Function json_createonion

lightningd/pay.c:2401–2459

AUTODATA(json_command, &delpay_command);

static struct command_result *json_createonion(struct command *cmd,
						const char *buffer,
						const jsmntok_t *obj UNNEEDED,
						const jsmntok_t *params)
{
	struct json_stream *response;
	struct secret *session_key, *shared_secrets;
	struct sphinx_path *sp;
	u8 *assocdata, *serialized;
	u32 *packet_size;
	struct onionpacket *packet;
	struct sphinx_hop *hops;

	if (!param_check(cmd, buffer, params,
			 p_req("hops", param_hops_array, &hops),
			 p_req("assocdata", param_bin_from_hex, &assocdata),
			 p_opt("session_key", param_secret, &session_key),
			 p_opt_def("onion_size", param_number, &packet_size, ROUTING_INFO_SIZE),
			 NULL)) {
		return command_param_failed();
	}

	if (session_key == NULL)
		sp = sphinx_path_new(cmd, assocdata, tal_bytelen(assocdata));
	else
		sp = sphinx_path_new_with_key(cmd, assocdata, tal_bytelen(assocdata),
					      session_key);

	for (size_t i=0; i<tal_count(hops); i++) {
		if (!sphinx_add_hop_has_length(sp, &hops[i].pubkey, hops[i].raw_payload))
			return command_fail(cmd, JSONRPC2_INVALID_PARAMS,
					    "hops[%zi] payload is not prefixed with length!",
					    i);
	}

	if (sphinx_path_payloads_size(sp) > *packet_size)
		return command_fail(
		    cmd, JSONRPC2_INVALID_PARAMS,
		    "Payloads exceed maximum onion packet size.");

	packet = create_onionpacket(cmd, sp, *packet_size, &shared_secrets);
	if (!packet)
		return command_fail(cmd, LIGHTNINGD,
				    "Could not create onion packet");

	if (command_check_only(cmd))
		return command_check_done(cmd);

	serialized = serialize_onionpacket(cmd, packet);

	response = json_stream_success(cmd);
	json_add_hex(response, "onion", serialized, tal_bytelen(serialized));
	json_array_start(response, "shared_secrets");
	for (size_t i=0; i<tal_count(hops); i++) {
		json_add_secret(response, NULL, &shared_secrets[i]);
	}
	json_array_end(response);
	return command_success(cmd, response);