diff --git a/user_sql.php b/user_sql.php
--- a/user_sql.php
+++ b/user_sql.php
@@ -1,780 +1,833 @@
 <?php
 
 /**
  * ownCloud - user_sql
  *
  * @author Andreas Böhler and contributors
  * @copyright 2012-2015 Andreas Böhler <dev (at) aboehler (dot) at>
  *
  * credits go to Ed W for several SQL injection fixes and caching support
  * credits go to Frédéric France for providing Joomla support
  * credits go to Mark Jansenn for providing Joomla 2.5.18+ / 3.2.1+ support
  * credits go to Dominik Grothaus for providing SSHA256 support and fixing a few bugs
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
  * License as published by the Free Software Foundation; either
  * version 3 of the License, or any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU AFFERO GENERAL PUBLIC LICENSE for more details.
  *
  * You should have received a copy of the GNU Affero General Public
  * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
  *
  */
 
 class OC_USER_SQL extends OC_User_Backend implements OC_User_Interface
 {
     protected $cache;
     // cached settings
     protected $sql_host;
     protected $sql_username;
     protected $sql_database;
     protected $sql_password;
     protected $sql_table;
     protected $sql_column_username;
     protected $sql_column_password;
     protected $sql_column_active;
     protected $sql_column_active_invert;
     protected $sql_column_displayname;
     protected $sql_column_email;
     protected $mail_sync_mode;
     protected $sql_type;
     protected $db_conn;
     protected $db;
     protected $default_domain;
     protected $strip_domain;
     protected $crypt_type;
     protected $domain_settings;
     protected $domain_array;
     protected $map_array;
     protected $allow_password_change;
+    protected $session_cache_name;
 
     public function __construct()
     {
         $this -> db_conn = false;
-        $this -> cache = \OC\Cache::getGlobalCache();
+		$memcache = \OC::$server->getMemCacheFactory();
+		if ( $memcache -> isAvailable())
+		{
+			$this -> cache = $memcache -> create();
+		}
         $this -> sql_host = OCP\Config::getAppValue('user_sql', 'sql_host', '');
         $this -> sql_username = OCP\Config::getAppValue('user_sql', 'sql_user', '');
         $this -> sql_database = OCP\Config::getAppValue('user_sql', 'sql_database', '');
         $this -> sql_password = OCP\Config::getAppValue('user_sql', 'sql_password', '');
         $this -> sql_table = OCP\Config::getAppValue('user_sql', 'sql_table', '');
         $this -> sql_column_username = OCP\Config::getAppValue('user_sql', 'sql_column_username', '');
         $this -> sql_column_password = OCP\Config::getAppValue('user_sql', 'sql_column_password', '');
         $this -> sql_column_displayname = OCP\Config::getAppValue('user_sql', 'sql_column_displayname', $this->sql_column_username);
         $this -> sql_column_email = OCP\Config::getAppValue('user_sql', 'sql_column_email', '');
         $this -> sql_column_active = OCP\Config::getAppValue('user_sql', 'sql_column_active', '');
         $this -> sql_column_active_invert = OCP\Config::getAppValue('user_sql', 'sql_column_active_invert', 0);
         $this -> sql_type = OCP\Config::getAppValue('user_sql', 'sql_type', '');
         $this -> default_domain = OCP\Config::getAppValue('user_sql', 'default_domain', '');
         $this -> strip_domain = OCP\Config::getAppValue('user_sql', 'strip_domain', 0);
         $this -> allow_password_change = OCP\Config::getAppValue('user_sql', 'allow_password_change', 0);        
         $this -> crypt_type = OCP\Config::getAppValue('user_sql', 'crypt_type', 'md5crypt');
         $this -> domain_settings = OCP\Config::getAppValue('user_sql', 'domain_settings', 'none');
         $this -> domain_array = explode(",", OCP\Config::getAppValue('user_sql', 'domain_array', ''));
         $this -> map_array = explode(",", OCP\Config::getAppValue('user_sql', 'map_array', ''));
         $this -> mail_sync_mode = OCP\Config::getAppValue('user_sql', 'mail_sync_mode', 'none');
+        $this -> session_cache_name = 'USER_SQL_CACHE';
         $dsn = $this -> sql_type . ":host=" . $this -> sql_host . ";dbname=" . $this -> sql_database;
         try
         {
             $this -> db = new PDO($dsn, $this -> sql_username, $this -> sql_password);
             $this -> db -> query("SET NAMES 'UTF8'");
             $this -> db_conn = true;
         } catch (PDOException $e)
         {
             OC_Log::write('OC_USER_SQL', 'Failed to connect to the database: ' . $e -> getMessage(), OC_Log::ERROR);
         }
         return false;
     }
 
     private function doEmailSync($uid)
     {
         OC_Log::write('OC_USER_SQL', "Entering doEmailSync for UID: $uid", OC_Log::DEBUG);
         if($this -> sql_column_email === '')
             return false;
         
         if($this -> mail_sync_mode == 'none')
             return false;
             
