Ограничение регистрации через VAuth по домен Google Apps

<?php

if( ! class_exists( 'GoFunctions' ) )    {

    class GoFunctions extends VAuthFunctions {

        function oauth_data() {
        
            global $site_url;
            global $vauth_config;
            
            $oauth = array();
            
            $oauth['prefix'] = 'go';
            $oauth['prefix2'] = 'google';
            $oauth['disconnect_str']     =    "updtime='', ".$oauth['prefix']."_connected='0', ".$oauth['prefix']."_user_id=''";
            
            $oauth['redirect_uri']        =    $site_url.'/engine/modules/vauth/callback.php';
            $oauth['app_id']            =    $vauth_config['google_app_id'];
            $oauth['app_secret']        =    $vauth_config['google_app_secret'];
            $oauth['auth_url']            =    'https://accounts.google.com/o/oauth2/auth?scope=https%3A%2F%2Fwww.googleapis.com%2Fauth%2Fuserinfo.email+https%3A%2F%2Fwww.googleapis.com%2Fauth%2Fuserinfo.profile&state=%2Fprofile&redirect_uri='.$oauth['redirect_uri'].'&response_type=code&client_id='.$oauth['app_id'].'&approval_prompt=auto&access_type=offline';
        
            $oauth['group']                =    $vauth_config['google_user_group'];

            if (empty($oauth['group'])) $oauth['group'] = 4;
            if (empty($oauth['app_id'])) die('Не указан идентификатор приложения Google');
            if (empty($oauth['app_secret'])) die('Не указан секретный код приложения Google');
            
            return $oauth;
            
        }    
    
        // ** Функция авторизации в google+
        function vauth_auth($go) {
        
            global $auth_code;
            global $vauth_text;
        
            $_SESSION['auth_from']    =    'google';
        
            if (empty($go['access_token']) and empty($auth_code)) {
                header('Location: '.$go['auth_url']);
                die;
            }
            
            if ( !empty($auth_code) ) {
            
                $go_auth = 'https://accounts.google.com/o/oauth2/token';
                
                $datascope = 'code='.$auth_code.'&client_id='.$go['app_id'].'&client_secret='.$go['app_secret'].'&redirect_uri='.$go['redirect_uri'].'&grant_type=authorization_code';
            
                $userinfo = json_decode($this->post_curl($go_auth,$datascope), FALSE); // * Плучаем секретный хэшкод    
                
                if (    !empty($userinfo->access_token) ) {
                
                    $access_token    = $userinfo->access_token;
                    $id_token    = $userinfo->id_token;
                    
                    $_SESSION['google_access_token']    =    $access_token;
                    $_SESSION['google_id_token']    =    $id_token;
                
                    $go['access_token'] = $access_token;
                    
                } else die($vauth_text['go_token_error']);
            
            }
            
            return $go;
        }

        function get_oauth_info($go) {
            
            global $vauth_text;
            global $db;
            global $site_url;
            
            $go['access_token'] = $_SESSION['google_access_token'];
            
            $go_info        =    json_decode($this->vauth_get_contents('https://www.googleapis.com/oauth2/v1/userinfo?access_token='.$go['access_token']), FALSE); //Получаем информцию о пользователе
            
            $go['uid']        =    $this->conv_it($go_info->id);
            if (!is_numeric($go['uid'])) { header('Location: '.$site_url); die(); }
            $go['gender']        =    $this->conv_it($go_info->gender);
            $go['email']        =    $this->conv_it($go_info->email);
            $go['avatar']        =    $this->conv_it($go_info->picture);
            
            if ( empty($go['avatar']) ) $go['avatar'] = $site_url . '/engine/modules/vauth/styles/photo.jpg';
            
            $go['firstname']    =    $this->conv_it($go_info->given_name);
            $go['lastname']        =    $this->conv_it($go_info->family_name);
            $go['fullname']        =    $this->conv_it($go_info->name);
            $go['nick']            =    $this->conv_it($go_info->name);
            
            
            switch(    $go['gender']    ) {
            
                case 'male'    : $go['sex'] = $vauth_text[4];    break;
                case 'female'    : $go['sex'] = $vauth_text[5];    break;
            
            }
            
            return $go;
        }    

    }

}

$vauth_api = new GoFunctions ();            
    
?>