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<?php
/**
* ownCloud
*
* @copyright (C) 2015 ownCloud, Inc.
*
* @author Bjoern Schiessle <schiessle@owncloud.com>
*
* 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/>.
*/
namespace OC\Encryption;
class KeyStorage implements \OCP\Encryption\IKeyStorage {
/** @var \OC\Files\View */
private $view;
/** @var \OC\Encryption\Util */
private $util;
// base dir where all the file related keys are stored
private static $keys_base_dir = '/files_encryption/keys/';
private static $encryption_base_dir = '/files_encryption';
private static $key_cache = array(); // cache keys
/**
* @param \OC\Files\View $view
* @param \OC\Encryption\Util $util
*/
public function __construct(\OC\Files\View $view, \OC\Encryption\Util $util) {
$this->view = $view;
$this->util = $util;
}
/**
* get user specific key
*
* @param string $uid ID if the user for whom we want the key
* @param string $keyid id of the key
*
* @return mixed key
*/
public function getUserKey($uid, $keyid) {
$path = '/' . $uid . self::$encryption_base_dir . '/' . $uid . '.' . $keyid;
return $this->getKey($path);
}
/**
* get file specific key
*
* @param string $path path to file
* @param string $keyId id of the key
*
* @return mixed key
*/
public function getFileKey($path, $keyId) {
$keyDir = $this->getFileKeyDir($path);
return $this->getKey($keyDir . $keyId);
}
/**
* get system-wide encryption keys not related to a specific user,
* e.g something like a key for public link shares
*
* @param string $keyId id of the key
*
* @return mixed key
*/
public function getSystemUserKey($keyId) {
$path = '/' . self::$encryption_base_dir . '/' . $keyId;
return $this->getKey($path);
}
/**
* set user specific key
*
* @param string $uid ID if the user for whom we want the key
* @param string $keyId id of the key
* @param mixed $key
*/
public function setUserKey($uid, $keyId, $key) {
$path = '/' . $uid . self::$encryption_base_dir . '/' . $uid . '.' . $keyId;
return $this->setKey($path, $key);
}
/**
* set file specific key
*
* @param string $path path to file
* @param string $keyId id of the key
* @param mixed $key
*/
public function setFileKey($path, $keyId, $key) {
$keyDir = $this->getFileKeyDir($path);
return $this->setKey($keyDir . $keyId, $key);
}
/**
* set system-wide encryption keys not related to a specific user,
* e.g something like a key for public link shares
*
* @param string $keyId id of the key
* @param mixed $key
*
* @return mixed key
*/
public function setSystemUserKey($keyId, $key) {
$path = '/' . self::$encryption_base_dir . '/' . $keyId;
return $this->setKey($path, $key);
}
/**
* read key from hard disk
*
* @param string $path to key
* @return string
*/
private function getKey($path) {
$key = '';
if (isset(self::$key_cache[$path])) {
$key = self::$key_cache[$path];
} else {
/** @var \OCP\Files\Storage $storage */
list($storage, $internalPath) = $this->view->resolvePath($path);
if ($storage->file_exists($internalPath)) {
$key = $storage->file_get_contents($internalPath);
self::$key_cache[$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));
/** @var \OCP\Files\Storage $storage */
list($storage, $internalPath) = \OC\Files\Filesystem::resolvePath($path);
$result = $storage->file_put_contents($internalPath, $key);
if (is_int($result) && $result > 0) {
self::$key_cache[$path] = $key;
return true;
}
return false;
}
/**
* get path to key folder for a given file
*
* @param string $path path to the file, relative to the users file directory
* @return string
*/
private function getFileKeyDir($path) {
if ($this->view->is_dir('/' . \OCP\User::getUser() . '/' . $path)) {
throw new Exception\EncryptionException('file was expected but directoy was given', Exception\EncryptionException::GENERIC);
}
list($owner, $filename) = $this->util->getUidAndFilename($path);
$filename = $this->util->stripPartialFileExtension($filename);
$filePath_f = ltrim($filename, '/');
// in case of system wide mount points the keys are stored directly in the data directory
if ($this->util->isSystemWideMountPoint($filename)) {
$keyPath = self::$keys_base_dir . $filePath_f . '/';
} else {
$keyPath = '/' . $owner . self::$keys_base_dir . $filePath_f . '/';
}
return $keyPath;
}
/**
* Make preparations to filesystem for saving a keyfile
*
* @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('/', $path);
$dir = '';
foreach ($sub_dirs as $sub_dir) {
$dir .= '/' . $sub_dir;
if (!$this->view->is_dir($dir)) {
$this->view->mkdir($dir);
}
}
}
}
}
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