         $ocUid = $uid;
         $uid = $this -> doUserDomainMapping($uid);
 
         $query = "SELECT $this->sql_column_email FROM $this->sql_table WHERE $this->sql_column_username = :uid";
         OC_Log::write('OC_USER_SQL', "Preparing query: $query", OC_Log::DEBUG);
         $result = $this -> db -> prepare($query);
         $result -> bindParam(":uid", $uid);
         OC_Log::write('OC_USER_SQL', "Executing query...", OC_Log::DEBUG);
         if(!$result -> execute())
         {
             return false;
         }
         OC_Log::write('OC_USER_SQL', "Fetching result...", OC_Log::DEBUG);
         $row = $result -> fetch();
         if(!$row)
         {
             return false;
         }
         $newMail = $row[$this -> sql_column_email];
         $currMail = OCP\Config::getUserValue($ocUid, 'settings', 'email', '');
         
         switch($this -> mail_sync_mode)
         {
             case 'initial':
                 if($currMail === '')
                     OCP\Config::setUserValue($ocUid, 'settings', 'email', $newMail);
                 break;
             case 'forcesql':
                 if($currMail != $newMail)
                     OCP\Config::setUserValue($ocUid, 'settings', 'email', $newMail);
                 break;
             case 'forceoc':
                 if(($currMail !== '') && ($currMail != $newMail))
                 {
                     $query = "UPDATE $this->sql_table SET $this->sql_column_email = :currMail WHERE $this->sql_column_username = :uid";
                     OC_Log::write('OC_USER_SQL', "Preapring query: $query", OC_Log::DEBUG);
                     $result = $this -> db -> prepare($query);
                     $result -> bindParam(":currMail", $currMail);
                     $result -> bindParam(":uid", $uid);
                     OC_Log::write('OC_USER_SQL', "Executing query...", OC_Log::DEBUG);
                     if(!$result -> execute())
                     {
                         $err = $result -> errorInfo();
                         OC_Log::write('OC_USER_SQL', "Query failed: " . $err[2], OC_Log::DEBUG);
                         OC_Log::write('OC_USER_SQL', "Could not update E-Mail address in SQL database!", OC_Log::ERROR);
                     }
                 }
                 break;
         }
         
         return true;
     }
 
     private function doUserDomainMapping($uid)
     {
         $uid = trim($uid);
 
         switch($this->domain_settings)
         {
             case "default" :
                 OC_Log::write('OC_USER_SQL', "Default mapping", OC_Log::DEBUG);
                 if($this -> default_domain && (strpos($uid, '@') === false))
                     $uid .= "@" . $this -> default_domain;
                 break;
             case "server" :
                 OC_Log::write('OC_USER_SQL', "Server based mapping", OC_Log::DEBUG);
                 if(strpos($uid, '@') === false)
                     $uid .= "@" . $_SERVER['SERVER_NAME'];
                 break;
             case "mapping" :
                 OC_Log::write('OC_USER_SQL', 'Domain mapping selected', OC_Log::DEBUG);
                 if(strpos($uid, '@') === false)
                 {
                     for($i = 0; $i < count($this -> domain_array); $i++)
                     {
                         OC_Log::write('OC_USER_SQL', 'Checking domain in mapping: ' . $this -> domain_array[$i], OC_Log::DEBUG);
                         if($_SERVER['SERVER_NAME'] == trim($this -> domain_array[$i]))
                         {
                             OC_Log::write('OC_USER_SQL', 'Found domain in mapping: ' . $this -> domain_array[$i], OC_Log::DEBUG);
                             $uid .= "@" . trim($this -> map_array[$i]);
                             break;
                         }
                     }
                 }
                 break;
             case "none" :
             default :
                 OC_Log::write('OC_USER_SQL', "No mapping", OC_Log::DEBUG);
                 break;
         }
 
