Make advance_path_by_one an associated method.

Author: valentinewallace

lightning/src/blinded_path/message.rs

@@ -138,6 +138,50 @@ impl BlindedMessagePath {
 		&self.0.blinded_hops
 	}
 
+	/// Advance the blinded onion message path by one hop, making the second hop into the new
+	/// introduction node.
+	///
+	/// Will only modify `path` when returning `Ok`.
+	pub fn advance_path_by_one<NS: Deref, NL: Deref, T>(
+		&mut self, node_signer: &NS, node_id_lookup: &NL, secp_ctx: &Secp256k1<T>
+	) -> Result<(), ()>
+	where
+			NS::Target: NodeSigner,
+			NL::Target: NodeIdLookUp,
+			T: secp256k1::Signing + secp256k1::Verification,
+	{
+		let control_tlvs_ss = node_signer.ecdh(Recipient::Node, &self.0.blinding_point, None)?;
+		let rho = onion_utils::gen_rho_from_shared_secret(&control_tlvs_ss.secret_bytes());
+		let encrypted_control_tlvs = &self.0.blinded_hops.get(0).ok_or(())?.encrypted_payload;
+		let mut s = Cursor::new(encrypted_control_tlvs);
+		let mut reader = FixedLengthReader::new(&mut s, encrypted_control_tlvs.len() as u64);
+		match ChaChaPolyReadAdapter::read(&mut reader, rho) {
+			Ok(ChaChaPolyReadAdapter {
+				readable: ControlTlvs::Forward(ForwardTlvs { next_hop, next_blinding_override })
+			}) => {
+				let next_node_id = match next_hop {
+					NextMessageHop::NodeId(pubkey) => pubkey,
+					NextMessageHop::ShortChannelId(scid) => match node_id_lookup.next_node_id(scid) {
+						Some(pubkey) => pubkey,
+						None => return Err(()),
+					},
+				};
+				let mut new_blinding_point = match next_blinding_override {
+					Some(blinding_point) => blinding_point,
+					None => {
+						onion_utils::next_hop_pubkey(secp_ctx, self.0.blinding_point,
+							control_tlvs_ss.as_ref()).map_err(|_| ())?
+					}
+				};
+				mem::swap(&mut self.0.blinding_point, &mut new_blinding_point);
+				self.0.introduction_node = IntroductionNode::NodeId(next_node_id);
+				self.0.blinded_hops.remove(0);
+				Ok(())
+			},
+			_ => Err(())
+		}
+	}
+
 	pub(crate) fn set_introduction_node_id(&mut self, node_id: PublicKey) {
 		self.0.introduction_node = IntroductionNode::NodeId(node_id);
 	}
@@ -345,46 +389,3 @@ pub(super) fn blinded_hops<T: secp256k1::Signing + secp256k1::Verification>(
 	utils::construct_blinded_hops(secp_ctx, pks, tlvs, session_priv)
 }
 
-/// Advance the blinded onion message path by one hop, making the second hop into the new
-/// introduction node.
-///
-/// Will only modify `path` when returning `Ok`.
-pub fn advance_path_by_one<NS: Deref, NL: Deref, T>(
-	path: &mut BlindedMessagePath, node_signer: &NS, node_id_lookup: &NL, secp_ctx: &Secp256k1<T>
-) -> Result<(), ()>
-where
-	NS::Target: NodeSigner,
-	NL::Target: NodeIdLookUp,
-	T: secp256k1::Signing + secp256k1::Verification,
-{
-	let control_tlvs_ss = node_signer.ecdh(Recipient::Node, &path.0.blinding_point, None)?;
-	let rho = onion_utils::gen_rho_from_shared_secret(&control_tlvs_ss.secret_bytes());
-	let encrypted_control_tlvs = &path.0.blinded_hops.get(0).ok_or(())?.encrypted_payload;
-	let mut s = Cursor::new(encrypted_control_tlvs);
-	let mut reader = FixedLengthReader::new(&mut s, encrypted_control_tlvs.len() as u64);
-	match ChaChaPolyReadAdapter::read(&mut reader, rho) {
-		Ok(ChaChaPolyReadAdapter {
-			readable: ControlTlvs::Forward(ForwardTlvs { next_hop, next_blinding_override })
-		}) => {
-			let next_node_id = match next_hop {
-				NextMessageHop::NodeId(pubkey) => pubkey,
-				NextMessageHop::ShortChannelId(scid) => match node_id_lookup.next_node_id(scid) {
-					Some(pubkey) => pubkey,
-					None => return Err(()),
-				},
-			};
-			let mut new_blinding_point = match next_blinding_override {
-				Some(blinding_point) => blinding_point,
-				None => {
-					onion_utils::next_hop_pubkey(secp_ctx, path.0.blinding_point,
-						control_tlvs_ss.as_ref()).map_err(|_| ())?
-				}
-			};
-			mem::swap(&mut path.0.blinding_point, &mut new_blinding_point);
-			path.0.introduction_node = IntroductionNode::NodeId(next_node_id);
-			path.0.blinded_hops.remove(0);
-			Ok(())
-		},
-		_ => Err(())
-	}
-}

