server/apps/files_encryption/lib/proxy.php
Vincent Petry fe44024868 Fix for extstorage + encryption where unencrypted size is not kept
Fix for external storage with encryption where the unencrypted size is
first written in the DB, then set back to zero, causing performance
issue because the file needs to be reopened every time to find out the
unencrypted size (and potentially needs a full redownload)
2013-11-20 16:22:55 +01:00

428 lines
10 KiB
PHP

<?php
/**
* ownCloud
*
* @author Sam Tuke, Robin Appelman
* @copyright 2012 Sam Tuke samtuke@owncloud.com, Robin Appelman
* icewind1991@gmail.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/>.
*
*/
/**
* @brief Encryption proxy which handles filesystem operations before and after
* execution and encrypts, and handles keyfiles accordingly. Used for
* webui.
*/
namespace OCA\Encryption;
/**
* Class Proxy
* @package OCA\Encryption
*/
class Proxy extends \OC_FileProxy {
private static $blackList = null; //mimetypes blacklisted from encryption
/**
* Check if a file requires encryption
* @param string $path
* @return bool
*
* Tests if server side encryption is enabled, and file is allowed by blacklists
*/
private static function shouldEncrypt($path) {
if (\OCP\App::isEnabled('files_encryption') === false || Crypt::mode() !== 'server' ||
strpos($path, '/' . \OCP\User::getUser() . '/files') !== 0) {
return false;
}
if (is_null(self::$blackList)) {
self::$blackList = explode(',', \OCP\Config::getAppValue('files_encryption', 'type_blacklist', ''));
}
if (Crypt::isCatfileContent($path)) {
return true;
}
$extension = substr($path, strrpos($path, '.') + 1);
if (array_search($extension, self::$blackList) === false) {
return true;
}
return false;
}
/**
* @param $path
* @param $data
* @return bool
*/
public function preFile_put_contents($path, &$data) {
if (self::shouldEncrypt($path)) {
if (!is_resource($data)) {
// get root view
$view = new \OC_FilesystemView('/');
// get relative path
$relativePath = \OCA\Encryption\Helper::stripUserFilesPath($path);
if (!isset($relativePath)) {
return true;
}
// create random cache folder
$cacheFolder = rand();
$path_slices = explode('/', \OC_Filesystem::normalizePath($path));
$path_slices[2] = "cache/".$cacheFolder;
$tmpPath = implode('/', $path_slices);
$handle = fopen('crypt://' . $tmpPath, 'w');
if (is_resource($handle)) {
// write data to stream
fwrite($handle, $data);
// close stream
fclose($handle);
// disable encryption proxy to prevent recursive calls
$proxyStatus = \OC_FileProxy::$enabled;
\OC_FileProxy::$enabled = false;
// get encrypted content
$data = $view->file_get_contents($tmpPath);
// remove our temp file
$view->deleteAll('/' . \OCP\User::getUser() . '/cache/' . $cacheFolder);
// re-enable proxy - our work is done
\OC_FileProxy::$enabled = $proxyStatus;
}
}
}
return true;
}
/**
* @param string $path Path of file from which has been read
* @param string $data Data that has been read from file
*/
public function postFile_get_contents($path, $data) {
$plainData = null;
$view = new \OC_FilesystemView('/');
// init session
$session = new \OCA\Encryption\Session($view);
// If data is a catfile
if (
Crypt::mode() === 'server'
&& Crypt::isCatfileContent($data)
) {
$handle = fopen('crypt://' . $path, 'r');
if (is_resource($handle)) {
while (($plainDataChunk = fgets($handle, 8192)) !== false) {
$plainData .= $plainDataChunk;
}
}
} elseif (
Crypt::mode() == 'server'
&& \OC::$session->exists('legacyenckey')
&& Crypt::isEncryptedMeta($path)
) {
// Disable encryption proxy to prevent recursive calls
$proxyStatus = \OC_FileProxy::$enabled;
\OC_FileProxy::$enabled = false;
$plainData = Crypt::legacyBlockDecrypt($data, $session->getLegacyKey());
\OC_FileProxy::$enabled = $proxyStatus;
}
if (!isset($plainData)) {
$plainData = $data;
}
return $plainData;
}
/**
* @brief When a file is deleted, remove its keyfile also
*/
public function preUnlink($path) {
// let the trashbin handle this
if (\OCP\App::isEnabled('files_trashbin')) {
return true;
}
// Disable encryption proxy to prevent recursive calls
$proxyStatus = \OC_FileProxy::$enabled;
\OC_FileProxy::$enabled = false;
$view = new \OC_FilesystemView('/');
$userId = \OCP\USER::getUser();
$util = new Util($view, $userId);
// get relative path
$relativePath = \OCA\Encryption\Helper::stripUserFilesPath($path);
list($owner, $ownerPath) = $util->getUidAndFilename($relativePath);
// Delete keyfile & shareKey so it isn't orphaned
if (!Keymanager::deleteFileKey($view, $owner, $ownerPath)) {
\OCP\Util::writeLog('Encryption library',
'Keyfile or shareKey could not be deleted for file "' . $ownerPath . '"', \OCP\Util::ERROR);
}
Keymanager::delAllShareKeys($view, $owner, $ownerPath);
\OC_FileProxy::$enabled = $proxyStatus;
// If we don't return true then file delete will fail; better