         $uid = strtolower($uid);
         OC_Log::write('OC_USER_SQL', 'Returning mapped UID: ' . $uid, OC_Log::DEBUG);
         return $uid;
     }
 
     public function implementsAction($actions)
     {
         return (bool)((OC_USER_BACKEND_CHECK_PASSWORD | OC_USER_BACKEND_GET_DISPLAYNAME) & $actions);
     }
 
     public function hasUserListings()
     {
         return true;
     }
 
     public function createUser()
     {
         // Can't create user
         OC_Log::write('OC_USER_SQL', 'Not possible to create local users from web frontend using SQL user backend', OC_Log::ERROR);
         return false;
     }
 
     public function deleteUser($uid)
     {
         // Can't delete user
         OC_Log::write('OC_USER_SQL', 'Not possible to delete local users from web frontend using SQL user backend', OC_Log::ERROR);
         return false;
     }
 
     public function setPassword($uid, $password)
     {
         // Update the user's password - this might affect other services, that
         // use the same database, as well
         OC_Log::write('OC_USER_SQL', "Entering setPassword for UID: $uid", OC_Log::DEBUG);
         if(!$this -> db_conn || !$this->allow_password_change)
         {
             return false;
         }
         $uid = $this -> doUserDomainMapping($uid);
 
         $query = "SELECT $this->sql_column_password FROM $this->sql_table WHERE $this->sql_column_username = :uid";
         OC_Log::write('OC_USER_SQL', "Preparing query: $query", OC_Log::DEBUG);
         $result = $this -> db -> prepare($query);
         $result -> bindParam(":uid", $uid);
         OC_Log::write('OC_USER_SQL', "Executing query...", OC_Log::DEBUG);
         if(!$result -> execute())
         {
             return false;
         }
         OC_Log::write('OC_USER_SQL', "Fetching result...", OC_Log::DEBUG);
         $row = $result -> fetch();
         if(!$row)
         {
             return false;
         }
         $old_password = $row[$this -> sql_column_password];
         if($this -> crypt_type == 'joomla2')
         {
             if(!class_exists('PasswordHash'))
                 require_once('PasswordHash.php');
             $hasher = new PasswordHash(10, true);
             $enc_password = $hasher->HashPassword($password);
         }         
         // Redmine stores the salt separatedly, this doesn't play nice with the way
         // we check passwords
         elseif($this -> crypt_type == 'redmine')
         {
         	$query = "SELECT salt FROM $this->sql_table WHERE $this->sql_column_username =:uid;";
         	$res = $this->db->prepare($query);
 			$res->bindparam(":uid", $uid);
 			if(!$res->execute())
 				return false;
 			$salt = $res->fetch();
 			if(!$salt)
 				return false;
 			$enc_password = sha1($salt['salt'].sha1($password));
         } else
         {
             $enc_password = $this -> pacrypt($password, $old_password);
         }
         $query = "UPDATE $this->sql_table SET $this->sql_column_password = :enc_password WHERE $this->sql_column_username = :uid";
         OC_Log::write('OC_USER_SQL', "Preapring query: $query", OC_Log::DEBUG);
         $result = $this -> db -> prepare($query);
         $result -> bindParam(":enc_password", $enc_password);
         $result -> bindParam(":uid", $uid);
         OC_Log::write('OC_USER_SQL', "Executing query...", OC_Log::DEBUG);
         if(!$result -> execute())
         {
             $err = $result -> errorInfo();
             OC_Log::write('OC_USER_SQL', "Query failed: " . $err[2], OC_Log::DEBUG);
             OC_Log::write('OC_USER_SQL', "Could not update password!", OC_Log::ERROR);
             return false;
         }
         OC_Log::write('OC_USER_SQL', "Updated password successfully, return true", OC_Log::DEBUG);
         return true;
     }
 
     /**
      * @brief Check if the password is correct
      * @param $uid The username
      * @param $password The password
      * @returns true/false
      *
      * Check if the password is correct without logging in the user
      */
     public function checkPassword($uid, $password)
     {
         OC_Log::write('OC_USER_SQL', "Entering checkPassword() for UID: $uid", OC_Log::DEBUG);
         if(!$this -> db_conn)
         {
             return false;
         }
         $uid = $this -> doUserDomainMapping($uid);
 
