nextcloud / server

apps/user_ldap/lib/User_LDAP.php

Indentation +577 added lines, -577 removed lines

@@ -52,585 +52,585 @@
 use OCP\Util;
 
 class User_LDAP extends BackendUtility implements \OCP\IUserBackend, \OCP\UserInterface, IUserLDAP {
-	/** @var \OCP\IConfig */
-	protected $ocConfig;
-
-	/** @var INotificationManager */
-	protected $notificationManager;
-
-	/** @var string */
-	protected $currentUserInDeletionProcess;
-
-	/** @var UserPluginManager */
-	protected $userPluginManager;
-
-	/**
-	 * @param Access $access
-	 * @param \OCP\IConfig $ocConfig
-	 * @param \OCP\Notification\IManager $notificationManager
-	 * @param IUserSession $userSession
-	 */
-	public function __construct(Access $access, IConfig $ocConfig, INotificationManager $notificationManager, IUserSession $userSession, UserPluginManager $userPluginManager) {
-		parent::__construct($access);
-		$this->ocConfig = $ocConfig;
-		$this->notificationManager = $notificationManager;
-		$this->userPluginManager = $userPluginManager;
-		$this->registerHooks($userSession);
-	}
-
-	protected function registerHooks(IUserSession $userSession) {
-		$userSession->listen('\OC\User', 'preDelete', [$this, 'preDeleteUser']);
-		$userSession->listen('\OC\User', 'postDelete', [$this, 'postDeleteUser']);
-	}
-
-	public function preDeleteUser(IUser $user) {
-		$this->currentUserInDeletionProcess = $user->getUID();
-	}
-
-	public function postDeleteUser() {
-		$this->currentUserInDeletionProcess = null;
-	}
-
-	/**
-	 * checks whether the user is allowed to change his avatar in Nextcloud
-	 *
-	 * @param string $uid the Nextcloud user name
-	 * @return boolean either the user can or cannot
-	 * @throws \Exception
-	 */
-	public function canChangeAvatar($uid) {
-		if ($this->userPluginManager->implementsActions(Backend::PROVIDE_AVATAR)) {
-			return $this->userPluginManager->canChangeAvatar($uid);
-		}
-
-		if(!$this->implementsActions(Backend::PROVIDE_AVATAR)) {
-			return true;
-		}
-
-		$user = $this->access->userManager->get($uid);
-		if(!$user instanceof User) {
-			return false;
-		}
-		$imageData = $user->getAvatarImage();
-		if($imageData === false) {
-			return true;
-		}
-		return !$user->updateAvatar(true);
-	}
-
-	/**
-	 * Return the username for the given login name, if available
-	 *
-	 * @param string $loginName
-	 * @return string|false
-	 * @throws \Exception
-	 */
-	public function loginName2UserName($loginName) {
-		$cacheKey = 'loginName2UserName-' . $loginName;
-		$username = $this->access->connection->getFromCache($cacheKey);
-
-		if ($username !== null) {
-			return $username;
-		}
-
-		try {
-			$ldapRecord = $this->getLDAPUserByLoginName($loginName);
-			$user = $this->access->userManager->get($ldapRecord['dn'][0]);
-			if ($user === null || $user instanceof OfflineUser) {
-				// this path is not really possible, however get() is documented
-				// to return User, OfflineUser or null so we are very defensive here.
-				$this->access->connection->writeToCache($cacheKey, false);
-				return false;
-			}
-			$username = $user->getUsername();
-			$this->access->connection->writeToCache($cacheKey, $username);
-			return $username;
-		} catch (NotOnLDAP $e) {
-			$this->access->connection->writeToCache($cacheKey, false);
-			return false;
-		}
-	}
+    /** @var \OCP\IConfig */
+    protected $ocConfig;
+
+    /** @var INotificationManager */
+    protected $notificationManager;
+
+    /** @var string */
+    protected $currentUserInDeletionProcess;
+
+    /** @var UserPluginManager */
+    protected $userPluginManager;
+
+    /**
+     * @param Access $access
+     * @param \OCP\IConfig $ocConfig
+     * @param \OCP\Notification\IManager $notificationManager
+     * @param IUserSession $userSession
+     */
+    public function __construct(Access $access, IConfig $ocConfig, INotificationManager $notificationManager, IUserSession $userSession, UserPluginManager $userPluginManager) {
+        parent::__construct($access);
+        $this->ocConfig = $ocConfig;
+        $this->notificationManager = $notificationManager;
+        $this->userPluginManager = $userPluginManager;
+        $this->registerHooks($userSession);
+    }
+
+    protected function registerHooks(IUserSession $userSession) {
+        $userSession->listen('\OC\User', 'preDelete', [$this, 'preDeleteUser']);
+        $userSession->listen('\OC\User', 'postDelete', [$this, 'postDeleteUser']);
+    }
+
+    public function preDeleteUser(IUser $user) {
+        $this->currentUserInDeletionProcess = $user->getUID();
+    }
+
+    public function postDeleteUser() {
