1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
|
<?php
/**
* ownCloud
*
* @author Robin Appelman
* @copyright 2011 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/>.
*
*/
/**
* transparently encrypted filestream
*
* you can use it as wrapper around an existing stream by setting OC_CryptStream::$sourceStreams['foo']=array('path'=>$path,'stream'=>$stream)
* and then fopen('crypt://streams/foo');
*/
class OC_CryptStream{
public static $sourceStreams=array();
private $source;
private $path;
private $readBuffer;//for streams that dont support seeking
private $meta=array();//header/meta for source stream
private $count;
private $writeCache;
private static $rootView;
public function stream_open($path, $mode, $options, &$opened_path){
if(!self::$rootView){
self::$rootView=new OC_FilesystemView('');
}
$path=str_replace('crypt://','',$path);
if(dirname($path)=='streams' and isset(self::$sourceStreams[basename($path)])){
$this->source=self::$sourceStreams[basename($path)]['stream'];
$this->path=self::$sourceStreams[basename($path)]['path'];
}else{
$this->path=$path;
OCP\Util::writeLog('files_encryption','open encrypted '.$path. ' in '.$mode,OCP\Util::DEBUG);
OC_FileProxy::$enabled=false;//disable fileproxies so we can open the source file
$this->source=self::$rootView->fopen($path,$mode);
OC_FileProxy::$enabled=true;
if(!is_resource($this->source)){
OCP\Util::writeLog('files_encryption','failed to open '.$path,OCP\Util::ERROR);
}
}
if(is_resource($this->source)){
$this->meta=stream_get_meta_data($this->source);
}
return is_resource($this->source);
}
public function stream_seek($offset, $whence=SEEK_SET){
$this->flush();
fseek($this->source,$offset,$whence);
}
public function stream_tell(){
return ftell($this->source);
}
public function stream_read($count){
//$count will always be 8192 https://bugs.php.net/bug.php?id=21641
//This makes this function a lot simpler but will breake everything the moment it's fixed
$this->writeCache='';
if($count!=8192){
OCP\Util::writeLog('files_encryption','php bug 21641 no longer holds, decryption will not work',OCP\Util::FATAL);
die();
}
$data=fread($this->source,8192);
if(strlen($data)){
$result=OC_Crypt::decrypt($data);
}else{
$result='';
}
return $result;
}
public function stream_write($data){
$length=strlen($data);
$written=0;
$currentPos=ftell($this->source);
if($this->writeCache){
$data=$this->writeCache.$data;
$this->writeCache='';
}
if($currentPos%8192!=0){
//make sure we always start on a block start
fseek($this->source,-($currentPos%8192),SEEK_CUR);
$encryptedBlock=fread($this->source,8192);
fseek($this->source,-($currentPos%8192),SEEK_CUR);
$block=OC_Crypt::decrypt($encryptedBlock);
$data=substr($block,0,$currentPos%8192).$data;
fseek($this->source,-($currentPos%8192),SEEK_CUR);
}
while(strlen($data)>0){
if(strlen($data)<8192){
$this->writeCache=$data;
$data='';
}else{
$encrypted=OC_Crypt::encrypt(substr($data,0,8192));
fwrite($this->source,$encrypted);
$data=substr($data,8192);
}
}
return $length;
}
public function stream_set_option($option,$arg1,$arg2){
switch($option){
case STREAM_OPTION_BLOCKING:
stream_set_blocking($this->source,$arg1);
break;
case STREAM_OPTION_READ_TIMEOUT:
stream_set_timeout($this->source,$arg1,$arg2);
break;
case STREAM_OPTION_WRITE_BUFFER:
stream_set_write_buffer($this->source,$arg1,$arg2);
}
}
public function stream_stat(){
return fstat($this->source);
}
public function stream_lock($mode){
flock($this->source,$mode);
}
public function stream_flush(){
return fflush($this->source);
}
public function stream_eof(){
return feof($this->source);
}
private function flush(){
if($this->writeCache){
$encrypted=OC_Crypt::encrypt($this->writeCache);
fwrite($this->source,$encrypted);
$this->writeCache='';
}
}
public function stream_close(){
$this->flush();
if($this->meta['mode']!='r' and $this->meta['mode']!='rb'){
OC_FileCache::put($this->path,array('encrypted'=>true));
}
return fclose($this->source);
}
}
|