         $query = "SELECT $this->sql_column_username, $this->sql_column_password FROM $this->sql_table WHERE $this->sql_column_username = :uid";
         if($this -> sql_column_active != '')
             $query .= " AND " .($this->sql_column_active_invert ? "NOT " : "" ).$this->sql_column_active;
         OC_Log::write('OC_USER_SQL', "Preparing query: $query", OC_Log::DEBUG);
         $result = $this -> db -> prepare($query);
         $result -> bindParam(":uid", $uid);
         OC_Log::write('OC_USER_SQL', "Executing query...", OC_Log::DEBUG);
         if(!$result -> execute())
         {
             $err = $result -> errorInfo();
             OC_Log::write('OC_USER_SQL', "Query failed: " . $err[2], OC_Log::DEBUG);
             return false;
         }
         OC_Log::write('OC_USER_SQL', "Fetching row...", OC_Log::DEBUG);
         $row = $result -> fetch();
         if(!$row)
         {
             OC_Log::write('OC_USER_SQL', "Got no row, return false", OC_Log::DEBUG);
             return false;
         }
         OC_Log::write('OC_USER_SQL', "Encrypting and checking password", OC_Log::DEBUG);
         // Joomla 2.5.18 switched to phPass, which doesn't play nice with the way
         // we check passwords
         if($this -> crypt_type == 'joomla2')
         {
             if(!class_exists('PasswordHash'))
                 require_once('PasswordHash.php');
             $hasher = new PasswordHash(10, true);
             $ret = $hasher -> CheckPassword($password, $row[$this -> sql_column_password]);
         } 
         // Redmine stores the salt separatedly, this doesn't play nice with the way
         // we check passwords
         elseif($this -> crypt_type == 'redmine')
         {
         	$query = "SELECT salt FROM $this->sql_table WHERE $this->sql_column_username =:uid;";
         	$res = $this->db->prepare($query);
 			$res->bindparam(":uid", $uid);
 			if(!$res->execute())
 				return false;
 			$salt = $res->fetch();
 			if(!$salt)
 				return false;
 			$ret = sha1($salt['salt'].sha1($password)) == $row[$this->sql_column_password];
         } else
         {
             $ret = $this -> pacrypt($password, $row[$this -> sql_column_password]) == $row[$this -> sql_column_password];
         }
         if($ret)
         {
             OC_Log::write('OC_USER_SQL', "Passwords matching, return true", OC_Log::DEBUG);
             if($this -> strip_domain)
             {
                 $uid = explode("@", $uid);
                 $uid = $uid[0];
             }
             return $uid;
         } else
         {
             OC_Log::write('OC_USER_SQL', "Passwords do not match, return false", OC_Log::DEBUG);
             return false;
         }
     }
 
     /**
      * @brief Get a list of all users
      * @returns array with all uids
      *
      * Get a list of all users.
      */
 
     public function getUsers($search = '', $limit = null, $offset = null)
     {
         OC_Log::write('OC_USER_SQL', "Entering getUsers() with Search: $search, Limit: $limit, Offset: $offset", OC_Log::DEBUG);
         $users = array();
         if(!$this -> db_conn)
         {
             return false;
         }
         $query = "SELECT $this->sql_column_username FROM $this->sql_table";
         $query .= " WHERE $this->sql_column_username LIKE :search";
         if($this -> sql_column_active != '')
             $query .= " AND " .($this->sql_column_active_invert ? "NOT " : "" ).$this->sql_column_active;
         $query .= " ORDER BY $this->sql_column_username";
         if($limit != null)
         {
             $limit = intval($limit);
             $query .= " LIMIT $limit";
         }
         if($offset != null)
         {
             $offset = intval($offset);
             $query .= " OFFSET $offset";
         }
         OC_Log::write('OC_USER_SQL', "Preparing query: $query", OC_Log::DEBUG);
         $result = $this -> db -> prepare($query);
         if($search != '')
         {
             $search = "%".$this -> doUserDomainMapping($search."%")."%";
         }
         else 
         {
 	       $search = "%".$this -> doUserDomainMapping("")."%";   
         }
         $result -> bindParam(":search", $search);
         
