Function get_default_ssh_signing_key

gpg-interface.c:872–927

Returns the first public key from an ssh-agent to use for signing */

/* Returns the first public key from an ssh-agent to use for signing */
static char *get_default_ssh_signing_key(void)
{
	struct child_process ssh_default_key = CHILD_PROCESS_INIT;
	int ret = -1;
	struct strbuf key_stdout = STRBUF_INIT, key_stderr = STRBUF_INIT;
	char *key_command = NULL;
	const char **argv;
	int n;
	char *default_key = NULL;
	const char *literal_key = NULL;
	char *begin, *new_line, *first_line;

	if (!ssh_default_key_command)
		die(_("either user.signingkey or gpg.ssh.defaultKeyCommand needs to be configured"));

	key_command = xstrdup(ssh_default_key_command);
	n = split_cmdline(key_command, &argv);

	if (n < 0)
		die(_("malformed build-time gpg.ssh.defaultKeyCommand: %s"),
		    split_cmdline_strerror(n));

	strvec_pushv(&ssh_default_key.args, argv);
	ret = pipe_command(&ssh_default_key, NULL, 0, &key_stdout, 0,
			   &key_stderr, 0);

	if (!ret) {
		begin = key_stdout.buf;
		new_line = strchr(begin, '\n');
		if (new_line)
			first_line = xmemdupz(begin, new_line - begin);
		else
			first_line = xstrdup(begin);
		if (is_literal_ssh_key(first_line, &literal_key)) {
			/*
			 * We only use `is_literal_ssh_key` here to check validity
			 * The prefix will be stripped when the key is used.
			 */
			default_key = first_line;
		} else {
			free(first_line);
			warning(_("gpg.ssh.defaultKeyCommand succeeded but returned no keys: %s %s"),
				key_stderr.buf, key_stdout.buf);
		}

	} else {
		warning(_("gpg.ssh.defaultKeyCommand failed: %s %s"),
			key_stderr.buf, key_stdout.buf);
	}

	free(key_command);
	free(argv);
	strbuf_release(&key_stdout);

	return default_key;
}

static char *get_ssh_key_id(void)