Working on stream{} writing

Development snapshot

apps/files_encryption/appinfo/spec.txt

@@ -71,3 +71,7 @@ Notes
   their files are scanned to detect unencrypted and legacy encrypted files, and 
   they are (re)encrypted as necessary. This may present a performance issue; we
   need to monitor this.
+- When files are saved to ownCloud via WebDAV, a .part file extension is used so
+  that the file isn't cached before the upload has been completed. .part files 
+  are not compatible with files_encrytion's key management system however, so 
+  we have to always sanitise such paths manually before using them.

apps/files_encryption/lib/keymanager.php

@@ -132,6 +132,28 @@ class Keymanager {
 		
 	}
 	
+	/**
+	 * @brief Remove .path extension from a file path
+	 * @param string $path Path that may identify a .part file
+	 * @return string File path without .part extension
+	 */
+	public static function fixPartialFilePath( $path ) {
+	
+		if ( preg_match( '/\.part$/', $path ) ) {
+		
+			$newLength = strlen( $path ) - 5;
+			$fPath = substr( $path, 0, $newLength );
+			
+			return $fPath;
+			
+		} else {
+		
+			return $path;
+			
+		}
+	
+	}
+	
 	/**
 	 * @brief retrieve keyfile for an encrypted file
 	 * @param \OC_FilesystemView $view

apps/files_encryption/lib/proxy.php

@@ -138,34 +138,9 @@ class Proxy extends \OC_FileProxy {
 				// Encrypt data
 				$encData = Crypt::symmetricEncryptFileContent( $data, $plainKey );
 				
-				// Check if key recovery is enabled
-				$recoveryEnabled = $util->recoveryEnabled();
+				$sharingEnabled = \OCP\Share::isEnabled();
 				
-				// Make sure that a share key is generated for the owner too
-				$userIds = array( $userId );
-				
-				if ( \OCP\Share::isEnabled() ) {
-				
-					// Find out who, if anyone, is sharing the file
-					$shareUids = \OCP\Share::getUsersSharingFile( $filePath, true, true, true );
-					
-					$userIds = array_merge( $userIds, $shareUids );
-				
-				}
-				
-				// If recovery is enabled, add the 
-				// Admin UID to list of users to share to
-				if ( $recoveryEnabled ) {
-				
-					// FIXME: Create a separate admin user purely for recovery, and create method in util for fetching this id from DB?
-					$adminUid = 'recoveryAdmin';
-				
-					$userIds[] = $adminUid;
-					
-				}
-				
-				// Remove duplicate UIDs
-				$uniqueUserIds = array_unique ( $userIds );
+				$uniqueUserIds = $util->getSharingUsersArray( $sharingEnabled, $filePath );
 				
 				// Fetch public keys for all users who will share the file
 				$publicKeys = Keymanager::getPublicKeys( $rootView, $uniqueUserIds );
@@ -280,6 +255,8 @@ class Proxy extends \OC_FileProxy {
 	 */
 	public function preUnlink( $path ) {
 	
+		$path = Keymanager::fixPartialFilePath( $path );
+	
 		// Disable encryption proxy to prevent recursive calls
 		\OC_FileProxy::$enabled = false;
 		
@@ -290,17 +267,20 @@ class Proxy extends \OC_FileProxy {
 		$util = new Util( $view, $userId );
 
 		// Format path to be relative to user files dir
-		$relPath = $util->stripUserFilesPath($path);
+		$relPath = $util->stripUserFilesPath( $path );
+
+// 		list( $owner, $ownerPath ) = $util->getUidAndFilename( $relPath );
 
-		list($owner, $ownerPath) = $util->getUidAndFilename($relPath);
+		$fileOwner = \OC\Files\Filesystem::getOwner( $path );
+		$ownerPath = $util->stripUserFilesPath( $path );  // TODO: Don't trust $path, fetch owner path
 
-		$filePath = $owner . '/' . 'files_encryption' . '/' . 'keyfiles' . '/'. $ownerPath;
+		$filePath = $fileOwner . '/' . 'files_encryption' . '/' . 'keyfiles' . '/'. $ownerPath;
 
