nextcloud / server

lib/private/Files/Storage/Wrapper/Encryption.php

Indentation +988 added lines, -988 removed lines

@@ -51,992 +51,992 @@
 use OCP\ILogger;
 
 class Encryption extends Wrapper {
-	use LocalTempFileTrait;
-
-	/** @var string */
-	private $mountPoint;
-
-	/** @var \OC\Encryption\Util */
-	private $util;
-
-	/** @var \OCP\Encryption\IManager */
-	private $encryptionManager;
-
-	/** @var \OCP\ILogger */
-	private $logger;
-
-	/** @var string */
-	private $uid;
-
-	/** @var array */
-	protected $unencryptedSize;
-
-	/** @var \OCP\Encryption\IFile */
-	private $fileHelper;
-
-	/** @var IMountPoint */
-	private $mount;
-
-	/** @var IStorage */
-	private $keyStorage;
-
-	/** @var Update */
-	private $update;
-
-	/** @var Manager */
-	private $mountManager;
-
-	/** @var array remember for which path we execute the repair step to avoid recursions */
-	private $fixUnencryptedSizeOf = [];
-
-	/** @var  ArrayCache */
-	private $arrayCache;
-
-	/**
-	 * @param array $parameters
-	 * @param IManager $encryptionManager
-	 * @param Util $util
-	 * @param ILogger $logger
-	 * @param IFile $fileHelper
-	 * @param string $uid
-	 * @param IStorage $keyStorage
-	 * @param Update $update
-	 * @param Manager $mountManager
-	 * @param ArrayCache $arrayCache
-	 */
-	public function __construct(
-		$parameters,
-		IManager $encryptionManager = null,
-		Util $util = null,
-		ILogger $logger = null,
-		IFile $fileHelper = null,
-		$uid = null,
-		IStorage $keyStorage = null,
-		Update $update = null,
-		Manager $mountManager = null,
-		ArrayCache $arrayCache = null
-	) {
-		$this->mountPoint = $parameters['mountPoint'];
-		$this->mount = $parameters['mount'];
-		$this->encryptionManager = $encryptionManager;
-		$this->util = $util;
-		$this->logger = $logger;
-		$this->uid = $uid;
-		$this->fileHelper = $fileHelper;
-		$this->keyStorage = $keyStorage;
-		$this->unencryptedSize = [];
-		$this->update = $update;
-		$this->mountManager = $mountManager;
-		$this->arrayCache = $arrayCache;
-		parent::__construct($parameters);
-	}
-
-	/**
-	 * see http://php.net/manual/en/function.filesize.php
-	 * The result for filesize when called on a folder is required to be 0
-	 *
-	 * @param string $path
-	 * @return int
-	 */
-	public function filesize($path) {
-		$fullPath = $this->getFullPath($path);
-
-		/** @var CacheEntry $info */
-		$info = $this->getCache()->get($path);
-		if (isset($this->unencryptedSize[$fullPath])) {
-			$size = $this->unencryptedSize[$fullPath];
-			// update file cache
-			if ($info instanceof ICacheEntry) {
-				$info = $info->getData();
-				$info['encrypted'] = $info['encryptedVersion'];
-			} else {
-				if (!is_array($info)) {
-					$info = [];
-				}
-				$info['encrypted'] = true;
-			}
-
-			$info['size'] = $size;
-			$this->getCache()->put($path, $info);
-
-			return $size;
-		}
-
-		if (isset($info['fileid']) && $info['encrypted']) {
-			return $this->verifyUnencryptedSize($path, $info['size']);
-		}
-
-		return $this->storage->filesize($path);
-	}
-
-	private function modifyMetaData(string $path, array $data): array {
-		$fullPath = $this->getFullPath($path);
-		$info = $this->getCache()->get($path);
-
-		if (isset($this->unencryptedSize[$fullPath])) {
-			$data['encrypted'] = true;
-			$data['size'] = $this->unencryptedSize[$fullPath];
-		} else {
-			if (isset($info['fileid']) && $info['encrypted']) {
-				$data['size'] = $this->verifyUnencryptedSize($path, $info['size']);
-				$data['encrypted'] = true;
-			}
-		}
-
-		if (isset($info['encryptedVersion']) && $info['encryptedVersion'] > 1) {
-			$data['encryptedVersion'] = $info['encryptedVersion'];
-		}
-
-		return $data;
-	}
-
-	/**
-	 * @param string $path
-	 * @return array
-	 */
-	public function getMetaData($path) {
-		$data = $this->storage->getMetaData($path);
-		if (is_null($data)) {
-			return null;
-		}
-		return $this->modifyMetaData($path, $data);
-	}
-
-	public function getDirectoryContent($directory): \Traversable {
-		$parent = rtrim($directory, '/');
-		foreach ($this->getWrapperStorage()->getDirectoryContent($directory) as $data) {
-			yield $this->modifyMetaData($parent . '/' . $data['name'], $data);
-		}
-	}
-
-	/**
-	 * see http://php.net/manual/en/function.file_get_contents.php
-	 *
-	 * @param string $path
-	 * @return string
-	 */
-	public function file_get_contents($path) {
-		$encryptionModule = $this->getEncryptionModule($path);
-
-		if ($encryptionModule) {
-			$handle = $this->fopen($path, "r");
-			if (!$handle) {
-				return false;
-			}
-			$data = stream_get_contents($handle);
-			fclose($handle);
-			return $data;
-		}
-		return $this->storage->file_get_contents($path);
-	}
-
-	/**
-	 * see http://php.net/manual/en/function.file_put_contents.php
-	 *
-	 * @param string $path
-	 * @param mixed $data
-	 * @return int|false
-	 */
-	public function file_put_contents($path, $data) {
-		// file put content will always be translated to a stream write
-		$handle = $this->fopen($path, 'w');
-		if (is_resource($handle)) {
-			$written = fwrite($handle, $data);
-			fclose($handle);
-			return $written;
-		}
-
-		return false;
-	}
-
-	/**
-	 * see http://php.net/manual/en/function.unlink.php
-	 *
-	 * @param string $path
-	 * @return bool
-	 */
-	public function unlink($path) {
-		$fullPath = $this->getFullPath($path);
-		if ($this->util->isExcluded($fullPath)) {
-			return $this->storage->unlink($path);
-		}
-
-		$encryptionModule = $this->getEncryptionModule($path);
-		if ($encryptionModule) {
-			$this->keyStorage->deleteAllFileKeys($fullPath);
-		}
-
-		return $this->storage->unlink($path);
-	}
-
-	/**
-	 * see http://php.net/manual/en/function.rename.php
-	 *
-	 * @param string $path1
-	 * @param string $path2
-	 * @return bool
-	 */
-	public function rename($path1, $path2) {
-		$result = $this->storage->rename($path1, $path2);
-
-		if ($result &&
-			// versions always use the keys from the original file, so we can skip
-			// this step for versions
-			$this->isVersion($path2) === false &&
-			$this->encryptionManager->isEnabled()) {
-			$source = $this->getFullPath($path1);
-			if (!$this->util->isExcluded($source)) {
-				$target = $this->getFullPath($path2);
-				if (isset($this->unencryptedSize[$source])) {
-					$this->unencryptedSize[$target] = $this->unencryptedSize[$source];
