Remove create_blinded_path_using_absolute_expiry

1. This function was initially introduced in commit
   `8012c2b213127372bdad150cdc354920d971087d` to allow using
   compact or full-length blinded paths based on the lifetime of
   Offers and Refunds.
2. With the introduction of `BlindedPathParams`, users can now
   explicitly specify the type of blinded path to be used, rendering
   this functionality redundant.
3. As a result, the corresponding `create_blinded_path` variant is removed.
4. The params parameter is introduced as an option, that allows the user
   to create Offers and Refund without BlindedPath if needed.

Author: shaavan

lightning/src/ln/channelmanager.rs

@@ -1725,12 +1725,16 @@ where
 /// # use lightning::events::{Event, EventsProvider, PaymentPurpose};
 /// # use lightning::ln::channelmanager::AChannelManager;
 /// # use lightning::offers::parse::Bolt12SemanticError;
+/// # use lightning::onion_message::messenger::BlindedPathParams;
 /// #
 /// # fn example<T: AChannelManager>(channel_manager: T) -> Result<(), Bolt12SemanticError> {
 /// # let channel_manager = channel_manager.get_cm();
-/// # let absolute_expiry = None;
+/// # let params = BlindedPathParams {
+/// # 	paths: 0,
+/// # 	is_compact: false,
+/// # };
 /// let offer = channel_manager
-///     .create_offer_builder(absolute_expiry)?
+///     .create_offer_builder(Some(params))?
 /// # ;
 /// # // Needed for compiling for c_bindings
 /// # let builder: lightning::offers::offer::OfferBuilder<_, _> = offer.into();
@@ -1828,16 +1832,21 @@ where
 /// # use lightning::events::{Event, EventsProvider};
 /// # use lightning::ln::channelmanager::{AChannelManager, PaymentId, RecentPaymentDetails, Retry};
 /// # use lightning::offers::parse::Bolt12SemanticError;
+/// # use lightning::onion_message::messenger::BlindedPathParams;
 /// #
 /// # fn example<T: AChannelManager>(
 /// #     channel_manager: T, amount_msats: u64, absolute_expiry: Duration, retry: Retry,
 /// #     max_total_routing_fee_msat: Option<u64>
 /// # ) -> Result<(), Bolt12SemanticError> {
 /// # let channel_manager = channel_manager.get_cm();
-/// let payment_id = PaymentId([42; 32]);
+/// # let params = BlindedPathParams {
+/// # 	paths: 0,
+/// # 	is_compact: false,
+/// # };
+/// # let payment_id = PaymentId([42; 32]);
 /// let refund = channel_manager
 ///     .create_refund_builder(
-///         amount_msats, absolute_expiry, payment_id, retry, max_total_routing_fee_msat
+///         Some(params), amount_msats, absolute_expiry, payment_id, retry, max_total_routing_fee_msat
 ///     )?
 /// # ;
 /// # // Needed for compiling for c_bindings
@@ -8831,7 +8840,7 @@ 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>
+		&$self, params: Option<BlindedPathParams>,
 	) -> Result<$builder, Bolt12SemanticError> {
 		let node_id = $self.get_our_node_id();
 		let expanded_key = &$self.inbound_payment_key;
@@ -8840,17 +8849,15 @@ macro_rules! create_offer_builder { ($self: ident, $builder: ty) => {
 
 		let nonce = Nonce::from_entropy_source(entropy);
 		let context = OffersContext::InvoiceRequest { nonce };
-		let path = $self.create_blinded_paths_using_absolute_expiry(context, absolute_expiry)
+		let mut builder = OfferBuilder::deriving_signing_pubkey(node_id, expanded_key, nonce, secp_ctx)
+			.chain_hash($self.chain_hash);
+		if let Some(params) = params {
+			let path = $self.create_blinded_paths(params, context)
 				.and_then(|paths| paths.into_iter().next().ok_or(()))
 				.map_err(|_| Bolt12SemanticError::MissingPaths)?;
-		let builder = OfferBuilder::deriving_signing_pubkey(node_id, expanded_key, nonce, secp_ctx)
-			.chain_hash($self.chain_hash)
-			.path(path);
-		
-		let builder = match absolute_expiry {
-			None => builder,
-			Some(absolute_expiry) => builder.absolute_expiry(absolute_expiry),
-		};
+
+			builder = builder.path(path);
+		}
 
