Test verification with experimental offer TLVs

Offer metadata is generated from the offer TLVs and should included
those in the experimental range. When verifying invoice request and
invoice messages, these TLVs must be included. Similarly, OfferId
construction should included these TLVs as well. Modify the BOLT12
verification tests to cover these TLVs.

Author: jkczyz

lightning/src/offers/invoice.rs

@@ -1706,7 +1706,9 @@ mod tests {
 					message_paths: None,
 				},
 				SignatureTlvStreamRef { signature: Some(&invoice.signature()) },
-				ExperimentalOfferTlvStreamRef {},
+				ExperimentalOfferTlvStreamRef {
+					experimental_foo: None,
+				},
 			),
 		);
 
@@ -1800,7 +1802,9 @@ mod tests {
 					message_paths: None,
 				},
 				SignatureTlvStreamRef { signature: Some(&invoice.signature()) },
-				ExperimentalOfferTlvStreamRef {},
+				ExperimentalOfferTlvStreamRef {
+					experimental_foo: None,
+				},
 			),
 		);
 
@@ -1894,6 +1898,7 @@ mod tests {
 		let offer = OfferBuilder::deriving_signing_pubkey(node_id, &expanded_key, nonce, &secp_ctx)
 			.amount_msats(1000)
 			.path(blinded_path)
+			.experimental_foo(42)
 			.build().unwrap();
 		let invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 			.build().unwrap()
@@ -1915,6 +1920,7 @@ mod tests {
 		let offer = OfferBuilder::deriving_signing_pubkey(node_id, &expanded_key, nonce, &secp_ctx)
 			.amount_msats(1000)
 			// Omit the path so that node_id is used for the signing pubkey instead of deriving it
+			.experimental_foo(42)
 			.build().unwrap();
 		let invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 			.build().unwrap()
@@ -1936,6 +1942,7 @@ mod tests {
 		let secp_ctx = Secp256k1::new();
 
 		let refund = RefundBuilder::new(vec![1; 32], payer_pubkey(), 1000).unwrap()
+			.experimental_foo(42)
 			.build().unwrap();
 
 		if let Err(e) = refund

lightning/src/offers/invoice_request.rs

@@ -1426,7 +1426,9 @@ mod tests {
 					paths: None,
 				},
 				SignatureTlvStreamRef { signature: Some(&invoice_request.signature()) },
-				ExperimentalOfferTlvStreamRef {},
+				ExperimentalOfferTlvStreamRef {
+					experimental_foo: None,
+				},
 			),
 		);
 
@@ -1474,6 +1476,7 @@ mod tests {
 
 		let offer = OfferBuilder::new(recipient_pubkey())
 			.amount_msats(1000)
+			.experimental_foo(42)
 			.build().unwrap();
 		let invoice_request = offer
 			.request_invoice_deriving_metadata(signing_pubkey, &expanded_key, nonce, payment_id)
@@ -1557,6 +1560,7 @@ mod tests {
 
 		let offer = OfferBuilder::new(recipient_pubkey())
 			.amount_msats(1000)
+			.experimental_foo(42)
 			.build().unwrap();
 		let invoice_request = offer
 			.request_invoice_deriving_signing_pubkey(&expanded_key, nonce, &secp_ctx, payment_id)

lightning/src/offers/offer.rs

@@ -225,6 +225,8 @@ macro_rules! offer_explicit_metadata_builder_methods { (
 				chains: None, metadata: None, amount: None, description: None,
 				features: OfferFeatures::empty(), absolute_expiry: None, issuer: None, paths: None,
 				supported_quantity: Quantity::One, issuer_signing_pubkey: Some(signing_pubkey),
+				#[cfg(test)]
+				experimental_foo: None,
 			},
 			metadata_strategy: core::marker::PhantomData,
 			secp_ctx: None,
@@ -266,6 +268,8 @@ macro_rules! offer_derived_metadata_builder_methods { ($secp_context: ty) => {
 				chains: None, metadata: Some(metadata), amount: None, description: None,
 				features: OfferFeatures::empty(), absolute_expiry: None, issuer: None, paths: None,
 				supported_quantity: Quantity::One, issuer_signing_pubkey: Some(node_id),
+				#[cfg(test)]
+				experimental_foo: None,
 			},
 			metadata_strategy: core::marker::PhantomData,
 			secp_ctx: Some(secp_ctx),
@@ -464,6 +468,12 @@ macro_rules! offer_builder_test_methods { (
 		$return_value
 	}
 
+	#[cfg_attr(c_bindings, allow(dead_code))]
+	pub(super) fn experimental_foo($($self_mut)* $self: $self_type, experimental_foo: u64) -> $return_type {
+		$self.offer.experimental_foo = Some(experimental_foo);
+		$return_value
+	}
+
 	#[cfg_attr(c_bindings, allow(dead_code))]
 	pub(super) fn build_unchecked($self: $self_type) -> Offer {
 		$self.build_without_checks()
@@ -571,6 +581,8 @@ pub(super) struct OfferContents {
 	paths: Option<Vec<BlindedMessagePath>>,
 	supported_quantity: Quantity,
 	issuer_signing_pubkey: Option<PublicKey>,
+	#[cfg(test)]
+	experimental_foo: Option<u64>,
 }
 
 macro_rules! offer_accessors { ($self: ident, $contents: expr) => {
@@ -1010,7 +1022,10 @@ impl OfferContents {
 			issuer_id: self.issuer_signing_pubkey.as_ref(),
 		};
 
