Update create_offer_builder to use create_blinded_paths

This change updates the default `create_offer_builder` to
always use `create_blinded_paths`, enabling deterministic
creation of only full-length blinded paths.

Now that we provide `create_offer_builder_using_router`, users
who need custom path logic (like compact blinded path) can pass
in their own `MessageRouter`. This allows the default builder to
remain simple and consistent, while offering flexibility through
the alternate function.

Author: shaavan

lightning-dns-resolver/src/lib.rs

@@ -396,7 +396,7 @@ mod test {
 		let name = HumanReadableName::from_encoded("[email protected]").unwrap();
 
 		// When we get the proof back, override its contents to an offer from nodes[1]
-		let bs_offer = nodes[1].node.create_offer_builder(None).unwrap().build().unwrap();
+		let bs_offer = nodes[1].node.create_offer_builder().unwrap().build().unwrap();
 		let proof_override = &nodes[0].node.testing_dnssec_proof_offer_resolution_override;
 		proof_override.lock().unwrap().insert(name.clone(), bs_offer);
 

lightning/src/ln/channelmanager.rs

@@ -2091,9 +2091,8 @@ where
 /// #
 /// # fn example<T: AChannelManager>(channel_manager: T) -> Result<(), Bolt12SemanticError> {
 /// # let channel_manager = channel_manager.get_cm();
-/// # let absolute_expiry = None;
 /// let offer = channel_manager
-///     .create_offer_builder(absolute_expiry)?
+///     .create_offer_builder()?
 /// # ;
 /// # // Needed for compiling for c_bindings
 /// # let builder: lightning::offers::offer::OfferBuilder<_, _> = offer.into();
@@ -10173,15 +10172,36 @@ impl Default for Bolt11InvoiceParameters {
 }
 
 macro_rules! create_offer_builder { ($self: ident, $builder: ty) => {
+	fn create_offer_builder_intern<PF>(&$self, make_path: PF) -> Result<$builder, Bolt12SemanticError>
+	where
+		PF: FnOnce(PublicKey, MessageContext, &secp256k1::Secp256k1<secp256k1::All>) -> Result<Option<BlindedMessagePath>, Bolt12SemanticError>,
+	{
+		let node_id = $self.get_our_node_id();
+		let expanded_key = &$self.inbound_payment_key;
+		let entropy = &*$self.entropy_source;
+		let secp_ctx = &$self.secp_ctx;
+
+		let nonce = Nonce::from_entropy_source(entropy);
+		let context = MessageContext::Offers(OffersContext::InvoiceRequest { nonce });
+
+		let mut builder = OfferBuilder::deriving_signing_pubkey(node_id, expanded_key, nonce, secp_ctx)
+			.chain_hash($self.chain_hash);
+
+		if let Some(path) = make_path(node_id, context, secp_ctx)? {
+			builder = builder.path(path)
+		}
+
+		Ok(builder.into())
+	}
+
 	/// Creates an [`OfferBuilder`] such that the [`Offer`] it builds is recognized by the
 	/// [`ChannelManager`] when handling [`InvoiceRequest`] messages for the offer. The offer's
 	/// expiration will be `absolute_expiry` if `Some`, otherwise it will not expire.
 	///
 	/// # Privacy
 	///
-	/// Uses [`MessageRouter`] to construct a [`BlindedMessagePath`] for the offer based on the given
-	/// `absolute_expiry` according to [`MAX_SHORT_LIVED_RELATIVE_EXPIRY`]. See those docs for
-	/// privacy implications as well as those of the parameterized [`Router`], which implements
+	/// Uses [`MessageRouter`] to construct a [`BlindedMessagePath`] for the offer. See those docs
+	/// for privacy implications as well as those of the parameterized [`Router`], which implements
 	/// [`MessageRouter`].
 	///
 	/// Also, uses a derived signing pubkey in the offer for recipient privacy.
@@ -10197,29 +10217,13 @@ macro_rules! create_offer_builder { ($self: ident, $builder: ty) => {
 	///
 	/// [`Offer`]: crate::offers::offer::Offer
 	/// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
-	pub fn create_offer_builder(
-		&$self, absolute_expiry: Option<Duration>
-	) -> Result<$builder, Bolt12SemanticError> {
-		let node_id = $self.get_our_node_id();
-		let expanded_key = &$self.inbound_payment_key;
-		let entropy = &*$self.entropy_source;
-		let secp_ctx = &$self.secp_ctx;
-
-		let nonce = Nonce::from_entropy_source(entropy);
-		let context = OffersContext::InvoiceRequest { nonce };
-		let path = $self.create_blinded_paths_using_absolute_expiry(context, absolute_expiry)
-			.and_then(|paths| paths.into_iter().next().ok_or(()))
-			.map_err(|_| Bolt12SemanticError::MissingPaths)?;
-		let builder = OfferBuilder::deriving_signing_pubkey(node_id, expanded_key, nonce, secp_ctx)
-			.chain_hash($self.chain_hash)
-			.path(path);
-
-		let builder = match absolute_expiry {
-			None => builder,
-			Some(absolute_expiry) => builder.absolute_expiry(absolute_expiry),
-		};
-
-		Ok(builder.into())
+	pub fn create_offer_builder(&$self) -> Result<$builder, Bolt12SemanticError> {
+		$self.create_offer_builder_intern(|_, context, _| {
+			$self.create_blinded_paths(context)
+				.and_then(|paths| paths.into_iter().next().ok_or(()))
+				.map(Some)
+				.map_err(|_| Bolt12SemanticError::MissingPaths)
+		})
 	}
 