 		// Delete keyfile & shareKey so it isn't orphaned
 		if (
 			! (
-				Keymanager::deleteFileKey( $view, $owner, $ownerPath )
-				&& Keymanager::delShareKey( $view, $owner, $ownerPath )
+				Keymanager::deleteFileKey( $view, $fileOwner, $ownerPath )
+				&& Keymanager::delShareKey( $view, $fileOwner, $ownerPath )
 			)
 		) {
 		

apps/files_encryption/lib/stream.php

@@ -44,6 +44,9 @@ namespace OCA\Encryption;
  * buffer size used internally by PHP. The encryption process makes the input 
  * data longer, and input is chunked into smaller pieces in order to result in 
  * a 8192 encrypted block size.
+ * @note When files are deleted via webdav, or when they are updated and the 
+ * previous version deleted, this is handled by OC\Files\View, and thus the 
+ * encryption proxies are used and keyfiles deleted.
  */
 class Stream {
 
@@ -172,15 +175,19 @@ class Stream {
 		// Get the data from the file handle
 		$data = fread( $this->handle, 8192 );
 		
+		$result = '';
+ 
 		if ( strlen( $data ) ) {
 			
-			$this->getKey();
+			if ( ! $this->getKey() ) {
 				
-			$result = Crypt::symmetricDecryptFileContent( $data, $this->keyfile );
+				// Error! We don't have a key to decrypt the file with
+				throw new \Exception( 'Encryption key not found for "' . $this->rawPath . '" during attempted read via stream' );
 			
-		} else {
+			}
 			
-			$result = '';
+			// Decrypt data
+			$result = Crypt::symmetricDecryptFileContent( $data, $this->plainKey );
 			
 		}
 
@@ -224,18 +231,20 @@ class Stream {
 	 */
 	public function getKey() {
 		
-        // fix performance issues
-        if(isset($this->keyfile) && isset($this->encKeyfile)) {
-            return true;
-        }
+		// Check if key is already set
+		if ( isset( $this->plainKey ) && isset( $this->encKeyfile ) ) {
 		
-		// If a keyfile already exists for a file named identically to 
-		// file to be written
-		if ( $this->rootView->file_exists( $this->userId . '/'. 'files_encryption' . '/' . 'keyfiles' . '/' . $this->relPath . '.key' ) ) {
+			return true;
+		
+		}
 		
-			// TODO: add error handling for when file exists but no 
-			// keyfile
+		// Avoid problems with .part file extensions
+		$this->relPath = Keymanager::fixPartialFilePath( $this->relPath );
 	
+		// If a keyfile already exists
+		if ( $this->rootView->file_exists( $this->userId . '/'. 'files_encryption' . '/' . 'keyfiles' . '/' . $this->relPath . '.key' ) ) {
+			
+			// Fetch and decrypt keyfile
 			// Fetch existing keyfile
 			$this->encKeyfile = Keymanager::getFileKey( $this->rootView, $this->userId, $this->relPath );
 			
@@ -247,7 +256,12 @@ class Stream {
 			
 			$shareKey = Keymanager::getShareKey( $this->rootView, $this->userId, $this->relPath );
 			
-			$this->keyfile = Crypt::multiKeyDecrypt( $this->encKeyfile, $shareKey, $privateKey );
+			$this->plainKey = Crypt::multiKeyDecrypt( $this->encKeyfile, $shareKey, $privateKey );
+			
+			trigger_error( '$this->relPath = '.$this->relPath );
+			trigger_error( '$this->userId = '.$this->userId);
+			trigger_error( '$this->encKeyfile  = '.$this->encKeyfile );
+			trigger_error( '$this->plainKey1 = '.var_export($this->plainKey, 1));
 			
 			return true;
 			
@@ -303,7 +317,7 @@ class Stream {
 		$pointer = ftell( $this->handle );
 		
 		// Make sure the userId is set
-		$this->getuser();
+		$this->setUserProperty();
 		
 		// TODO: Check if file is shared, if so, use multiKeyEncrypt and
 		// save shareKeys in necessary user directories
@@ -313,21 +327,34 @@ class Stream {
 		// one), save the newly generated keyfile
 		if ( ! $this->getKey() ) {
 		
-			// TODO: Reuse the keyfile, it it exists, instead of making a new one
-			$this->keyfile = Crypt::generateKey();
+			$util = new Util( $this->rootView, $this->userId );
+		
+			$this->plainKey = Crypt::generateKey();
 			