lightning/src/blinded_path/payment.rs

@@ -121,6 +121,43 @@ impl BlindedPaymentPath {
 		&self.0.blinded_hops
 	}
 
+	/// Advance the blinded onion payment path by one hop, making the second hop into the new
+	/// introduction node.
+	///
+	/// Will only modify `path` when returning `Ok`.
+	pub fn advance_path_by_one<NS: Deref, NL: Deref, T>(
+		&mut self, node_signer: &NS, node_id_lookup: &NL, secp_ctx: &Secp256k1<T>
+	) -> Result<(), ()>
+	where
+			NS::Target: NodeSigner,
+			NL::Target: NodeIdLookUp,
+			T: secp256k1::Signing + secp256k1::Verification,
+	{
+		let control_tlvs_ss = node_signer.ecdh(Recipient::Node, &self.0.blinding_point, None)?;
+		let rho = onion_utils::gen_rho_from_shared_secret(&control_tlvs_ss.secret_bytes());
+		let encrypted_control_tlvs = &self.0.blinded_hops.get(0).ok_or(())?.encrypted_payload;
+		let mut s = Cursor::new(encrypted_control_tlvs);
+		let mut reader = FixedLengthReader::new(&mut s, encrypted_control_tlvs.len() as u64);
+		match ChaChaPolyReadAdapter::read(&mut reader, rho) {
+			Ok(ChaChaPolyReadAdapter {
+				readable: BlindedPaymentTlvs::Forward(ForwardTlvs { short_channel_id, .. })
+			}) => {
+				let next_node_id = match node_id_lookup.next_node_id(short_channel_id) {
+					Some(node_id) => node_id,
+					None => return Err(()),
+				};
+				let mut new_blinding_point = onion_utils::next_hop_pubkey(
+					secp_ctx, self.0.blinding_point, control_tlvs_ss.as_ref()
+				).map_err(|_| ())?;
+				mem::swap(&mut self.0.blinding_point, &mut new_blinding_point);
+				self.0.introduction_node = IntroductionNode::NodeId(next_node_id);
+				self.0.blinded_hops.remove(0);
+				Ok(())
+			},
+			_ => Err(())
+		}
+	}
+
 	#[cfg(any(test, fuzzing))]
 	pub fn from_raw(
 		introduction_node_id: PublicKey, blinding_point: PublicKey, blinded_hops: Vec<BlindedHop>
@@ -383,43 +420,6 @@ pub(super) fn blinded_hops<T: secp256k1::Signing + secp256k1::Verification>(
 	utils::construct_blinded_hops(secp_ctx, pks, tlvs, session_priv)
 }
 