 	/// Creates an [`OfferBuilder`] such that the [`Offer`] it builds is recognized by the
@@ -10248,28 +10252,12 @@ macro_rules! create_offer_builder { ($self: ident, $builder: ty) => {
 		&$self,
 		router: ME,
 	) -> Result<$builder, Bolt12SemanticError> {
-		let node_id = $self.get_our_node_id();
-		let expanded_key = &$self.inbound_payment_key;
-		let entropy = &*$self.entropy_source;
-		let secp_ctx = &$self.secp_ctx;
-
-		let nonce = Nonce::from_entropy_source(entropy);
-		let context = MessageContext::Offers(OffersContext::InvoiceRequest { nonce });
-
-		let peers = $self.get_peers_for_blinded_path();
-
-		let path = router.create_blinded_paths(node_id, context, peers, secp_ctx)
-			.map_err(|_| Bolt12SemanticError::MissingPaths)?
-			.into_iter().next();
-
-		let mut builder = OfferBuilder::deriving_signing_pubkey(node_id, expanded_key, nonce, secp_ctx)
-			.chain_hash($self.chain_hash);
-
-		if let Some(path) = path {
-			builder = builder.path(path)
-		}
-
-		Ok(builder.into())
+		$self.create_offer_builder_intern(|node_id, context, secp_ctx| {
+			let peers = $self.get_peers_for_blinded_path();
+			router.create_blinded_paths(node_id, context, peers, secp_ctx)
+				.map(|paths| paths.into_iter().next())
+				.map_err(|_| Bolt12SemanticError::MissingPaths)
+		})
 	}
 } }
 

lightning/src/ln/max_payment_path_len_tests.rs

@@ -396,7 +396,7 @@ fn bolt12_invoice_too_large_blinded_paths() {
 		)
 	]);
 
