lib/private/Encryption/Keys/Storage.php
<?php
/**
* @author Björn Schießle <bjoern@schiessle.org>
* @author Joas Schilling <coding@schilljs.com>
* @author Thomas Müller <thomas.mueller@tmit.eu>
* @author Vincent Petry <pvince81@owncloud.com>
*
* @copyright Copyright (c) 2018, ownCloud GmbH
* @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 OC\Encryption\Keys;
use OC\Encryption\Util;
use OC\Files\Filesystem;
use OC\Files\View;
use OCP\Encryption\Keys\IStorage;
use OCP\IUserSession;
use OC\User\NoUserException;
use OC_Util;
class Storage implements IStorage {
// hidden file which indicate that the folder is a valid key storage
public const KEY_STORAGE_MARKER = '.oc_key_storage';
/** @var View */
private $view;
/** @var Util */
private $util;
// base dir where all the file related keys are stored
/** @var string */
private $keys_base_dir;
// root of the key storage default is empty which means that we use the data folder
/** @var string */
private $root_dir;
/** @var string */
private $encryption_base_dir;
/** @var array */
private $keyCache = [];
/** @var string */
private $currentUser = null;
/**
* @param View $view view
* @param Util $util encryption util class
* @param IUserSession $session user session
*/
public function __construct(View $view, Util $util, IUserSession $session) {
$this->view = $view;
$this->util = $util;
$this->encryption_base_dir = '/files_encryption';
$this->keys_base_dir = $this->encryption_base_dir .'/keys';
$this->root_dir = $this->util->getKeyStorageRoot();
if ($session !== null && $session->getUser() !== null) {
$this->currentUser = $session->getUser()->getUID();
}
}
/**
* @inheritdoc
*/
public function getUserKey($uid, $keyId, $encryptionModuleId) {
$path = $this->constructUserKeyPath($encryptionModuleId, $keyId, $uid);
return $this->getKey($path);
}
/**
* @inheritdoc
*/
public function getFileKey($path, $keyId, $encryptionModuleId) {
$realFile = OC_Util::stripPartialFileExtension($path);
$keyDir = $this->getFileKeyDir($encryptionModuleId, $realFile);
$key = $this->getKey($keyDir . $keyId);
if ($key === '' && $realFile !== $path) {
// Check if the part file has keys and use them, if no normal keys
// exist. This is required to fix copyBetweenStorage() when we
// rename a .part file over storage borders.
$keyDir = $this->getFileKeyDir($encryptionModuleId, $path);
$key = $this->getKey($keyDir . $keyId);
}
return $key;
}
/**
* @inheritdoc
*/
public function getSystemUserKey($keyId, $encryptionModuleId) {
$path = $this->constructUserKeyPath($encryptionModuleId, $keyId, null);
return $this->getKey($path);
}
/**
* @inheritdoc
*/
public function setUserKey($uid, $keyId, $key, $encryptionModuleId) {
$path = $this->constructUserKeyPath($encryptionModuleId, $keyId, $uid);
return $this->setKey($path, $key);
}
/**
* @inheritdoc
*/
public function setFileKey($path, $keyId, $key, $encryptionModuleId) {
$keyDir = $this->getFileKeyDir($encryptionModuleId, $path);
return $this->setKey($keyDir . $keyId, $key);
}
/**
* @inheritdoc
*/
public function setSystemUserKey($keyId, $key, $encryptionModuleId) {
$path = $this->constructUserKeyPath($encryptionModuleId, $keyId, null);
return $this->setKey($path, $key);
}
/**
* @inheritdoc
*/
public function deleteUserKey($uid, $keyId, $encryptionModuleId) {
try {
$path = $this->constructUserKeyPath($encryptionModuleId, $keyId, $uid);
return !$this->view->file_exists($path) || $this->view->unlink($path);
} catch (NoUserException $e) {
// this exception can come from initMountPoints() from setupUserMounts()
// for a deleted user.
//
// It means, that:
// - we are not running in alternative storage mode because we don't call
// initMountPoints() in that mode
// - the keys were in the user's home but since the user was deleted, the
// user's home is gone and so are the keys
//
// So there is nothing to do, just ignore.
