until the remote node resolves the HTLC, or until we
 -      /// unilaterally close the channel due to a timeout with an uncooperative remote node.
 -      Committed,
 -      /// The HTLC has been fulfilled successfully by the remote with a preimage in update_fulfill_htlc,
 -      /// and we removed the HTLC from our commitment transaction by receiving commitment_signed and
 -      /// returning revoke_and_ack. We are awaiting the appropriate revoke_and_ack's from the remote
 -      /// for the removal from its commitment transaction.
 -      AwaitingRemoteRevokeToRemoveSuccess,
 -      /// The HTLC has been failed by the remote with update_fail_htlc or update_fail_malformed_htlc,
 -      /// and we removed the HTLC from our commitment transaction by receiving commitment_signed and
 -      /// returning revoke_and_ack. We are awaiting the appropriate revoke_and_ack's from the remote
 -      /// for the removal from its commitment transaction.
 -      AwaitingRemoteRevokeToRemoveFailure,
 -}
 -
  impl From<&OutboundHTLCState> for OutboundHTLCStateDetails {
        fn from(state: &OutboundHTLCState) -> OutboundHTLCStateDetails {
                match state {
        }
  }
  
 -impl_writeable_tlv_based_enum_upgradable!(OutboundHTLCStateDetails,
 -      (0, AwaitingRemoteRevokeToAdd) => {},
 -      (2, Committed) => {},
 -      (4, AwaitingRemoteRevokeToRemoveSuccess) => {},
 -      (6, AwaitingRemoteRevokeToRemoveFailure) => {};
 -);
 -
  #[derive(Clone)]
  #[cfg_attr(test, derive(Debug, PartialEq))]
  enum OutboundHTLCOutcome {
@@@ -309,6 -443,58 +309,6 @@@ struct OutboundHTLCOutput 
        skimmed_fee_msat: Option<u64>,
  }
  
 -/// Exposes details around pending outbound HTLCs.
 -#[derive(Clone, Debug, PartialEq)]
 -pub struct OutboundHTLCDetails {
 -      /// The HTLC ID.
 -      /// The IDs are incremented by 1 starting from 0 for each offered HTLC.
 -      /// They are unique per channel and inbound/outbound direction, unless an HTLC was only announced
 -      /// and not part of any commitment transaction.
 -      ///
 -      /// Not present when we are awaiting a remote revocation and the HTLC is not added yet.
 -      pub htlc_id: Option<u64>,
 -      /// The amount in msat.
 -      pub amount_msat: u64,
 -      /// The block height at which this HTLC expires.
 -      pub cltv_expiry: u32,
 -      /// The payment hash.
 -      pub payment_hash: PaymentHash,
 -      /// The state of the HTLC in the state machine.
 -      ///
 -      /// Determines on which commitment transactions the HTLC is included and what message the HTLC is
 -      /// waiting for to advance to the next state.
 -      ///
 -      /// See [`OutboundHTLCStateDetails`] for information on the specific states.
 -      ///
 -      /// LDK will always fill this field in, but when downgrading to prior versions of LDK, new
 -      /// states may result in `None` here.
 -      pub state: Option<OutboundHTLCStateDetails>,
 -      /// The extra fee being skimmed off the top of this HTLC.
 -      pub skimmed_fee_msat: Option<u64>,
 -      /// Whether the HTLC has an output below the local dust limit. If so, the output will be trimmed
 -      /// from the local commitment transaction and added to the commitment transaction fee.
 -      /// For non-anchor channels, this takes into account the cost of the second-stage HTLC
 -      /// transactions as well.
 -      ///
 -      /// When the local commitment transaction is broadcasted as part of a unilateral closure,
 -      /// the value of this HTLC will therefore not be claimable but instead burned as a transaction
 -      /// fee.
 -      ///
 -      /// Note that dust limits are specific to each party. An HTLC can be dust for the local
 -      /// commitment transaction but not for the counterparty's commitment transaction and vice versa.
 -      pub is_dust: bool,
 -}
 -
 -impl_writeable_tlv_based!(OutboundHTLCDetails, {
 -      (0, htlc_id, required),
 -      (2, amount_msat, required),
 -      (4, cltv_expiry, required),
 -      (6, payment_hash, required),
 -      (7, state, upgradable_option),
 -      (8, skimmed_fee_msat, required),
 -      (10, is_dust, required),
 -});
 -
  /// See AwaitingRemoteRevoke ChannelState for more info
  #[cfg_attr(test, derive(Clone, Debug, PartialEq))]
  enum HTLCUpdateAwaitingACK {
@@@ -933,6 -1119,75 +933,75 @@@ pub(crate) struct ShutdownResult 
        pub(crate) channel_funding_txo: Option<OutPoint>,
  }
  