+        $this->currentUserInDeletionProcess = null;
+    }
+
+    /**
+     * checks whether the user is allowed to change his avatar in Nextcloud
+     *
+     * @param string $uid the Nextcloud user name
+     * @return boolean either the user can or cannot
+     * @throws \Exception
+     */
+    public function canChangeAvatar($uid) {
+        if ($this->userPluginManager->implementsActions(Backend::PROVIDE_AVATAR)) {
+            return $this->userPluginManager->canChangeAvatar($uid);
+        }
+
+        if(!$this->implementsActions(Backend::PROVIDE_AVATAR)) {
+            return true;
+        }
+
+        $user = $this->access->userManager->get($uid);
+        if(!$user instanceof User) {
+            return false;
+        }
+        $imageData = $user->getAvatarImage();
+        if($imageData === false) {
+            return true;
+        }
+        return !$user->updateAvatar(true);
+    }
+
+    /**
+     * Return the username for the given login name, if available
+     *
+     * @param string $loginName
+     * @return string|false
+     * @throws \Exception
+     */
+    public function loginName2UserName($loginName) {
+        $cacheKey = 'loginName2UserName-' . $loginName;
+        $username = $this->access->connection->getFromCache($cacheKey);
+
+        if ($username !== null) {
+            return $username;
+        }
+
+        try {
+            $ldapRecord = $this->getLDAPUserByLoginName($loginName);
+            $user = $this->access->userManager->get($ldapRecord['dn'][0]);
+            if ($user === null || $user instanceof OfflineUser) {
+                // this path is not really possible, however get() is documented
+                // to return User, OfflineUser or null so we are very defensive here.
+                $this->access->connection->writeToCache($cacheKey, false);
+                return false;
+            }
+            $username = $user->getUsername();
+            $this->access->connection->writeToCache($cacheKey, $username);
+            return $username;
+        } catch (NotOnLDAP $e) {
+            $this->access->connection->writeToCache($cacheKey, false);
+            return false;
+        }
+    }
 	
-	/**
-	 * returns the username for the given LDAP DN, if available
-	 *
-	 * @param string $dn
-	 * @return string|false with the username
-	 */
-	public function dn2UserName($dn) {
-		return $this->access->dn2username($dn);
-	}
-
-	/**
-	 * returns an LDAP record based on a given login name
-	 *
-	 * @param string $loginName
-	 * @return array
-	 * @throws NotOnLDAP
-	 */
-	public function getLDAPUserByLoginName($loginName) {
-		//find out dn of the user name
-		$attrs = $this->access->userManager->getAttributes();
-		$users = $this->access->fetchUsersByLoginName($loginName, $attrs);
-		if(count($users) < 1) {
-			throw new NotOnLDAP('No user available for the given login name on ' .
-				$this->access->connection->ldapHost . ':' . $this->access->connection->ldapPort);
-		}
-		return $users[0];
-	}
-
-	/**
-	 * Check if the password is correct without logging in the user
-	 *
-	 * @param string $uid The username
-	 * @param string $password The password
-	 * @return false|string
-	 */
-	public function checkPassword($uid, $password) {
-		try {
-			$ldapRecord = $this->getLDAPUserByLoginName($uid);
-		} catch(NotOnLDAP $e) {
-			\OC::$server->getLogger()->logException($e, ['app' => 'user_ldap', 'level' => ILogger::DEBUG]);
-			return false;
-		}
-		$dn = $ldapRecord['dn'][0];
-		$user = $this->access->userManager->get($dn);
-
-		if(!$user instanceof User) {
-			Util::writeLog('user_ldap',
-				'LDAP Login: Could not get user object for DN ' . $dn .
-				'. Maybe the LDAP entry has no set display name attribute?',
-				ILogger::WARN);
-			return false;
-		}
-		if($user->getUsername() !== false) {
-			//are the credentials OK?
-			if(!$this->access->areCredentialsValid($dn, $password)) {
-				return false;
-			}
-
-			$this->access->cacheUserExists($user->getUsername());
-			$user->processAttributes($ldapRecord);
-			$user->markLogin();
-
-			return $user->getUsername();
-		}
-
-		return false;
-	}
-
-	/**
-	 * Set password
-	 * @param string $uid The username
-	 * @param string $password The new password
-	 * @return bool
-	 */
-	public function setPassword($uid, $password) {
-		if ($this->userPluginManager->implementsActions(Backend::SET_PASSWORD)) {
-			return $this->userPluginManager->setPassword($uid, $password);
-		}
-
-		$user = $this->access->userManager->get($uid);
-
-		if(!$user instanceof User) {
-			throw new \Exception('LDAP setPassword: Could not get user object for uid ' . $uid .
