Pass channel params to sign_closing_transaction

Now that channel_value_satoshis has been moved to
ChannelTransactionParameters, pass the entire parameters when calling
each method on EcdsaChannelSigner. This will remove the need for
ChannelSigner::provide_channel_parameters. Instead, the parameters from
the FundingScope will be passed in to each method. This simplifies the
interaction with a ChannelSigner when needing to be called for more than
one FundingScope, which will be the case for pending splices and RBF
attempts.

Author: jkczyz

lightning/src/ln/async_signer_tests.rs

@@ -1022,10 +1022,11 @@ fn do_test_closing_signed(extra_closing_signed: bool, reconnect: bool) {
 
 			let per_peer_state = nodes[1].node.per_peer_state.read().unwrap();
 			let mut chan_lock = per_peer_state.get(&nodes[0].node.get_our_node_id()).unwrap().lock().unwrap();
-			let context = chan_lock.channel_by_id.get_mut(&chan_id).map(|chan| chan.context_mut()).unwrap();
+			let channel = chan_lock.channel_by_id.get_mut(&chan_id).unwrap();
+			let (funding, context) = channel.funding_and_context_mut();
 
 			let signer = context.get_mut_signer().as_mut_ecdsa().unwrap();
-			let signature = signer.sign_closing_transaction(&closing_tx_2, &Secp256k1::new()).unwrap();
+			let signature = signer.sign_closing_transaction(&funding.channel_transaction_parameters, &closing_tx_2, &Secp256k1::new()).unwrap();
 			node_1_closing_signed_2.signature = signature;
 			node_1_closing_signed_2
 		};

lightning/src/ln/channel.rs

@@ -7265,7 +7265,7 @@ impl<SP: Deref> FundedChannel<SP> where
 		where L::Target: Logger
 	{
 		let sig = match &self.context.holder_signer {
-			ChannelSignerType::Ecdsa(ecdsa) => ecdsa.sign_closing_transaction(closing_tx, &self.context.secp_ctx).ok(),
+			ChannelSignerType::Ecdsa(ecdsa) => ecdsa.sign_closing_transaction(&self.funding.channel_transaction_parameters, closing_tx, &self.context.secp_ctx).ok(),
 			// TODO (taproot|arik)
 			#[cfg(taproot)]
 			_ => todo!()

lightning/src/sign/ecdsa.rs

@@ -209,7 +209,8 @@ pub trait EcdsaChannelSigner: ChannelSigner {
 	///
 	/// [`ChannelManager::signer_unblocked`]: crate::ln::channelmanager::ChannelManager::signer_unblocked
 	fn sign_closing_transaction(
-		&self, closing_tx: &ClosingTransaction, secp_ctx: &Secp256k1<secp256k1::All>,
+		&self, channel_parameters: &ChannelTransactionParameters, closing_tx: &ClosingTransaction,
+		secp_ctx: &Secp256k1<secp256k1::All>,
 	) -> Result<Signature, ()>;
 	/// Computes the signature for a commitment transaction's anchor output used as an
 	/// input within `anchor_tx`, which spends the commitment transaction, at index `input`.

lightning/src/sign/mod.rs

@@ -1161,14 +1161,6 @@ impl InMemorySigner {
 		self.get_channel_parameters().map(|params| params.is_outbound_from_holder)
 	}
 
-	/// Funding outpoint
-	///
-	/// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called.
-	/// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation.
-	pub fn funding_outpoint(&self) -> Option<&OutPoint> {
-		self.get_channel_parameters().map(|params| params.funding_outpoint.as_ref()).flatten()
-	}
-
 	/// Returns a [`ChannelTransactionParameters`] for this channel, to be used when verifying or
 	/// building transactions.
 	///
@@ -1653,17 +1645,18 @@ impl EcdsaChannelSigner for InMemorySigner {
 	}
 
 	fn sign_closing_transaction(
-		&self, closing_tx: &ClosingTransaction, secp_ctx: &Secp256k1<secp256k1::All>,
+		&self, channel_parameters: &ChannelTransactionParameters, closing_tx: &ClosingTransaction,
+		secp_ctx: &Secp256k1<secp256k1::All>,
 	) -> Result<Signature, ()> {
 		let funding_pubkey = PublicKey::from_secret_key(secp_ctx, &self.funding_key);
 		let counterparty_funding_key =
-			&self.counterparty_pubkeys().expect(MISSING_PARAMS_ERR).funding_pubkey;
+			&channel_parameters.counterparty_pubkeys().expect(MISSING_PARAMS_ERR).funding_pubkey;
 		let channel_funding_redeemscript =
 			make_funding_redeemscript(&funding_pubkey, counterparty_funding_key);
 		Ok(closing_tx.trust().sign(
 			&self.funding_key,
 			&channel_funding_redeemscript,
-			self.channel_value_satoshis,
+			channel_parameters.channel_value_satoshis,
 			secp_ctx,
 		))
 	}

lightning/src/util/test_channel_signer.rs

@@ -434,16 +434,17 @@ impl EcdsaChannelSigner for TestChannelSigner {
 	}
 
 	fn sign_closing_transaction(
-		&self, closing_tx: &ClosingTransaction, secp_ctx: &Secp256k1<secp256k1::All>,
+		&self, channel_parameters: &ChannelTransactionParameters, closing_tx: &ClosingTransaction,
+		secp_ctx: &Secp256k1<secp256k1::All>,
 	) -> Result<Signature, ()> {
 		#[cfg(test)]
 		if !self.is_signer_available(SignerOp::SignClosingTransaction) {
 			return Err(());
 		}
 		closing_tx
-			.verify(self.inner.funding_outpoint().unwrap().into_bitcoin_outpoint())
+			.verify(channel_parameters.funding_outpoint.as_ref().unwrap().into_bitcoin_outpoint())
 			.expect("derived different closing transaction");
-		Ok(self.inner.sign_closing_transaction(closing_tx, secp_ctx).unwrap())
+		Ok(self.inner.sign_closing_transaction(channel_parameters, closing_tx, secp_ctx).unwrap())
 	}
 
 	fn sign_holder_anchor_input(