+ /// Tracks the transaction number, along with current and next commitment points.
+ /// This consolidates the logic to advance our commitment number and request new
+ /// commitment points from our signer.
+ #[derive(Debug, Copy, Clone)]
+ enum HolderCommitmentPoint {
+       // TODO: add a variant for before our first commitment point is retrieved
+       /// We've advanced our commitment number and are waiting on the next commitment point.
+       /// Until the `get_per_commitment_point` signer method becomes async, this variant
+       /// will not be used.
+       PendingNext { transaction_number: u64, current: PublicKey },
+       /// Our current commitment point is ready, we've cached our next point,
+       /// and we are not pending a new one.
+       Available { transaction_number: u64, current: PublicKey, next: PublicKey },
+ }
+ impl HolderCommitmentPoint {
+       pub fn new<SP: Deref>(signer: &ChannelSignerType<SP>, secp_ctx: &Secp256k1<secp256k1::All>) -> Self
+               where SP::Target: SignerProvider
+       {
+               HolderCommitmentPoint::Available {
+                       transaction_number: INITIAL_COMMITMENT_NUMBER,
+                       current: signer.as_ref().get_per_commitment_point(INITIAL_COMMITMENT_NUMBER, secp_ctx),
+                       next: signer.as_ref().get_per_commitment_point(INITIAL_COMMITMENT_NUMBER - 1, secp_ctx),
+               }
+       }
+       pub fn is_available(&self) -> bool {
+               if let HolderCommitmentPoint::Available { .. } = self { true } else { false }
+       }
+       pub fn transaction_number(&self) -> u64 {
+               match self {
+                       HolderCommitmentPoint::PendingNext { transaction_number, .. } => *transaction_number,
+                       HolderCommitmentPoint::Available { transaction_number, .. } => *transaction_number,
+               }
+       }
+       pub fn current_point(&self) -> PublicKey {
+               match self {
+                       HolderCommitmentPoint::PendingNext { current, .. } => *current,
+                       HolderCommitmentPoint::Available { current, .. } => *current,
+               }
+       }
+       pub fn next_point(&self) -> Option<PublicKey> {
+               match self {
+                       HolderCommitmentPoint::PendingNext { .. } => None,
+                       HolderCommitmentPoint::Available { next, .. } => Some(*next),
+               }
+       }
+       pub fn advance<SP: Deref, L: Deref>(&mut self, signer: &ChannelSignerType<SP>, secp_ctx: &Secp256k1<secp256k1::All>, logger: &L)
+               where SP::Target: SignerProvider, L::Target: Logger
+       {
+               if let HolderCommitmentPoint::Available { transaction_number, next, .. } = self {
+                       *self = HolderCommitmentPoint::PendingNext {
+                               transaction_number: *transaction_number - 1,
+                               current: *next,
+                       };
+               }
+               if let HolderCommitmentPoint::PendingNext { transaction_number, current } = self {
+                       let next = signer.as_ref().get_per_commitment_point(*transaction_number - 1, secp_ctx);
+                       log_trace!(logger, "Retrieved next per-commitment point {}", *transaction_number - 1);
+                       *self = HolderCommitmentPoint::Available { transaction_number: *transaction_number, current: *current, next };
+               }
+       }
+ }
  /// If the majority of the channels funds are to the fundee and the initiator holds only just
  /// enough funds to cover their reserve value, channels are at risk of getting "stuck". Because the
  /// initiator controls the feerate, if they then go to increase the channel fee, they may have no
@@@ -1111,7 -1366,7 +1180,7 @@@ pub(super) struct ChannelContext<SP: De
        // generation start at 0 and count up...this simplifies some parts of implementation at the
        // cost of others, but should really just be changed.
  
-       cur_holder_commitment_transaction_number: u64,
+       holder_commitment_point: HolderCommitmentPoint,
        cur_counterparty_commitment_transaction_number: u64,
        value_to_self_msat: u64, // Excluding all pending_htlcs, fees, and anchor outputs
        pending_inbound_htlcs: Vec<InboundHTLCOutput>,
@@@ -1553,6 -1808,9 +1622,9 @@@ impl<SP: Deref> ChannelContext<SP> wher
  
                let value_to_self_msat = our_funding_satoshis * 1000 + msg_push_msat;
  
+               let holder_signer = ChannelSignerType::Ecdsa(holder_signer);
+               let holder_commitment_point = HolderCommitmentPoint::new(&holder_signer, &secp_ctx);
                // TODO(dual_funding): Checks for `funding_feerate_sat_per_1000_weight`?
  
                let channel_context = ChannelContext {
  
                        latest_monitor_update_id: 0,
  
-                       holder_signer: ChannelSignerType::Ecdsa(holder_signer),
+                       holder_signer,
                        shutdown_scriptpubkey,
                        destination_script,
  
-                       cur_holder_commitment_transaction_number: INITIAL_COMMITMENT_NUMBER,
+                       holder_commitment_point,
                        cur_counterparty_commitment_transaction_number: INITIAL_COMMITMENT_NUMBER,
                        value_to_self_msat,
  
  
                let temporary_channel_id = temporary_channel_id.unwrap_or_else(|| ChannelId::temporary_from_entropy_source(entropy_source));
  
+               let holder_signer = ChannelSignerType::Ecdsa(holder_signer);
+               let holder_commitment_point = HolderCommitmentPoint::new(&holder_signer, &secp_ctx);
                Ok(Self {
                        user_id,
  
  
                        latest_monitor_update_id: 0,
  
-                       holder_signer: ChannelSignerType::Ecdsa(holder_signer),
+                       holder_signer,
                        shutdown_scriptpubkey,
                        destination_script,
  
-                       cur_holder_commitment_transaction_number: INITIAL_COMMITMENT_NUMBER,
+                       holder_commitment_point,
                        cur_counterparty_commitment_transaction_number: INITIAL_COMMITMENT_NUMBER,
                        value_to_self_msat,
  
        /// our counterparty!)
        /// The result is a transaction which we can revoke broadcastership of (ie a "local" transaction)
        /// TODO Some magic rust shit to compile-time check this?
-       fn build_holder_transaction_keys(&self, commitment_number: u64) -> TxCreationKeys {
-               let per_commitment_point = self.holder_signer.as_ref().get_per_commitment_point(commitment_number, &self.secp_ctx);
+       fn build_holder_transaction_keys(&self) -> TxCreationKeys {
+               let per_commitment_point = self.holder_commitment_point.current_point();
                let delayed_payment_base = &self.get_holder_pubkeys().delayed_payment_basepoint;
                let htlc_basepoint = &self.get_holder_pubkeys().htlc_basepoint;
                let counterparty_pubkeys = self.get_counterparty_pubkeys();
@@@ -4195,9 -4456,9 +4270,9 @@@ impl<SP: Deref> Channel<SP> wher
  
                let funding_script = self.context.get_funding_redeemscript();
  