-				'. Maybe the LDAP entry has no set display name attribute?');
-		}
-		if($user->getUsername() !== false && $this->access->setPassword($user->getDN(), $password)) {
-			$ldapDefaultPPolicyDN = $this->access->connection->ldapDefaultPPolicyDN;
-			$turnOnPasswordChange = $this->access->connection->turnOnPasswordChange;
-			if (!empty($ldapDefaultPPolicyDN) && ((int)$turnOnPasswordChange === 1)) {
-				//remove last password expiry warning if any
-				$notification = $this->notificationManager->createNotification();
-				$notification->setApp('user_ldap')
-					->setUser($uid)
-					->setObject('pwd_exp_warn', $uid)
-				;
-				$this->notificationManager->markProcessed($notification);
-			}
-			return true;
-		}
-
-		return false;
-	}
-
-	/**
-	 * Get a list of all users
-	 *
-	 * @param string $search
-	 * @param integer $limit
-	 * @param integer $offset
-	 * @return string[] an array of all uids
-	 */
-	public function getUsers($search = '', $limit = 10, $offset = 0) {
-		$search = $this->access->escapeFilterPart($search, true);
-		$cachekey = 'getUsers-'.$search.'-'.$limit.'-'.$offset;
-
-		//check if users are cached, if so return
-		$ldap_users = $this->access->connection->getFromCache($cachekey);
-		if(!is_null($ldap_users)) {
-			return $ldap_users;
-		}
-
-		// if we'd pass -1 to LDAP search, we'd end up in a Protocol
-		// error. With a limit of 0, we get 0 results. So we pass null.
-		if($limit <= 0) {
-			$limit = null;
-		}
-		$filter = $this->access->combineFilterWithAnd(array(
-			$this->access->connection->ldapUserFilter,
-			$this->access->connection->ldapUserDisplayName . '=*',
-			$this->access->getFilterPartForUserSearch($search)
-		));
-
-		Util::writeLog('user_ldap',
-			'getUsers: Options: search '.$search.' limit '.$limit.' offset '.$offset.' Filter: '.$filter,
-			ILogger::DEBUG);
-		//do the search and translate results to Nextcloud names
-		$ldap_users = $this->access->fetchListOfUsers(
-			$filter,
-			$this->access->userManager->getAttributes(true),
-			$limit, $offset);
-		$ldap_users = $this->access->nextcloudUserNames($ldap_users);
-		Util::writeLog('user_ldap', 'getUsers: '.count($ldap_users). ' Users found', ILogger::DEBUG);
-
-		$this->access->connection->writeToCache($cachekey, $ldap_users);
-		return $ldap_users;
-	}
-
-	/**
-	 * checks whether a user is still available on LDAP
-	 *
-	 * @param string|\OCA\User_LDAP\User\User $user either the Nextcloud user
-	 * name or an instance of that user
-	 * @return bool
-	 * @throws \Exception
-	 * @throws \OC\ServerNotAvailableException
-	 */
-	public function userExistsOnLDAP($user) {
-		if(is_string($user)) {
-			$user = $this->access->userManager->get($user);
-		}
-		if(is_null($user)) {
-			return false;
-		}
-
-		$dn = $user->getDN();
-		//check if user really still exists by reading its entry
-		if(!is_array($this->access->readAttribute($dn, '', $this->access->connection->ldapUserFilter))) {
-			try {
-				$uuid = $this->access->getUserMapper()->getUUIDByDN($dn);
-				if (!$uuid) {
-					return false;
-				}
-				$newDn = $this->access->getUserDnByUuid($uuid);
-				//check if renamed user is still valid by reapplying the ldap filter
-				if ($newDn === $dn || !is_array($this->access->readAttribute($newDn, '', $this->access->connection->ldapUserFilter))) {
-					return false;
-				}
-				$this->access->getUserMapper()->setDNbyUUID($newDn, $uuid);
-				return true;
-			} catch (ServerNotAvailableException $e) {
-				throw $e;
-			} catch (\Exception $e) {
-				return false;
-			}
-		}
-
-		if($user instanceof OfflineUser) {
-			$user->unmark();
-		}
-
-		return true;
-	}
-
-	/**
-	 * check if a user exists
-	 * @param string $uid the username
-	 * @return boolean
-	 * @throws \Exception when connection could not be established
-	 */
-	public function userExists($uid) {
-		$userExists = $this->access->connection->getFromCache('userExists'.$uid);
-		if(!is_null($userExists)) {
-			return (bool)$userExists;
-		}
-		//getting dn, if false the user does not exist. If dn, he may be mapped only, requires more checking.
-		$user = $this->access->userManager->get($uid);
-
-		if(is_null($user)) {
-			Util::writeLog('user_ldap', 'No DN found for '.$uid.' on '.
