nextcloud/lib/private/files/storage/wrapper/encryption.php

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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\Files\Storage\Wrapper;
use OC\Encryption\Exceptions\ModuleDoesNotExistsException;
class Encryption extends Wrapper {
/** @var string */
private $mountPoint;
/** @var \OC\Encryption\Util */
private $util;
/** @var \OC\Encryption\Manager */
private $encryptionManager;
/** @var \OC\Log */
private $logger;
/** @var string */
private $uid;
/** @var array */
private $unencryptedSize;
/**
* @param array $parameters
* @param \OC\Encryption\Manager $encryptionManager
* @param \OC\Encryption\Util $util
* @param \OC\Log $logger
* @param string $uid user who perform the read/write operation (null for public access)
*/
public function __construct(
$parameters,
\OC\Encryption\Manager $encryptionManager = null,
\OC\Encryption\Util $util = null,
\OC\Log $logger = null,
$uid = null
) {
$this->mountPoint = $parameters['mountPoint'];
$this->encryptionManager = $encryptionManager;
$this->util = $util;
$this->logger = $logger;
$this->uid = $uid;
$this->unencryptedSize = array();
parent::__construct($parameters);
}
/**
* see http://php.net/manual/en/function.filesize.php
* The result for filesize when called on a folder is required to be 0
*
* @param string $path
* @return int
*/
public function filesize($path) {
$size = 0;
$fullPath = $this->getFullPath($path);
$encryptedSize = $this->storage->filesize($path);
$info = $this->getCache()->get($path);
if($encryptedSize > 0 && $info['encrypted']) {
$size = $info['unencrypted_size'];
if ($size <= 0) {
$encryptionModule = $this->getEncryptionModule($path);
if ($encryptionModule) {
$size = $encryptionModule->calculateUnencryptedSize($fullPath);
$this->getCache()->update($info['fileid'], array('unencrypted_size' => $size));
}
}
} else if (isset($this->unencryptedSize[$fullPath]) && isset($info['fileid'])) {
$size = $this->unencryptedSize[$fullPath];
$info['encrypted'] = true;
$info['unencrypted_size'] = $size;
$info['size'] = $encryptedSize;
$this->getCache()->put($path, $info);
}
return $size;
}
/**
* see http://php.net/manual/en/function.file_get_contents.php
*
* @param string $path
* @return string
*/
public function file_get_contents($path) {
$data = null;
$encryptionModule = $this->getEncryptionModule($path);
if ($encryptionModule) {
$handle = $this->fopen($path, 'r');
if (is_resource($handle)) {
while (!feof($handle)) {
$data .= fread($handle, $this->util->getBlockSize());
}
}
} else {
$data = $this->storage->file_get_contents($path);
}
return $data;
}
/**
* see http://php.net/manual/en/function.file_put_contents.php
*
* @param string $path
* @param string $data
* @return bool
*/
public function file_put_contents($path, $data) {
// file put content will always be translated to a stream write
$handle = $this->fopen($path, 'w');
fwrite($handle, $data);
return fclose($handle);
}
/**
* see http://php.net/manual/en/function.unlink.php
*
* @param string $path
* @return bool
*/
public function unlink($path) {
if ($this->util->isExcluded($path)) {
return $this->storage->unlink($path);
}
$encryptionModule = $this->getEncryptionModule($path);
if ($encryptionModule) {
$keyStorage = \OC::$server->getEncryptionKeyStorage($encryptionModule->getId());
$keyStorage->deleteAllFileKeys($this->getFullPath($path));
}
return $this->storage->unlink($path);
}
/**
* see http://php.net/manual/en/function.rename.php
*
* @param string $path1
* @param string $path2
* @return bool
*/
public function rename($path1, $path2) {
if ($this->util->isExcluded($path1)) {
return $this->storage->rename($path1, $path2);
}
$fullPath1 = $this->getFullPath($path1);
list($owner, $source) = $this->util->getUidAndFilename($fullPath1);
$result = $this->storage->rename($path1, $path2);
if ($result) {