-               let keys = self.context.build_holder_transaction_keys(self.context.cur_holder_commitment_transaction_number);
+               let keys = self.context.build_holder_transaction_keys();
  
-               let commitment_stats = self.context.build_commitment_transaction(self.context.cur_holder_commitment_transaction_number, &keys, true, false, logger);
+               let commitment_stats = self.context.build_commitment_transaction(self.context.holder_commitment_point.transaction_number(), &keys, true, false, logger);
                let commitment_txid = {
                        let trusted_tx = commitment_stats.tx.trust();
                        let bitcoin_tx = trusted_tx.built_transaction();
  
                                let htlc_redeemscript = chan_utils::get_htlc_redeemscript(&htlc, &self.context.channel_type, &keys);
                                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()[..]);
 +                              let htlc_sighash = hash_to_message!(&sighash::SighashCache::new(&htlc_tx).p2wsh_signature_hash(0, &htlc_redeemscript, htlc.to_bitcoin_amount(), 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.to_public_key().serialize()),
                                        encode::serialize_hex(&htlc_tx), log_bytes!(htlc_sighash[..]), encode::serialize_hex(&htlc_redeemscript), &self.context.channel_id());
                        channel_id: Some(self.context.channel_id()),
                };
  
-               self.context.cur_holder_commitment_transaction_number -= 1;
+               self.context.holder_commitment_point.advance(&self.context.holder_signer, &self.context.secp_ctx, logger);
                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.
                // Before proposing a feerate update, check that we can actually afford the new fee.
                let dust_exposure_limiting_feerate = self.context.get_dust_exposure_limiting_feerate(&fee_estimator);
                let htlc_stats = self.context.get_pending_htlc_stats(Some(feerate_per_kw), dust_exposure_limiting_feerate);
-               let keys = self.context.build_holder_transaction_keys(self.context.cur_holder_commitment_transaction_number);
-               let commitment_stats = self.context.build_commitment_transaction(self.context.cur_holder_commitment_transaction_number, &keys, true, true, logger);
+               let keys = self.context.build_holder_transaction_keys();
+               let commitment_stats = self.context.build_commitment_transaction(self.context.holder_commitment_point.transaction_number(), &keys, true, true, logger);
                let buffer_fee_msat = commit_tx_fee_sat(feerate_per_kw, commitment_stats.num_nondust_htlcs + htlc_stats.on_holder_tx_outbound_holding_cell_htlcs_count as usize + CONCURRENT_INBOUND_HTLC_FEE_BUFFER as usize, self.context.get_channel_type()) * 1000;
                let holder_balance_msat = commitment_stats.local_balance_msat - htlc_stats.outbound_holding_cell_msat;
                if holder_balance_msat < buffer_fee_msat  + self.context.counterparty_selected_channel_reserve_satoshis.unwrap() * 1000 {
                        assert!(!self.context.is_outbound() || self.context.minimum_depth == Some(0),
                                "Funding transaction broadcast by the local client before it should have - LDK didn't do it!");
                        self.context.monitor_pending_channel_ready = false;
-                       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);
-                       Some(msgs::ChannelReady {
-                               channel_id: self.context.channel_id(),
-                               next_per_commitment_point,
-                               short_channel_id_alias: Some(self.context.outbound_scid_alias),
-                       })
+                       Some(self.get_channel_ready())
                } else { None };
  
                let announcement_sigs = self.get_announcement_sigs(node_signer, chain_hash, user_config, best_block_height, logger);
                        self.context.get_funding_signed_msg(logger).1
                } else { None };
                let channel_ready = if funding_signed.is_some() {
-                       self.check_get_channel_ready(0)
+                       self.check_get_channel_ready(0, logger)
                } else { None };
  
                log_trace!(logger, "Signer unblocked with {} commitment_update, {} funding_signed and {} 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);
+               debug_assert!(self.context.holder_commitment_point.transaction_number() <= INITIAL_COMMITMENT_NUMBER + 2);
+               // TODO: handle non-available case when get_per_commitment_point becomes async
+               debug_assert!(self.context.holder_commitment_point.is_available());
+               let next_per_commitment_point = self.context.holder_commitment_point.current_point();
+               let per_commitment_secret = self.context.holder_signer.as_ref().release_commitment_secret(self.context.holder_commitment_point.transaction_number() + 2);
                msgs::RevokeAndACK {
                        channel_id: self.context.channel_id,
                        per_commitment_secret,
                        return Err(ChannelError::Close("Peer sent an invalid channel_reestablish to force close in a non-standard way".to_owned()));
                }
  
-               let our_commitment_transaction = INITIAL_COMMITMENT_NUMBER - self.context.cur_holder_commitment_transaction_number - 1;
+               let our_commitment_transaction = INITIAL_COMMITMENT_NUMBER - self.context.holder_commitment_point.transaction_number() - 1;
                if msg.next_remote_commitment_number > 0 {
                        let expected_point = self.context.holder_signer.as_ref().get_per_commitment_point(INITIAL_COMMITMENT_NUMBER - msg.next_remote_commitment_number + 1, &self.context.secp_ctx);
                        let given_secret = SecretKey::from_slice(&msg.your_last_per_commitment_secret)
                        }
  
