nextcloud/apps/dav/lib/Connector/Sabre/DavAclPlugin.php

99 lines
3.1 KiB
PHP

<?php
/**
* @copyright Copyright (c) 2016, ownCloud, Inc.
*
* @author Lukas Reschke <lukas@statuscode.ch>
* @author Thomas Müller <thomas.mueller@tmit.eu>
*
* @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/>
*
*/
namespace OCA\DAV\Connector\Sabre;
use OCA\DAV\CardDAV\AddressBook;
use Sabre\CalDAV\Principal\User;
use Sabre\DAV\Exception\NotFound;
use Sabre\DAV\INode;
use Sabre\DAV\PropFind;
use Sabre\HTTP\RequestInterface;
use Sabre\HTTP\ResponseInterface;
/**
* Class DavAclPlugin is a wrapper around \Sabre\DAVACL\Plugin that returns 404
* responses in case the resource to a response has been forbidden instead of
* a 403. This is used to prevent enumeration of valid resources.
*
* @see https://github.com/owncloud/core/issues/22578
* @package OCA\DAV\Connector\Sabre
*/
class DavAclPlugin extends \Sabre\DAVACL\Plugin {
public function __construct() {
$this->hideNodesFromListings = true;
$this->allowUnauthenticatedAccess = false;
}
function checkPrivileges($uri, $privileges, $recursion = self::R_PARENT, $throwExceptions = true) {
$access = parent::checkPrivileges($uri, $privileges, $recursion, false);
if($access === false && $throwExceptions) {
/** @var INode $node */
$node = $this->server->tree->getNodeForPath($uri);
switch(get_class($node)) {
case AddressBook::class:
$type = 'Addressbook';
break;
default:
$type = 'Node';
break;
}
throw new NotFound(
sprintf(
"%s with name '%s' could not be found",
$type,
$node->getName()
)
);
}
return $access;
}
public function propFind(PropFind $propFind, INode $node) {
// If the node is neither readable nor writable then fail unless its of
// the standard user-principal
if(!($node instanceof User)) {
$path = $propFind->getPath();
$readPermissions = $this->checkPrivileges($path, '{DAV:}read', self::R_PARENT, false);
$writePermissions = $this->checkPrivileges($path, '{DAV:}write', self::R_PARENT, false);
if ($readPermissions === false && $writePermissions === false) {
$this->checkPrivileges($path, '{DAV:}read', self::R_PARENT, true);
$this->checkPrivileges($path, '{DAV:}write', self::R_PARENT, true);
}
}
return parent::propFind($propFind, $node);
}
function beforeMethod(RequestInterface $request, ResponseInterface $response) {
$path = $request->getPath();
// prevent the plugin from causing an unneeded overhead for file requests
if (strpos($path, 'files/') !== 0) {
parent::beforeMethod($request, $response);
}
}
}