Update docs and method names for blinded payment paths

Author: valentinewallace

fuzz/src/invoice_request_deser.rs

@@ -74,8 +74,8 @@ fn build_response<'a, T: secp256k1::Signing + secp256k1::Verification>(
 ) -> Result<UnsignedInvoice<'a>, SemanticError> {
 	let entropy_source = Randomness {};
 	let paths = vec![
-		BlindedPath::new(&[pubkey(43), pubkey(44), pubkey(42)], &entropy_source, secp_ctx).unwrap(),
-		BlindedPath::new(&[pubkey(45), pubkey(46), pubkey(42)], &entropy_source, secp_ctx).unwrap(),
+		BlindedPath::new_for_message(&[pubkey(43), pubkey(44), pubkey(42)], &entropy_source, secp_ctx).unwrap(),
+		BlindedPath::new_for_message(&[pubkey(45), pubkey(46), pubkey(42)], &entropy_source, secp_ctx).unwrap(),
 	];
 
 	let payinfo = vec![

fuzz/src/refund_deser.rs

@@ -63,8 +63,8 @@ fn build_response<'a, T: secp256k1::Signing + secp256k1::Verification>(
 ) -> Result<UnsignedInvoice<'a>, SemanticError> {
 	let entropy_source = Randomness {};
 	let paths = vec![
-		BlindedPath::new(&[pubkey(43), pubkey(44), pubkey(42)], &entropy_source, secp_ctx).unwrap(),
-		BlindedPath::new(&[pubkey(45), pubkey(46), pubkey(42)], &entropy_source, secp_ctx).unwrap(),
+		BlindedPath::new_for_message(&[pubkey(43), pubkey(44), pubkey(42)], &entropy_source, secp_ctx).unwrap(),
+		BlindedPath::new_for_message(&[pubkey(45), pubkey(46), pubkey(42)], &entropy_source, secp_ctx).unwrap(),
 	];
 
 	let payinfo = vec![

lightning/src/blinded_path/mod.rs

@@ -27,18 +27,18 @@ use core::ops::Deref;
 use crate::io::{self, Cursor};
 use crate::prelude::*;
 
-/// Onion messages can be sent and received to blinded paths, which serve to hide the identity of
-/// the recipient.
+/// Onion messages and payments can be sent and received to blinded paths, which serve to hide the
+/// identity of the recipient.
 #[derive(Clone, Debug, PartialEq)]
 pub struct BlindedPath {
 	/// To send to a blinded path, the sender first finds a route to the unblinded
 	/// `introduction_node_id`, which can unblind its [`encrypted_payload`] to find out the onion
-	/// message's next hop and forward it along.
+	/// message or payment's next hop and forward it along.
 	///
 	/// [`encrypted_payload`]: BlindedHop::encrypted_payload
 	pub(crate) introduction_node_id: PublicKey,
 	/// Used by the introduction node to decrypt its [`encrypted_payload`] to forward the onion
-	/// message.
+	/// message or payment.
 	///
 	/// [`encrypted_payload`]: BlindedHop::encrypted_payload
 	pub(crate) blinding_point: PublicKey,
@@ -59,12 +59,12 @@ pub struct BlindedHop {
 }
 
 impl BlindedPath {
-	/// Create a blinded path to be forwarded along `node_pks`. The last node pubkey in `node_pks`
-	/// will be the destination node.
+	/// Create a blinded path for an onion message, to be forwarded along `node_pks`. The last node
+	/// pubkey in `node_pks` will be the destination node.
 	///
 	/// Errors if less than two hops are provided or if `node_pk`(s) are invalid.
 	//  TODO: make all payloads the same size with padding + add dummy hops
-	pub fn new<ES: EntropySource, T: secp256k1::Signing + secp256k1::Verification>
+	pub fn new_for_message<ES: EntropySource, T: secp256k1::Signing + secp256k1::Verification>
 		(node_pks: &[PublicKey], entropy_source: &ES, secp_ctx: &Secp256k1<T>) -> Result<Self, ()>
 	{
 		if node_pks.len() < 2 { return Err(()) }
@@ -75,12 +75,13 @@ impl BlindedPath {
 		Ok(BlindedPath {
 			introduction_node_id,
 			blinding_point: PublicKey::from_secret_key(secp_ctx, &blinding_secret),
-			blinded_hops: blinded_hops(secp_ctx, node_pks, &blinding_secret).map_err(|_| ())?,
+			blinded_hops: blinded_message_hops(secp_ctx, node_pks, &blinding_secret).map_err(|_| ())?,
 		})
 	}
 