                        // We have OurChannelReady set!
-                       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);
                        return Ok(ReestablishResponses {
-                               channel_ready: Some(msgs::ChannelReady {
-                                       channel_id: self.context.channel_id(),
-                                       next_per_commitment_point,
-                                       short_channel_id_alias: Some(self.context.outbound_scid_alias),
-                               }),
+                               channel_ready: Some(self.get_channel_ready()),
                                raa: None, commitment_update: None,
                                order: RAACommitmentOrder::CommitmentFirst,
                                shutdown_msg, announcement_sigs,
                }
                let next_counterparty_commitment_number = INITIAL_COMMITMENT_NUMBER - self.context.cur_counterparty_commitment_transaction_number + if is_awaiting_remote_revoke { 1 } else { 0 };
  
-               let channel_ready = if msg.next_local_commitment_number == 1 && INITIAL_COMMITMENT_NUMBER - self.context.cur_holder_commitment_transaction_number == 1 {
+               let channel_ready = if msg.next_local_commitment_number == 1 && INITIAL_COMMITMENT_NUMBER - self.context.holder_commitment_point.transaction_number() == 1 {
                        // We should never have to worry about MonitorUpdateInProgress resending ChannelReady
-                       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);
-                       Some(msgs::ChannelReady {
-                               channel_id: self.context.channel_id(),
-                               next_per_commitment_point,
-                               short_channel_id_alias: Some(self.context.outbound_scid_alias),
-                       })
+                       Some(self.get_channel_ready())
                } else { None };
  
                if msg.next_local_commitment_number == next_counterparty_commitment_number {
                };
  
                for outp in closing_tx.trust().built_transaction().output.iter() {
 -                      if !outp.script_pubkey.is_witness_program() && outp.value < MAX_STD_OUTPUT_DUST_LIMIT_SATOSHIS {
 +                      if !outp.script_pubkey.is_witness_program() && outp.value < Amount::from_sat(MAX_STD_OUTPUT_DUST_LIMIT_SATOSHIS) {
                                return Err(ChannelError::Close("Remote sent us a closing_signed with a dust output. Always use segwit closing scripts!".to_owned()));
                        }
                }
        }
  
        pub fn get_cur_holder_commitment_transaction_number(&self) -> u64 {
-               self.context.cur_holder_commitment_transaction_number + 1
+               self.context.holder_commitment_point.transaction_number() + 1
        }
  
        pub fn get_cur_counterparty_commitment_transaction_number(&self) -> u64 {
                        debug_assert!(self.context.minimum_depth.unwrap_or(1) > 0);
                        return true;
                }
-               if self.context.cur_holder_commitment_transaction_number == INITIAL_COMMITMENT_NUMBER - 1 &&
+               if self.context.holder_commitment_point.transaction_number() == INITIAL_COMMITMENT_NUMBER - 1 &&
                        self.context.cur_counterparty_commitment_transaction_number == INITIAL_COMMITMENT_NUMBER - 1 {
                        // If we're a 0-conf channel, we'll move beyond AwaitingChannelReady immediately even while
                        // waiting for the initial monitor persistence. Thus, we check if our commitment
                self.context.channel_update_status = status;
        }
  
-       fn check_get_channel_ready(&mut self, height: u32) -> Option<msgs::ChannelReady> {
+       fn check_get_channel_ready<L: Deref>(&mut self, height: u32, logger: &L) -> Option<msgs::ChannelReady>
+               where L::Target: Logger
+       {
                // Called:
                //  * always when a new block/transactions are confirmed with the new height
                //  * when funding is signed with a height of 0
                // 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 {
+                       // TODO: set signer_pending_channel_ready
+                       log_debug!(logger, "Can't produce channel_ready: the signer is pending funding.");
                        return None;
                }
  
                        false
                };
  
-               if need_commitment_update {
-                       if !self.context.channel_state.is_monitor_update_in_progress() {
-                               if !self.context.channel_state.is_peer_disconnected() {
-                                       let next_per_commitment_point =
-                                               self.context.holder_signer.as_ref().get_per_commitment_point(INITIAL_COMMITMENT_NUMBER - 1, &self.context.secp_ctx);
-                                       return Some(msgs::ChannelReady {
-                                               channel_id: self.context.channel_id,
-                                               next_per_commitment_point,
-                                               short_channel_id_alias: Some(self.context.outbound_scid_alias),
-                                       });
-                               }
-                       } else {
-                               self.context.monitor_pending_channel_ready = true;
-                       }
+               if !need_commitment_update {
+                       log_debug!(logger, "Not producing channel_ready: we do not need a commitment update");
+                       return None;
+               }
+               if self.context.channel_state.is_monitor_update_in_progress() {
+                       log_debug!(logger, "Not producing channel_ready: a monitor update is in progress. Setting monitor_pending_channel_ready.");
+                       self.context.monitor_pending_channel_ready = true;
+                       return None;
+               }
+               if self.context.channel_state.is_peer_disconnected() {
+                       log_debug!(logger, "Not producing channel_ready: the peer is disconnected.");
+                       return None;
+               }
+               // TODO: when get_per_commiment_point becomes async, check if the point is
+               // available, if not, set signer_pending_channel_ready and return None
+               Some(self.get_channel_ready())
+       }
+       fn get_channel_ready(&self) -> msgs::ChannelReady {
+               debug_assert!(self.context.holder_commitment_point.is_available());
+               msgs::ChannelReady {
+                       channel_id: self.context.channel_id(),
+                       next_per_commitment_point: self.context.holder_commitment_point.current_point(),
+                       short_channel_id_alias: Some(self.context.outbound_scid_alias),
                }
-               None
        }
  