-				$this->access->connection->ldapHost, ILogger::DEBUG);
-			$this->access->connection->writeToCache('userExists'.$uid, false);
-			return false;
-		} else if($user instanceof OfflineUser) {
-			//express check for users marked as deleted. Returning true is
-			//necessary for cleanup
-			return true;
-		}
-
-		$result = $this->userExistsOnLDAP($user);
-		$this->access->connection->writeToCache('userExists'.$uid, $result);
-		return $result;
-	}
-
-	/**
-	* returns whether a user was deleted in LDAP
-	*
-	* @param string $uid The username of the user to delete
-	* @return bool
-	*/
-	public function deleteUser($uid) {
-		if ($this->userPluginManager->canDeleteUser()) {
-			return $this->userPluginManager->deleteUser($uid);
-		}
-
-		$marked = $this->ocConfig->getUserValue($uid, 'user_ldap', 'isDeleted', 0);
-		if((int)$marked === 0) {
-			\OC::$server->getLogger()->notice(
-				'User '.$uid . ' is not marked as deleted, not cleaning up.',
-				array('app' => 'user_ldap'));
-			return false;
-		}
-		\OC::$server->getLogger()->info('Cleaning up after user ' . $uid,
-			array('app' => 'user_ldap'));
-
-		$this->access->getUserMapper()->unmap($uid); // we don't emit unassign signals here, since it is implicit to delete signals fired from core
-		$this->access->userManager->invalidate($uid);
-		return true;
-	}
-
-	/**
-	 * get the user's home directory
-	 *
-	 * @param string $uid the username
-	 * @return bool|string
-	 * @throws NoUserException
-	 * @throws \Exception
-	 */
-	public function getHome($uid) {
-		// user Exists check required as it is not done in user proxy!
-		if(!$this->userExists($uid)) {
-			return false;
-		}
-
-		if ($this->userPluginManager->implementsActions(Backend::GET_HOME)) {
-			return $this->userPluginManager->getHome($uid);
-		}
-
-		$cacheKey = 'getHome'.$uid;
-		$path = $this->access->connection->getFromCache($cacheKey);
-		if(!is_null($path)) {
-			return $path;
-		}
-
-		// early return path if it is a deleted user
-		$user = $this->access->userManager->get($uid);
-		if($user instanceof OfflineUser) {
-			if($this->currentUserInDeletionProcess !== null
-				&& $this->currentUserInDeletionProcess === $user->getOCName()
-			) {
-				return $user->getHomePath();
-			} else {
-				throw new NoUserException($uid . ' is not a valid user anymore');
-			}
-		} else if ($user === null) {
-			throw new NoUserException($uid . ' is not a valid user anymore');
-		}
-
-		$path = $user->getHomePath();
-		$this->access->cacheUserHome($uid, $path);
-
-		return $path;
-	}
-
-	/**
-	 * get display name of the user
-	 * @param string $uid user ID of the user
-	 * @return string|false display name
-	 */
-	public function getDisplayName($uid) {
-		if ($this->userPluginManager->implementsActions(Backend::GET_DISPLAYNAME)) {
-			return $this->userPluginManager->getDisplayName($uid);
-		}
-
-		if(!$this->userExists($uid)) {
-			return false;
-		}
-
-		$cacheKey = 'getDisplayName'.$uid;
-		if(!is_null($displayName = $this->access->connection->getFromCache($cacheKey))) {
-			return $displayName;
-		}
-
-		//Check whether the display name is configured to have a 2nd feature
-		$additionalAttribute = $this->access->connection->ldapUserDisplayName2;
-		$displayName2 = '';
-		if ($additionalAttribute !== '') {
-			$displayName2 = $this->access->readAttribute(
-				$this->access->username2dn($uid),
-				$additionalAttribute);
-		}
-
-		$displayName = $this->access->readAttribute(
-			$this->access->username2dn($uid),
-			$this->access->connection->ldapUserDisplayName);
-
-		if($displayName && (count($displayName) > 0)) {
-			$displayName = $displayName[0];
-
-			if (is_array($displayName2)){
-				$displayName2 = count($displayName2) > 0 ? $displayName2[0] : '';
-			}
-
-			$user = $this->access->userManager->get($uid);
-			if ($user instanceof User) {
-				$displayName = $user->composeAndStoreDisplayName($displayName, $displayName2);
-				$this->access->connection->writeToCache($cacheKey, $displayName);
-			}
-			if ($user instanceof OfflineUser) {
-				/** @var OfflineUser $user*/
-				$displayName = $user->getDisplayName();
-			}
-			return $displayName;
-		}
-
-		return null;
-	}
-
-	/**
-	 * set display name of the user
-	 * @param string $uid user ID of the user
-	 * @param string $displayName new display name of the user
-	 * @return string|false display name
-	 */
-	public function setDisplayName($uid, $displayName) {
-		if ($this->userPluginManager->implementsActions(Backend::SET_DISPLAYNAME)) {
-			$this->userPluginManager->setDisplayName($uid, $displayName);
-			$this->access->cacheUserDisplayName($uid, $displayName);
-			return $displayName;
-		}
-		return false;
-	}
-
-	/**
-	 * Get a list of all display names
-	 *
-	 * @param string $search
-	 * @param string|null $limit
-	 * @param string|null $offset
-	 * @return array an array of all displayNames (value) and the corresponding uids (key)
-	 */
-	public function getDisplayNames($search = '', $limit = null, $offset = null) {
-		$cacheKey = 'getDisplayNames-'.$search.'-'.$limit.'-'.$offset;
-		if(!is_null($displayNames = $this->access->connection->getFromCache($cacheKey))) {
-			return $displayNames;
-		}
-
-		$displayNames = array();
-		$users = $this->getUsers($search, $limit, $offset);
-		foreach ($users as $user) {
-			$displayNames[$user] = $this->getDisplayName($user);
-		}
-		$this->access->connection->writeToCache($cacheKey, $displayNames);
-		return $displayNames;
-	}
-
-	/**
-	* Check if backend implements actions
-	* @param int $actions bitwise-or'ed actions
-	* @return boolean
-	*
-	* Returns the supported actions as int to be
-	* compared with \OC\User\Backend::CREATE_USER etc.