-	// Advance the blinded path by one hop, so make the second hop into the new introduction node.
-	pub(super) fn advance_by_one<NS: Deref, T: secp256k1::Signing + secp256k1::Verification>
+	// Advance the blinded onion message path by one hop, so make the second hop into the new
+	// introduction node.
+	pub(super) fn advance_message_path_by_one<NS: Deref, T: secp256k1::Signing + secp256k1::Verification>
 		(&mut self, node_signer: &NS, secp_ctx: &Secp256k1<T>) -> Result<(), ()>
 		where NS::Target: NodeSigner
 	{
@@ -115,8 +116,8 @@ impl BlindedPath {
 	}
 }
 
-/// Construct blinded hops for the given `unblinded_path`.
-fn blinded_hops<T: secp256k1::Signing + secp256k1::Verification>(
+/// Construct blinded onion message hops for the given `unblinded_path`.
+fn blinded_message_hops<T: secp256k1::Signing + secp256k1::Verification>(
 	secp_ctx: &Secp256k1<T>, unblinded_path: &[PublicKey], session_priv: &SecretKey
 ) -> Result<Vec<BlindedHop>, secp256k1::Error> {
 	let mut blinded_hops = Vec::with_capacity(unblinded_path.len());

lightning/src/onion_message/functional_tests.rs

@@ -136,7 +136,7 @@ fn two_unblinded_two_blinded() {
 	let test_msg = OnionMessageContents::Custom(TestCustomMessage {});
 
 	let secp_ctx = Secp256k1::new();
-	let blinded_path = BlindedPath::new(&[nodes[3].get_node_pk(), nodes[4].get_node_pk()], &*nodes[4].keys_manager, &secp_ctx).unwrap();
+	let blinded_path = BlindedPath::new_for_message(&[nodes[3].get_node_pk(), nodes[4].get_node_pk()], &*nodes[4].keys_manager, &secp_ctx).unwrap();
 
 	nodes[0].messenger.send_onion_message(&[nodes[1].get_node_pk(), nodes[2].get_node_pk()], Destination::BlindedPath(blinded_path), test_msg, None).unwrap();
 	pass_along_path(&nodes, None);
@@ -148,7 +148,7 @@ fn three_blinded_hops() {
 	let test_msg = OnionMessageContents::Custom(TestCustomMessage {});
 
 	let secp_ctx = Secp256k1::new();
-	let blinded_path = BlindedPath::new(&[nodes[1].get_node_pk(), nodes[2].get_node_pk(), nodes[3].get_node_pk()], &*nodes[3].keys_manager, &secp_ctx).unwrap();
+	let blinded_path = BlindedPath::new_for_message(&[nodes[1].get_node_pk(), nodes[2].get_node_pk(), nodes[3].get_node_pk()], &*nodes[3].keys_manager, &secp_ctx).unwrap();
 
 	nodes[0].messenger.send_onion_message(&[], Destination::BlindedPath(blinded_path), test_msg, None).unwrap();
 	pass_along_path(&nodes, None);
@@ -174,13 +174,13 @@ fn we_are_intro_node() {
 	let test_msg = TestCustomMessage {};
 
 	let secp_ctx = Secp256k1::new();
-	let blinded_path = BlindedPath::new(&[nodes[0].get_node_pk(), nodes[1].get_node_pk(), nodes[2].get_node_pk()], &*nodes[2].keys_manager, &secp_ctx).unwrap();
+	let blinded_path = BlindedPath::new_for_message(&[nodes[0].get_node_pk(), nodes[1].get_node_pk(), nodes[2].get_node_pk()], &*nodes[2].keys_manager, &secp_ctx).unwrap();
 
 	nodes[0].messenger.send_onion_message(&[], Destination::BlindedPath(blinded_path), OnionMessageContents::Custom(test_msg.clone()), None).unwrap();
 	pass_along_path(&nodes, None);
 
 	// Try with a two-hop blinded path where we are the introduction node.
-	let blinded_path = BlindedPath::new(&[nodes[0].get_node_pk(), nodes[1].get_node_pk()], &*nodes[1].keys_manager, &secp_ctx).unwrap();
+	let blinded_path = BlindedPath::new_for_message(&[nodes[0].get_node_pk(), nodes[1].get_node_pk()], &*nodes[1].keys_manager, &secp_ctx).unwrap();
 	nodes[0].messenger.send_onion_message(&[], Destination::BlindedPath(blinded_path), OnionMessageContents::Custom(test_msg), None).unwrap();
 	nodes.remove(2);
 	pass_along_path(&nodes, None);
@@ -194,13 +194,13 @@ fn invalid_blinded_path_error() {
 
