Introduce Stronger Typing for VerifiedInvoiceRequest and Refactor Invoice Building Flow

lightning/src/ln/channelmanager.rs

@@ -91,11 +91,9 @@ use crate::ln::outbound_payment::{
 use crate::ln::types::ChannelId;
 use crate::offers::async_receive_offer_cache::AsyncReceiveOfferCache;
 use crate::offers::flow::{InvreqResponseInstructions, OffersMessageFlow};
-use crate::offers::invoice::{
-	Bolt12Invoice, DerivedSigningPubkey, InvoiceBuilder, DEFAULT_RELATIVE_EXPIRY,
-};
+use crate::offers::invoice::{Bolt12Invoice, UnsignedBolt12Invoice};
 use crate::offers::invoice_error::InvoiceError;
-use crate::offers::invoice_request::InvoiceRequest;
+use crate::offers::invoice_request::{InvoiceRequest, VerifiedInvoiceRequestEnum};
 use crate::offers::nonce::Nonce;
 use crate::offers::offer::Offer;
 use crate::offers::parse::Bolt12SemanticError;
@@ -7199,7 +7197,7 @@ where
 								};
 								let payment_purpose_context =
 									PaymentContext::Bolt12Offer(Bolt12OfferContext {
-										offer_id: verified_invreq.offer_id,
+										offer_id: verified_invreq.offer_id(),
 										invoice_request: verified_invreq.fields(),
 									});
 								let from_parts_res = events::PaymentPurpose::from_parts(
@@ -11999,27 +11997,24 @@ where
 	) -> Result<Bolt12Invoice, Bolt12SemanticError> {
 		let secp_ctx = &self.secp_ctx;
 
-		let amount_msats = refund.amount_msats();
-		let relative_expiry = DEFAULT_RELATIVE_EXPIRY.as_secs() as u32;
-
 		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(self);
 
-		match self.create_inbound_payment(Some(amount_msats), relative_expiry, None) {
-			Ok((payment_hash, payment_secret)) => {
-				let entropy = &*self.entropy_source;
-				let builder = self.flow.create_invoice_builder_from_refund(
-					&self.router, entropy, refund, payment_hash,
-					payment_secret, self.list_usable_channels()
-				)?;
-
-				let invoice = builder.allow_mpp().build_and_sign(secp_ctx)?;
+		let entropy = &*self.entropy_source;
+		let builder = self.flow.create_invoice_builder_from_refund(
+			&self.router, entropy, refund, self.list_usable_channels(),
+			|amount_msats, relative_expiry| {
+				self.create_inbound_payment(
+					Some(amount_msats),
+					relative_expiry,
+					None
+				).map_err(|()| Bolt12SemanticError::InvalidAmount)
+			}
+		)?;
 
-				self.flow.enqueue_invoice(invoice.clone(), refund, self.get_peers_for_blinded_path())?;
+		let invoice = builder.allow_mpp().build_and_sign(secp_ctx)?;
 
-				Ok(invoice)
-			},
-			Err(()) => Err(Bolt12SemanticError::InvalidAmount),
-		}
+		self.flow.enqueue_invoice(invoice.clone(), refund, self.get_peers_for_blinded_path())?;
+		Ok(invoice)
 	}
 
 	/// Pays for an [`Offer`] looked up using [BIP 353] Human Readable Names resolved by the DNS
@@ -14094,34 +14089,83 @@ where
 					Err(_) => return None,
 				};
 
-				let amount_msats = match InvoiceBuilder::<DerivedSigningPubkey>::amount_msats(
-					&invoice_request.inner
-				) {
-					Ok(amount_msats) => amount_msats,
-					Err(error) => return Some((OffersMessage::InvoiceError(error.into()), responder.respond())),
+				let get_payment_info = |amount_msats, relative_expiry| {
+					self.create_inbound_payment(
+						Some(amount_msats),
+						relative_expiry,
+						None
+					).map_err(|_| Bolt12SemanticError::InvalidAmount)
 				};
 
