Return offer id in Bolt12ReceiveResponse

Same motivation as the bolt11 change, allow us to track bolt 12 receives
without having to decode the offer.

Author: benthecarman

e2e-tests/tests/e2e.rs

@@ -17,6 +17,7 @@ use e2e_tests::{
 use hex_conservative::{DisplayHex, FromHex};
 use ldk_node::bitcoin::hashes::{sha256, Hash};
 use ldk_node::lightning::ln::msgs::SocketAddress;
+use ldk_node::lightning::offers::offer::Offer;
 use ldk_node::lightning_invoice::Bolt11Invoice;
 use ldk_server_client::ldk_server_protos::api::{
 	Bolt11ReceiveRequest, Bolt12ReceiveRequest, OnchainReceiveRequest,
@@ -156,8 +157,12 @@ async fn test_cli_bolt12_receive() {
 	setup_funded_channel(&bitcoind, &server_a, &server_b, 100_000).await;
 
 	let output = run_cli(&server_a, &["bolt12-receive", "test offer"]);
-	let offer = output["offer"].as_str().unwrap();
-	assert!(offer.starts_with("lno"), "Expected lno prefix, got: {}", offer);
+	let offer_str = output["offer"].as_str().unwrap();
+	assert!(offer_str.starts_with("lno"), "Expected lno prefix, got: {}", offer_str);
+
+	let offer: Offer = offer_str.parse().unwrap();
+	let offer_id = <[u8; 32]>::from_hex(output["offer_id"].as_str().unwrap()).unwrap();
+	assert_eq!(offer.id().0, offer_id);
 }
 
 #[tokio::test]

ldk-server-protos/src/api.rs

@@ -395,6 +395,9 @@ pub struct Bolt12ReceiveResponse {
 	/// to the recipient.
 	#[prost(string, tag = "1")]
 	pub offer: ::prost::alloc::string::String,
+	/// The hex-encoded offer id.
+	#[prost(string, tag = "2")]
+	pub offer_id: ::prost::alloc::string::String,
 }
 /// Send a payment for a BOLT12 offer.
 /// See more:

ldk-server-protos/src/proto/api.proto

@@ -328,6 +328,9 @@ message Bolt12ReceiveResponse {
   // With the details of the offer, the sender has all the data necessary to send a payment
   // to the recipient.
   string offer = 1;
+
+  // The hex-encoded offer id.
+  string offer_id = 2;
 }
 
 // Send a payment for a BOLT12 offer.

ldk-server/src/api/bolt12_receive.rs

@@ -7,6 +7,7 @@
 // You may not use this file except in accordance with one or both of these
 // licenses.
 
+use hex::DisplayHex;
 use ldk_server_protos::api::{Bolt12ReceiveRequest, Bolt12ReceiveResponse};
 
 use crate::api::error::LdkServerError;
@@ -28,6 +29,7 @@ pub(crate) fn handle_bolt12_receive_request(
 			.receive_variable_amount(&request.description, request.expiry_secs)?,
 	};
 
-	let response = Bolt12ReceiveResponse { offer: offer.to_string() };
+	let offer_id = offer.id().0.to_lower_hex_string();
+	let response = Bolt12ReceiveResponse { offer: offer.to_string(), offer_id };
 	Ok(response)
 }