-	*/
-	public function implementsActions($actions) {
-		return (bool)((Backend::CHECK_PASSWORD
-			| Backend::GET_HOME
-			| Backend::GET_DISPLAYNAME
-			| (($this->access->connection->ldapUserAvatarRule !== 'none') ? Backend::PROVIDE_AVATAR : 0)
-			| Backend::COUNT_USERS
-			| (((int)$this->access->connection->turnOnPasswordChange === 1)? Backend::SET_PASSWORD :0)
-			| $this->userPluginManager->getImplementedActions())
-			& $actions);
-	}
-
-	/**
-	 * @return bool
-	 */
-	public function hasUserListings() {
-		return true;
-	}
-
-	/**
-	 * counts the users in LDAP
-	 *
-	 * @return int|bool
-	 */
-	public function countUsers() {
-		if ($this->userPluginManager->implementsActions(Backend::COUNT_USERS)) {
-			return $this->userPluginManager->countUsers();
-		}
-
-		$filter = $this->access->getFilterForUserCount();
-		$cacheKey = 'countUsers-'.$filter;
-		if(!is_null($entries = $this->access->connection->getFromCache($cacheKey))) {
-			return $entries;
-		}
-		$entries = $this->access->countUsers($filter);
-		$this->access->connection->writeToCache($cacheKey, $entries);
-		return $entries;
-	}
-
-	/**
-	 * Backend name to be shown in user management
-	 * @return string the name of the backend to be shown
-	 */
-	public function getBackendName(){
-		return 'LDAP';
-	}
+    /**
+     * returns the username for the given LDAP DN, if available
+     *
+     * @param string $dn
+     * @return string|false with the username
+     */
+    public function dn2UserName($dn) {
+        return $this->access->dn2username($dn);
+    }
+
+    /**
+     * returns an LDAP record based on a given login name
+     *
+     * @param string $loginName
+     * @return array
+     * @throws NotOnLDAP
+     */
+    public function getLDAPUserByLoginName($loginName) {
+        //find out dn of the user name
+        $attrs = $this->access->userManager->getAttributes();
+        $users = $this->access->fetchUsersByLoginName($loginName, $attrs);
+        if(count($users) < 1) {
+            throw new NotOnLDAP('No user available for the given login name on ' .
+                $this->access->connection->ldapHost . ':' . $this->access->connection->ldapPort);
+        }
+        return $users[0];
+    }
+
+    /**
+     * Check if the password is correct without logging in the user
+     *
+     * @param string $uid The username
+     * @param string $password The password
+     * @return false|string
+     */
+    public function checkPassword($uid, $password) {
+        try {
+            $ldapRecord = $this->getLDAPUserByLoginName($uid);
+        } catch(NotOnLDAP $e) {
+            \OC::$server->getLogger()->logException($e, ['app' => 'user_ldap', 'level' => ILogger::DEBUG]);
+            return false;
+        }
+        $dn = $ldapRecord['dn'][0];
+        $user = $this->access->userManager->get($dn);
+
+        if(!$user instanceof User) {
+            Util::writeLog('user_ldap',
+                'LDAP Login: Could not get user object for DN ' . $dn .
+                '. Maybe the LDAP entry has no set display name attribute?',
+                ILogger::WARN);
+            return false;
+        }
+        if($user->getUsername() !== false) {
+            //are the credentials OK?
+            if(!$this->access->areCredentialsValid($dn, $password)) {
+                return false;
+            }
+
+            $this->access->cacheUserExists($user->getUsername());
+            $user->processAttributes($ldapRecord);
+            $user->markLogin();
+
+            return $user->getUsername();
+        }
+
+        return false;
+    }
+
+    /**
+     * Set password
+     * @param string $uid The username
+     * @param string $password The new password
+     * @return bool
+     */
+    public function setPassword($uid, $password) {
+        if ($this->userPluginManager->implementsActions(Backend::SET_PASSWORD)) {
+            return $this->userPluginManager->setPassword($uid, $password);
+        }
+
+        $user = $this->access->userManager->get($uid);
+
+        if(!$user instanceof User) {
+            throw new \Exception('LDAP setPassword: Could not get user object for uid ' . $uid .
