nextcloud/apps/user_webdavauth/user_webdavauth.php

<?php
/**
 * @author Bart Visscher <bartv@thisnet.nl>
 * @author Felix Moeller <mail@felixmoeller.de>
 * @author Frank Karlitschek <frank@owncloud.org>
 * @author Georg Ehrke <georg@ownCloud.com>
 * @author Morris Jobke <hey@morrisjobke.de>
 * @author opensaucesystems <ashley@opensaucesystems.com>
 * @author Thomas Müller <thomas.mueller@tmit.eu>
 *
 * @copyright Copyright (c) 2015, ownCloud, Inc.
 * @license AGPL-3.0
 *
 * This code is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License, version 3,
 * as published by the Free Software Foundation.
 *
 * This program 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, version 3,
 * along with this program.  If not, see <http://www.gnu.org/licenses/>
 *
 */
class OC_USER_WEBDAVAUTH extends OC_User_Backend implements \OCP\IUserBackend {
	protected $webdavauth_url;

	public function __construct() {
		$this->webdavauth_url = OC_Config::getValue( "user_webdavauth_url" );
	}

	public function deleteUser($uid) {
		// Can't delete user
		OC_Log::write('OC_USER_WEBDAVAUTH', 'Not possible to delete users from web frontend using WebDAV user backend', 3);
		return false;
	}

	public function setPassword ( $uid, $password ) {
		// We can't change user password
		OC_Log::write('OC_USER_WEBDAVAUTH', 'Not possible to change password for users from web frontend using WebDAV user backend', 3);
		return false;
	}

	public function checkPassword( $uid, $password ) {
		$arr = explode('://', $this->webdavauth_url, 2);
		if( ! isset($arr) OR count($arr) !== 2) {
			OC_Log::write('OC_USER_WEBDAVAUTH', 'Invalid Url: "'.$this->webdavauth_url.'" ', 3);
			return false;
		}
		list($webdavauth_protocol, $webdavauth_url_path) = $arr;
		$url= $webdavauth_protocol.'://'.urlencode($uid).':'.urlencode($password).'@'.$webdavauth_url_path;
		$headers = get_headers($url);
		if($headers==false) {
			OC_Log::write('OC_USER_WEBDAVAUTH', 'Not possible to connect to WebDAV Url: "'.$webdavauth_protocol.'://'.$webdavauth_url_path.'" ', 3);
			return false;

		}
		$returncode= substr($headers[0], 9, 3);

		if(substr($returncode, 0, 1) === '2') {
			return $uid;
		} else {
			return false;
		}

	}

	/*
	* we don´t know if a user exists without the password. so we have to return true all the time
	*/
	public function userExists( $uid ){
		return true;
	}

	/**
	 * @return bool
	 */
	public function hasUserListings() {
		return false;
	}

	/*
	* we don´t know the users so all we can do it return an empty array here
	*/
	public function getUsers($search = '', $limit = 10, $offset = 0) {
		$returnArray = array();

		return $returnArray;
	}

	/**
	 * Backend name to be shown in user management
	 * @return string the name of the backend to be shown
	 */
	public function getBackendName(){
		return 'WebDAV';
	}
}