         OC_Log::write('OC_USER_SQL', "Executing query...", OC_Log::DEBUG);
         if(!$result -> execute())
         {
             $err = $result -> errorInfo();
             OC_Log::write('OC_USER_SQL', "Query failed: " . $err[2], OC_Log::DEBUG);
             return array();
         }
         OC_Log::write('OC_USER_SQL', "Fetching results...", OC_Log::DEBUG);
         while($row = $result -> fetch())
         {
             $uid = $row[$this -> sql_column_username];
             if($this -> strip_domain)
             {
                 $uid = explode("@", $uid);
                 $uid = $uid[0];
             }
             $users[] = strtolower($uid);
         }
         OC_Log::write('OC_USER_SQL', "Return list of results", OC_Log::DEBUG);
         return $users;
     }
 
     /**
      * @brief check if a user exists
      * @param string $uid the username
      * @return boolean
      */
 
     public function userExists($uid)
     {
 
         $cacheKey = 'sql_user_exists_' . $uid;
-        $cacheVal = $this -> cache -> get($cacheKey);
+        $cacheVal = $this -> getCache ($cacheKey);
         if(!is_null($cacheVal))
             return (bool)$cacheVal;
 
         OC_Log::write('OC_USER_SQL', "Entering userExists() for UID: $uid", OC_Log::DEBUG);
         if(!$this -> db_conn)
         {
             return false;
         }
         $uid = $this -> doUserDomainMapping($uid);
         $query = "SELECT $this->sql_column_username FROM $this->sql_table WHERE $this->sql_column_username = :uid";
         if($this -> sql_column_active != '')
             $query .= " AND " .($this->sql_column_active_invert ? "NOT " : "" ).$this->sql_column_active;
         OC_Log::write('OC_USER_SQL', "Preparing query: $query", OC_Log::DEBUG);
         $result = $this -> db -> prepare($query);
         $result -> bindParam(":uid", $uid);
         OC_Log::write('OC_USER_SQL', "Executing query...", OC_Log::DEBUG);
         if(!$result -> execute())
         {
             $err = $result -> errorInfo();
             OC_Log::write('OC_USER_SQL', "Query failed: " . $err[2], OC_Log::DEBUG);
             return false;
         }
         OC_Log::write('OC_USER_SQL', "Fetching results...", OC_Log::DEBUG);
 
         $exists = (bool)$result -> fetch();
-        $this -> cache -> set($cacheKey, $exists, 60);
+        $this -> setCache ($cacheKey, $exists, 60);
 
         if(!$exists)
         {
             OC_Log::write('OC_USER_SQL', "Empty row, user does not exists, return false", OC_Log::DEBUG);
             return false;
         } else
         {
             OC_Log::write('OC_USER_SQL', "User exists, return true", OC_Log::DEBUG);
             return true;
         }
 
     }
 
     public function getDisplayName($uid)
     {
         OC_Log::write('OC_USER_SQL', "Entering getDisplayName() for UID: $uid", OC_Log::DEBUG);
         if(!$this -> db_conn)
         {
             return false;
         }
         $this -> doEmailSync($uid);
         $uid = $this -> doUserDomainMapping($uid);
 
         if(!$this -> userExists($uid))
         {
             return false;
         }
 
         $query = "SELECT $this->sql_column_displayname FROM $this->sql_table WHERE $this->sql_column_username = :uid";
         if($this -> sql_column_active != '')
             $query .= " AND " .($this->sql_column_active_invert ? "NOT " : "" ).$this->sql_column_active;
         OC_Log::write('OC_USER_SQL', "Preparing query: $query", OC_Log::DEBUG);
         $result = $this -> db -> prepare($query);
         $result -> bindParam(":uid", $uid);
         OC_Log::write('OC_USER_SQL', "Executing query...", OC_Log::DEBUG);
         if(!$result -> execute())
         {
             $err = $result -> errorInfo();
             OC_Log::write('OC_USER_SQL', "Query failed: " . $err[2], OC_Log::DEBUG);
             return false;
         }
         OC_Log::write('OC_USER_SQL', "Fetching results...", OC_Log::DEBUG);
         $row = $result -> fetch();
         if(!$row)
         {
             OC_Log::write('OC_USER_SQL', "Empty row, user has no display name or does not exist, return false", OC_Log::DEBUG);
             return false;
         } else
         {
             OC_Log::write('OC_USER_SQL', "User exists, return true", OC_Log::DEBUG);
             $displayName = $row[$this -> sql_column_displayname];
             return $displayName; ;
         }
         return false;
     }
 
     public function getDisplayNames($search = '', $limit = null, $offset = null)
     {
         $uids = $this -> getUsers($search, $limit, $offset);
         $displayNames = array();
         foreach($uids as $uid)
         {
             $displayNames[$uid] = $this -> getDisplayName($uid);
         }
         return $displayNames;
     }
 