-				}
-				$this->keyStorage->renameKeys($source, $target);
-				$module = $this->getEncryptionModule($path2);
-				if ($module) {
-					$module->update($target, $this->uid, []);
-				}
-			}
-		}
-
-		return $result;
-	}
-
-	/**
-	 * see http://php.net/manual/en/function.rmdir.php
-	 *
-	 * @param string $path
-	 * @return bool
-	 */
-	public function rmdir($path) {
-		$result = $this->storage->rmdir($path);
-		$fullPath = $this->getFullPath($path);
-		if ($result &&
-			$this->util->isExcluded($fullPath) === false &&
-			$this->encryptionManager->isEnabled()
-		) {
-			$this->keyStorage->deleteAllFileKeys($fullPath);
-		}
-
-		return $result;
-	}
-
-	/**
-	 * check if a file can be read
-	 *
-	 * @param string $path
-	 * @return bool
-	 */
-	public function isReadable($path) {
-		$isReadable = true;
-
-		$metaData = $this->getMetaData($path);
-		if (
-			!$this->is_dir($path) &&
-			isset($metaData['encrypted']) &&
-			$metaData['encrypted'] === true
-		) {
-			$fullPath = $this->getFullPath($path);
-			$module = $this->getEncryptionModule($path);
-			$isReadable = $module->isReadable($fullPath, $this->uid);
-		}
-
-		return $this->storage->isReadable($path) && $isReadable;
-	}
-
-	/**
-	 * see http://php.net/manual/en/function.copy.php
-	 *
-	 * @param string $path1
-	 * @param string $path2
-	 * @return bool
-	 */
-	public function copy($path1, $path2) {
-		$source = $this->getFullPath($path1);
-
-		if ($this->util->isExcluded($source)) {
-			return $this->storage->copy($path1, $path2);
-		}
-
-		// need to stream copy file by file in case we copy between a encrypted
-		// and a unencrypted storage
-		$this->unlink($path2);
-		return $this->copyFromStorage($this, $path1, $path2);
-	}
-
-	/**
-	 * see http://php.net/manual/en/function.fopen.php
-	 *
-	 * @param string $path
-	 * @param string $mode
-	 * @return resource|bool
-	 * @throws GenericEncryptionException
-	 * @throws ModuleDoesNotExistsException
-	 */
-	public function fopen($path, $mode) {
-
-		// check if the file is stored in the array cache, this means that we
-		// copy a file over to the versions folder, in this case we don't want to
-		// decrypt it
-		if ($this->arrayCache->hasKey('encryption_copy_version_' . $path)) {
-			$this->arrayCache->remove('encryption_copy_version_' . $path);
-			return $this->storage->fopen($path, $mode);
-		}
-
-		$encryptionEnabled = $this->encryptionManager->isEnabled();
-		$shouldEncrypt = false;
-		$encryptionModule = null;
-		$header = $this->getHeader($path);
-		$signed = isset($header['signed']) && $header['signed'] === 'true';
-		$fullPath = $this->getFullPath($path);
-		$encryptionModuleId = $this->util->getEncryptionModuleId($header);
-
-		if ($this->util->isExcluded($fullPath) === false) {
-			$size = $unencryptedSize = 0;
-			$realFile = $this->util->stripPartialFileExtension($path);
-			$targetExists = $this->file_exists($realFile) || $this->file_exists($path);
-			$targetIsEncrypted = false;
-			if ($targetExists) {
-				// in case the file exists we require the explicit module as
-				// specified in the file header - otherwise we need to fail hard to
-				// prevent data loss on client side
-				if (!empty($encryptionModuleId)) {
-					$targetIsEncrypted = true;
-					$encryptionModule = $this->encryptionManager->getEncryptionModule($encryptionModuleId);
-				}
-
-				if ($this->file_exists($path)) {
-					$size = $this->storage->filesize($path);
-					$unencryptedSize = $this->filesize($path);
-				} else {
-					$size = $unencryptedSize = 0;
-				}
-			}
-
-			try {
-				if (
-					$mode === 'w'
-					|| $mode === 'w+'
-					|| $mode === 'wb'
-					|| $mode === 'wb+'
-				) {
-					// if we update a encrypted file with a un-encrypted one we change the db flag
-					if ($targetIsEncrypted && $encryptionEnabled === false) {
-						$cache = $this->storage->getCache();
-						if ($cache) {
-							$entry = $cache->get($path);
-							$cache->update($entry->getId(), ['encrypted' => 0]);
-						}
-					}
-					if ($encryptionEnabled) {
-						// if $encryptionModuleId is empty, the default module will be used
-						$encryptionModule = $this->encryptionManager->getEncryptionModule($encryptionModuleId);
-						$shouldEncrypt = $encryptionModule->shouldEncrypt($fullPath);
-						$signed = true;
-					}
-				} else {
-					$info = $this->getCache()->get($path);
-					// only get encryption module if we found one in the header
-					// or if file should be encrypted according to the file cache
-					if (!empty($encryptionModuleId)) {
-						$encryptionModule = $this->encryptionManager->getEncryptionModule($encryptionModuleId);
-						$shouldEncrypt = true;
-					} elseif (empty($encryptionModuleId) && $info['encrypted'] === true) {
-						// we come from a old installation. No header and/or no module defined
-						// but the file is encrypted. In this case we need to use the
-						// OC_DEFAULT_MODULE to read the file
-						$encryptionModule = $this->encryptionManager->getEncryptionModule('OC_DEFAULT_MODULE');
-						$shouldEncrypt = true;
-						$targetIsEncrypted = true;
-					}
-				}
-			} catch (ModuleDoesNotExistsException $e) {
-				$this->logger->logException($e, [
-					'message' => 'Encryption module "' . $encryptionModuleId . '" not found, file will be stored unencrypted',
-					'level' => ILogger::WARN,
-					'app' => 'core',
-				]);
-			}
-
-			// encryption disabled on write of new file and write to existing unencrypted file -> don't encrypt
-			if (!$encryptionEnabled || !$this->shouldEncrypt($path)) {
-				if (!$targetExists || !$targetIsEncrypted) {
-					$shouldEncrypt = false;
-				}
-			}
-
-			if ($shouldEncrypt === true && $encryptionModule !== null) {
-				$headerSize = $this->getHeaderSize($path);
-				$source = $this->storage->fopen($path, $mode);
-				if (!is_resource($source)) {
-					return false;
-				}
-				$handle = \OC\Files\Stream\Encryption::wrap($source, $path, $fullPath, $header,
-					$this->uid, $encryptionModule, $this->storage, $this, $this->util, $this->fileHelper, $mode,
-					$size, $unencryptedSize, $headerSize, $signed);
-				return $handle;
-			}
-		}
-
-		return $this->storage->fopen($path, $mode);
-	}
-
-
-	/**
-	 * perform some plausibility checks if the the unencrypted size is correct.
