renepay: collect shared secrets

Collect the shared secrets when making a payment request.
We would need this if we use injectpaymentonion instead of sendonion.

Changelog-None.

Signed-off-by: Lagrang3 <[email protected]>

Author: Lagrang3

plugins/renepay/json.c

@@ -64,6 +64,7 @@ struct route *tal_route_from_json(const tal_t *ctx, const char *buf,
 	route->hops = NULL;
 	route->final_msg = NULL;
 	route->final_error = LIGHTNINGD;
+	route->shared_secrets = NULL;
 
 	return route;
 fail:

plugins/renepay/route.c

@@ -20,6 +20,7 @@ struct route *new_route(const tal_t *ctx, u32 groupid,
 	route->amount_deliver = amount_deliver;
 	route->amount_sent = amount_sent;
 	route->path_num = -1;
+	route->shared_secrets = NULL;
 	return route;
 }
 

plugins/renepay/route.h

@@ -59,6 +59,9 @@ struct route {
 	/* The series of channels and nodes to traverse. */
 	struct route_hop *hops;
 
+	/* shared secrets to unwrap the onions */
+	struct secret *shared_secrets;
+
 	/* amounts are redundant here if we know the hops, however sometimes we
 	 * don't know the hops, eg. by calling listsendpays, or if we have
 	 * blinded paths */

plugins/renepay/routetracker.c

@@ -195,13 +195,28 @@ static void route_pending_register(struct routetracker *routetracker,
 /* Callback function for sendpay request success. */
 static struct command_result *sendpay_done(struct command *cmd,
 					   const char *method UNUSED,
-					   const char *buf UNUSED,
-					   const jsmntok_t *result UNUSED,
+					   const char *buf,
+					   const jsmntok_t *result,
 					   struct route *route)
 {
 	assert(route);
 	struct payment *payment = route_get_payment_verify(route);
 	route_pending_register(payment->routetracker, route);
+
+	const jsmntok_t *t;
+	size_t i;
+	bool ret;
+
+	const jsmntok_t *secretstok =
+	    json_get_member(buf, result, "shared_secrets");
+	assert(secretstok->type == JSMN_ARRAY);
+
+	route->shared_secrets = tal_arr(route, struct secret, secretstok->size);
+	json_for_each_arr(i, t, secretstok)
+	{
+		ret = json_to_secret(buf, t, &route->shared_secrets[i]);
+		assert(ret);
+	}
 	return command_still_pending(cmd);
 }
 

plugins/renepay/sendpay.c

@@ -306,6 +306,16 @@ static struct command_result *sendonion_done(struct command *cmd,
 		json_add_hex_talarr(response, "payment_metadata",
 				    renesendpay->metadata);
 
+	if (renesendpay->shared_secrets) {
+		json_array_start(response, "shared_secrets");
+		for (size_t i = 0; i < tal_count(renesendpay->shared_secrets);
+		     i++) {
+			json_add_secret(response, NULL,
+					&renesendpay->shared_secrets[i]);
+		}
+		json_array_end(response);
+	}
+
 	/* FIXME: shall we report the blinded path, secret and route used? */
 	return command_finished(cmd, response);
 }
@@ -435,6 +445,7 @@ struct command_result *json_renesendpay(struct command *cmd,
 	renesendpay->label = tal_steal(renesendpay, label);
 	renesendpay->description = tal_steal(renesendpay, description);
 	renesendpay->metadata = tal_steal(renesendpay, metadata);
+	renesendpay->shared_secrets = NULL;
 
 	struct out_req *req =
 	    jsonrpc_request_start(cmd, "waitblockheight", waitblockheight_done,