+                '. Maybe the LDAP entry has no set display name attribute?');
+        }
+        if($user->getUsername() !== false && $this->access->setPassword($user->getDN(), $password)) {
+            $ldapDefaultPPolicyDN = $this->access->connection->ldapDefaultPPolicyDN;
+            $turnOnPasswordChange = $this->access->connection->turnOnPasswordChange;
+            if (!empty($ldapDefaultPPolicyDN) && ((int)$turnOnPasswordChange === 1)) {
+                //remove last password expiry warning if any
+                $notification = $this->notificationManager->createNotification();
+                $notification->setApp('user_ldap')
+                    ->setUser($uid)
+                    ->setObject('pwd_exp_warn', $uid)
+                ;
+                $this->notificationManager->markProcessed($notification);
+            }
+            return true;
+        }
+
+        return false;
+    }
+
+    /**
+     * Get a list of all users
+     *
+     * @param string $search
+     * @param integer $limit
+     * @param integer $offset
+     * @return string[] an array of all uids
+     */
+    public function getUsers($search = '', $limit = 10, $offset = 0) {
+        $search = $this->access->escapeFilterPart($search, true);
+        $cachekey = 'getUsers-'.$search.'-'.$limit.'-'.$offset;
+
+        //check if users are cached, if so return
+        $ldap_users = $this->access->connection->getFromCache($cachekey);
+        if(!is_null($ldap_users)) {
+            return $ldap_users;
+        }
+
+        // if we'd pass -1 to LDAP search, we'd end up in a Protocol
+        // error. With a limit of 0, we get 0 results. So we pass null.
+        if($limit <= 0) {
+            $limit = null;
+        }
+        $filter = $this->access->combineFilterWithAnd(array(
+            $this->access->connection->ldapUserFilter,
+            $this->access->connection->ldapUserDisplayName . '=*',
+            $this->access->getFilterPartForUserSearch($search)
+        ));
+
+        Util::writeLog('user_ldap',
+            'getUsers: Options: search '.$search.' limit '.$limit.' offset '.$offset.' Filter: '.$filter,
+            ILogger::DEBUG);
+        //do the search and translate results to Nextcloud names
+        $ldap_users = $this->access->fetchListOfUsers(
+            $filter,
+            $this->access->userManager->getAttributes(true),
+            $limit, $offset);
+        $ldap_users = $this->access->nextcloudUserNames($ldap_users);
+        Util::writeLog('user_ldap', 'getUsers: '.count($ldap_users). ' Users found', ILogger::DEBUG);
+
+        $this->access->connection->writeToCache($cachekey, $ldap_users);
+        return $ldap_users;
+    }
+
+    /**
+     * checks whether a user is still available on LDAP
+     *
+     * @param string|\OCA\User_LDAP\User\User $user either the Nextcloud user
+     * name or an instance of that user
+     * @return bool
+     * @throws \Exception
+     * @throws \OC\ServerNotAvailableException
+     */
+    public function userExistsOnLDAP($user) {
+        if(is_string($user)) {
+            $user = $this->access->userManager->get($user);
+        }
+        if(is_null($user)) {
+            return false;
+        }
+
+        $dn = $user->getDN();
+        //check if user really still exists by reading its entry
+        if(!is_array($this->access->readAttribute($dn, '', $this->access->connection->ldapUserFilter))) {
+            try {
+                $uuid = $this->access->getUserMapper()->getUUIDByDN($dn);
+                if (!$uuid) {
+                    return false;
+                }
+                $newDn = $this->access->getUserDnByUuid($uuid);
+                //check if renamed user is still valid by reapplying the ldap filter
+                if ($newDn === $dn || !is_array($this->access->readAttribute($newDn, '', $this->access->connection->ldapUserFilter))) {
+                    return false;
+                }
+                $this->access->getUserMapper()->setDNbyUUID($newDn, $uuid);
+                return true;
+            } catch (ServerNotAvailableException $e) {
+                throw $e;
+            } catch (\Exception $e) {
+                return false;
+            }
+        }
+
+        if($user instanceof OfflineUser) {
+            $user->unmark();
+        }
+
+        return true;
+    }
+
+    /**
+     * check if a user exists
+     * @param string $uid the username
+     * @return boolean
+     * @throws \Exception when connection could not be established
+     */
+    public function userExists($uid) {
+        $userExists = $this->access->connection->getFromCache('userExists'.$uid);
+        if(!is_null($userExists)) {
+            return (bool)$userExists;
+        }
+        //getting dn, if false the user does not exist. If dn, he may be mapped only, requires more checking.
+        $user = $this->access->userManager->get($uid);
+
+        if(is_null($user)) {
+            Util::writeLog('user_ldap', 'No DN found for '.$uid.' on '.