-	 * If not, we calculate the correct unencrypted size and return it
-	 *
-	 * @param string $path internal path relative to the storage root
-	 * @param int $unencryptedSize size of the unencrypted file
-	 *
-	 * @return int unencrypted size
-	 */
-	protected function verifyUnencryptedSize($path, $unencryptedSize) {
-		$size = $this->storage->filesize($path);
-		$result = $unencryptedSize;
-
-		if ($unencryptedSize < 0 ||
-			($size > 0 && $unencryptedSize === $size)
-		) {
-			// check if we already calculate the unencrypted size for the
-			// given path to avoid recursions
-			if (isset($this->fixUnencryptedSizeOf[$this->getFullPath($path)]) === false) {
-				$this->fixUnencryptedSizeOf[$this->getFullPath($path)] = true;
-				try {
-					$result = $this->fixUnencryptedSize($path, $size, $unencryptedSize);
-				} catch (\Exception $e) {
-					$this->logger->error('Couldn\'t re-calculate unencrypted size for ' . $path);
-					$this->logger->logException($e);
-				}
-				unset($this->fixUnencryptedSizeOf[$this->getFullPath($path)]);
-			}
-		}
-
-		return $result;
-	}
-
-	/**
-	 * calculate the unencrypted size
-	 *
-	 * @param string $path internal path relative to the storage root
-	 * @param int $size size of the physical file
-	 * @param int $unencryptedSize size of the unencrypted file
-	 *
-	 * @return int calculated unencrypted size
-	 */
-	protected function fixUnencryptedSize($path, $size, $unencryptedSize) {
-		$headerSize = $this->getHeaderSize($path);
-		$header = $this->getHeader($path);
-		$encryptionModule = $this->getEncryptionModule($path);
-
-		$stream = $this->storage->fopen($path, 'r');
-
-		// if we couldn't open the file we return the old unencrypted size
-		if (!is_resource($stream)) {
-			$this->logger->error('Could not open ' . $path . '. Recalculation of unencrypted size aborted.');
-			return $unencryptedSize;
-		}
-
-		$newUnencryptedSize = 0;
-		$size -= $headerSize;
-		$blockSize = $this->util->getBlockSize();
-
-		// if a header exists we skip it
-		if ($headerSize > 0) {
-			fread($stream, $headerSize);
-		}
-
-		// fast path, else the calculation for $lastChunkNr is bogus
-		if ($size === 0) {
-			return 0;
-		}
-
-		$signed = isset($header['signed']) && $header['signed'] === 'true';
-		$unencryptedBlockSize = $encryptionModule->getUnencryptedBlockSize($signed);
-
-		// calculate last chunk nr
-		// next highest is end of chunks, one subtracted is last one
-		// we have to read the last chunk, we can't just calculate it (because of padding etc)
-
-		$lastChunkNr = ceil($size / $blockSize) - 1;
-		// calculate last chunk position
-		$lastChunkPos = ($lastChunkNr * $blockSize);
-		// try to fseek to the last chunk, if it fails we have to read the whole file
-		if (@fseek($stream, $lastChunkPos, SEEK_CUR) === 0) {
-			$newUnencryptedSize += $lastChunkNr * $unencryptedBlockSize;
-		}
-
-		$lastChunkContentEncrypted = '';
-		$count = $blockSize;
-
-		while ($count > 0) {
-			$data = fread($stream, $blockSize);
-			$count = strlen($data);
-			$lastChunkContentEncrypted .= $data;
-			if (strlen($lastChunkContentEncrypted) > $blockSize) {
-				$newUnencryptedSize += $unencryptedBlockSize;
-				$lastChunkContentEncrypted = substr($lastChunkContentEncrypted, $blockSize);
-			}
-		}
-
-		fclose($stream);
-
-		// we have to decrypt the last chunk to get it actual size
-		$encryptionModule->begin($this->getFullPath($path), $this->uid, 'r', $header, []);
-		$decryptedLastChunk = $encryptionModule->decrypt($lastChunkContentEncrypted, $lastChunkNr . 'end');
-		$decryptedLastChunk .= $encryptionModule->end($this->getFullPath($path), $lastChunkNr . 'end');
-
-		// calc the real file size with the size of the last chunk
-		$newUnencryptedSize += strlen($decryptedLastChunk);
-
-		$this->updateUnencryptedSize($this->getFullPath($path), $newUnencryptedSize);
-
-		// write to cache if applicable
-		$cache = $this->storage->getCache();
-		if ($cache) {
-			$entry = $cache->get($path);
-			$cache->update($entry['fileid'], ['size' => $newUnencryptedSize]);
-		}
-
-		return $newUnencryptedSize;
-	}
-
-	/**
-	 * @param Storage\IStorage $sourceStorage
-	 * @param string $sourceInternalPath
-	 * @param string $targetInternalPath
-	 * @param bool $preserveMtime
-	 * @return bool
-	 */
-	public function moveFromStorage(Storage\IStorage $sourceStorage, $sourceInternalPath, $targetInternalPath, $preserveMtime = true) {
-		if ($sourceStorage === $this) {
-			return $this->rename($sourceInternalPath, $targetInternalPath);
-		}
-
-		// TODO clean this up once the underlying moveFromStorage in OC\Files\Storage\Wrapper\Common is fixed:
-		// - call $this->storage->moveFromStorage() instead of $this->copyBetweenStorage
-		// - copy the file cache update from  $this->copyBetweenStorage to this method
-		// - copy the copyKeys() call from  $this->copyBetweenStorage to this method
-		// - remove $this->copyBetweenStorage
-
-		if (!$sourceStorage->isDeletable($sourceInternalPath)) {
-			return false;
-		}
-
-		$result = $this->copyBetweenStorage($sourceStorage, $sourceInternalPath, $targetInternalPath, $preserveMtime, true);
-		if ($result) {
-			if ($sourceStorage->is_dir($sourceInternalPath)) {
-				$result &= $sourceStorage->rmdir($sourceInternalPath);
-			} else {
-				$result &= $sourceStorage->unlink($sourceInternalPath);
-			}
-		}
-		return $result;
-	}
-
-
-	/**
-	 * @param Storage\IStorage $sourceStorage
-	 * @param string $sourceInternalPath
-	 * @param string $targetInternalPath
-	 * @param bool $preserveMtime
-	 * @param bool $isRename
-	 * @return bool
-	 */
-	public function copyFromStorage(Storage\IStorage $sourceStorage, $sourceInternalPath, $targetInternalPath, $preserveMtime = false, $isRename = false) {
-
-		// TODO clean this up once the underlying moveFromStorage in OC\Files\Storage\Wrapper\Common is fixed:
-		// - call $this->storage->copyFromStorage() instead of $this->copyBetweenStorage
-		// - copy the file cache update from  $this->copyBetweenStorage to this method
-		// - copy the copyKeys() call from  $this->copyBetweenStorage to this method
-		// - remove $this->copyBetweenStorage
-
-		return $this->copyBetweenStorage($sourceStorage, $sourceInternalPath, $targetInternalPath, $preserveMtime, $isRename);
-	}
-
-	/**
-	 * Update the encrypted cache version in the database
-	 *
-	 * @param Storage\IStorage $sourceStorage
-	 * @param string $sourceInternalPath
-	 * @param string $targetInternalPath
-	 * @param bool $isRename
-	 * @param bool $keepEncryptionVersion
-	 */
-	private function updateEncryptedVersion(Storage\IStorage $sourceStorage, $sourceInternalPath, $targetInternalPath, $isRename, $keepEncryptionVersion) {
-		$isEncrypted = $this->encryptionManager->isEnabled() && $this->shouldEncrypt($targetInternalPath);
-		$cacheInformation = [
-			'encrypted' => $isEncrypted,
-		];
-		if ($isEncrypted) {
-			$encryptedVersion = $sourceStorage->getCache()->get($sourceInternalPath)['encryptedVersion'];
-
-			// In case of a move operation from an unencrypted to an encrypted
-			// storage the old encrypted version would stay with "0" while the
-			// correct value would be "1". Thus we manually set the value to "1"
-			// for those cases.