 			$this->publicKey = Keymanager::getPublicKey( $this->rootView, $this->userId );
 			
-			$this->encKeyfile = Crypt::keyEncrypt( $this->keyfile, $this->publicKey );
+			$sharingEnabled = \OCP\Share::isEnabled();
+			
+			$uniqueUserIds = $util->getSharingUsersArray( $sharingEnabled, $this->relPath );
+			
+			// Fetch public keys for all users who will share the file
+			$publicKeys = Keymanager::getPublicKeys( $this->rootView, $uniqueUserIds );
+			
+			$this->encKeyfiles = Crypt::multiKeyEncrypt( $this->plainKey, $publicKeys );
 			
 			$view = new \OC_FilesystemView( '/' );
-			$userId = \OCP\User::getUser();
 			
 			// Save the new encrypted file key
-			Keymanager::setFileKey( $view, $this->relPath, $userId, $this->encKeyfile );
+			Keymanager::setShareKeys( $view, $this->relPath, $this->encKeyfiles['keys'] );
+			
+// 			trigger_error( '$this->relPath = '.$this->relPath );
+// 			trigger_error( '$this->userId = '.$this->userId);
+// 			trigger_error( '$this->encKeyfile  = '.var_export($this->encKeyfiles, 1) );
 			
 		}
 		
+// 		trigger_error( '$this->plainKey2 = '.var_export($this->plainKey, 1));
+		
 		// If extra data is left over from the last round, make sure it 
 		// is integrated into the next 6126 / 8192 block
 		if ( $this->writeCache ) {
@@ -355,7 +382,7 @@ class Stream {
 // 			
 // 			fseek( $this->handle, - ( $currentPos % 8192 ), SEEK_CUR );
 // 
-// 			$block = Crypt::symmetricDecryptFileContent( $unencryptedNewBlock, $this->keyfile );
+// 			$block = Crypt::symmetricDecryptFileContent( $unencryptedNewBlock, $this->plainKey );
 // 
 // 			$x =  substr( $block, 0, $currentPos % 8192 );
 // 
@@ -396,7 +423,7 @@ class Stream {
 				// Read the chunk from the start of $data
 				$chunk = substr( $data, 0, 6126 );
 				
-				$encrypted = $this->preWriteEncrypt( $chunk, $this->keyfile );
+				$encrypted = $this->preWriteEncrypt( $chunk, $this->plainKey );
 				
 				// Write the data chunk to disk. This will be 
 				// attended to the last data chunk if the file
@@ -461,7 +488,7 @@ class Stream {
 			// Set keyfile property for file in question
 			$this->getKey();
 			
-			$encrypted = $this->preWriteEncrypt( $this->writeCache, $this->keyfile );
+			$encrypted = $this->preWriteEncrypt( $this->writeCache, $this->plainKey );
 			
 			fwrite( $this->handle, $encrypted );
 			

apps/files_encryption/lib/util.php

@@ -865,6 +865,45 @@ class Util {
 	
 	}
 	
+	/**
+	 * @brief Find, sanitise and format users sharing a file
+	 * @note This wraps other methods into a portable bundle
+	 */
+	public function getSharingUsersArray( $sharingEnabled, $filePath ) {
+
+		// Check if key recovery is enabled
+		$recoveryEnabled = $this->recoveryEnabled();
+		
+		// Make sure that a share key is generated for the owner too
+		$userIds = array( $this->userId );
+		
+		if ( $sharingEnabled ) {
+		
+			// Find out who, if anyone, is sharing the file
+			$shareUids = \OCP\Share::getUsersSharingFile( $filePath, true, true, true );
+			
+			$userIds = array_merge( $userIds, $shareUids );
+		
+		}
+		
+		// If recovery is enabled, add the 
+		// Admin UID to list of users to share to
+		if ( $recoveryEnabled ) {
+		
+			// FIXME: Create a separate admin user purely for recovery, and create method in util for fetching this id from DB?
+			$adminUid = 'recoveryAdmin';
+		
+			$userIds[] = $adminUid;
+			
+		}
+		
+		// Remove duplicate UIDs
+		$uniqueUserIds = array_unique ( $userIds );
+		
+		return $uniqueUserIds;
+
+	}
+		
 	/**
 	 * @brief get uid of the owners of the file and the path to the file
 	 * @param $shareFilePath Path of the file to check