Add TaprootSigner variant to SignerProvider.

Author: arik-so

fuzz/src/chanmon_consistency.rs

@@ -220,6 +220,7 @@ impl NodeSigner for KeyProvider {
 
 impl SignerProvider for KeyProvider {
 	type EcdsaSigner = EnforcingSigner;
+	type TaprootSigner = EnforcingSigner;
 
 	fn generate_channel_keys_id(&self, _inbound: bool, _channel_value_satoshis: u64, _user_channel_id: u128) -> [u8; 32] {
 		let id = self.rand_bytes_id.fetch_add(1, atomic::Ordering::Relaxed) as u8;

fuzz/src/full_stack.rs

@@ -325,6 +325,7 @@ impl NodeSigner for KeyProvider {
 
 impl SignerProvider for KeyProvider {
 	type EcdsaSigner = EnforcingSigner;
+	type TaprootSigner = EnforcingSigner;
 
 	fn generate_channel_keys_id(&self, inbound: bool, _channel_value_satoshis: u64, _user_channel_id: u128) -> [u8; 32] {
 		let ctr = self.counter.fetch_add(1, Ordering::Relaxed) as u8;

fuzz/src/onion_message.rs

@@ -160,6 +160,7 @@ impl NodeSigner for KeyProvider {
 
 impl SignerProvider for KeyProvider {
 	type EcdsaSigner = EnforcingSigner;
+	type TaprootSigner = EnforcingSigner;
 
 	fn generate_channel_keys_id(&self, _inbound: bool, _channel_value_satoshis: u64, _user_channel_id: u128) -> [u8; 32] { unreachable!() }
 

lightning/src/ln/channel.rs

@@ -7539,6 +7539,7 @@ mod tests {
 
 	impl SignerProvider for Keys {
 		type EcdsaSigner = InMemorySigner;
+		type TaprootSigner = InMemorySigner;
 
 		fn generate_channel_keys_id(&self, _inbound: bool, _channel_value_satoshis: u64, _user_channel_id: u128) -> [u8; 32] {
 			self.signer.channel_keys_id()

lightning/src/sign/mod.rs

@@ -50,6 +50,8 @@ use core::sync::atomic::{AtomicUsize, Ordering};
 use crate::io::{self, Error};
 use crate::ln::features::ChannelTypeFeatures;
 use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
+#[cfg(taproot)]
+use crate::sign::taproot::TaprootChannelSigner;
 use crate::util::atomic_counter::AtomicCounter;
 use crate::util::chacha20::ChaCha20;
 use crate::util::invoice::construct_invoice_preimage;
@@ -638,6 +640,9 @@ pub trait NodeSigner {
 pub trait SignerProvider {
 	/// A type which implements [`WriteableEcdsaChannelSigner`] which will be returned by [`Self::derive_channel_signer`].
 	type EcdsaSigner: WriteableEcdsaChannelSigner;
+	#[cfg(taproot)]
+	/// A type which implements [`TaprootChannelSigner`]
+	type TaprootSigner: TaprootChannelSigner;
 
 	/// Generates a unique `channel_keys_id` that can be used to obtain a [`Self::EcdsaSigner`] through
 	/// [`SignerProvider::derive_channel_signer`]. The `user_channel_id` is provided to allow
@@ -1463,6 +1468,8 @@ impl NodeSigner for KeysManager {
 
 impl SignerProvider for KeysManager {
 	type EcdsaSigner = InMemorySigner;
+	#[cfg(taproot)]
+	type TaprootSigner = InMemorySigner;
 
 	fn generate_channel_keys_id(&self, _inbound: bool, _channel_value_satoshis: u64, user_channel_id: u128) -> [u8; 32] {
 		let child_idx = self.channel_child_index.fetch_add(1, Ordering::AcqRel);
@@ -1570,6 +1577,8 @@ impl NodeSigner for PhantomKeysManager {
 
 impl SignerProvider for PhantomKeysManager {
 	type EcdsaSigner = InMemorySigner;
+	#[cfg(taproot)]
+	type TaprootSigner = InMemorySigner;
 
 	fn generate_channel_keys_id(&self, inbound: bool, channel_value_satoshis: u64, user_channel_id: u128) -> [u8; 32] {
 		self.inner.generate_channel_keys_id(inbound, channel_value_satoshis, user_channel_id)

lightning/src/sign/taproot.rs

@@ -147,3 +147,5 @@ pub trait TaprootChannelSigner: ChannelSigner {
 
 	// TODO: sign channel announcement
 }
+
+impl TaprootChannelSigner for super::InMemorySigner {}

lightning/src/util/enforcing_trait_impls.rs

@@ -27,6 +27,8 @@ use crate::events::bump_transaction::HTLCDescriptor;
 use crate::util::ser::{Writeable, Writer};
 use crate::io::Error;
 use crate::ln::features::ChannelTypeFeatures;
+#[cfg(taproot)]
+use crate::sign::taproot::TaprootChannelSigner;
 
 /// Initial value for revoked commitment downward counter
 pub const INITIAL_REVOKED_COMMITMENT_NUMBER: u64 = 1 << 48;
@@ -243,6 +245,9 @@ impl EcdsaChannelSigner for EnforcingSigner {
 
 impl WriteableEcdsaChannelSigner for EnforcingSigner {}
 
+#[cfg(taproot)]
+impl TaprootChannelSigner for EnforcingSigner {}
+
 impl Writeable for EnforcingSigner {
 	fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
 		// EnforcingSigner has two fields - `inner` ([`InMemorySigner`]) and `state`

lightning/src/util/test_utils.rs

@@ -169,6 +169,8 @@ impl EntropySource for OnlyReadsKeysInterface {
 
 impl SignerProvider for OnlyReadsKeysInterface {
 	type EcdsaSigner = EnforcingSigner;
+	#[cfg(taproot)]
+	type TaprootSigner = EnforcingSigner;
 
 	fn generate_channel_keys_id(&self, _inbound: bool, _channel_value_satoshis: u64, _user_channel_id: u128) -> [u8; 32] { unreachable!(); }
 
@@ -847,6 +849,8 @@ impl NodeSigner for TestKeysInterface {
 
 impl SignerProvider for TestKeysInterface {
 	type EcdsaSigner = EnforcingSigner;
+	#[cfg(taproot)]
+	type TaprootSigner = EnforcingSigner;
 
 	fn generate_channel_keys_id(&self, inbound: bool, channel_value_satoshis: u64, user_channel_id: u128) -> [u8; 32] {
 		self.backing.generate_channel_keys_id(inbound, channel_value_satoshis, user_channel_id)