$fullPath2 = $this->getFullPath($path2);
$systemWide = $this->util->isSystemWideMountPoint($this->mountPoint);
list(, $target) = $this->util->getUidAndFilename($fullPath2);
$encryptionModule = $this->getEncryptionModule($path2);
if ($encryptionModule) {
$keyStorage = \OC::$server->getEncryptionKeyStorage($encryptionModule->getId());
$keyStorage->renameKeys($source, $target, $owner, $systemWide);
}
}
return $result;
}
/**
* see http://php.net/manual/en/function.copy.php
*
* @param string $path1
* @param string $path2
* @return bool
*/
public function copy($path1, $path2) {
// todo copy encryption keys, get users with access to the file and reencrypt
// or is this to encryption module specific? Then we can hand this over
return $this->storage->copy($path1, $path2);
}
/**
* see http://php.net/manual/en/function.fopen.php
*
* @param string $path
* @param string $mode
* @return resource
*/
public function fopen($path, $mode) {
$shouldEncrypt = false;
$encryptionModule = null;
$header = $this->getHeader($path);
$fullPath = $this->getFullPath($path);
$encryptionModuleId = $this->util->getEncryptionModuleId($header);
$size = $unencryptedSize = 0;
if ($this->file_exists($path)) {
$size = $this->storage->filesize($path);
$unencryptedSize = $this->filesize($path);
}
try {
if (
$mode === 'w'
|| $mode === 'w+'
|| $mode === 'wb'
|| $mode === 'wb+'
) {
if (!empty($encryptionModuleId)) {
$encryptionModule = $this->encryptionManager->getEncryptionModule($encryptionModuleId);
} else {
$encryptionModule = $this->encryptionManager->getDefaultEncryptionModule();
}
$shouldEncrypt = $encryptionModule->shouldEncrypt($fullPath);
} else {
// only get encryption module if we found one in the header
if (!empty($encryptionModuleId)) {
$encryptionModule = $this->encryptionManager->getEncryptionModule($encryptionModuleId);
$shouldEncrypt = true;
}
}
} catch (ModuleDoesNotExistsException $e) {
$this->logger->warning('Encryption module "' . $encryptionModuleId .
'" not found, file will be stored unencrypted');
}
if($shouldEncrypt === true && !$this->util->isExcluded($fullPath) && $encryptionModule !== null) {
$source = $this->storage->fopen($path, $mode);
$handle = \OC\Files\Stream\Encryption::wrap($source, $path, $fullPath, $header,
$this->uid, $encryptionModule, $this->storage, $this, $this->util, $mode,
$size, $unencryptedSize);
return $handle;
} else {
return $this->storage->fopen($path, $mode);
}
}
/**
* return full path, including mount point
*
* @param string $path relative to mount point
* @return string full path including mount point
*/
protected function getFullPath($path) {
return \OC\Files\Filesystem::normalizePath($this->mountPoint . '/' . $path);
}
/**
* read header from file
*
* @param string $path
* @return array
*/
protected function getHeader($path) {
$header = '';
if ($this->storage->file_exists($path)) {
$handle = $this->storage->fopen($path, 'r');
$header = fread($handle, $this->util->getHeaderSize());
fclose($handle);
}
return $this->util->readHeader($header);
}
/**
* read encryption module needed to read/write the file located at $path
*
* @param string $path
* @return null|\OCP\Encryption\IEncryptionModule
* @throws ModuleDoesNotExistsException
* @throws \Exception
*/
protected function getEncryptionModule($path) {
$encryptionModule = null;
$header = $this->getHeader($path);
$encryptionModuleId = $this->util->getEncryptionModuleId($header);
if (!empty($encryptionModuleId)) {
try {
$encryptionModule = $this->encryptionManager->getEncryptionModule($encryptionModuleId);
} catch (ModuleDoesNotExistsException $e) {
$this->logger->critical('Encryption module defined in "' . $path . '" not loaded!');
throw $e;
}
}
return $encryptionModule;
}
public function updateUnencryptedSize($path, $unencryptedSize) {
$this->unencryptedSize[$path] = $unencryptedSize;
}
}