        /// When a transaction is confirmed, we check whether it is or spends the funding transaction
                                if self.context.funding_tx_confirmation_height == 0 {
                                        if tx.txid() == funding_txo.txid {
                                                let txo_idx = funding_txo.index as usize;
 -                                              if txo_idx >= tx.output.len() || tx.output[txo_idx].script_pubkey != self.context.get_funding_redeemscript().to_v0_p2wsh() ||
 -                                                              tx.output[txo_idx].value != self.context.channel_value_satoshis {
 +                                              if txo_idx >= tx.output.len() || tx.output[txo_idx].script_pubkey != self.context.get_funding_redeemscript().to_p2wsh() ||
 +                                                              tx.output[txo_idx].value.to_sat() != self.context.channel_value_satoshis {
                                                        if self.context.is_outbound() {
                                                                // If we generated the funding transaction and it doesn't match what it
                                                                // should, the client is really broken and we should just panic and
                                                        return Err(ClosureReason::ProcessingError { err: err_reason.to_owned() });
                                                } else {
                                                        if self.context.is_outbound() {
 -                                                              if !tx.is_coin_base() {
 +                                                              if !tx.is_coinbase() {
                                                                        for input in tx.input.iter() {
                                                                                if input.witness.is_empty() {
                                                                                        // We generated a malleable funding transaction, implying we've
                                                }
                                                // If this is a coinbase transaction and not a 0-conf channel
                                                // we should update our min_depth to 100 to handle coinbase maturity
 -                                              if tx.is_coin_base() &&
 +                                              if tx.is_coinbase() &&
                                                        self.context.minimum_depth.unwrap_or(0) > 0 &&
                                                        self.context.minimum_depth.unwrap_or(0) < COINBASE_MATURITY {
                                                        self.context.minimum_depth = Some(COINBASE_MATURITY);
                                        // If we allow 1-conf funding, we may need to check for channel_ready here and
                                        // send it immediately instead of waiting for a best_block_updated call (which
                                        // may have already happened for this block).
-                                       if let Some(channel_ready) = self.check_get_channel_ready(height) {
+                                       if let Some(channel_ready) = self.check_get_channel_ready(height, logger) {
                                                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, chain_hash, user_config, height, logger);
                                                msgs = (Some(channel_ready), announcement_sigs);
  
                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) {
+               if let Some(channel_ready) = self.check_get_channel_ready(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 };
  
                        // next_local_commitment_number is the next commitment_signed number we expect to
                        // receive (indicating if they need to resend one that we missed).
-                       next_local_commitment_number: INITIAL_COMMITMENT_NUMBER - self.context.cur_holder_commitment_transaction_number,
+                       next_local_commitment_number: INITIAL_COMMITMENT_NUMBER - self.context.holder_commitment_point.transaction_number(),
                        // We have to set next_remote_commitment_number to the next revoke_and_ack we expect to
                        // receive, however we track it by the next commitment number for a remote transaction
                        // (which is one further, as they always revoke previous commitment transaction, not
@@@ -7282,7 -7548,7 +7362,7 @@@ impl<SP: Deref> OutboundV1Channel<SP> w
                }
                if self.context.commitment_secrets.get_min_seen_secret() != (1 << 48) ||
                                self.context.cur_counterparty_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER ||
-                               self.context.cur_holder_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER {
+                               self.context.holder_commitment_point.transaction_number() != INITIAL_COMMITMENT_NUMBER {
                        panic!("Should not have advanced channel commitment tx numbers prior to funding_created");
                }
  
  
                // If the funding transaction is a coinbase transaction, we need to set the minimum depth to 100.
                // We can skip this if it is a zero-conf channel.
 -              if funding_transaction.is_coin_base() &&
 +              if funding_transaction.is_coinbase() &&
                        self.context.minimum_depth.unwrap_or(0) > 0 &&
                        self.context.minimum_depth.unwrap_or(0) < COINBASE_MATURITY {
                        self.context.minimum_depth = Some(COINBASE_MATURITY);
        /// Returns true if we can resume the channel by sending the [`msgs::OpenChannel`] again.
        pub fn is_resumable(&self) -> bool {
                !self.context.have_received_message() &&
-                       self.context.cur_holder_commitment_transaction_number == INITIAL_COMMITMENT_NUMBER
+                       self.context.holder_commitment_point.transaction_number() == INITIAL_COMMITMENT_NUMBER
        }
  
        pub fn get_open_channel(&self, chain_hash: ChainHash) -> msgs::OpenChannel {
                        panic!("Cannot generate an open_channel after we've moved forward");
                }
  
-               if self.context.cur_holder_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER {
+               if self.context.holder_commitment_point.transaction_number() != INITIAL_COMMITMENT_NUMBER {
                        panic!("Tried to send an open_channel for a channel that has already advanced");
                }
  
-               let first_per_commitment_point = self.context.holder_signer.as_ref().get_per_commitment_point(self.context.cur_holder_commitment_transaction_number, &self.context.secp_ctx);
+               debug_assert!(self.context.holder_commitment_point.is_available());
+               let first_per_commitment_point = self.context.holder_commitment_point.current_point();
                let keys = self.context.get_holder_pubkeys();
  
                msgs::OpenChannel {
                }
                if self.context.commitment_secrets.get_min_seen_secret() != (1 << 48) ||
                                self.context.cur_counterparty_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER ||
-                               self.context.cur_holder_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER {
+                               self.context.holder_commitment_point.transaction_number() != INITIAL_COMMITMENT_NUMBER {
                        panic!("Should not have advanced channel commitment tx numbers prior to funding_created");
                }
  
                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));
  