     /**
      * The following functions were directly taken from PostfixAdmin and just
      * slightly modified
      * to suit our needs.
      * Encrypt a password, using the apparopriate hashing mechanism as defined in
      * config.inc.php ($this->crypt_type).
      * When wanting to compare one pw to another, it's necessary to provide the
      * salt used - hence
      * the second parameter ($pw_db), which is the existing hash from the DB.
      *
      * @param string $pw
      * @param string $encrypted password
      * @return string encrypted password.
      */
     private function pacrypt($pw, $pw_db = "")
     {
         OC_Log::write('OC_USER_SQL', "Entering private pacrypt()", OC_Log::DEBUG);
         $pw = stripslashes($pw);
         $password = "";
         $salt = "";
 
         if($this -> crypt_type == 'md5crypt')
         {
             $split_salt = preg_split('/\$/', $pw_db);
             if(isset($split_salt[2]))
             {
                 $salt = $split_salt[2];
             }
             $password = $this -> md5crypt($pw, $salt);
         } elseif($this -> crypt_type == 'md5')
         {
             $password = md5($pw);
         } elseif($this -> crypt_type == 'system')
         {
             // We never generate salts, as user creation is not allowed here
             $password = crypt($pw, $pw_db);
         } elseif($this -> crypt_type == 'cleartext')
         {
             $password = $pw;
         }
 
         // See
         // https://sourceforge.net/tracker/?func=detail&atid=937966&aid=1793352&group_id=191583
         // this is apparently useful for pam_mysql etc.
         elseif($this -> crypt_type == 'mysql_encrypt')
         {
             if(!$this -> db_conn)
             {
                 return false;
             }
             if($pw_db != "")
             {
                 $salt = substr($pw_db, 0, 2);
                 $query = "SELECT ENCRYPT(:pw, :salt);";
             } else
             {
                 $query = "SELECT ENCRYPT(:pw);";
             }
 
             $result = $this -> db -> prepare($query);
             $result -> bindParam(":pw", $pw);
             if($pw_db != "")
                 $result -> bindParam(":salt", $salt);
             if(!$result -> execute())
             {
                 return false;
             }
             $row = $result -> fetch();
             if(!$row)
             {
                 return false;
             }
             $password = $row[0];
         } elseif($this -> crypt_type == 'mysql_password')
         {
             if(!$this -> db_conn)
             {
                 return false;
             }
             $query = "SELECT PASSWORD(:pw);";
 
             $result = $this -> db -> prepare($query);
             $result -> bindParam(":pw", $pw);
             if(!$result -> execute())
             {
                 return false;
             }
             $row = $result -> fetch();
             if(!$row)
             {
                 return false;
             }
             $password = $row[0];
         }
 
         // The following is by Frédéric France
         elseif($this -> crypt_type == 'joomla')
         {
             $split_salt = preg_split('/:/', $pw_db);
             if(isset($split_salt[1]))
             {
                 $salt = $split_salt[1];
             }
             $password = ($salt) ? md5($pw . $salt) : md5($pw);
             $password .= ':' . $salt;
 		}
 
 		elseif($this-> crypt_type == 'ssha256')
 		{
 			$salted_password = base64_decode(preg_replace('/{SSHA256}/i','',$pw_db));
 			$salt = substr($salted_password,-(strlen($salted_password)-32));
 			$password = $this->ssha256($pw,$salt);
         } else
         {
             OC_Log::write('OC_USER_SQL', "unknown/invalid crypt_type settings: $this->crypt_type", OC_Log::ERROR);
             die('unknown/invalid Encryption type setting: ' . $this -> crypt_type);
         }
         OC_Log::write('OC_USER_SQL', "pacrypt() done, return", OC_Log::DEBUG);
         return $password;
     }
 
     //
     // md5crypt
     // Action: Creates MD5 encrypted password
     // Call: md5crypt (string cleartextpassword)
     //
 
     private function md5crypt($pw, $salt = "", $magic = "")
     {
         $MAGIC = "$1$";
 
         if($magic == "")
             $magic = $MAGIC;
         if($salt == "")
             $salt = $this -> create_salt();
         $slist = explode("$", $salt);
         if($slist[0] == "1")
             $salt = $slist[1];
 