-			// See also https://github.com/owncloud/core/issues/23078
-			if ($encryptedVersion === 0 || !$keepEncryptionVersion) {
-				$encryptedVersion = 1;
-			}
-
-			$cacheInformation['encryptedVersion'] = $encryptedVersion;
-		}
-
-		// in case of a rename we need to manipulate the source cache because
-		// this information will be kept for the new target
-		if ($isRename) {
-			$sourceStorage->getCache()->put($sourceInternalPath, $cacheInformation);
-		} else {
-			$this->getCache()->put($targetInternalPath, $cacheInformation);
-		}
-	}
-
-	/**
-	 * copy file between two storages
-	 *
-	 * @param Storage\IStorage $sourceStorage
-	 * @param string $sourceInternalPath
-	 * @param string $targetInternalPath
-	 * @param bool $preserveMtime
-	 * @param bool $isRename
-	 * @return bool
-	 * @throws \Exception
-	 */
-	private function copyBetweenStorage(Storage\IStorage $sourceStorage, $sourceInternalPath, $targetInternalPath, $preserveMtime, $isRename) {
-
-		// for versions we have nothing to do, because versions should always use the
-		// key from the original file. Just create a 1:1 copy and done
-		if ($this->isVersion($targetInternalPath) ||
-			$this->isVersion($sourceInternalPath)) {
-			// remember that we try to create a version so that we can detect it during
-			// fopen($sourceInternalPath) and by-pass the encryption in order to
-			// create a 1:1 copy of the file
-			$this->arrayCache->set('encryption_copy_version_' . $sourceInternalPath, true);
-			$result = $this->storage->copyFromStorage($sourceStorage, $sourceInternalPath, $targetInternalPath);
-			$this->arrayCache->remove('encryption_copy_version_' . $sourceInternalPath);
-			if ($result) {
-				$info = $this->getCache('', $sourceStorage)->get($sourceInternalPath);
-				// make sure that we update the unencrypted size for the version
-				if (isset($info['encrypted']) && $info['encrypted'] === true) {
-					$this->updateUnencryptedSize(
-						$this->getFullPath($targetInternalPath),
-						$info['size']
-					);
-				}
-				$this->updateEncryptedVersion($sourceStorage, $sourceInternalPath, $targetInternalPath, $isRename, true);
-			}
-			return $result;
-		}
-
-		// first copy the keys that we reuse the existing file key on the target location
-		// and don't create a new one which would break versions for example.
-		$mount = $this->mountManager->findByStorageId($sourceStorage->getId());
-		if (count($mount) === 1) {
-			$mountPoint = $mount[0]->getMountPoint();
-			$source = $mountPoint . '/' . $sourceInternalPath;
-			$target = $this->getFullPath($targetInternalPath);
-			$this->copyKeys($source, $target);
-		} else {
-			$this->logger->error('Could not find mount point, can\'t keep encryption keys');
-		}
-
-		if ($sourceStorage->is_dir($sourceInternalPath)) {
-			$dh = $sourceStorage->opendir($sourceInternalPath);
-			$result = $this->mkdir($targetInternalPath);
-			if (is_resource($dh)) {
-				while ($result and ($file = readdir($dh)) !== false) {
-					if (!Filesystem::isIgnoredDir($file)) {
-						$result &= $this->copyFromStorage($sourceStorage, $sourceInternalPath . '/' . $file, $targetInternalPath . '/' . $file, false, $isRename);
-					}
-				}
-			}
-		} else {
-			try {
-				$source = $sourceStorage->fopen($sourceInternalPath, 'r');
-				$target = $this->fopen($targetInternalPath, 'w');
-				[, $result] = \OC_Helper::streamCopy($source, $target);
-				fclose($source);
-				fclose($target);
-			} catch (\Exception $e) {
-				fclose($source);
-				fclose($target);
-				throw $e;
-			}
-			if ($result) {
-				if ($preserveMtime) {
-					$this->touch($targetInternalPath, $sourceStorage->filemtime($sourceInternalPath));
-				}
-				$this->updateEncryptedVersion($sourceStorage, $sourceInternalPath, $targetInternalPath, $isRename, false);
-			} else {
-				// delete partially written target file
-				$this->unlink($targetInternalPath);
-				// delete cache entry that was created by fopen
-				$this->getCache()->remove($targetInternalPath);
-			}
-		}
-		return (bool)$result;
-	}
-
-	/**
-	 * get the path to a local version of the file.