-               let holder_signer = 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, &holder_signer, true, false, logger).tx;
+               let holder_signer = self.context.build_holder_transaction_keys();
+               let initial_commitment_tx = self.context.build_commitment_transaction(self.context.holder_commitment_point.transaction_number(), &holder_signer, true, false, logger).tx;
                {
                        let trusted_tx = initial_commitment_tx.trust();
                        let initial_commitment_bitcoin_tx = trusted_tx.built_transaction();
  
                let funding_redeemscript = self.context.get_funding_redeemscript();
                let funding_txo = self.context.get_funding_txo().unwrap();
 -              let funding_txo_script = funding_redeemscript.to_v0_p2wsh();
 +              let funding_txo_script = funding_redeemscript.to_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());
                let shutdown_script = self.context.shutdown_scriptpubkey.clone().map(|script| script.into_inner());
                let mut monitor_signer = signer_provider.derive_channel_signer(self.context.channel_value_satoshis, self.context.channel_keys_id);
                } else {
                        self.context.channel_state = ChannelState::AwaitingChannelReady(AwaitingChannelReadyFlags::new());
                }
-               self.context.cur_holder_commitment_transaction_number -= 1;
+               self.context.holder_commitment_point.advance(&self.context.holder_signer, &self.context.secp_ctx, logger);
                self.context.cur_counterparty_commitment_transaction_number -= 1;
  
                log_info!(logger, "Received funding_signed from peer for channel {}", &self.context.channel_id());
                        dual_funding_channel_context: None,
                };
  
-               let need_channel_ready = channel.check_get_channel_ready(0).is_some();
+               let need_channel_ready = channel.check_get_channel_ready(0, logger).is_some();
                channel.monitor_updating_paused(false, false, need_channel_ready, Vec::new(), Vec::new(), Vec::new());
                Ok((channel, channel_monitor))
        }
@@@ -7737,7 -8004,7 +7818,7 @@@ impl<SP: Deref> InboundV1Channel<SP> wh
                ) {
                        panic!("Tried to send accept_channel after channel had moved forward");
                }
-               if self.context.cur_holder_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER {
+               if self.context.holder_commitment_point.transaction_number() != INITIAL_COMMITMENT_NUMBER {
                        panic!("Tried to send an accept_channel for a channel that has already advanced");
                }
  
        ///
        /// [`msgs::AcceptChannel`]: crate::ln::msgs::AcceptChannel
        fn generate_accept_channel_message(&self) -> msgs::AcceptChannel {
-               let first_per_commitment_point = self.context.holder_signer.as_ref().get_per_commitment_point(self.context.cur_holder_commitment_transaction_number, &self.context.secp_ctx);
+               debug_assert!(self.context.holder_commitment_point.is_available());
+               let first_per_commitment_point = self.context.holder_commitment_point.current_point();
                let keys = self.context.get_holder_pubkeys();
  
                msgs::AcceptChannel {
        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 keys = self.context.build_holder_transaction_keys();
+               let initial_commitment_tx = self.context.build_commitment_transaction(self.context.holder_commitment_point.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);
                }
                if self.context.commitment_secrets.get_min_seen_secret() != (1 << 48) ||
                                self.context.cur_counterparty_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER ||
-                               self.context.cur_holder_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER {
+                               self.context.holder_commitment_point.transaction_number() != INITIAL_COMMITMENT_NUMBER {
                        panic!("Should not have advanced channel commitment tx numbers prior to funding_created");
                }
  
                self.context.channel_state = ChannelState::AwaitingChannelReady(AwaitingChannelReadyFlags::new());
                self.context.channel_id = ChannelId::v1_from_funding_outpoint(funding_txo);
                self.context.cur_counterparty_commitment_transaction_number -= 1;
-               self.context.cur_holder_commitment_transaction_number -= 1;
+               self.context.holder_commitment_point.advance(&self.context.holder_signer, &self.context.secp_ctx, logger);
  
                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 funding_txo_script = funding_redeemscript.to_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());
                let shutdown_script = self.context.shutdown_scriptpubkey.clone().map(|script| script.into_inner());
                let mut monitor_signer = signer_provider.derive_channel_signer(self.context.channel_value_satoshis, self.context.channel_keys_id);
                        #[cfg(any(dual_funding, splicing))]
                        dual_funding_channel_context: None,
                };
-               let need_channel_ready = channel.check_get_channel_ready(0).is_some();
+               let need_channel_ready = channel.check_get_channel_ready(0, logger).is_some();
                channel.monitor_updating_paused(false, false, need_channel_ready, Vec::new(), Vec::new(), Vec::new());
  
                Ok((channel, funding_signed, channel_monitor))
@@@ -7988,15 -8256,15 +8070,15 @@@ impl<SP: Deref> OutboundV2Channel<SP> w
                        debug_assert!(false, "Cannot generate an open_channel2 after we've moved forward");
                }
  
-               if self.context.cur_holder_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER {
+               if self.context.holder_commitment_point.transaction_number() != INITIAL_COMMITMENT_NUMBER {
                        debug_assert!(false, "Tried to send an open_channel2 for a channel that has already advanced");
                }
  
                let first_per_commitment_point = self.context.holder_signer.as_ref()
-                       .get_per_commitment_point(self.context.cur_holder_commitment_transaction_number,
+                       .get_per_commitment_point(self.context.holder_commitment_point.transaction_number(),
                                &self.context.secp_ctx);
                let second_per_commitment_point = self.context.holder_signer.as_ref()
-                       .get_per_commitment_point(self.context.cur_holder_commitment_transaction_number - 1,
+                       .get_per_commitment_point(self.context.holder_commitment_point.transaction_number() - 1,
                                &self.context.secp_ctx);
                let keys = self.context.get_holder_pubkeys();
  
