truncate decrypted files based on filelength

3 files changed, 41 insertions, 7 deletions

diff --git a/apps/files_encryption/lib/crypt.php b/apps/files_encryption/lib/crypt.php
index 4c0ffa978ed..1c90954cec8 100644
--- a/apps/files_encryption/lib/crypt.php
+++ b/apps/files_encryption/lib/crypt.php
@@ -206,12 +206,16 @@ class OC_Crypt {
 	/**
 	 * decrypt data in 8192b sized blocks
 	 */
-	public static function blockDecrypt($data, $key=''){
+	public static function blockDecrypt($data, $key='',$maxLength=0){
 		$result='';
 		while(strlen($data)){
 			$result.=self::decrypt(substr($data,0,8192),$key);
 			$data=substr($data,8192);
 		}
-		return rtrim($result, "\0");
+		if($maxLength>0){
+			return substr($result,0,$maxLength);
+		}else{
+			return rtrim($result, "\0");
+		}
 	}
 }
diff --git a/apps/files_encryption/lib/cryptstream.php b/apps/files_encryption/lib/cryptstream.php
index 64fec381ded..4ef7d1e08bb 100644
--- a/apps/files_encryption/lib/cryptstream.php
+++ b/apps/files_encryption/lib/cryptstream.php
@@ -35,6 +35,7 @@ class OC_CryptStream{
 	private $meta=array();//header/meta for source stream
 	private $count;
 	private $writeCache;
+	private $size;
 	private static $rootView;
 
 	public function stream_open($path, $mode, $options, &$opened_path){
@@ -45,8 +46,14 @@ class OC_CryptStream{
 		if(dirname($path)=='streams' and isset(self::$sourceStreams[basename($path)])){
 			$this->source=self::$sourceStreams[basename($path)]['stream'];
 			$this->path=self::$sourceStreams[basename($path)]['path'];
+			$this->size=self::$sourceStreams[basename($path)]['size'];
 		}else{
 			$this->path=$path;
+			if($mode=='w' or $mode=='w+' or $mode=='wb' or $mode=='wb+'){
+				$this->size=0;
+			}else{
+				$this->size=self::$rootView->filesize($path,$mode);
+			}
 			OC_FileProxy::$enabled=false;//disable fileproxies so we can open the source file
 			$this->source=self::$rootView->fopen($path,$mode);
 			OC_FileProxy::$enabled=true;
@@ -77,14 +84,16 @@ class OC_CryptStream{
 			OCP\Util::writeLog('files_encryption','php bug 21641 no longer holds, decryption will not work',OCP\Util::FATAL);
 			die();
 		}
+		$pos=ftell($this->source);
 		$data=fread($this->source,8192);
 		if(strlen($data)){
 			$result=OC_Crypt::decrypt($data);
 		}else{
 			$result='';
 		}
-		if($this->stream_eof()){
-			$result=rtrim($result, "\0");
+		$length=$this->size-$pos;
+		if($length<8192){
+			$result=substr($result,0,$length);
 		}
 		return $result;
 	}
@@ -116,6 +125,8 @@ class OC_CryptStream{
 				$data=substr($data,8192);
 			}
 		}
+		$currentPos=ftell($this->source);
+		$this->size=max($this->size,$currentPos);
 		return $length;
 	}
 
@@ -159,7 +170,7 @@ class OC_CryptStream{
 	public function stream_close(){
 		$this->flush();
 		if($this->meta['mode']!='r' and $this->meta['mode']!='rb'){
-			OC_FileCache::put($this->path,array('encrypted'=>true),'');
+			OC_FileCache::put($this->path,array('encrypted'=>true,'size'=>$this->size),'');
 		}
 		return fclose($this->source);
 	}
diff --git a/apps/files_encryption/lib/proxy.php b/apps/files_encryption/lib/proxy.php
index b9e719448a3..f25e4a662f6 100644
--- a/apps/files_encryption/lib/proxy.php
+++ b/apps/files_encryption/lib/proxy.php
@@ -66,15 +66,17 @@ class OC_FileProxy_Encryption extends OC_FileProxy{
 	public function preFile_put_contents($path,&$data){
 		if(self::shouldEncrypt($path)){
 			if (!is_resource($data)) {//stream put contents should have been converter to fopen
+				$size=strlen($data);
 				$data=OC_Crypt::blockEncrypt($data);
-				OC_FileCache::put($path,array('encrypted'=>true),'');
+				OC_FileCache::put($path,array('encrypted'=>true,'size'=>$size),'');
 			}
 		}
 	}
 	
 	public function postFile_get_contents($path,$data){
 		if(self::isEncrypted($path)){
-			$data=OC_Crypt::blockDecrypt($data);
+			$cached=OC_FileCache_Cached::get($path,'');
+			$data=OC_Crypt::blockDecrypt($data,'',$cached['size']);
 		}
 		return $data;
 	}
@@ -108,4 +110,21 @@ class OC_FileProxy_Encryption extends OC_FileProxy{
 		}
 		return $mime;
 	}
+
+	public function postStat($path,$data){
+		if(self::isEncrypted($path)){
+			$cached=OC_FileCache_Cached::get($path,'');
+			$data['size']=$cached['size'];
+		}
+		return $data;
+	}
+
+	public function postFileSize($path,$size){
+		if(self::isEncrypted($path)){
+			$cached=OC_FileCache_Cached::get($path,'');
+			return  $cached['size'];
+		}else{
+			return $size;
+		}
+	}
 }