Auth::authorizeById

static function authorizeById($userId, $setCookie = null, $skipAuthorizeCheck = false)
{
	global $USER;

	if (!$skipAuthorizeCheck && $USER->IsAuthorized())
	{
		return false;
	}

	$context = BitrixMainContext::getCurrent();

	if ($USER->GetID() != $userId)
	{
		$USER->Authorize($userId, false, false, 'public');
	}

	$authCode = str_replace(self::AUTH_TYPE.'|', '', $USER->GetParam("XML_ID"));

	$cookie = new BitrixMainWebCookie('LIVECHAT_HASH', $authCode, null, false);
	$cookie->setHttpOnly(false);
	$context->getResponse()->addCookie($cookie);

	return true;
}