-	 * The local version of the file can be temporary and doesn't have to be persistent across requests
-	 *
-	 * @param string $path
-	 * @return string
-	 */
-	public function getLocalFile($path) {
-		if ($this->encryptionManager->isEnabled()) {
-			$cachedFile = $this->getCachedFile($path);
-			if (is_string($cachedFile)) {
-				return $cachedFile;
-			}
-		}
-		return $this->storage->getLocalFile($path);
-	}
-
-	/**
-	 * Returns the wrapped storage's value for isLocal()
-	 *
-	 * @return bool wrapped storage's isLocal() value
-	 */
-	public function isLocal() {
-		if ($this->encryptionManager->isEnabled()) {
-			return false;
-		}
-		return $this->storage->isLocal();
-	}
-
-	/**
-	 * see http://php.net/manual/en/function.stat.php
-	 * only the following keys are required in the result: size and mtime
-	 *
-	 * @param string $path
-	 * @return array
-	 */
-	public function stat($path) {
-		$stat = $this->storage->stat($path);
-		$fileSize = $this->filesize($path);
-		$stat['size'] = $fileSize;
-		$stat[7] = $fileSize;
-		$stat['hasHeader'] = $this->getHeaderSize($path) > 0;
-		return $stat;
-	}
-
-	/**
-	 * see http://php.net/manual/en/function.hash.php
-	 *
-	 * @param string $type
-	 * @param string $path
-	 * @param bool $raw
-	 * @return string
-	 */
-	public function hash($type, $path, $raw = false) {
-		$fh = $this->fopen($path, 'rb');
-		$ctx = hash_init($type);
-		hash_update_stream($ctx, $fh);
-		fclose($fh);
-		return hash_final($ctx, $raw);
-	}
-
-	/**
-	 * return full path, including mount point
-	 *
-	 * @param string $path relative to mount point
-	 * @return string full path including mount point
-	 */
-	protected function getFullPath($path) {
-		return Filesystem::normalizePath($this->mountPoint . '/' . $path);
-	}
-
-	/**
-	 * read first block of encrypted file, typically this will contain the
-	 * encryption header
-	 *
-	 * @param string $path
-	 * @return string
-	 */
-	protected function readFirstBlock($path) {
-		$firstBlock = '';
-		if ($this->storage->file_exists($path)) {
-			$handle = $this->storage->fopen($path, 'r');
-			$firstBlock = fread($handle, $this->util->getHeaderSize());
-			fclose($handle);
-		}
-		return $firstBlock;
-	}
-
-	/**
-	 * return header size of given file
-	 *
-	 * @param string $path
-	 * @return int
-	 */
-	protected function getHeaderSize($path) {
-		$headerSize = 0;
-		$realFile = $this->util->stripPartialFileExtension($path);
-		if ($this->storage->file_exists($realFile)) {
-			$path = $realFile;
-		}
-		$firstBlock = $this->readFirstBlock($path);
-
-		if (substr($firstBlock, 0, strlen(Util::HEADER_START)) === Util::HEADER_START) {
-			$headerSize = $this->util->getHeaderSize();
-		}
-
-		return $headerSize;
-	}
-
-	/**
-	 * parse raw header to array
-	 *
-	 * @param string $rawHeader
-	 * @return array
-	 */
-	protected function parseRawHeader($rawHeader) {
-		$result = [];
-		if (substr($rawHeader, 0, strlen(Util::HEADER_START)) === Util::HEADER_START) {
-			$header = $rawHeader;
-			$endAt = strpos($header, Util::HEADER_END);
-			if ($endAt !== false) {
-				$header = substr($header, 0, $endAt + strlen(Util::HEADER_END));
-
-				// +1 to not start with an ':' which would result in empty element at the beginning
-				$exploded = explode(':', substr($header, strlen(Util::HEADER_START) + 1));
-
-				$element = array_shift($exploded);
-				while ($element !== Util::HEADER_END) {
-					$result[$element] = array_shift($exploded);
-					$element = array_shift($exploded);
-				}
-			}
-		}
-
-		return $result;
-	}
-
-	/**
-	 * read header from file
-	 *
-	 * @param string $path
-	 * @return array
-	 */
-	protected function getHeader($path) {
-		$realFile = $this->util->stripPartialFileExtension($path);
-		$exists = $this->storage->file_exists($realFile);
-		if ($exists) {
-			$path = $realFile;
-		}
-
-		$firstBlock = $this->readFirstBlock($path);
-		$result = $this->parseRawHeader($firstBlock);
-
-		// if the header doesn't contain a encryption module we check if it is a
-		// legacy file. If true, we add the default encryption module
-		if (!isset($result[Util::HEADER_ENCRYPTION_MODULE_KEY])) {
-			if (!empty($result)) {
-				$result[Util::HEADER_ENCRYPTION_MODULE_KEY] = 'OC_DEFAULT_MODULE';
-			} elseif ($exists) {
-				// if the header was empty we have to check first if it is a encrypted file at all
-				// We would do query to filecache only if we know that entry in filecache exists
-				$info = $this->getCache()->get($path);
-				if (isset($info['encrypted']) && $info['encrypted'] === true) {
-					$result[Util::HEADER_ENCRYPTION_MODULE_KEY] = 'OC_DEFAULT_MODULE';
-				}
-			}
-		}
-
-		return $result;
-	}
-
-	/**
-	 * read encryption module needed to read/write the file located at $path
-	 *
-	 * @param string $path
-	 * @return null|\OCP\Encryption\IEncryptionModule
-	 * @throws ModuleDoesNotExistsException
-	 * @throws \Exception
-	 */
-	protected function getEncryptionModule($path) {
-		$encryptionModule = null;
-		$header = $this->getHeader($path);
-		$encryptionModuleId = $this->util->getEncryptionModuleId($header);
-		if (!empty($encryptionModuleId)) {
-			try {
-				$encryptionModule = $this->encryptionManager->getEncryptionModule($encryptionModuleId);
-			} catch (ModuleDoesNotExistsException $e) {
-				$this->logger->critical('Encryption module defined in "' . $path . '" not loaded!');
-				throw $e;
-			}
-		}
-
-		return $encryptionModule;
-	}
-
-	/**
-	 * @param string $path
-	 * @param int $unencryptedSize
-	 */
-	public function updateUnencryptedSize($path, $unencryptedSize) {
-		$this->unencryptedSize[$path] = $unencryptedSize;
-	}
-
-	/**
-	 * copy keys to new location
-	 *
-	 * @param string $source path relative to data/
-	 * @param string $target path relative to data/
-	 * @return bool
-	 */
-	protected function copyKeys($source, $target) {
-		if (!$this->util->isExcluded($source)) {
-			return $this->keyStorage->copyKeys($source, $target);
-		}
-
-		return false;
-	}
-
-	/**
-	 * check if path points to a files version
-	 *
-	 * @param $path
-	 * @return bool
-	 */
-	protected function isVersion($path) {
-		$normalized = Filesystem::normalizePath($path);
-		return substr($normalized, 0, strlen('/files_versions/')) === '/files_versions/';
-	}
-
-	/**
-	 * check if the given storage should be encrypted or not
-	 *
-	 * @param $path
-	 * @return bool
-	 */
-	protected function shouldEncrypt($path) {
-		$fullPath = $this->getFullPath($path);
-		$mountPointConfig = $this->mount->getOption('encrypt', true);
-		if ($mountPointConfig === false) {
-			return false;
-		}
-
-		try {
-			$encryptionModule = $this->getEncryptionModule($fullPath);
-		} catch (ModuleDoesNotExistsException $e) {
-			return false;
-		}
-
-		if ($encryptionModule === null) {
-			$encryptionModule = $this->encryptionManager->getEncryptionModule();
-		}
-
-		return $encryptionModule->shouldEncrypt($fullPath);
-	}
-
-	public function writeStream(string $path, $stream, int $size = null): int {
-		// always fall back to fopen
-		$target = $this->fopen($path, 'w');
-		[$count, $result] = \OC_Helper::streamCopy($stream, $target);
-		fclose($target);
-		return $count;
-	}
+    use LocalTempFileTrait;
+
+    /** @var string */
+    private $mountPoint;
+
+    /** @var \OC\Encryption\Util */
+    private $util;
+
+    /** @var \OCP\Encryption\IManager */
+    private $encryptionManager;
+
+    /** @var \OCP\ILogger */
+    private $logger;
+