-		let experimental_offer = ExperimentalOfferTlvStreamRef {};
+		let experimental_offer = ExperimentalOfferTlvStreamRef {
+			#[cfg(test)]
+			experimental_foo: self.experimental_foo,
+		};
 
 		(offer, experimental_offer)
 	}
@@ -1107,9 +1122,15 @@ tlv_stream!(OfferTlvStream, OfferTlvStreamRef<'a>, OFFER_TYPES, {
 /// Valid type range for experimental offer TLV records.
 pub(super) const EXPERIMENTAL_OFFER_TYPES: core::ops::Range<u64> = 1_000_000_000..2_000_000_000;
 
+#[cfg(not(test))]
 tlv_stream!(ExperimentalOfferTlvStream, ExperimentalOfferTlvStreamRef, EXPERIMENTAL_OFFER_TYPES, {
 });
 
+#[cfg(test)]
+tlv_stream!(ExperimentalOfferTlvStream, ExperimentalOfferTlvStreamRef, EXPERIMENTAL_OFFER_TYPES, {
+	(1_999_999_999, experimental_foo: (u64, HighZeroBytesDroppedBigSize)),
+});
+
 type FullOfferTlvStream = (OfferTlvStream, ExperimentalOfferTlvStream);
 
 type FullOfferTlvStreamRef<'a> = (OfferTlvStreamRef<'a>, ExperimentalOfferTlvStreamRef);
@@ -1157,7 +1178,10 @@ impl TryFrom<FullOfferTlvStream> for OfferContents {
 				chains, metadata, currency, amount, description, features, absolute_expiry, paths,
 				issuer, quantity_max, issuer_id,
 			},
-			ExperimentalOfferTlvStream {},
+			ExperimentalOfferTlvStream {
+				#[cfg(test)]
+				experimental_foo,
+			},
 		) = tlv_stream;
 
 		let metadata = metadata.map(|metadata| Metadata::Bytes(metadata));
@@ -1196,6 +1220,8 @@ impl TryFrom<FullOfferTlvStream> for OfferContents {
 		Ok(OfferContents {
 			chains, metadata, amount, description, features, absolute_expiry, issuer, paths,
 			supported_quantity, issuer_signing_pubkey,
+			#[cfg(test)]
+			experimental_foo,
 		})
 	}
 }
@@ -1274,7 +1300,9 @@ mod tests {
 					quantity_max: None,
 					issuer_id: Some(&pubkey(42)),
 				},
-				ExperimentalOfferTlvStreamRef {},
+				ExperimentalOfferTlvStreamRef {
+					experimental_foo: None,
+				},
 			),
 		);
 
@@ -1354,6 +1382,7 @@ mod tests {
 		use super::OfferWithDerivedMetadataBuilder as OfferBuilder;
 		let offer = OfferBuilder::deriving_signing_pubkey(node_id, &expanded_key, nonce, &secp_ctx)
 			.amount_msats(1000)
+			.experimental_foo(42)
 			.build().unwrap();
 		assert!(offer.metadata().is_some());
 		assert_eq!(offer.issuer_signing_pubkey(), Some(node_id));
@@ -1423,6 +1452,7 @@ mod tests {
 		let offer = OfferBuilder::deriving_signing_pubkey(node_id, &expanded_key, nonce, &secp_ctx)
 			.amount_msats(1000)
 			.path(blinded_path)
+			.experimental_foo(42)
 			.build().unwrap();
 		assert!(offer.metadata().is_none());
 		assert_ne!(offer.issuer_signing_pubkey(), Some(node_id));

lightning/src/offers/refund.rs

@@ -176,6 +176,8 @@ macro_rules! refund_explicit_metadata_builder_methods { () => {
 				payer: PayerContents(metadata), description: String::new(), absolute_expiry: None,
 				issuer: None, chain: None, amount_msats, features: InvoiceRequestFeatures::empty(),
 				quantity: None, payer_signing_pubkey: signing_pubkey, payer_note: None, paths: None,
+				#[cfg(test)]
+				experimental_foo: None,
 			},
 			secp_ctx: None,
 		})
@@ -218,6 +220,8 @@ macro_rules! refund_builder_methods { (
 				payer: PayerContents(metadata), description: String::new(), absolute_expiry: None,
 				issuer: None, chain: None, amount_msats, features: InvoiceRequestFeatures::empty(),
 				quantity: None, payer_signing_pubkey: node_id, payer_note: None, paths: None,
+				#[cfg(test)]
+				experimental_foo: None,
 			},
 			secp_ctx: Some(secp_ctx),
 		})
@@ -358,6 +362,12 @@ macro_rules! refund_builder_test_methods { (
 		$self.refund.features = features;
 		$return_value
 	}
+
+	#[cfg_attr(c_bindings, allow(dead_code))]
+	pub(super) fn experimental_foo($($self_mut)* $self: $self_type, experimental_foo: u64) -> $return_type {
+		$self.refund.experimental_foo = Some(experimental_foo);
+		$return_value
+	}
 } }
 
