CWebDavTools::getUser

static function getUser($userId, $photo = false)
{
	global $USER;
	if (is_object($USER) && intval($userId) == $USER->GetId() && !$photo)
	{
		$user = array(
			'ID' => $USER->GetId(),
			'NAME' => $USER->GetFirstName(),
			'LAST_NAME' => $USER->GetLastName(),
			'SECOND_NAME' => $USER->GetParam('SECOND_NAME'),
			'LOGIN' => $USER->GetLogin(),
		);
	}
	else
	{
		$user = CUser::getByID(intval($userId))->Fetch();
	}
	return $user;
}