+    /** @var string */
+    private $uid;
+
+    /** @var array */
+    protected $unencryptedSize;
+
+    /** @var \OCP\Encryption\IFile */
+    private $fileHelper;
+
+    /** @var IMountPoint */
+    private $mount;
+
+    /** @var IStorage */
+    private $keyStorage;
+
+    /** @var Update */
+    private $update;
+
+    /** @var Manager */
+    private $mountManager;
+
+    /** @var array remember for which path we execute the repair step to avoid recursions */
+    private $fixUnencryptedSizeOf = [];
+
+    /** @var  ArrayCache */
+    private $arrayCache;
+
+    /**
+     * @param array $parameters
+     * @param IManager $encryptionManager
+     * @param Util $util
+     * @param ILogger $logger
+     * @param IFile $fileHelper
+     * @param string $uid
+     * @param IStorage $keyStorage
+     * @param Update $update
+     * @param Manager $mountManager
+     * @param ArrayCache $arrayCache
+     */
+    public function __construct(
+        $parameters,
+        IManager $encryptionManager = null,
+        Util $util = null,
+        ILogger $logger = null,
+        IFile $fileHelper = null,
+        $uid = null,
+        IStorage $keyStorage = null,
+        Update $update = null,
+        Manager $mountManager = null,
+        ArrayCache $arrayCache = null
+    ) {
+        $this->mountPoint = $parameters['mountPoint'];
+        $this->mount = $parameters['mount'];
+        $this->encryptionManager = $encryptionManager;
+        $this->util = $util;
+        $this->logger = $logger;
+        $this->uid = $uid;
+        $this->fileHelper = $fileHelper;
+        $this->keyStorage = $keyStorage;
+        $this->unencryptedSize = [];
+        $this->update = $update;
+        $this->mountManager = $mountManager;
+        $this->arrayCache = $arrayCache;
+        parent::__construct($parameters);
+    }
+
+    /**
+     * see http://php.net/manual/en/function.filesize.php
+     * The result for filesize when called on a folder is required to be 0
+     *
+     * @param string $path
+     * @return int
+     */
+    public function filesize($path) {
+        $fullPath = $this->getFullPath($path);
+
+        /** @var CacheEntry $info */
+        $info = $this->getCache()->get($path);
+        if (isset($this->unencryptedSize[$fullPath])) {
+            $size = $this->unencryptedSize[$fullPath];
+            // update file cache
+            if ($info instanceof ICacheEntry) {
+                $info = $info->getData();
+                $info['encrypted'] = $info['encryptedVersion'];
+            } else {
+                if (!is_array($info)) {
+                    $info = [];
+                }
+                $info['encrypted'] = true;
+            }
+
+            $info['size'] = $size;
+            $this->getCache()->put($path, $info);
+
+            return $size;
+        }
+
+        if (isset($info['fileid']) && $info['encrypted']) {
+            return $this->verifyUnencryptedSize($path, $info['size']);
+        }
+
+        return $this->storage->filesize($path);
+    }
+
+    private function modifyMetaData(string $path, array $data): array {
+        $fullPath = $this->getFullPath($path);
+        $info = $this->getCache()->get($path);
+
+        if (isset($this->unencryptedSize[$fullPath])) {
+            $data['encrypted'] = true;
+            $data['size'] = $this->unencryptedSize[$fullPath];
+        } else {
+            if (isset($info['fileid']) && $info['encrypted']) {
+                $data['size'] = $this->verifyUnencryptedSize($path, $info['size']);
+                $data['encrypted'] = true;
+            }
+        }
+
+        if (isset($info['encryptedVersion']) && $info['encryptedVersion'] > 1) {
+            $data['encryptedVersion'] = $info['encryptedVersion'];
+        }
+
+        return $data;
+    }
+
+    /**
+     * @param string $path
+     * @return array
+     */
+    public function getMetaData($path) {
+        $data = $this->storage->getMetaData($path);
+        if (is_null($data)) {
+            return null;
+        }
+        return $this->modifyMetaData($path, $data);
+    }
+
+    public function getDirectoryContent($directory): \Traversable {
+        $parent = rtrim($directory, '/');
+        foreach ($this->getWrapperStorage()->getDirectoryContent($directory) as $data) {
+            yield $this->modifyMetaData($parent . '/' . $data['name'], $data);
+        }
+    }
+
+    /**
+     * see http://php.net/manual/en/function.file_get_contents.php
+     *
+     * @param string $path
+     * @return string
+     */
+    public function file_get_contents($path) {
+        $encryptionModule = $this->getEncryptionModule($path);
+
+        if ($encryptionModule) {
+            $handle = $this->fopen($path, "r");
+            if (!$handle) {
+                return false;
+            }
+            $data = stream_get_contents($handle);
+            fclose($handle);
+            return $data;
+        }
+        return $this->storage->file_get_contents($path);
+    }
+
+    /**
+     * see http://php.net/manual/en/function.file_put_contents.php
+     *
+     * @param string $path
+     * @param mixed $data
+     * @return int|false
+     */
+    public function file_put_contents($path, $data) {
+        // file put content will always be translated to a stream write
+        $handle = $this->fopen($path, 'w');
+        if (is_resource($handle)) {
+            $written = fwrite($handle, $data);
+            fclose($handle);
+            return $written;
+        }
+
+        return false;
+    }
+
+    /**
+     * see http://php.net/manual/en/function.unlink.php
+     *
+     * @param string $path
+     * @return bool
+     */
+    public function unlink($path) {
+        $fullPath = $this->getFullPath($path);
+        if ($this->util->isExcluded($fullPath)) {
+            return $this->storage->unlink($path);
+        }
+
+        $encryptionModule = $this->getEncryptionModule($path);
+        if ($encryptionModule) {
+            $this->keyStorage->deleteAllFileKeys($fullPath);
+        }
+
+        return $this->storage->unlink($path);
+    }
+
+    /**
+     * see http://php.net/manual/en/function.rename.php
+     *
+     * @param string $path1
+     * @param string $path2
+     * @return bool
+     */
+    public function rename($path1, $path2) {
+        $result = $this->storage->rename($path1, $path2);
+
+        if ($result &&
+            // versions always use the keys from the original file, so we can skip
+            // this step for versions
+            $this->isVersion($path2) === false &&
+            $this->encryptionManager->isEnabled()) {
+            $source = $this->getFullPath($path1);
+            if (!$this->util->isExcluded($source)) {
+                $target = $this->getFullPath($path2);
+                if (isset($this->unencryptedSize[$source])) {
+                    $this->unencryptedSize[$target] = $this->unencryptedSize[$source];
+                }
+                $this->keyStorage->renameKeys($source, $target);
+                $module = $this->getEncryptionModule($path2);
+                if ($module) {
+                    $module->update($target, $this->uid, []);
+                }
+            }
+        }
+
+        return $result;
+    }
+
+    /**
+     * see http://php.net/manual/en/function.rmdir.php
+     *
+     * @param string $path
+     * @return bool
+     */
+    public function rmdir($path) {
