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    $(document).on('click', '#auth-send-sms, a.js-auth-resend', function (e) {
        e.preventDefault();
        $.ajax({
            method: "POST",
            dataType: 'json',
            url: '/ajax/sms_auth.php',
            data: {action: 'send_sms', phone: $('form[name="form_sms_auth"] input[name="phone"]').val()}
        }).done(function (result) {
            if (result.status == 'error') {
            console.log('error');
                $('.qv-auth-error').text(result.message);
            } else if(result.status == 'success') {
            console.log('succ');
                $('#auth-row-with-phone').addClass('hide');
                $('#auth-row-with-sms').removeClass('hide');
                $('#auth-send-sms').addClass('hide');
                $('#auth-enter').removeClass('hide');
                startTimerAuth(59);
         }
        })
      .fail(function(jqXHR, textStatus) {  
         console.log( jqXHR ); 
       });
    });

<?php
define("NO_KEEP_STATISTIC", true);
define("NO_AGENT_CHECK", true);
define('PUBLIC_AJAX_MODE', true);
require($_SERVER["DOCUMENT_ROOT"] . "/bitrix/modules/main/include/prolog_before.php");
$_SESSION["SESS_SHOW_INCLUDE_TIME_EXEC"] = "N";
$APPLICATION->ShowIncludeStat = false;

$request = \Bitrix\Main\Context::getCurrent()->getRequest();
$salt = '0000000';

try {
    if (!$request->isAjaxRequest()) {
        throw new ErrorException("is not ajax");
    }
    try {
        $action = $request->get('action');
        if (empty($action)) {
            throw new \ErrorException('action is not define');
        }
        $phone = htmlspecialchars($request->get("phone"));
        $phone = preparePhone($phone);
        if($error = validatePhone($phone)){
            throw new \ErrorException($error);
        }
        $res_user = \Bitrix\Main\UserTable::query()
            ->addFilter('PERSONAL_PHONE', $phone)
            ->addFilter('PHONE_AUTH.PHONE_NUMBER', '+'.$phone)
            ->addSelect('ID')
            ->addFilter('ACTIVE', 'Y')
            ->setLimit(1)
            ->exec();
        $user_id = null;

        if ($user_fields = $res_user->fetch()) {
            $user_id = $user_fields['ID'];
        }
        if (empty($user_id)) {
         throw new \ErrorException('Пользователь с таким телефоном не найден');
        }

        switch ($action) {
            case 'send_sms':
                if (\Bitrix\Main\Loader::includeModule('messageservice')) {
                    $code = generateText(4);
                    $sender = \Bitrix\MessageService\Sender\SmsManager::getDefaultSender();
                    $message = \Bitrix\MessageService\Sender\SmsManager::createMessage(
                        array(
                            'MESSAGE_TO' => $phone,
                            'MESSAGE_BODY' => 'Ваш код: '.$code,
                            'MESSAGE_FROM' => $sender->getDefaultFrom()
                        ), $sender);

                    if($sendResult = $message->sendDirectly()){
                  Bitrix\Main\Diag\Debug::writeToFile(json_encode(['status' => 'success']),"","debug.txt");
                  Bitrix\Main\Diag\Debug::writeToFile(json_last_error(),"","debug.txt");

                        setSmsCookie($salt . $user_id . $code);
                  $APPLICATION->RestartBuffer();
                  echo json_encode(['status' => 'success']);
                        die();
               }
                }
                break;
            case 'check_sms':
                $code = $request->get("sms_code");
                $user_remember = $request->get('user_remember');
                if(!checkSmsCode($salt . $user_id . $code)) {
                    throw new \ErrorException('Код SMS не правильный');
                }
                $USER->Authorize($user_id, ($user_remember == 'Y' ? true : false));
                echo json_encode(['status' => 'success']);
                die();
                break;
            default:
                throw new \ErrorException('action is not define');
        }

    } catch (ErrorException $e) {
        echo json_encode(['status' => 'error', 'message' => $e->getMessage()]);
    }


} catch (ErrorException $e) {
    CHTTP::SetStatus("403 Forbidden");
    echo $e->getMessage();
}
//require($_SERVER["DOCUMENT_ROOT"] . "/bitrix/modules/main/include/epilog_after.php");
?>