+ #[test]
+ fn builds_invoice_request_with_derived_metadata() {
+ let payer_id = payer_pubkey();
+ let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
+ let entropy = FixedEntropy {};
+ let secp_ctx = Secp256k1::new();
+
+ let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
+ .amount_msats(1000)
+ .build().unwrap();
+ let invoice_request = offer
+ .request_invoice_deriving_metadata(payer_id, &expanded_key, &entropy)
+ .unwrap()
+ .build().unwrap()
+ .sign(payer_sign).unwrap();
+ assert_eq!(invoice_request.payer_id(), payer_pubkey());
+
+ let invoice = invoice_request.respond_with_no_std(payment_paths(), payment_hash(), now())
+ .unwrap()
+ .build().unwrap()
+ .sign(recipient_sign).unwrap();
+ assert!(invoice.verify(&expanded_key, &secp_ctx));
+
+ // Fails verification with altered fields
+ let (
+ payer_tlv_stream, offer_tlv_stream, mut invoice_request_tlv_stream,
+ mut invoice_tlv_stream, mut signature_tlv_stream
+ ) = invoice.as_tlv_stream();
+ invoice_request_tlv_stream.amount = Some(2000);
+ invoice_tlv_stream.amount = Some(2000);
+
+ let tlv_stream =
+ (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream);
+ let mut bytes = Vec::new();
+ tlv_stream.write(&mut bytes).unwrap();
+
+ let signature = merkle::sign_message(
+ recipient_sign, INVOICE_SIGNATURE_TAG, &bytes, recipient_pubkey()
+ ).unwrap();
+ signature_tlv_stream.signature = Some(&signature);
+
+ let mut encoded_invoice = bytes;
+ signature_tlv_stream.write(&mut encoded_invoice).unwrap();
+
+ let invoice = Invoice::try_from(encoded_invoice).unwrap();
+ assert!(!invoice.verify(&expanded_key, &secp_ctx));
+
+ // Fails verification with altered metadata
+ let (
+ mut payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream,
+ mut signature_tlv_stream
+ ) = invoice.as_tlv_stream();
+ let metadata = payer_tlv_stream.metadata.unwrap().iter().copied().rev().collect();
+ payer_tlv_stream.metadata = Some(&metadata);
+
+ let tlv_stream =
+ (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream);
+ let mut bytes = Vec::new();
+ tlv_stream.write(&mut bytes).unwrap();
+
+ let signature = merkle::sign_message(
+ recipient_sign, INVOICE_SIGNATURE_TAG, &bytes, recipient_pubkey()
+ ).unwrap();
+ signature_tlv_stream.signature = Some(&signature);
+
+ let mut encoded_invoice = bytes;
+ signature_tlv_stream.write(&mut encoded_invoice).unwrap();
+
+ let invoice = Invoice::try_from(encoded_invoice).unwrap();
+ assert!(!invoice.verify(&expanded_key, &secp_ctx));
+ }
+
+ #[test]
+ fn builds_invoice_request_with_derived_payer_id() {
+ let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
+ let entropy = FixedEntropy {};
+ let secp_ctx = Secp256k1::new();
+
+ let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
+ .amount_msats(1000)
+ .build().unwrap();
+ let invoice_request = offer
+ .request_invoice_deriving_payer_id(&expanded_key, &entropy, &secp_ctx)
+ .unwrap()
+ .build_and_sign()
+ .unwrap();
+
+ let invoice = invoice_request.respond_with_no_std(payment_paths(), payment_hash(), now())
+ .unwrap()
+ .build().unwrap()
+ .sign(recipient_sign).unwrap();
+ assert!(invoice.verify(&expanded_key, &secp_ctx));
+
+ // Fails verification with altered fields
+ let (
+ payer_tlv_stream, offer_tlv_stream, mut invoice_request_tlv_stream,
+ mut invoice_tlv_stream, mut signature_tlv_stream
+ ) = invoice.as_tlv_stream();
+ invoice_request_tlv_stream.amount = Some(2000);
+ invoice_tlv_stream.amount = Some(2000);
+
+ let tlv_stream =
+ (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream);
+ let mut bytes = Vec::new();
+ tlv_stream.write(&mut bytes).unwrap();
+
+ let signature = merkle::sign_message(
+ recipient_sign, INVOICE_SIGNATURE_TAG, &bytes, recipient_pubkey()
+ ).unwrap();
+ signature_tlv_stream.signature = Some(&signature);
+
+ let mut encoded_invoice = bytes;
+ signature_tlv_stream.write(&mut encoded_invoice).unwrap();
+
+ let invoice = Invoice::try_from(encoded_invoice).unwrap();
+ assert!(!invoice.verify(&expanded_key, &secp_ctx));
+
+ // Fails verification with altered payer id
+ let (
+ payer_tlv_stream, offer_tlv_stream, mut invoice_request_tlv_stream, invoice_tlv_stream,
+ mut signature_tlv_stream
+ ) = invoice.as_tlv_stream();
+ let payer_id = pubkey(1);
+ invoice_request_tlv_stream.payer_id = Some(&payer_id);
+
+ let tlv_stream =
+ (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream);
+ let mut bytes = Vec::new();
+ tlv_stream.write(&mut bytes).unwrap();
+
+ let signature = merkle::sign_message(
+ recipient_sign, INVOICE_SIGNATURE_TAG, &bytes, recipient_pubkey()
+ ).unwrap();
+ signature_tlv_stream.signature = Some(&signature);
+
+ let mut encoded_invoice = bytes;
+ signature_tlv_stream.write(&mut encoded_invoice).unwrap();
+
+ let invoice = Invoice::try_from(encoded_invoice).unwrap();
+ assert!(!invoice.verify(&expanded_key, &secp_ctx));
+ }
+