+                $this->access->connection->ldapHost, ILogger::DEBUG);
+            $this->access->connection->writeToCache('userExists'.$uid, false);
+            return false;
+        } else if($user instanceof OfflineUser) {
+            //express check for users marked as deleted. Returning true is
+            //necessary for cleanup
+            return true;
+        }
+
+        $result = $this->userExistsOnLDAP($user);
+        $this->access->connection->writeToCache('userExists'.$uid, $result);
+        return $result;
+    }
+
+    /**
+     * returns whether a user was deleted in LDAP
+     *
+     * @param string $uid The username of the user to delete
+     * @return bool
+     */
+    public function deleteUser($uid) {
+        if ($this->userPluginManager->canDeleteUser()) {
+            return $this->userPluginManager->deleteUser($uid);
+        }
+
+        $marked = $this->ocConfig->getUserValue($uid, 'user_ldap', 'isDeleted', 0);
+        if((int)$marked === 0) {
+            \OC::$server->getLogger()->notice(
+                'User '.$uid . ' is not marked as deleted, not cleaning up.',
+                array('app' => 'user_ldap'));
+            return false;
+        }
+        \OC::$server->getLogger()->info('Cleaning up after user ' . $uid,
+            array('app' => 'user_ldap'));
+
+        $this->access->getUserMapper()->unmap($uid); // we don't emit unassign signals here, since it is implicit to delete signals fired from core
+        $this->access->userManager->invalidate($uid);
+        return true;
+    }
+
+    /**
+     * get the user's home directory
+     *
+     * @param string $uid the username
+     * @return bool|string
+     * @throws NoUserException
+     * @throws \Exception
+     */
+    public function getHome($uid) {
+        // user Exists check required as it is not done in user proxy!
+        if(!$this->userExists($uid)) {
+            return false;
+        }
+
+        if ($this->userPluginManager->implementsActions(Backend::GET_HOME)) {
+            return $this->userPluginManager->getHome($uid);
+        }
+
+        $cacheKey = 'getHome'.$uid;
+        $path = $this->access->connection->getFromCache($cacheKey);
+        if(!is_null($path)) {
+            return $path;
+        }
+
+        // early return path if it is a deleted user
+        $user = $this->access->userManager->get($uid);
+        if($user instanceof OfflineUser) {
+            if($this->currentUserInDeletionProcess !== null
+                && $this->currentUserInDeletionProcess === $user->getOCName()
+            ) {
+                return $user->getHomePath();
+            } else {
+                throw new NoUserException($uid . ' is not a valid user anymore');
+            }
+        } else if ($user === null) {
+            throw new NoUserException($uid . ' is not a valid user anymore');
+        }
+
+        $path = $user->getHomePath();
+        $this->access->cacheUserHome($uid, $path);
+
+        return $path;
+    }
+
+    /**
+     * get display name of the user
+     * @param string $uid user ID of the user
+     * @return string|false display name
+     */
+    public function getDisplayName($uid) {
+        if ($this->userPluginManager->implementsActions(Backend::GET_DISPLAYNAME)) {
+            return $this->userPluginManager->getDisplayName($uid);
+        }
+
+        if(!$this->userExists($uid)) {
+            return false;
+        }
+
+        $cacheKey = 'getDisplayName'.$uid;
+        if(!is_null($displayName = $this->access->connection->getFromCache($cacheKey))) {
+            return $displayName;
+        }
+
+        //Check whether the display name is configured to have a 2nd feature
+        $additionalAttribute = $this->access->connection->ldapUserDisplayName2;
+        $displayName2 = '';
+        if ($additionalAttribute !== '') {
+            $displayName2 = $this->access->readAttribute(
+                $this->access->username2dn($uid),
+                $additionalAttribute);
+        }
+
+        $displayName = $this->access->readAttribute(
+            $this->access->username2dn($uid),
+            $this->access->connection->ldapUserDisplayName);
+
+        if($displayName && (count($displayName) > 0)) {
+            $displayName = $displayName[0];
+
+            if (is_array($displayName2)){
+                $displayName2 = count($displayName2) > 0 ? $displayName2[0] : '';
+            }
+
+            $user = $this->access->userManager->get($uid);
+            if ($user instanceof User) {
+                $displayName = $user->composeAndStoreDisplayName($displayName, $displayName2);
+                $this->access->connection->writeToCache($cacheKey, $displayName);
+            }
+            if ($user instanceof OfflineUser) {
+                /** @var OfflineUser $user*/
+                $displayName = $user->getDisplayName();
+            }
+            return $displayName;
+        }
+
+        return null;
+    }
+
+    /**
+     * set display name of the user
+     * @param string $uid user ID of the user
+     * @param string $displayName new display name of the user
+     * @return string|false display name
+     */
+    public function setDisplayName($uid, $displayName) {
+        if ($this->userPluginManager->implementsActions(Backend::SET_DISPLAYNAME)) {
+            $this->userPluginManager->setDisplayName($uid, $displayName);
+            $this->access->cacheUserDisplayName($uid, $displayName);
+            return $displayName;
+        }
+        return false;
+    }
+
+    /**
+     * Get a list of all display names
+     *
+     * @param string $search
+     * @param string|null $limit
+     * @param string|null $offset
+     * @return array an array of all displayNames (value) and the corresponding uids (key)
+     */
+    public function getDisplayNames($search = '', $limit = null, $offset = null) {
+        $cacheKey = 'getDisplayNames-'.$search.'-'.$limit.'-'.$offset;
+        if(!is_null($displayNames = $this->access->connection->getFromCache($cacheKey))) {
+            return $displayNames;
+        }
+
+        $displayNames = array();
+        $users = $this->getUsers($search, $limit, $offset);
+        foreach ($users as $user) {
+            $displayNames[$user] = $this->getDisplayName($user);
+        }
+        $this->access->connection->writeToCache($cacheKey, $displayNames);
+        return $displayNames;
+    }
+
+    /**
+     * Check if backend implements actions
+     * @param int $actions bitwise-or'ed actions
+     * @return boolean
+     *
+     * Returns the supported actions as int to be
+     * compared with \OC\User\Backend::CREATE_USER etc.