return true;
}
}
/**
* @inheritdoc
*/
public function deleteFileKey($path, $keyId, $encryptionModuleId) {
$keyDir = $this->getFileKeyDir($encryptionModuleId, $path);
return !$this->view->file_exists($keyDir . $keyId) || $this->view->unlink($keyDir . $keyId);
}
/**
* @inheritdoc
*/
public function deleteAllFileKeys($path) {
$keyDir = $this->getFileKeyDir('', $path);
return !$this->view->file_exists($keyDir) || $this->view->deleteAll($keyDir);
}
/**
* @inheritdoc
*/
public function deleteSystemUserKey($keyId, $encryptionModuleId) {
$path = $this->constructUserKeyPath($encryptionModuleId, $keyId, null);
return !$this->view->file_exists($path) || $this->view->unlink($path);
}
/**
* @inheritdoc
*/
public function deleteAltUserStorageKeys($uid) {
if (\OC::$server->getEncryptionManager()->isEnabled()) {
/**
* If the key storage is not the default
* location, then we need to remove the keys
* in the alternate key location
*/
$keyStorageRoot = $this->util->getKeyStorageRoot();
if ($keyStorageRoot !== '') {
$this->view->rmdir($keyStorageRoot . '/' . $uid);
return true;
}
return false;
}
return false;
}
/**
* construct path to users key
*
* @param string $encryptionModuleId
* @param string $keyId
* @param string $uid
* @return string
*/
protected function constructUserKeyPath($encryptionModuleId, $keyId, $uid) {
if ($uid === null) {
$path = $this->root_dir . '/' . $this->encryption_base_dir . '/' . $encryptionModuleId . '/' . $keyId;
} else {
$this->setupUserMounts($uid);
$path = $this->root_dir . '/' . $uid . $this->encryption_base_dir . '/'
. $encryptionModuleId . '/' . $uid . '.' . $keyId;
}
return \OC\Files\Filesystem::normalizePath($path);
}
/**
* read key from hard disk
*
* @param string $path to key
* @return string
*/
private function getKey($path) {
$key = '';
if ($this->view->file_exists($path)) {
if (isset($this->keyCache[$path])) {
$key = $this->keyCache[$path];
} else {
$key = $this->view->file_get_contents($path);
$this->keyCache[$path] = $key;
}
}
return $key;
}
/**
* write key to disk
*
*
* @param string $path path to key directory
* @param string $key key
* @return bool
*/
private function setKey($path, $key) {
$this->keySetPreparation(\dirname($path));
$result = $this->view->file_put_contents($path, $key);
if (\is_int($result) && $result > 0) {
$this->keyCache[$path] = $key;
return true;
}
return false;
}
/**
* get path to key folder for a given file
*
* @param string $encryptionModuleId
* @param string $path path to the file, relative to data/
* @return string
*/
private function getFileKeyDir($encryptionModuleId, $path) {
list($owner, $filename) = $this->util->getUidAndFilename($path);
// in case of system wide mount points the keys are stored directly in the data directory
if ($this->util->isSystemWideMountPoint($filename, $owner)) {
$keyPath = $this->root_dir . '/' . $this->keys_base_dir . $filename . '/';
} else {
$this->setupUserMounts($owner);
$keyPath = $this->root_dir . '/' . $owner . $this->keys_base_dir . $filename . '/';
}
return Filesystem::normalizePath($keyPath . $encryptionModuleId . '/', false);
}
/**
* move keys if a file was renamed
*
* @param string $source
* @param string $target
* @return boolean
*/
public function renameKeys($source, $target) {
$sourcePath = $this->getPathToKeys($source);
$targetPath = $this->getPathToKeys($target);
if ($this->view->file_exists($sourcePath)) {
$this->keySetPreparation(\dirname($targetPath));
return $this->view->rename($sourcePath, $targetPath);
}
return true;
}
/**
* copy keys if a file was renamed
*
* @param string $source
* @param string $target
* @return boolean
*/
public function copyKeys($source, $target) {
$sourcePath = $this->getPathToKeys($source);
$targetPath = $this->getPathToKeys($target);
if ($this->view->file_exists($sourcePath)) {
$this->keySetPreparation(\dirname($targetPath));
return $this->view->copy($sourcePath, $targetPath);
}
return true;
}
/**
* get system wide path and detect mount points
*
* @param string $path
* @return string
*/
protected function getPathToKeys($path) {
list($owner, $relativePath) = $this->util->getUidAndFilename($path);
$systemWideMountPoint = $this->util->isSystemWideMountPoint($relativePath, $owner);
if ($systemWideMountPoint) {
$systemPath = $this->root_dir . '/' . $this->keys_base_dir . $relativePath . '/';
} else {
$this->setupUserMounts($owner);
$systemPath = $this->root_dir . '/' . $owner . $this->keys_base_dir . $relativePath . '/';
}
return Filesystem::normalizePath($systemPath, false);
}
/**
* Make preparations to filesystem for saving a key file
*
* @param string $path relative to the views root
*/
protected function keySetPreparation($path) {
// If the file resides within a subdirectory, create it
if (!$this->view->file_exists($path)) {
$sub_dirs = \explode('/', \ltrim($path, '/'));
$dir = '';
foreach ($sub_dirs as $sub_dir) {
$dir .= '/' . $sub_dir;
if (!$this->view->is_dir($dir)) {
$this->view->mkdir($dir);
}
}
}
}
/**
* Setup the mounts of the given user if different than
* the current user.
*
* This is needed because in many cases the keys are stored
* within the user's home storage.
*
* @param string $uid user id
*/
protected function setupUserMounts($uid) {
if ($this->root_dir !== '') {
// this means that the keys are stored outside of the user's homes,
// so we don't need to mount anything
return;
}
if ($uid !== null && $uid !== '' && $uid !== $this->currentUser) {
\OC\Files\Filesystem::initMountPoints($uid);
}
}
}