 		Ok(builder.into())
 	}
@@ -8903,7 +8910,8 @@ macro_rules! create_refund_builder { ($self: ident, $builder: ty) => {
 	/// [`Bolt12Invoice::payment_paths`]: crate::offers::invoice::Bolt12Invoice::payment_paths
 	/// [Avoiding Duplicate Payments]: #avoiding-duplicate-payments
 	pub fn create_refund_builder(
-		&$self, amount_msats: u64, absolute_expiry: Duration, payment_id: PaymentId,
+		&$self, params: Option<BlindedPathParams>, amount_msats: u64,
+		absolute_expiry: Duration, payment_id: PaymentId,
 		retry_strategy: Retry, max_total_routing_fee_msat: Option<u64>
 	) -> Result<$builder, Bolt12SemanticError> {
 		let node_id = $self.get_our_node_id();
@@ -8914,15 +8922,19 @@ macro_rules! create_refund_builder { ($self: ident, $builder: ty) => {
 		let nonce = Nonce::from_entropy_source(entropy);
 		let context = OffersContext::OutboundPayment { payment_id, nonce, hmac: None };
 
-		let path = $self.create_blinded_paths_using_absolute_expiry(context, Some(absolute_expiry))
-			.and_then(|paths| paths.into_iter().next().ok_or(()))
-			.map_err(|_| Bolt12SemanticError::MissingPaths)?;
-		let builder = RefundBuilder::deriving_payer_id(
+		let mut builder = RefundBuilder::deriving_payer_id(
 			node_id, expanded_key, nonce, secp_ctx, amount_msats, payment_id
 		)?
 			.chain_hash($self.chain_hash)
-			.absolute_expiry(absolute_expiry)
-			.path(path);
+			.absolute_expiry(absolute_expiry);
+
+		if let Some(params) = params {
+			let path = $self.create_blinded_paths(params, context)
+				.and_then(|paths| paths.into_iter().next().ok_or(()))
+				.map_err(|_| Bolt12SemanticError::MissingPaths)?;
+
+			builder = builder.path(path);
+		};
 
 		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop($self);
 
@@ -9296,29 +9308,7 @@ where
 		inbound_payment::get_payment_preimage(payment_hash, payment_secret, &self.inbound_payment_key)
 	}
 
-	/// Creates a collection of blinded paths by delegating to [`MessageRouter`] based on
-	/// the path's intended lifetime.
-	///
-	/// Whether or not the path is compact depends on whether the path is short-lived or long-lived,
-	/// respectively, based on the given `absolute_expiry` as seconds since the Unix epoch. See
-	/// [`MAX_SHORT_LIVED_RELATIVE_EXPIRY`].
-	fn create_blinded_paths_using_absolute_expiry(
-		&self, context: OffersContext, absolute_expiry: Option<Duration>,
-	) -> Result<Vec<BlindedMessagePath>, ()> {
-		let now = self.duration_since_epoch();
-		let max_short_lived_absolute_expiry = now.saturating_add(MAX_SHORT_LIVED_RELATIVE_EXPIRY);
-
-		if absolute_expiry.unwrap_or(Duration::MAX) <= max_short_lived_absolute_expiry {
-			self.create_compact_blinded_paths(context)
-		} else {
-			let params = BlindedPathParams {
-				paths: PATHS_PLACEHOLDER,
-				is_compact: false
-			};
-			self.create_blinded_paths(params, context)
-		}
-	}
-
+	#[cfg(test)]
 	pub(super) fn duration_since_epoch(&self) -> Duration {
 		#[cfg(not(feature = "std"))]
 		let now = Duration::from_secs(
@@ -9357,6 +9347,7 @@ where
 	/// [`MessageRouter::create_compact_blinded_paths`].
 	///
 	/// Errors if the `MessageRouter` errors.
+	#[allow(unused)]
 	fn create_compact_blinded_paths(&self, context: OffersContext) -> Result<Vec<BlindedMessagePath>, ()> {
 		let recipient = self.get_our_node_id();
 		let secp_ctx = &self.secp_ctx;

lightning/src/ln/max_payment_path_len_tests.rs

@@ -24,6 +24,7 @@ use crate::ln::msgs::OnionMessageHandler;
 use crate::ln::onion_utils;
 use crate::ln::onion_utils::MIN_FINAL_VALUE_ESTIMATE_WITH_OVERPAY;
 use crate::ln::outbound_payment::{RecipientOnionFields, Retry, RetryableSendFailure};
+use crate::onion_message::messenger::{BlindedPathParams, PATHS_PLACEHOLDER};
 use crate::prelude::*;
 use crate::routing::router::{DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA, PaymentParameters, RouteParameters};
 use crate::util::errors::APIError;
@@ -377,7 +378,11 @@ fn bolt12_invoice_too_large_blinded_paths() {
 		)
 	]);
 
-	let offer = nodes[1].node.create_offer_builder(None).unwrap().build().unwrap();
+	let params = BlindedPathParams {
+		paths: PATHS_PLACEHOLDER,
+		is_compact: false,
+	};
+	let offer = nodes[1].node.create_offer_builder(Some(params)).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), None).unwrap();
 	let invreq_om = nodes[0].onion_messenger.next_onion_message_for_peer(nodes[1].node.get_our_node_id()).unwrap();