-	let offer = nodes[1].node.create_offer_builder(None).unwrap().build().unwrap();
+	let offer = nodes[1].node.create_offer_builder().unwrap().build().unwrap();
 	let payment_id = PaymentId([1; 32]);
 	nodes[0].node.pay_for_offer(&offer, None, Some(5000), None, payment_id, Retry::Attempts(0), RouteParametersConfig::default()).unwrap();
 	let invreq_om = nodes[0].onion_messenger.next_onion_message_for_peer(nodes[1].node.get_our_node_id()).unwrap();

lightning/src/ln/offers_tests.rs

@@ -58,7 +58,7 @@ use crate::offers::invoice_error::InvoiceError;
 use crate::offers::invoice_request::{InvoiceRequest, InvoiceRequestFields};
 use crate::offers::nonce::Nonce;
 use crate::offers::parse::Bolt12SemanticError;
-use crate::onion_message::messenger::{Destination, PeeledOnion, MessageSendInstructions};
+use crate::onion_message::messenger::{Destination, MessageSendInstructions, PeeledOnion};
 use crate::onion_message::offers::OffersMessage;
 use crate::onion_message::packet::ParsedOnionMessageContents;
 use crate::routing::gossip::{NodeAlias, NodeId};
@@ -307,7 +307,7 @@ fn prefers_non_tor_nodes_in_blinded_paths() {
 	announce_node_address(charlie, &[alice, bob, david, &nodes[4], &nodes[5]], tor.clone());
 
 	let offer = bob.node
-		.create_offer_builder(None).unwrap()
+		.create_offer_builder().unwrap()
 		.amount_msats(10_000_000)
 		.build().unwrap();
 	assert_ne!(offer.issuer_signing_pubkey(), Some(bob_id));
@@ -323,7 +323,7 @@ fn prefers_non_tor_nodes_in_blinded_paths() {
 	announce_node_address(&nodes[5], &[alice, bob, charlie, david, &nodes[4]], tor.clone());
 
 	let offer = bob.node
-		.create_offer_builder(None).unwrap()
+		.create_offer_builder().unwrap()
 		.amount_msats(10_000_000)
 		.build().unwrap();
 	assert_ne!(offer.issuer_signing_pubkey(), Some(bob_id));
@@ -374,7 +374,7 @@ fn prefers_more_connected_nodes_in_blinded_paths() {
 	disconnect_peers(david, &[bob, &nodes[4], &nodes[5]]);
 
 	let offer = bob.node
-		.create_offer_builder(None).unwrap()
+		.create_offer_builder().unwrap()
 		.amount_msats(10_000_000)
 		.build().unwrap();
 	assert_ne!(offer.issuer_signing_pubkey(), Some(bob_id));
@@ -401,7 +401,8 @@ fn creates_short_lived_offer() {
 
 	let absolute_expiry = alice.node.duration_since_epoch() + MAX_SHORT_LIVED_RELATIVE_EXPIRY;
 	let offer = alice.node
-		.create_offer_builder(Some(absolute_expiry)).unwrap()
+		.create_offer_builder().unwrap()
+		.absolute_expiry(absolute_expiry)
 		.build().unwrap();
 	assert_eq!(offer.absolute_expiry(), Some(absolute_expiry));
 	assert!(!offer.paths().is_empty());
@@ -428,8 +429,9 @@ fn creates_long_lived_offer() {
 	let absolute_expiry = alice.node.duration_since_epoch() + MAX_SHORT_LIVED_RELATIVE_EXPIRY
 		+ Duration::from_secs(1);
 	let offer = alice.node
-		.create_offer_builder(Some(absolute_expiry))
+		.create_offer_builder()
 		.unwrap()
+		.absolute_expiry(absolute_expiry)
 		.build().unwrap();
 	assert_eq!(offer.absolute_expiry(), Some(absolute_expiry));
 	assert!(!offer.paths().is_empty());
@@ -438,7 +440,7 @@ fn creates_long_lived_offer() {
 	}
 
 	let offer = alice.node
-		.create_offer_builder(None).unwrap()
+		.create_offer_builder().unwrap()
 		.build().unwrap();
 	assert_eq!(offer.absolute_expiry(), None);
 	assert!(!offer.paths().is_empty());
@@ -542,7 +544,7 @@ fn creates_and_pays_for_offer_using_two_hop_blinded_path() {
 	disconnect_peers(david, &[bob, &nodes[4], &nodes[5]]);
 