-/// Advance the blinded onion payment path by one hop, making the second hop into the new
-/// introduction node.
-///
-/// Will only modify `path` when returning `Ok`.
-pub fn advance_path_by_one<NS: Deref, NL: Deref, T>(
-	path: &mut BlindedPaymentPath, node_signer: &NS, node_id_lookup: &NL, secp_ctx: &Secp256k1<T>
-) -> Result<(), ()>
-where
-	NS::Target: NodeSigner,
-	NL::Target: NodeIdLookUp,
-	T: secp256k1::Signing + secp256k1::Verification,
-{
-	let control_tlvs_ss = node_signer.ecdh(Recipient::Node, &path.0.blinding_point, None)?;
-	let rho = onion_utils::gen_rho_from_shared_secret(&control_tlvs_ss.secret_bytes());
-	let encrypted_control_tlvs = &path.0.blinded_hops.get(0).ok_or(())?.encrypted_payload;
-	let mut s = Cursor::new(encrypted_control_tlvs);
-	let mut reader = FixedLengthReader::new(&mut s, encrypted_control_tlvs.len() as u64);
-	match ChaChaPolyReadAdapter::read(&mut reader, rho) {
-		Ok(ChaChaPolyReadAdapter {
-			readable: BlindedPaymentTlvs::Forward(ForwardTlvs { short_channel_id, .. })
-		}) => {
-			let next_node_id = match node_id_lookup.next_node_id(short_channel_id) {
-				Some(node_id) => node_id,
-				None => return Err(()),
-			};
-			let mut new_blinding_point = onion_utils::next_hop_pubkey(
-				secp_ctx, path.0.blinding_point, control_tlvs_ss.as_ref()
-			).map_err(|_| ())?;
-			mem::swap(&mut path.0.blinding_point, &mut new_blinding_point);
-			path.0.introduction_node = IntroductionNode::NodeId(next_node_id);
-			path.0.blinded_hops.remove(0);
-			Ok(())
-		},
-		_ => Err(())
-	}
-}
-
 /// `None` if underflow occurs.
 pub(crate) fn amt_to_forward_msat(inbound_amt_msat: u64, payment_relay: &PaymentRelay) -> Option<u64> {
 	let inbound_amt = inbound_amt_msat as u128;

lightning/src/ln/outbound_payment.rs

@@ -14,7 +14,6 @@ use bitcoin::hashes::sha256::Hash as Sha256;
 use bitcoin::secp256k1::{self, Secp256k1, SecretKey};
 
 use crate::blinded_path::{IntroductionNode, NodeIdLookUp};
-use crate::blinded_path::payment::advance_path_by_one;
 use crate::events::{self, PaymentFailureReason};
 use crate::ln::types::{PaymentHash, PaymentPreimage, PaymentSecret};
 use crate::ln::channel_state::ChannelDetails;
@@ -845,7 +844,7 @@ impl OutboundPayments {
 					},
 				};
 				if introduction_node_id == our_node_id {
-					let _ = advance_path_by_one(path, node_signer, node_id_lookup, secp_ctx);
+					let _ = path.advance_path_by_one(node_signer, node_id_lookup, secp_ctx);
 				}
 			}
 		}

lightning/src/onion_message/messenger.rs

@@ -16,7 +16,7 @@ use bitcoin::hashes::sha256::Hash as Sha256;
 use bitcoin::secp256k1::{self, PublicKey, Scalar, Secp256k1, SecretKey};
 
 use crate::blinded_path::{IntroductionNode, NodeIdLookUp};
-use crate::blinded_path::message::{advance_path_by_one, BlindedMessagePath, ForwardNode, ForwardTlvs, MessageContext, NextMessageHop, ReceiveTlvs};
+use crate::blinded_path::message::{BlindedMessagePath, ForwardNode, ForwardTlvs, MessageContext, NextMessageHop, ReceiveTlvs};
 use crate::blinded_path::utils;
 use crate::events::{Event, EventHandler, EventsProvider, ReplayEvent};
 use crate::sign::{EntropySource, NodeSigner, Recipient};
@@ -901,7 +901,7 @@ where
 				},
 			};
 			if introduction_node_id == our_node_id {
-				advance_path_by_one(blinded_path, node_signer, node_id_lookup, &secp_ctx)
+				blinded_path.advance_path_by_one(node_signer, node_id_lookup, &secp_ctx)
 					.map_err(|()| SendError::BlindedPathAdvanceFailed)?;
 			}
 		}