+        $result = $this->storage->rmdir($path);
+        $fullPath = $this->getFullPath($path);
+        if ($result &&
+            $this->util->isExcluded($fullPath) === false &&
+            $this->encryptionManager->isEnabled()
+        ) {
+            $this->keyStorage->deleteAllFileKeys($fullPath);
+        }
+
+        return $result;
+    }
+
+    /**
+     * check if a file can be read
+     *
+     * @param string $path
+     * @return bool
+     */
+    public function isReadable($path) {
+        $isReadable = true;
+
+        $metaData = $this->getMetaData($path);
+        if (
+            !$this->is_dir($path) &&
+            isset($metaData['encrypted']) &&
+            $metaData['encrypted'] === true
+        ) {
+            $fullPath = $this->getFullPath($path);
+            $module = $this->getEncryptionModule($path);
+            $isReadable = $module->isReadable($fullPath, $this->uid);
+        }
+
+        return $this->storage->isReadable($path) && $isReadable;
+    }
+
+    /**
+     * see http://php.net/manual/en/function.copy.php
+     *
+     * @param string $path1
+     * @param string $path2
+     * @return bool
+     */
+    public function copy($path1, $path2) {
+        $source = $this->getFullPath($path1);
+
+        if ($this->util->isExcluded($source)) {
+            return $this->storage->copy($path1, $path2);
+        }
+
+        // need to stream copy file by file in case we copy between a encrypted
+        // and a unencrypted storage
+        $this->unlink($path2);
+        return $this->copyFromStorage($this, $path1, $path2);
+    }
+
+    /**
+     * see http://php.net/manual/en/function.fopen.php
+     *
+     * @param string $path
+     * @param string $mode
+     * @return resource|bool
+     * @throws GenericEncryptionException
+     * @throws ModuleDoesNotExistsException
+     */
+    public function fopen($path, $mode) {
+
+        // check if the file is stored in the array cache, this means that we
+        // copy a file over to the versions folder, in this case we don't want to
+        // decrypt it
+        if ($this->arrayCache->hasKey('encryption_copy_version_' . $path)) {
+            $this->arrayCache->remove('encryption_copy_version_' . $path);
+            return $this->storage->fopen($path, $mode);
+        }
+
+        $encryptionEnabled = $this->encryptionManager->isEnabled();
+        $shouldEncrypt = false;
+        $encryptionModule = null;
+        $header = $this->getHeader($path);
+        $signed = isset($header['signed']) && $header['signed'] === 'true';
+        $fullPath = $this->getFullPath($path);
+        $encryptionModuleId = $this->util->getEncryptionModuleId($header);
+
+        if ($this->util->isExcluded($fullPath) === false) {
+            $size = $unencryptedSize = 0;
+            $realFile = $this->util->stripPartialFileExtension($path);
+            $targetExists = $this->file_exists($realFile) || $this->file_exists($path);
+            $targetIsEncrypted = false;
+            if ($targetExists) {
+                // in case the file exists we require the explicit module as
+                // specified in the file header - otherwise we need to fail hard to
+                // prevent data loss on client side
+                if (!empty($encryptionModuleId)) {
+                    $targetIsEncrypted = true;
+                    $encryptionModule = $this->encryptionManager->getEncryptionModule($encryptionModuleId);
+                }
+
+                if ($this->file_exists($path)) {
+                    $size = $this->storage->filesize($path);
+                    $unencryptedSize = $this->filesize($path);
+                } else {
+                    $size = $unencryptedSize = 0;
+                }
+            }
+
+            try {
+                if (
+                    $mode === 'w'
+                    || $mode === 'w+'
+                    || $mode === 'wb'
+                    || $mode === 'wb+'
+                ) {
+                    // if we update a encrypted file with a un-encrypted one we change the db flag
+                    if ($targetIsEncrypted && $encryptionEnabled === false) {
+                        $cache = $this->storage->getCache();
+                        if ($cache) {
+                            $entry = $cache->get($path);
+                            $cache->update($entry->getId(), ['encrypted' => 0]);
+                        }
+                    }
+                    if ($encryptionEnabled) {
+                        // if $encryptionModuleId is empty, the default module will be used
+                        $encryptionModule = $this->encryptionManager->getEncryptionModule($encryptionModuleId);
+                        $shouldEncrypt = $encryptionModule->shouldEncrypt($fullPath);
+                        $signed = true;
+                    }
+                } else {
+                    $info = $this->getCache()->get($path);
+                    // only get encryption module if we found one in the header
+                    // or if file should be encrypted according to the file cache
+                    if (!empty($encryptionModuleId)) {
+                        $encryptionModule = $this->encryptionManager->getEncryptionModule($encryptionModuleId);
+                        $shouldEncrypt = true;
+                    } elseif (empty($encryptionModuleId) && $info['encrypted'] === true) {
+                        // we come from a old installation. No header and/or no module defined
+                        // but the file is encrypted. In this case we need to use the
+                        // OC_DEFAULT_MODULE to read the file
+                        $encryptionModule = $this->encryptionManager->getEncryptionModule('OC_DEFAULT_MODULE');
+                        $shouldEncrypt = true;
+                        $targetIsEncrypted = true;
+                    }
+                }
+            } catch (ModuleDoesNotExistsException $e) {
+                $this->logger->logException($e, [
+                    'message' => 'Encryption module "' . $encryptionModuleId . '" not found, file will be stored unencrypted',
+                    'level' => ILogger::WARN,
+                    'app' => 'core',
+                ]);
+            }
+
+            // encryption disabled on write of new file and write to existing unencrypted file -> don't encrypt
+            if (!$encryptionEnabled || !$this->shouldEncrypt($path)) {
+                if (!$targetExists || !$targetIsEncrypted) {
+                    $shouldEncrypt = false;
+                }
+            }
+
+            if ($shouldEncrypt === true && $encryptionModule !== null) {
+                $headerSize = $this->getHeaderSize($path);
+                $source = $this->storage->fopen($path, $mode);
+                if (!is_resource($source)) {
+                    return false;
+                }
+                $handle = \OC\Files\Stream\Encryption::wrap($source, $path, $fullPath, $header,
+                    $this->uid, $encryptionModule, $this->storage, $this, $this->util, $this->fileHelper, $mode,
+                    $size, $unencryptedSize, $headerSize, $signed);
+                return $handle;
+            }
+        }
+
+        return $this->storage->fopen($path, $mode);
+    }
+
+
+    /**
+     * perform some plausibility checks if the the unencrypted size is correct.