@@@ -8130,7 -8398,7 +8212,7 @@@ impl<SP: Deref> InboundV2Channel<SP> wh
                ) {
                        debug_assert!(false, "Tried to send accept_channel2 after channel had moved forward");
                }
-               if self.context.cur_holder_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER {
+               if self.context.holder_commitment_point.transaction_number() != INITIAL_COMMITMENT_NUMBER {
                        debug_assert!(false, "Tried to send an accept_channel2 for a channel that has already advanced");
                }
  
        /// [`msgs::AcceptChannelV2`]: crate::ln::msgs::AcceptChannelV2
        fn generate_accept_channel_v2_message(&self) -> msgs::AcceptChannelV2 {
                let first_per_commitment_point = self.context.holder_signer.as_ref().get_per_commitment_point(
-                       self.context.cur_holder_commitment_transaction_number, &self.context.secp_ctx);
+                       self.context.holder_commitment_point.transaction_number(), &self.context.secp_ctx);
                let second_per_commitment_point = self.context.holder_signer.as_ref().get_per_commitment_point(
-                       self.context.cur_holder_commitment_transaction_number - 1, &self.context.secp_ctx);
+                       self.context.holder_commitment_point.transaction_number() - 1, &self.context.secp_ctx);
                let keys = self.context.get_holder_pubkeys();
  
                msgs::AcceptChannelV2 {
@@@ -8319,7 -8587,7 +8401,7 @@@ impl<SP: Deref> Writeable for Channel<S
                }
                self.context.destination_script.write(writer)?;
  
-               self.context.cur_holder_commitment_transaction_number.write(writer)?;
+               self.context.holder_commitment_point.transaction_number().write(writer)?;
                self.context.cur_counterparty_commitment_transaction_number.write(writer)?;
                self.context.value_to_self_msat.write(writer)?;
  
                        monitor_pending_update_adds = Some(&self.context.monitor_pending_update_adds);
                }
  
+               // `current_point` will become optional when async signing is implemented.
+               let cur_holder_commitment_point = Some(self.context.holder_commitment_point.current_point());
+               let next_holder_commitment_point = self.context.holder_commitment_point.next_point();
                write_tlv_fields!(writer, {
                        (0, self.context.announcement_sigs, option),
                        // minimum_depth and counterparty_selected_channel_reserve_satoshis used to have a
                        (39, pending_outbound_blinding_points, optional_vec),
                        (41, holding_cell_blinding_points, optional_vec),
                        (43, malformed_htlcs, optional_vec), // Added in 0.0.119
-                       // 45 and 47 are reserved for async signing
+                       (45, cur_holder_commitment_point, option),
+                       (47, next_holder_commitment_point, option),
                        (49, self.context.local_initiated_shutdown, option), // Added in 0.0.122
                });
  
@@@ -8940,6 -9213,9 +9027,9 @@@ impl<'a, 'b, 'c, ES: Deref, SP: Deref> 
                let mut malformed_htlcs: Option<Vec<(u64, u16, [u8; 32])>> = None;
                let mut monitor_pending_update_adds: Option<Vec<msgs::UpdateAddHTLC>> = None;
  
+               let mut cur_holder_commitment_point_opt: Option<PublicKey> = None;
+               let mut next_holder_commitment_point_opt: Option<PublicKey> = None;
                read_tlv_fields!(reader, {
                        (0, announcement_sigs, option),
                        (1, minimum_depth, option),
                        (39, pending_outbound_blinding_points_opt, optional_vec),
                        (41, holding_cell_blinding_points_opt, optional_vec),
                        (43, malformed_htlcs, optional_vec), // Added in 0.0.119
-                       // 45 and 47 are reserved for async signing
+                       (45, cur_holder_commitment_point_opt, option),
+                       (47, next_holder_commitment_point_opt, option),
                        (49, local_initiated_shutdown, option),
                });
  
                        }
                }
  
+               // If we're restoring this channel for the first time after an upgrade, then we require that the
+               // signer be available so that we can immediately populate the current commitment point. Channel
+               // restoration will fail if this is not possible.
+               let holder_commitment_point = match (cur_holder_commitment_point_opt, next_holder_commitment_point_opt) {
+                       (Some(current), Some(next)) => HolderCommitmentPoint::Available {
+                               transaction_number: cur_holder_commitment_transaction_number, current, next
+                       },
+                       (Some(current), _) => HolderCommitmentPoint::Available {
+                               transaction_number: cur_holder_commitment_transaction_number, current,
+                               next: holder_signer.get_per_commitment_point(cur_holder_commitment_transaction_number - 1, &secp_ctx),
+                       },
+                       (_, _) => HolderCommitmentPoint::Available {
+                               transaction_number: cur_holder_commitment_transaction_number,
+                               current: holder_signer.get_per_commitment_point(cur_holder_commitment_transaction_number, &secp_ctx),
+                               next: holder_signer.get_per_commitment_point(cur_holder_commitment_transaction_number - 1, &secp_ctx),
+                       },
+               };
                Ok(Channel {
                        context: ChannelContext {
                                user_id,
                                shutdown_scriptpubkey,
                                destination_script,
  
-                               cur_holder_commitment_transaction_number,
+                               holder_commitment_point,
                                cur_counterparty_commitment_transaction_number,
                                value_to_self_msat,
  