 impl<'a> RefundBuilder<'a, secp256k1::SignOnly> {
@@ -437,6 +447,8 @@ pub(super) struct RefundContents {
 	payer_signing_pubkey: PublicKey,
 	payer_note: Option<String>,
 	paths: Option<Vec<BlindedMessagePath>>,
+	#[cfg(test)]
+	experimental_foo: Option<u64>,
 }
 
 impl Refund {
@@ -770,7 +782,10 @@ impl RefundContents {
 			paths: self.paths.as_ref(),
 		};
 
-		let experimental_offer = ExperimentalOfferTlvStreamRef {};
+		let experimental_offer = ExperimentalOfferTlvStreamRef {
+			#[cfg(test)]
+			experimental_foo: self.experimental_foo,
+		};
 
 		(payer, offer, invoice_request, experimental_offer)
 	}
@@ -855,7 +870,10 @@ impl TryFrom<RefundTlvStream> for RefundContents {
 			InvoiceRequestTlvStream {
 				chain, amount, features, quantity, payer_id, payer_note, paths
 			},
-			_experimental_offer_tlv_stream,
+			ExperimentalOfferTlvStream {
+				#[cfg(test)]
+				experimental_foo,
+			},
 		) = tlv_stream;
 
 		let payer = match payer_metadata {
@@ -916,6 +934,8 @@ impl TryFrom<RefundTlvStream> for RefundContents {
 		Ok(RefundContents {
 			payer, description, absolute_expiry, issuer, chain, amount_msats, features, quantity,
 			payer_signing_pubkey, payer_note, paths,
+			#[cfg(test)]
+			experimental_foo,
 		})
 	}
 }
@@ -1021,7 +1041,9 @@ mod tests {
 					payer_note: None,
 					paths: None,
 				},
-				ExperimentalOfferTlvStreamRef {},
+				ExperimentalOfferTlvStreamRef {
+					experimental_foo: None,
+				},
 			),
 		);
 
@@ -1050,6 +1072,7 @@ mod tests {
 		let refund = RefundBuilder
 			::deriving_signing_pubkey(node_id, &expanded_key, nonce, &secp_ctx, 1000, payment_id)
 			.unwrap()
+			.experimental_foo(42)
 			.build().unwrap();
 		assert_eq!(refund.payer_signing_pubkey(), node_id);
 
@@ -1117,6 +1140,7 @@ mod tests {
 			::deriving_signing_pubkey(node_id, &expanded_key, nonce, &secp_ctx, 1000, payment_id)
 			.unwrap()
 			.path(blinded_path)
+			.experimental_foo(42)
 			.build().unwrap();
 		assert_ne!(refund.payer_signing_pubkey(), node_id);
 

lightning/src/offers/static_invoice.rs

@@ -840,7 +840,7 @@ mod tests {
 					message_paths: Some(&paths),
 				},
 				SignatureTlvStreamRef { signature: Some(&invoice.signature()) },
-				ExperimentalOfferTlvStreamRef {},
+				ExperimentalOfferTlvStreamRef { experimental_foo: None },
 			)
 		);
 
@@ -908,6 +908,52 @@ mod tests {
 		}
 	}
 
+	#[test]
+	fn builds_invoice_from_offer_using_derived_key() {
+		let node_id = recipient_pubkey();
+		let now = now();
+		let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
+		let entropy = FixedEntropy {};
+		let nonce = Nonce::from_entropy_source(&entropy);
+		let secp_ctx = Secp256k1::new();
+
+		let offer = OfferBuilder::deriving_signing_pubkey(node_id, &expanded_key, nonce, &secp_ctx)
+			.path(blinded_path())
+			.experimental_foo(42)
+			.build()
+			.unwrap();
+
+		if let Err(e) = StaticInvoiceBuilder::for_offer_using_derived_keys(
+			&offer,
+			payment_paths(),
+			vec![blinded_path()],
+			now,
+			&expanded_key,
+			nonce,
+			&secp_ctx,
+		)
+		.unwrap()
+		.build_and_sign(&secp_ctx)
+		{
+			panic!("error building invoice: {:?}", e);
+		}
+
+		let expanded_key = ExpandedKey::new(&KeyMaterial([41; 32]));
+		if let Err(e) = StaticInvoiceBuilder::for_offer_using_derived_keys(
+			&offer,
+			payment_paths(),
+			vec![blinded_path()],
+			now,
+			&expanded_key,
+			nonce,
+			&secp_ctx,
+		) {
+			assert_eq!(e, Bolt12SemanticError::InvalidMetadata);
+		} else {
+			panic!("expected error")
+		}
+	}
+
 	#[test]
 	fn fails_build_with_missing_paths() {
 		let node_id = recipient_pubkey();