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<?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/>.
*
*/
/**
* transparent encryption
*/
namespace OCA_Encryption;
class Proxy extends \OC_FileProxy {
private static $blackList = null; //mimetypes blacklisted from encryption
private static $enableEncryption = null;
/**
* 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( $path ) {
if ( is_null( self::$enableEncryption ) ) {
self::$enableEncryption = ( \OCP\Config::getAppValue( 'files_encryption', 'enable_encryption', 'true' ) == 'true' && Crypt::mode() == 'server' );
}
if( !self::$enableEncryption ) {
return false;
}
if( is_null(self::$blackList ) ) {
self::$blackList = explode(',', \OCP\Config::getAppValue( 'files_encryption','type_blacklist','jpg,png,jpeg,avi,mpg,mpeg,mkv,mp3,oga,ogv,ogg' ) );
}
if( Crypt::isEncryptedContent( $path ) ) {
return true;
}
$extension = substr( $path, strrpos( $path,'.' ) +1 );
if ( array_search( $extension, self::$blackList ) === false ){
return true;
}
return false;
}
/**
* Check if a file is encrypted according to database file cache
* @param string $path
* @return bool
*/
private static function isEncrypted( $path ){
// Fetch all file metadata from DB
$metadata = \OC_FileCache_Cached::get( $path, '' );
// Return encryption status
return isset( $metadata['encrypted'] ) and ( bool )$metadata['encrypted'];
}
public function preFile_put_contents( $path, &$data ) {
if ( self::shouldEncrypt( $path ) ) {
if ( !is_resource( $data ) ) { //stream put contents should have been converter to fopen
// Set the filesize for userland, before encrypting
$size = strlen( $data );
// Disable encryption proxy to prevent recursive calls
\OC_FileProxy::$enabled = false;
// Encrypt plain data and fetch key
$encrypted = Crypt::keyEncryptKeyfile( $data, Keymanager::getPublicKey() );
// Replace plain content with encrypted content by reference
$data = $encrypted['data'];
$filePath = explode( '/', $path );
$filePath = array_slice( $filePath, 3 );
$filePath = '/' . implode( '/', $filePath );
# TODO: make keyfile dir dynamic from app config
$view = new \OC_FilesystemView( '/' . \OCP\USER::getUser() . '/files_encryption/keyfiles' );
// Save keyfile for newly encrypted file in parallel directory tree
Keymanager::setFileKey( $filePath, $encrypted['key'], $view, '\OC_DB' );
// Update the file cache with file info
\OC_FileCache::put( $path, array( 'encrypted'=>true, 'size' => $size ), '' );
\OC_FileProxy::$enabled = true;
}
}
}
public function postFile_get_contents( $path, $data ) {
if ( Crypt::mode() == 'server' && Crypt::isEncryptedContent( $data ) ) {
$filePath = explode( '/', $path );
$filePath = array_slice( $filePath, 3 );
$filePath = '/' . implode( '/', $filePath );
$cached = \OC_FileCache_Cached::get( $path, '' );
// Disable encryption proxy to prevent recursive calls
\OC_FileProxy::$enabled = false;
$keyFile = Keymanager::getFileKey( $filePath );
$privateKey = Keymanager::getPrivateKey();
$data = Crypt::keyDecryptKeyfile( $data, $keyFile, $privateKey );
\OC_FileProxy::$enabled = true;
}
return $data;
}
public function postFopen( $path, &$result ){
if ( !$result ) {
return $result;
}
$meta = stream_get_meta_data( $result );
// If file is encrypted, decrypt using crypto protocol
if ( Crypt::mode() == 'server' && Crypt::isEncryptedContent( $path ) ) {
fclose ( $result );
$result = fopen( 'crypt://'.$path, $meta['mode'] );
} elseif (
self::shouldEncrypt( $path )
and $meta ['mode'] != 'r'
and $meta['mode'] != 'rb'
) {
# TODO: figure out what this does
if (
\OC_Filesystem::file_exists( $path )
and \OC_Filesystem::filesize( $path ) > 0
) {
//first encrypt the target file so we don't end up with a half encrypted file
\OCP\Util::writeLog( 'files_encryption', 'Decrypting '.$path.' before writing', \OCP\Util::DEBUG );
$tmp = fopen( 'php://temp' );
\OCP\Files::streamCopy( $result, $tmp );
// Close the original stream, we'll return another one
fclose( $result );
\OC_Filesystem::file_put_contents( $path, $tmp );
fclose( $tmp );
}
$result = fopen( 'crypt://'.$path, $meta['mode'] );
}
return $result;
}
public function postGetMimeType($path,$mime){
if( Crypt::isEncryptedContent($path)){
$mime = \OCP\Files::getMimeType('crypt://'.$path,'w');
}
return $mime;
}
public function postStat($path,$data){
if( Crypt::isEncryptedContent($path)){
$cached= \OC_FileCache_Cached::get($path,'');
$data['size']=$cached['size'];
}
return $data;
}
public function postFileSize($path,$size){
if( Crypt::isEncryptedContent($path)){
$cached = \OC_FileCache_Cached::get($path,'');
return $cached['size'];
}else{
return $size;
}
}
}
|