+     */
+    public function implementsActions($actions) {
+        return (bool)((Backend::CHECK_PASSWORD
+            | Backend::GET_HOME
+            | Backend::GET_DISPLAYNAME
+            | (($this->access->connection->ldapUserAvatarRule !== 'none') ? Backend::PROVIDE_AVATAR : 0)
+            | Backend::COUNT_USERS
+            | (((int)$this->access->connection->turnOnPasswordChange === 1)? Backend::SET_PASSWORD :0)
+            | $this->userPluginManager->getImplementedActions())
+            & $actions);
+    }
+
+    /**
+     * @return bool
+     */
+    public function hasUserListings() {
+        return true;
+    }
+
+    /**
+     * counts the users in LDAP
+     *
+     * @return int|bool
+     */
+    public function countUsers() {
+        if ($this->userPluginManager->implementsActions(Backend::COUNT_USERS)) {
+            return $this->userPluginManager->countUsers();
+        }
+
+        $filter = $this->access->getFilterForUserCount();
+        $cacheKey = 'countUsers-'.$filter;
+        if(!is_null($entries = $this->access->connection->getFromCache($cacheKey))) {
+            return $entries;
+        }
+        $entries = $this->access->countUsers($filter);
+        $this->access->connection->writeToCache($cacheKey, $entries);
+        return $entries;
+    }
+
+    /**
+     * Backend name to be shown in user management
+     * @return string the name of the backend to be shown
+     */
+    public function getBackendName(){
+        return 'LDAP';
+    }
 	
-	/**
-	 * Return access for LDAP interaction.
-	 * @param string $uid
-	 * @return Access instance of Access for LDAP interaction
-	 */
-	public function getLDAPAccess($uid) {
-		return $this->access;
-	}
+    /**
+     * Return access for LDAP interaction.
+     * @param string $uid
+     * @return Access instance of Access for LDAP interaction
+     */
+    public function getLDAPAccess($uid) {
+        return $this->access;
+    }
 	
-	/**
-	 * Return LDAP connection resource from a cloned connection.
-	 * The cloned connection needs to be closed manually.
-	 * of the current access.
-	 * @param string $uid
-	 * @return resource of the LDAP connection
-	 */
-	public function getNewLDAPConnection($uid) {
-		$connection = clone $this->access->getConnection();
-		return $connection->getConnectionResource();
-	}
-
-	/**
-	 * create new user
-	 * @param string $username username of the new user
-	 * @param string $password password of the new user
-	 * @throws \UnexpectedValueException
-	 * @return bool
-	 */
-	public function createUser($username, $password) {
-		if ($this->userPluginManager->implementsActions(Backend::CREATE_USER)) {
-			if ($dn = $this->userPluginManager->createUser($username, $password)) {
-				if (is_string($dn)) {
-					//updates user mapping
-					$this->access->dn2ocname($dn, $username, true);
-				} else {
-					throw new \UnexpectedValueException("LDAP Plugin: Method createUser changed to return the user DN instead of boolean.");
-				}
-			}
-			return (bool) $dn;
-		}
-		return false;
-	}
+    /**
+     * Return LDAP connection resource from a cloned connection.
+     * The cloned connection needs to be closed manually.
+     * of the current access.
+     * @param string $uid
+     * @return resource of the LDAP connection
+     */
+    public function getNewLDAPConnection($uid) {
+        $connection = clone $this->access->getConnection();
+        return $connection->getConnectionResource();
+    }
+
+    /**
+     * create new user
+     * @param string $username username of the new user
+     * @param string $password password of the new user
+     * @throws \UnexpectedValueException
+     * @return bool
+     */
+    public function createUser($username, $password) {
+        if ($this->userPluginManager->implementsActions(Backend::CREATE_USER)) {
+            if ($dn = $this->userPluginManager->createUser($username, $password)) {
+                if (is_string($dn)) {
+                    //updates user mapping
+                    $this->access->dn2ocname($dn, $username, true);
+                } else {
+                    throw new \UnexpectedValueException("LDAP Plugin: Method createUser changed to return the user DN instead of boolean.");
+                }
+            }
+            return (bool) $dn;
+        }
+        return false;
+    }
 
 }