  #[cfg(test)]
  mod tests {
        use std::cmp;
 +      use bitcoin::amount::Amount;
        use bitcoin::blockdata::constants::ChainHash;
        use bitcoin::blockdata::script::{ScriptBuf, Builder};
 -      use bitcoin::blockdata::transaction::{Transaction, TxOut};
 +      use bitcoin::blockdata::transaction::{Transaction, TxOut, Version};
        use bitcoin::blockdata::opcodes;
 -      use bitcoin::network::constants::Network;
 +      use bitcoin::network::Network;
        use crate::ln::onion_utils::INVALID_ONION_BLINDING;
        use crate::ln::types::{PaymentHash, PaymentPreimage};
        use crate::ln::channel_keys::{RevocationKey, RevocationBasepoint};
        use bitcoin::hashes::sha256::Hash as Sha256;
        use bitcoin::hashes::Hash;
        use bitcoin::hashes::hex::FromHex;
 -      use bitcoin::hash_types::WPubkeyHash;
        use bitcoin::blockdata::locktime::absolute::LockTime;
 -      use bitcoin::address::{WitnessProgram, WitnessVersion};
 +      use bitcoin::{WitnessProgram, WitnessVersion, WPubkeyHash};
        use crate::prelude::*;
  
        #[test]
  
                // Node A --> Node B: funding created
                let output_script = node_a_chan.context.get_funding_redeemscript();
 -              let tx = Transaction { version: 1, lock_time: LockTime::ZERO, input: Vec::new(), output: vec![TxOut {
 -                      value: 10000000, script_pubkey: output_script.clone(),
 +              let tx = Transaction { version: Version::ONE, lock_time: LockTime::ZERO, input: Vec::new(), output: vec![TxOut {
 +                      value: Amount::from_sat(10000000), script_pubkey: output_script.clone(),
                }]};
                let funding_outpoint = OutPoint{ txid: tx.txid(), index: 0 };
                let funding_created_msg = node_a_chan.get_funding_created(tx.clone(), funding_outpoint, false, &&logger).map_err(|_| ()).unwrap();
  
                // Node A --> Node B: funding created
                let output_script = node_a_chan.context.get_funding_redeemscript();
 -              let tx = Transaction { version: 1, lock_time: LockTime::ZERO, input: Vec::new(), output: vec![TxOut {
 -                      value: 10000000, script_pubkey: output_script.clone(),
 +              let tx = Transaction { version: Version::ONE, lock_time: LockTime::ZERO, input: Vec::new(), output: vec![TxOut {
 +                      value: Amount::from_sat(10000000), script_pubkey: output_script.clone(),
                }]};
                let funding_outpoint = OutPoint{ txid: tx.txid(), index: 0 };
                let funding_created_msg = node_a_chan.get_funding_created(tx.clone(), funding_outpoint, false, &&logger).map_err(|_| ()).unwrap();
  
                // Node A --> Node B: funding created
                let output_script = node_a_chan.context.get_funding_redeemscript();
 -              let tx = Transaction { version: 1, lock_time: LockTime::ZERO, input: Vec::new(), output: vec![TxOut {
 -                      value: 10000000, script_pubkey: output_script.clone(),
 +              let tx = Transaction { version: Version::ONE, lock_time: LockTime::ZERO, input: Vec::new(), output: vec![TxOut {
 +                      value: Amount::from_sat(10000000), script_pubkey: output_script.clone(),
                }]};
                let funding_outpoint = OutPoint{ txid: tx.txid(), index: 0 };
                let funding_created_msg = node_a_chan.get_funding_created(tx.clone(), funding_outpoint, false, &&logger).map_err(|_| ()).unwrap();
                        &features, &outbound_chan.get_open_channel(ChainHash::using_genesis_block(network)), 7, &config, 0, &&logger, false
                ).unwrap();
                outbound_chan.accept_channel(&inbound_chan.get_accept_channel_message(), &config.channel_handshake_limits, &features).unwrap();
 -              let tx = Transaction { version: 1, lock_time: LockTime::ZERO, input: Vec::new(), output: vec![TxOut {
 -                      value: 10000000, script_pubkey: outbound_chan.context.get_funding_redeemscript(),
 +              let tx = Transaction { version: Version::ONE, lock_time: LockTime::ZERO, input: Vec::new(), output: vec![TxOut {
 +                      value: Amount::from_sat(10000000), script_pubkey: outbound_chan.context.get_funding_redeemscript(),
                }]};
                let funding_outpoint = OutPoint{ txid: tx.txid(), index: 0 };
                let funding_created = outbound_chan.get_funding_created(tx.clone(), funding_outpoint, false, &&logger).map_err(|_| ()).unwrap().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();
 +                                      let htlc_sighash = Message::from_digest(sighash::SighashCache::new(&htlc_tx).p2wsh_signature_hash(0, &htlc_redeemscript, htlc.to_bitcoin_amount(), htlc_sighashtype).unwrap().as_raw_hash().to_byte_array());
                                        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;
                // Fund the channel with a batch funding transaction.
                let output_script = node_a_chan.context.get_funding_redeemscript();
                let tx = Transaction {
 -                      version: 1,
 +                      version: Version::ONE,
                        lock_time: LockTime::ZERO,
                        input: Vec::new(),
                        output: vec![
                                TxOut {
 -                                      value: 10000000, script_pubkey: output_script.clone(),
 +                                      value: Amount::from_sat(10000000), script_pubkey: output_script.clone(),
                                },
                                TxOut {
 -                                      value: 10000000, script_pubkey: Builder::new().into_script(),
 +                                      value: Amount::from_sat(10000000), script_pubkey: Builder::new().into_script(),
                                },
                        ]};
                let funding_outpoint = OutPoint{ txid: tx.txid(), index: 0 };
                // Clear the ChannelState::WaitingForBatch only when called by ChannelManager.
                node_a_chan.set_batch_ready();
                assert_eq!(node_a_chan.context.channel_state, ChannelState::AwaitingChannelReady(AwaitingChannelReadyFlags::THEIR_CHANNEL_READY));
-               assert!(node_a_chan.check_get_channel_ready(0).is_some());
+               assert!(node_a_chan.check_get_channel_ready(0, &&logger).is_some());
        }
  }