Include experimental TLV records when verifying

Upcoming commits will allow parsing BOLT12 messages that include TLV
records in the experimental range. Include these ranges when verifying
messages since they will be included in the message bytes.

Author: jkczyz

lightning/src/offers/invoice.rs

@@ -1147,6 +1147,9 @@ impl InvoiceContents {
 		&self, bytes: &[u8], metadata: &Metadata, key: &ExpandedKey, iv_bytes: &[u8; IV_LEN],
 		secp_ctx: &Secp256k1<T>
 	) -> Result<PaymentId, ()> {
+		const EXPERIMENTAL_TYPES: core::ops::Range<u64> =
+			EXPERIMENTAL_OFFER_TYPES.start..EXPERIMENTAL_INVOICE_REQUEST_TYPES.end;
+
 		let offer_records = TlvStream::new(bytes).range(OFFER_TYPES);
 		let invreq_records = TlvStream::new(bytes).range(INVOICE_REQUEST_TYPES).filter(|record| {
 			match record.r#type {
@@ -1155,7 +1158,8 @@ impl InvoiceContents {
 				_ => true,
 			}
 		});
-		let tlv_stream = offer_records.chain(invreq_records);
+		let experimental_records = TlvStream::new(bytes).range(EXPERIMENTAL_TYPES);
+		let tlv_stream = offer_records.chain(invreq_records).chain(experimental_records);
 
 		let signing_pubkey = self.payer_signing_pubkey();
 		signer::verify_payer_metadata(

lightning/src/offers/offer.rs

@@ -963,7 +963,9 @@ impl OfferContents {
 						OFFER_ISSUER_ID_TYPE => !metadata.derives_recipient_keys(),
 						_ => true,
 					}
-				});
+				})
+				.chain(TlvStream::new(bytes).range(EXPERIMENTAL_OFFER_TYPES));
+
 				let signing_pubkey = match self.issuer_signing_pubkey() {
 					Some(signing_pubkey) => signing_pubkey,
 					None => return Err(()),