-				let relative_expiry = DEFAULT_RELATIVE_EXPIRY.as_secs() as u32;
-				let (payment_hash, payment_secret) = match self.create_inbound_payment(
-					Some(amount_msats), relative_expiry, None
-				) {
-					Ok((payment_hash, payment_secret)) => (payment_hash, payment_secret),
-					Err(()) => {
-						let error = Bolt12SemanticError::InvalidAmount;
-						return Some((OffersMessage::InvoiceError(error.into()), responder.respond()));
+				let (result, context) = match invoice_request {
+					VerifiedInvoiceRequestEnum::WithKeys(request) => {
+						let result = self.flow.create_invoice_builder_from_invoice_request_with_keys(
+							&self.router,
+							&*self.entropy_source,
+							&request,
+							self.list_usable_channels(),
+							get_payment_info,
+						);
+
+						match result {
+							Ok((builder, context)) => {
+								let res = builder
+									.build_and_sign(&self.secp_ctx)
+									.map_err(InvoiceError::from);
+
+								(res, context)
+							},
+							Err(error) => {
+								return Some((
+									OffersMessage::InvoiceError(InvoiceError::from(error)),
+									responder.respond(),
+								));
+							},
+						}
 					},
-				};
+					VerifiedInvoiceRequestEnum::WithoutKeys(request) => {
+						let result = self.flow.create_invoice_builder_from_invoice_request_without_keys(
+							&self.router,
+							&*self.entropy_source,
+							&request,
+							self.list_usable_channels(),
+							get_payment_info,
+						);
 
-				let entropy = &*self.entropy_source;
-				let (response, context) = self.flow.create_response_for_invoice_request(
-					&self.node_signer, &self.router, entropy, invoice_request, amount_msats,
-					payment_hash, payment_secret, self.list_usable_channels()
-				);
+						match result {
+							Ok((builder, context)) => {
+								let res = builder.
+									build()
+									.map_err(InvoiceError::from)
+									.and_then(|invoice| {
+										#[cfg(c_bindings)]
+										let mut invoice = invoice;
+										invoice
+											.sign(|invoice: &UnsignedBolt12Invoice| self.node_signer.sign_bolt12_invoice(invoice))
+											.map_err(InvoiceError::from)
+									});
+								(res, context)
+							},
+							Err(error) => {
+								return Some((
+									OffersMessage::InvoiceError(InvoiceError::from(error)),
+									responder.respond(),
+								));
+							},
+						}
+					}
+				};
 
-				match context {
-					Some(context) => Some((response, responder.respond_with_reply_path(context))),
-					None => Some((response, responder.respond()))
-				}
+				Some(match result {
+					Ok(invoice) => (
+						OffersMessage::Invoice(invoice),
+						responder.respond_with_reply_path(context),
+					),
+					Err(error) => (
+						OffersMessage::InvoiceError(error),
+						responder.respond(),
+					),
+				})
 			},
 			OffersMessage::Invoice(invoice) => {
 				let payment_id = match self.flow.verify_bolt12_invoice(&invoice, context.as_ref()) {

lightning/src/ln/offers_tests.rs

@@ -57,7 +57,7 @@ use crate::ln::msgs::{BaseMessageHandler, ChannelMessageHandler, Init, NodeAnnou
 use crate::ln::outbound_payment::IDEMPOTENCY_TIMEOUT_TICKS;
 use crate::offers::invoice::Bolt12Invoice;
 use crate::offers::invoice_error::InvoiceError;
-use crate::offers::invoice_request::{InvoiceRequest, InvoiceRequestFields};
+use crate::offers::invoice_request::{InvoiceRequest, InvoiceRequestFields, VerifiedInvoiceRequestEnum};
 use crate::offers::nonce::Nonce;
 use crate::offers::parse::Bolt12SemanticError;
 use crate::onion_message::messenger::{Destination, MessageSendInstructions, NodeIdMessageRouter, NullMessageRouter, PeeledOnion};
@@ -2279,11 +2279,19 @@ fn fails_paying_invoice_with_unknown_required_features() {
 	let secp_ctx = Secp256k1::new();
 
 	let created_at = alice.node.duration_since_epoch();
-	let invoice = invoice_request
-		.verify_using_recipient_data(nonce, &expanded_key, &secp_ctx).unwrap()
-		.respond_using_derived_keys_no_std(payment_paths, payment_hash, created_at).unwrap()
-		.features_unchecked(Bolt12InvoiceFeatures::unknown())
-		.build_and_sign(&secp_ctx).unwrap();
+	let verified_invoice_request = invoice_request
+		.verify_using_recipient_data(nonce, &expanded_key, &secp_ctx).unwrap();
+
+	let invoice = match verified_invoice_request {
+		VerifiedInvoiceRequestEnum::WithKeys(request) => {
+			request.respond_using_derived_keys_no_std(payment_paths, payment_hash, created_at).unwrap()
+				.features_unchecked(Bolt12InvoiceFeatures::unknown())
+				.build_and_sign(&secp_ctx).unwrap()
+		},
+		VerifiedInvoiceRequestEnum::WithoutKeys(_) => {
+			panic!("Expected invoice request with keys");
+		},
+	};
 
 	// Enqueue an onion message containing the new invoice.
 	let instructions = MessageSendInstructions::WithoutReplyPath {