 	let offer = alice.node
-		.create_offer_builder(None)
+		.create_offer_builder()
 		.unwrap()
 		.amount_msats(10_000_000)
 		.build().unwrap();
@@ -709,7 +711,7 @@ fn creates_and_pays_for_offer_using_one_hop_blinded_path() {
 	let bob_id = bob.node.get_our_node_id();
 
 	let offer = alice.node
-		.create_offer_builder(None).unwrap()
+		.create_offer_builder().unwrap()
 		.amount_msats(10_000_000)
 		.build().unwrap();
 	assert_ne!(offer.issuer_signing_pubkey(), Some(alice_id));
@@ -832,7 +834,7 @@ fn pays_for_offer_without_blinded_paths() {
 	let bob_id = bob.node.get_our_node_id();
 
 	let offer = alice.node
-		.create_offer_builder(None).unwrap()
+		.create_offer_builder().unwrap()
 		.clear_paths()
 		.amount_msats(10_000_000)
 		.build().unwrap();
@@ -956,7 +958,7 @@ fn send_invoice_requests_with_distinct_reply_path() {
 	disconnect_peers(david, &[bob, &nodes[4], &nodes[5]]);
 
 	let offer = alice.node
-		.create_offer_builder(None)
+		.create_offer_builder()
 		.unwrap()
 		.amount_msats(10_000_000)
 		.build().unwrap();
@@ -1092,7 +1094,7 @@ fn creates_and_pays_for_offer_with_retry() {
 	let bob_id = bob.node.get_our_node_id();
 
 	let offer = alice.node
-		.create_offer_builder(None).unwrap()
+		.create_offer_builder().unwrap()
 		.amount_msats(10_000_000)
 		.build().unwrap();
 	assert_ne!(offer.issuer_signing_pubkey(), Some(alice_id));
@@ -1168,7 +1170,7 @@ fn pays_bolt12_invoice_asynchronously() {
 	let bob_id = bob.node.get_our_node_id();
 
 	let offer = alice.node
-		.create_offer_builder(None).unwrap()
+		.create_offer_builder().unwrap()
 		.amount_msats(10_000_000)
 		.build().unwrap();
 
@@ -1253,7 +1255,7 @@ fn creates_offer_with_blinded_path_using_unannounced_introduction_node() {
 	let bob_id = bob.node.get_our_node_id();
 
 	let offer = alice.node
-		.create_offer_builder(None).unwrap()
+		.create_offer_builder().unwrap()
 		.amount_msats(10_000_000)
 		.build().unwrap();
 	assert_ne!(offer.issuer_signing_pubkey(), Some(alice_id));
@@ -1383,7 +1385,7 @@ fn fails_authentication_when_handling_invoice_request() {
 	disconnect_peers(david, &[bob, &nodes[4], &nodes[5]]);
 
 	let offer = alice.node
-		.create_offer_builder(None)
+		.create_offer_builder()
 		.unwrap()
 		.amount_msats(10_000_000)
 		.build().unwrap();
@@ -1395,7 +1397,7 @@ fn fails_authentication_when_handling_invoice_request() {
 	}
 
 	let invalid_path = alice.node
-		.create_offer_builder(None)
+		.create_offer_builder()
 		.unwrap()
 		.build().unwrap()
 		.paths().first().unwrap()
@@ -1495,7 +1497,7 @@ fn fails_authentication_when_handling_invoice_for_offer() {
 	disconnect_peers(david, &[bob, &nodes[4], &nodes[5]]);
 
 	let offer = alice.node
-		.create_offer_builder(None)
+		.create_offer_builder()
 		.unwrap()
 		.amount_msats(10_000_000)
 		.build().unwrap();
@@ -1692,7 +1694,7 @@ fn fails_creating_or_paying_for_offer_without_connected_peers() {
 	disconnect_peers(david, &[bob, charlie, &nodes[4], &nodes[5]]);
 
