Use HolderCommitmentPoint for commitment number

Author: alecchendev

lightning/src/ln/channel.rs

@@ -1367,7 +1367,6 @@ pub(super) struct ChannelContext<SP: Deref> where SP::Target: SignerProvider {
 	// cost of others, but should really just be changed.
 
 	holder_commitment_point: HolderCommitmentPoint,
-	cur_holder_commitment_transaction_number: u64,
 	cur_counterparty_commitment_transaction_number: u64,
 	value_to_self_msat: u64, // Excluding all pending_htlcs, fees, and anchor outputs
 	pending_inbound_htlcs: Vec<InboundHTLCOutput>,
@@ -1842,7 +1841,6 @@ impl<SP: Deref> ChannelContext<SP> where SP::Target: SignerProvider  {
 			destination_script,
 
 			holder_commitment_point,
-			cur_holder_commitment_transaction_number: INITIAL_COMMITMENT_NUMBER,
 			cur_counterparty_commitment_transaction_number: INITIAL_COMMITMENT_NUMBER,
 			value_to_self_msat,
 
@@ -2068,7 +2066,6 @@ impl<SP: Deref> ChannelContext<SP> where SP::Target: SignerProvider  {
 			destination_script,
 
 			holder_commitment_point,
-			cur_holder_commitment_transaction_number: INITIAL_COMMITMENT_NUMBER,
 			cur_counterparty_commitment_transaction_number: INITIAL_COMMITMENT_NUMBER,
 			value_to_self_msat,
 
@@ -4459,9 +4456,9 @@ impl<SP: Deref> Channel<SP> where
 
 		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(self.context.holder_commitment_point.transaction_number());
 
-		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();
@@ -4624,7 +4621,7 @@ impl<SP: Deref> Channel<SP> where
 			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.
@@ -5135,8 +5132,8 @@ impl<SP: Deref> Channel<SP> where
 		// 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(self.context.holder_commitment_point.transaction_number());
+		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 {
@@ -5318,7 +5315,7 @@ impl<SP: Deref> Channel<SP> where
 			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);
+			let next_per_commitment_point = self.context.holder_signer.as_ref().get_per_commitment_point(self.context.holder_commitment_point.transaction_number(), &self.context.secp_ctx);
 			Some(msgs::ChannelReady {
 				channel_id: self.context.channel_id(),
 				next_per_commitment_point,
@@ -5425,8 +5422,8 @@ impl<SP: Deref> Channel<SP> where
 	}
 
 	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);
+		let next_per_commitment_point = self.context.holder_signer.as_ref().get_per_commitment_point(self.context.holder_commitment_point.transaction_number(), &self.context.secp_ctx);
+		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,
@@ -5559,7 +5556,7 @@ impl<SP: Deref> Channel<SP> where
 			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)
@@ -5621,7 +5618,7 @@ impl<SP: Deref> Channel<SP> where
 			}
 
 			// 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);
+			let next_per_commitment_point = self.context.holder_signer.as_ref().get_per_commitment_point(self.context.holder_commitment_point.transaction_number(), &self.context.secp_ctx);
 			return Ok(ReestablishResponses {
 				channel_ready: Some(msgs::ChannelReady {
 					channel_id: self.context.channel_id(),
@@ -5664,9 +5661,9 @@ impl<SP: Deref> Channel<SP> where
 		}
 		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);
+			let next_per_commitment_point = self.context.holder_signer.as_ref().get_per_commitment_point(self.context.holder_commitment_point.transaction_number(), &self.context.secp_ctx);
 			Some(msgs::ChannelReady {
 				channel_id: self.context.channel_id(),
 				next_per_commitment_point,
@@ -6317,7 +6314,7 @@ impl<SP: Deref> Channel<SP> where
 	}
 
 	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 {
@@ -6432,7 +6429,7 @@ impl<SP: Deref> Channel<SP> where
 			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
@@ -6994,7 +6991,7 @@ impl<SP: Deref> Channel<SP> where
 
 			// 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
@@ -7546,7 +7543,7 @@ impl<SP: Deref> OutboundV1Channel<SP> where SP::Target: SignerProvider {
 		}
 		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");
 		}
 
@@ -7601,7 +7598,7 @@ impl<SP: Deref> OutboundV1Channel<SP> where SP::Target: SignerProvider {
 	/// 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 {
@@ -7612,11 +7609,11 @@ impl<SP: Deref> OutboundV1Channel<SP> where SP::Target: SignerProvider {
 			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);
+		let first_per_commitment_point = self.context.holder_signer.as_ref().get_per_commitment_point(self.context.holder_commitment_point.transaction_number(), &self.context.secp_ctx);
 		let keys = self.context.get_holder_pubkeys();
 
 		msgs::OpenChannel {
@@ -7797,7 +7794,7 @@ impl<SP: Deref> OutboundV1Channel<SP> where SP::Target: SignerProvider {
 		}
 		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");
 		}
 
@@ -7811,8 +7808,8 @@ impl<SP: Deref> OutboundV1Channel<SP> where SP::Target: SignerProvider {
 		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(self.context.holder_commitment_point.transaction_number());
+		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();
@@ -7865,7 +7862,7 @@ impl<SP: Deref> OutboundV1Channel<SP> where SP::Target: SignerProvider {
 		} 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());
@@ -8001,7 +7998,7 @@ impl<SP: Deref> InboundV1Channel<SP> where SP::Target: SignerProvider {
 		) {
 			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");
 		}
 
@@ -8014,7 +8011,7 @@ impl<SP: Deref> InboundV1Channel<SP> where SP::Target: SignerProvider {
 	///
 	/// [`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);
+		let first_per_commitment_point = self.context.holder_signer.as_ref().get_per_commitment_point(self.context.holder_commitment_point.transaction_number(), &self.context.secp_ctx);
 		let keys = self.context.get_holder_pubkeys();
 
 		msgs::AcceptChannel {
@@ -8056,8 +8053,8 @@ impl<SP: Deref> InboundV1Channel<SP> where SP::Target: SignerProvider {
 	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(self.context.holder_commitment_point.transaction_number());
+		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);
@@ -8091,7 +8088,7 @@ impl<SP: Deref> InboundV1Channel<SP> where SP::Target: SignerProvider {
 		}
 		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");
 		}
 
@@ -8131,7 +8128,7 @@ impl<SP: Deref> InboundV1Channel<SP> where SP::Target: SignerProvider {
 		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);
 
@@ -8252,15 +8249,15 @@ impl<SP: Deref> OutboundV2Channel<SP> where SP::Target: SignerProvider {
 			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();
 
@@ -8394,7 +8391,7 @@ impl<SP: Deref> InboundV2Channel<SP> where SP::Target: SignerProvider {
 		) {
 			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");
 		}
 
@@ -8408,9 +8405,9 @@ impl<SP: Deref> InboundV2Channel<SP> where SP::Target: SignerProvider {
 	/// [`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 {
@@ -8583,7 +8580,7 @@ impl<SP: Deref> Writeable for Channel<SP> where SP::Target: SignerProvider {
 		}
 		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)?;
 
@@ -9399,7 +9396,6 @@ impl<'a, 'b, 'c, ES: Deref, SP: Deref> ReadableArgs<(&'a ES, &'b SP, u32, &'c Ch
 				destination_script,
 
 				holder_commitment_point,
-				cur_holder_commitment_transaction_number,
 				cur_counterparty_commitment_transaction_number,
 				value_to_self_msat,