// to leave orphaned keyfiles than to disallow file deletion
return true;
}
/**
* @param $path
* @return bool
*/
public function postTouch($path) {
$this->handleFile($path);
return true;
}
/**
* @param $path
* @param $result
* @return resource
*/
public function postFopen($path, &$result) {
$path = \OC\Files\Filesystem::normalizePath($path);
if (!$result) {
return $result;
}
// split the path parts
$pathParts = explode('/', $path);
// get relative path
$relativePath = \OCA\Encryption\Helper::stripUserFilesPath($path);
// FIXME: handling for /userId/cache used by webdav for chunking. The cache chunks are NOT encrypted
if (isset($pathParts[2]) && $pathParts[2] === 'cache') {
return $result;
}
// Disable encryption proxy to prevent recursive calls
$proxyStatus = \OC_FileProxy::$enabled;
\OC_FileProxy::$enabled = false;
$meta = stream_get_meta_data($result);
$view = new \OC_FilesystemView('');
$util = new Util($view, \OCP\USER::getUser());
// If file is already encrypted, decrypt using crypto protocol
if (
Crypt::mode() === 'server'
&& $util->isEncryptedPath($path)
) {
// Close the original encrypted file
fclose($result);
// Open the file using the crypto stream wrapper
// protocol and let it do the decryption work instead
$result = fopen('crypt://' . $path, $meta['mode']);
} elseif (
self::shouldEncrypt($path)
and $meta ['mode'] !== 'r'
and $meta['mode'] !== 'rb'
) {
$result = fopen('crypt://' . $path, $meta['mode']);
}
// Re-enable the proxy
\OC_FileProxy::$enabled = $proxyStatus;
return $result;
}
/**
* @param $path
* @param $data
* @return array
*/
public function postGetFileInfo($path, $data) {
// if path is a folder do nothing
if (\OCP\App::isEnabled('files_encryption') && is_array($data) && array_key_exists('size', $data)) {
// Disable encryption proxy to prevent recursive calls
$proxyStatus = \OC_FileProxy::$enabled;
\OC_FileProxy::$enabled = false;
// get file size
$data['size'] = self::postFileSize($path, $data['size']);
// Re-enable the proxy
\OC_FileProxy::$enabled = $proxyStatus;
}
return $data;
}
/**
* @param $path
* @param $size
* @return bool
*/
public function postFileSize($path, $size) {
$view = new \OC_FilesystemView('/');
$userId = \OCP\User::getUser();
$util = new Util($view, $userId);
// if encryption is no longer enabled or if the files aren't migrated yet
// we return the default file size
if(!\OCP\App::isEnabled('files_encryption') ||
$util->getMigrationStatus() !== Util::MIGRATION_COMPLETED) {
return $size;
}
// if path is a folder do nothing
if ($view->is_dir($path)) {
return $size;
}
// get relative path
$relativePath = \OCA\Encryption\Helper::stripUserFilesPath($path);
// if path is empty we cannot resolve anything
if (empty($relativePath)) {
return $size;
}
$fileInfo = false;
// get file info from database/cache if not .part file
if (!Helper::isPartialFilePath($path)) {
$proxyState = \OC_FileProxy::$enabled;
\OC_FileProxy::$enabled = false;
$fileInfo = $view->getFileInfo($path);
\OC_FileProxy::$enabled = $proxyState;
}
// if file is encrypted return real file size
if (is_array($fileInfo) && $fileInfo['encrypted'] === true) {
// try to fix unencrypted file size if it doesn't look plausible
if ((int)$fileInfo['size'] > 0 && (int)$fileInfo['unencrypted_size'] === 0 ) {
$fixSize = $util->getFileSize($path);
$fileInfo['unencrypted_size'] = $fixSize;
// put file info if not .part file
if (!Helper::isPartialFilePath($relativePath)) {
$view->putFileInfo($path, $fileInfo);
}
}
$size = $fileInfo['unencrypted_size'];
} else {
// self healing if file was removed from file cache
if (!is_array($fileInfo)) {
$fileInfo = array();
}
$fixSize = $util->getFileSize($path);
if ($fixSize > 0) {
$size = $fixSize;
$fileInfo['encrypted'] = true;
$fileInfo['unencrypted_size'] = $size;
// put file info if not .part file
if (!Helper::isPartialFilePath($relativePath)) {
$view->putFileInfo($path, $fileInfo);
}
}
}
return $size;
}
/**
* @param $path
*/
public function handleFile($path) {
// Disable encryption proxy to prevent recursive calls
$proxyStatus = \OC_FileProxy::$enabled;
\OC_FileProxy::$enabled = false;
$view = new \OC_FilesystemView('/');
$session = new \OCA\Encryption\Session($view);
$userId = \OCP\User::getUser();
$util = new Util($view, $userId);
// split the path parts
$pathParts = explode('/', $path);
// get relative path
$relativePath = \OCA\Encryption\Helper::stripUserFilesPath($path);
// only if file is on 'files' folder fix file size and sharing
if (isset($pathParts[2]) && $pathParts[2] === 'files' && $util->fixFileSize($path)) {
// get sharing app state
$sharingEnabled = \OCP\Share::isEnabled();
// get users
$usersSharing = $util->getSharingUsersArray($sharingEnabled, $relativePath);
// update sharing-keys
$util->setSharedFileKeyfiles($session, $usersSharing, $relativePath);
}
\OC_FileProxy::$enabled = $proxyStatus;
}
}