         $salt = substr($salt, 0, 8);
         $ctx = $pw . $magic . $salt;
         $final = $this -> pahex2bin(md5($pw . $salt . $pw));
 
         for($i = strlen($pw); $i > 0; $i -= 16)
         {
             if($i > 16)
             {
                 $ctx .= substr($final, 0, 16);
             } else
             {
                 $ctx .= substr($final, 0, $i);
             }
         }
         $i = strlen($pw);
 
         while($i > 0)
         {
             if($i & 1)
                 $ctx .= chr(0);
             else
                 $ctx .= $pw[0];
             $i = $i>>1;
         }
         $final = $this -> pahex2bin(md5($ctx));
 
         for($i = 0; $i < 1000; $i++)
         {
             $ctx1 = "";
             if($i & 1)
             {
                 $ctx1 .= $pw;
             } else
             {
                 $ctx1 .= substr($final, 0, 16);
             }
             if($i % 3)
                 $ctx1 .= $salt;
             if($i % 7)
                 $ctx1 .= $pw;
             if($i & 1)
             {
                 $ctx1 .= substr($final, 0, 16);
             } else
             {
                 $ctx1 .= $pw;
             }
             $final = $this -> pahex2bin(md5($ctx1));
         }
         $passwd = "";
         $passwd .= $this -> to64(((ord($final[0])<<16) | (ord($final[6])<<8) | (ord($final[12]))), 4);
         $passwd .= $this -> to64(((ord($final[1])<<16) | (ord($final[7])<<8) | (ord($final[13]))), 4);
         $passwd .= $this -> to64(((ord($final[2])<<16) | (ord($final[8])<<8) | (ord($final[14]))), 4);
         $passwd .= $this -> to64(((ord($final[3])<<16) | (ord($final[9])<<8) | (ord($final[15]))), 4);
         $passwd .= $this -> to64(((ord($final[4])<<16) | (ord($final[10])<<8) | (ord($final[5]))), 4);
         $passwd .= $this -> to64(ord($final[11]), 2);
         return "$magic$salt\$$passwd";
     }
 
     private function create_salt()
     {
         srand((double) microtime() * 1000000);
         $salt = substr(md5(rand(0, 9999999)), 0, 8);
         return $salt;
     }
 
     private function ssha256($pw, $salt)
 	{
 	    return '{SSHA256}'.base64_encode(hash('sha256',$pw.$salt,true).$salt);
 	}
 
     private function pahex2bin($str)
     {
         if(function_exists('hex2bin'))
         {
             return hex2bin($str);
         } else
         {
             $len = strlen($str);
             $nstr = "";
             for($i = 0; $i < $len; $i += 2)
             {
                 $num = sscanf(substr($str, $i, 2), "%x");
                 $nstr .= chr($num[0]);
             }
             return $nstr;
         }
     }
 
     private function to64($v, $n)
     {
         $ITOA64 = "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
         $ret = "";
         while(($n - 1) >= 0)
         {
             $n--;
             $ret .= $ITOA64[$v & 0x3f];
             $v = $v>>6;
         }
         return $ret;
     }
 
+	/**
+	 * Store a value in memcache or the session, if no memcache is available
+	 * @param string $key
+	 * @param mixed $value
+	 * @param int $ttl (optional) defaults to 3600 seconds.
+	 */
+	private function setCache($key,$value,$ttl=3600)
+	{
+		if ($this -> cache === NULL)
+		{
+			$_SESSION[$this -> session_cache_name][$key] = array(
+				'value' => $value,
+				'time' => time(),
+				'ttl' => $ttl,
+			);
+		} else
+		{
+			$this -> cache -> set($key,$value,$ttl);
+		}
+	}
+
+	/**
+	 * Fetch a value from memcache or session, if memcache is not available.
+	 * Returns NULL if there's no value stored or the value expired.
+	 * @param string $key
+	 * @return mixed|NULL
+	 */
+	private function getCache($key)
+	{
+		$retVal = NULL;
+		if ($this -> cache === NULL)
+		{
+			if (isset($_SESSION[$this -> session_cache_name],$_SESSION[$this -> session_cache_name][$key]))
+			{
+				$value = $_SESSION[$this -> session_cache_name][$key];
+				if (time() < $value['time'] + $value['ttl'])
+				{
+					$retVal = $value['value'];
+				}
+			}
+		} else
+		{
+			$retVal = $this -> cache -> get ($key);
+		}
+		return $retVal;
+	}
+
 }
 ?>