 	// 0 hops
 	let secp_ctx = Secp256k1::new();
-	let mut blinded_path = BlindedPath::new(&[nodes[1].get_node_pk(), nodes[2].get_node_pk()], &*nodes[2].keys_manager, &secp_ctx).unwrap();
+	let mut blinded_path = BlindedPath::new_for_message(&[nodes[1].get_node_pk(), nodes[2].get_node_pk()], &*nodes[2].keys_manager, &secp_ctx).unwrap();
 	blinded_path.blinded_hops.clear();
 	let err = nodes[0].messenger.send_onion_message(&[], Destination::BlindedPath(blinded_path), OnionMessageContents::Custom(test_msg.clone()), None).unwrap_err();
 	assert_eq!(err, SendError::TooFewBlindedHops);
 
 	// 1 hop
-	let mut blinded_path = BlindedPath::new(&[nodes[1].get_node_pk(), nodes[2].get_node_pk()], &*nodes[2].keys_manager, &secp_ctx).unwrap();
+	let mut blinded_path = BlindedPath::new_for_message(&[nodes[1].get_node_pk(), nodes[2].get_node_pk()], &*nodes[2].keys_manager, &secp_ctx).unwrap();
 	blinded_path.blinded_hops.remove(0);
 	assert_eq!(blinded_path.blinded_hops.len(), 1);
 	let err = nodes[0].messenger.send_onion_message(&[], Destination::BlindedPath(blinded_path), OnionMessageContents::Custom(test_msg), None).unwrap_err();
@@ -214,7 +214,7 @@ fn reply_path() {
 	let secp_ctx = Secp256k1::new();
 
 	// Destination::Node
-	let reply_path = BlindedPath::new(&[nodes[2].get_node_pk(), nodes[1].get_node_pk(), nodes[0].get_node_pk()], &*nodes[0].keys_manager, &secp_ctx).unwrap();
+	let reply_path = BlindedPath::new_for_message(&[nodes[2].get_node_pk(), nodes[1].get_node_pk(), nodes[0].get_node_pk()], &*nodes[0].keys_manager, &secp_ctx).unwrap();
 	nodes[0].messenger.send_onion_message(&[nodes[1].get_node_pk(), nodes[2].get_node_pk()], Destination::Node(nodes[3].get_node_pk()), OnionMessageContents::Custom(test_msg.clone()), Some(reply_path)).unwrap();
 	pass_along_path(&nodes, None);
 	// Make sure the last node successfully decoded the reply path.
@@ -223,8 +223,8 @@ fn reply_path() {
 		&format!("Received an onion message with path_id None and a reply_path"), 1);
 
 	// Destination::BlindedPath
-	let blinded_path = BlindedPath::new(&[nodes[1].get_node_pk(), nodes[2].get_node_pk(), nodes[3].get_node_pk()], &*nodes[3].keys_manager, &secp_ctx).unwrap();
-	let reply_path = BlindedPath::new(&[nodes[2].get_node_pk(), nodes[1].get_node_pk(), nodes[0].get_node_pk()], &*nodes[0].keys_manager, &secp_ctx).unwrap();
+	let blinded_path = BlindedPath::new_for_message(&[nodes[1].get_node_pk(), nodes[2].get_node_pk(), nodes[3].get_node_pk()], &*nodes[3].keys_manager, &secp_ctx).unwrap();
+	let reply_path = BlindedPath::new_for_message(&[nodes[2].get_node_pk(), nodes[1].get_node_pk(), nodes[0].get_node_pk()], &*nodes[0].keys_manager, &secp_ctx).unwrap();
 
 	nodes[0].messenger.send_onion_message(&[], Destination::BlindedPath(blinded_path), OnionMessageContents::Custom(test_msg), Some(reply_path)).unwrap();
 	pass_along_path(&nodes, None);

lightning/src/onion_message/messenger.rs

@@ -91,7 +91,7 @@ use crate::prelude::*;
 /// // Create a blinded path to yourself, for someone to send an onion message to.
 /// # let your_node_id = hop_node_id1;
 /// let hops = [hop_node_id3, hop_node_id4, your_node_id];
-/// let blinded_path = BlindedPath::new(&hops, &keys_manager, &secp_ctx).unwrap();
+/// let blinded_path = BlindedPath::new_for_message(&hops, &keys_manager, &secp_ctx).unwrap();
 ///
 /// // Send a custom onion message to a blinded path.
 /// # let intermediate_hops = [hop_node_id1, hop_node_id2];
@@ -226,7 +226,7 @@ impl<ES: Deref, NS: Deref, L: Deref, CMH: Deref> OnionMessenger<ES, NS, L, CMH>
 				let our_node_id = self.node_signer.get_node_id(Recipient::Node)
 					.map_err(|()| SendError::GetNodeIdFailed)?;
 				if blinded_path.introduction_node_id == our_node_id {
-					blinded_path.advance_by_one(&self.node_signer, &self.secp_ctx)
+					blinded_path.advance_message_path_by_one(&self.node_signer, &self.secp_ctx)
 						.map_err(|()| SendError::BlindedPathAdvanceFailed)?;
 				}
 			}