 	let absolute_expiry = alice.node.duration_since_epoch() + MAX_SHORT_LIVED_RELATIVE_EXPIRY;
-	match alice.node.create_offer_builder(Some(absolute_expiry)) {
+	match alice.node.create_offer_builder() {
 		Ok(_) => panic!("Expected error"),
 		Err(e) => assert_eq!(e, Bolt12SemanticError::MissingPaths),
 	}
@@ -1702,8 +1704,9 @@ fn fails_creating_or_paying_for_offer_without_connected_peers() {
 	reconnect_nodes(args);
 
 	let offer = alice.node
-		.create_offer_builder(Some(absolute_expiry)).unwrap()
+		.create_offer_builder().unwrap()
 		.amount_msats(10_000_000)
+		.absolute_expiry(absolute_expiry)
 		.build().unwrap();
 
 	let payment_id = PaymentId([1; 32]);
@@ -1806,7 +1809,7 @@ fn fails_creating_invoice_request_for_unsupported_chain() {
 	let bob = &nodes[1];
 
 	let offer = alice.node
-		.create_offer_builder(None).unwrap()
+		.create_offer_builder().unwrap()
 		.clear_chains()
 		.chain(Network::Signet)
 		.build().unwrap();
@@ -1865,7 +1868,7 @@ fn fails_creating_invoice_request_without_blinded_reply_path() {
 	disconnect_peers(david, &[bob, charlie, &nodes[4], &nodes[5]]);
 
 	let offer = alice.node
-		.create_offer_builder(None).unwrap()
+		.create_offer_builder().unwrap()
 		.amount_msats(10_000_000)
 		.build().unwrap();
 
@@ -1899,7 +1902,7 @@ fn fails_creating_invoice_request_with_duplicate_payment_id() {
 	disconnect_peers(alice, &[charlie, david, &nodes[4], &nodes[5]]);
 
 	let offer = alice.node
-		.create_offer_builder(None).unwrap()
+		.create_offer_builder().unwrap()
 		.amount_msats(10_000_000)
 		.build().unwrap();
 
@@ -1985,7 +1988,7 @@ fn fails_sending_invoice_without_blinded_payment_paths_for_offer() {
 	disconnect_peers(david, &[bob, &nodes[4], &nodes[5]]);
 
 	let offer = alice.node
-		.create_offer_builder(None).unwrap()
+		.create_offer_builder().unwrap()
 		.amount_msats(10_000_000)
 		.build().unwrap();
 
@@ -2194,7 +2197,7 @@ fn fails_paying_invoice_with_unknown_required_features() {
 	disconnect_peers(david, &[bob, &nodes[4], &nodes[5]]);
 
 	let offer = alice.node
-		.create_offer_builder(None).unwrap()
+		.create_offer_builder().unwrap()
 		.amount_msats(10_000_000)
 		.build().unwrap();
 
@@ -2273,7 +2276,7 @@ fn rejects_keysend_to_non_static_invoice_path() {
 	create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1_000_000, 0);
 
 	// First pay the offer and save the payment preimage and invoice.
-	let offer = nodes[1].node.create_offer_builder(None).unwrap().build().unwrap();
+	let offer = nodes[1].node.create_offer_builder().unwrap().build().unwrap();
 	let amt_msat = 5000;
 	let payment_id = PaymentId([1; 32]);
 	nodes[0].node.pay_for_offer(&offer, None, Some(amt_msat), None, payment_id, Retry::Attempts(1), RouteParametersConfig::default()).unwrap();
@@ -2353,7 +2356,7 @@ fn no_double_pay_with_stale_channelmanager() {
 
 	let amt_msat = nodes[0].node.list_usable_channels()[0].next_outbound_htlc_limit_msat + 1; // Force MPP
 	let offer = nodes[1].node
-		.create_offer_builder(None).unwrap()
+		.create_offer_builder().unwrap()
 		.clear_paths()
 		.amount_msats(amt_msat)
 		.build().unwrap();