+     * If not, we calculate the correct unencrypted size and return it
+     *
+     * @param string $path internal path relative to the storage root
+     * @param int $unencryptedSize size of the unencrypted file
+     *
+     * @return int unencrypted size
+     */
+    protected function verifyUnencryptedSize($path, $unencryptedSize) {
+        $size = $this->storage->filesize($path);
+        $result = $unencryptedSize;
+
+        if ($unencryptedSize < 0 ||
+            ($size > 0 && $unencryptedSize === $size)
+        ) {
+            // check if we already calculate the unencrypted size for the
+            // given path to avoid recursions
+            if (isset($this->fixUnencryptedSizeOf[$this->getFullPath($path)]) === false) {
+                $this->fixUnencryptedSizeOf[$this->getFullPath($path)] = true;
+                try {
+                    $result = $this->fixUnencryptedSize($path, $size, $unencryptedSize);
+                } catch (\Exception $e) {
+                    $this->logger->error('Couldn\'t re-calculate unencrypted size for ' . $path);
+                    $this->logger->logException($e);
+                }
+                unset($this->fixUnencryptedSizeOf[$this->getFullPath($path)]);
+            }
+        }
+
+        return $result;
+    }
+
+    /**
+     * calculate the unencrypted size
+     *
+     * @param string $path internal path relative to the storage root
+     * @param int $size size of the physical file
+     * @param int $unencryptedSize size of the unencrypted file
+     *
+     * @return int calculated unencrypted size
+     */
+    protected function fixUnencryptedSize($path, $size, $unencryptedSize) {
+        $headerSize = $this->getHeaderSize($path);
+        $header = $this->getHeader($path);
+        $encryptionModule = $this->getEncryptionModule($path);
+
+        $stream = $this->storage->fopen($path, 'r');
+
+        // if we couldn't open the file we return the old unencrypted size
+        if (!is_resource($stream)) {
+            $this->logger->error('Could not open ' . $path . '. Recalculation of unencrypted size aborted.');
+            return $unencryptedSize;
+        }
+
+        $newUnencryptedSize = 0;
+        $size -= $headerSize;
+        $blockSize = $this->util->getBlockSize();
+
+        // if a header exists we skip it
+        if ($headerSize > 0) {
+            fread($stream, $headerSize);
+        }
+
+        // fast path, else the calculation for $lastChunkNr is bogus
+        if ($size === 0) {
+            return 0;
+        }
+
+        $signed = isset($header['signed']) && $header['signed'] === 'true';
+        $unencryptedBlockSize = $encryptionModule->getUnencryptedBlockSize($signed);
+
+        // calculate last chunk nr
+        // next highest is end of chunks, one subtracted is last one
+        // we have to read the last chunk, we can't just calculate it (because of padding etc)
+
+        $lastChunkNr = ceil($size / $blockSize) - 1;
+        // calculate last chunk position
+        $lastChunkPos = ($lastChunkNr * $blockSize);
+        // try to fseek to the last chunk, if it fails we have to read the whole file
+        if (@fseek($stream, $lastChunkPos, SEEK_CUR) === 0) {
+            $newUnencryptedSize += $lastChunkNr * $unencryptedBlockSize;
+        }
+
+        $lastChunkContentEncrypted = '';
+        $count = $blockSize;
+
+        while ($count > 0) {
+            $data = fread($stream, $blockSize);
+            $count = strlen($data);
+            $lastChunkContentEncrypted .= $data;
+            if (strlen($lastChunkContentEncrypted) > $blockSize) {
+                $newUnencryptedSize += $unencryptedBlockSize;
+                $lastChunkContentEncrypted = substr($lastChunkContentEncrypted, $blockSize);
+            }
+        }
+
+        fclose($stream);
+
+        // we have to decrypt the last chunk to get it actual size
+        $encryptionModule->begin($this->getFullPath($path), $this->uid, 'r', $header, []);
+        $decryptedLastChunk = $encryptionModule->decrypt($lastChunkContentEncrypted, $lastChunkNr . 'end');
+        $decryptedLastChunk .= $encryptionModule->end($this->getFullPath($path), $lastChunkNr . 'end');
+
+        // calc the real file size with the size of the last chunk
+        $newUnencryptedSize += strlen($decryptedLastChunk);
+
+        $this->updateUnencryptedSize($this->getFullPath($path), $newUnencryptedSize);
+
+        // write to cache if applicable
+        $cache = $this->storage->getCache();
+        if ($cache) {
+            $entry = $cache->get($path);
+            $cache->update($entry['fileid'], ['size' => $newUnencryptedSize]);
+        }
+
+        return $newUnencryptedSize;
+    }
+
+    /**
+     * @param Storage\IStorage $sourceStorage
+     * @param string $sourceInternalPath
+     * @param string $targetInternalPath
+     * @param bool $preserveMtime
+     * @return bool
+     */
+    public function moveFromStorage(Storage\IStorage $sourceStorage, $sourceInternalPath, $targetInternalPath, $preserveMtime = true) {
+        if ($sourceStorage === $this) {
+            return $this->rename($sourceInternalPath, $targetInternalPath);
+        }
+
+        // TODO clean this up once the underlying moveFromStorage in OC\Files\Storage\Wrapper\Common is fixed:
+        // - call $this->storage->moveFromStorage() instead of $this->copyBetweenStorage
+        // - copy the file cache update from  $this->copyBetweenStorage to this method
+        // - copy the copyKeys() call from  $this->copyBetweenStorage to this method
+        // - remove $this->copyBetweenStorage
+
+        if (!$sourceStorage->isDeletable($sourceInternalPath)) {
+            return false;
+        }
+
+        $result = $this->copyBetweenStorage($sourceStorage, $sourceInternalPath, $targetInternalPath, $preserveMtime, true);
+        if ($result) {
+            if ($sourceStorage->is_dir($sourceInternalPath)) {
+                $result &= $sourceStorage->rmdir($sourceInternalPath);
+            } else {
+                $result &= $sourceStorage->unlink($sourceInternalPath);
+            }
+        }
+        return $result;
+    }
+
+
+    /**
+     * @param Storage\IStorage $sourceStorage
+     * @param string $sourceInternalPath
+     * @param string $targetInternalPath
+     * @param bool $preserveMtime
+     * @param bool $isRename
+     * @return bool
+     */
+    public function copyFromStorage(Storage\IStorage $sourceStorage, $sourceInternalPath, $targetInternalPath, $preserveMtime = false, $isRename = false) {
+
+        // TODO clean this up once the underlying moveFromStorage in OC\Files\Storage\Wrapper\Common is fixed:
+        // - call $this->storage->copyFromStorage() instead of $this->copyBetweenStorage
+        // - copy the file cache update from  $this->copyBetweenStorage to this method
+        // - copy the copyKeys() call from  $this->copyBetweenStorage to this method
+        // - remove $this->copyBetweenStorage
+
+        return $this->copyBetweenStorage($sourceStorage, $sourceInternalPath, $targetInternalPath, $preserveMtime, $isRename);
+    }
+
+    /**
+     * Update the encrypted cache version in the database
+     *
+     * @param Storage\IStorage $sourceStorage
+     * @param string $sourceInternalPath
+     * @param string $targetInternalPath
+     * @param bool $isRename
+     * @param bool $keepEncryptionVersion
+     */
+    private function updateEncryptedVersion(Storage\IStorage $sourceStorage, $sourceInternalPath, $targetInternalPath, $isRename, $keepEncryptionVersion) {
+        $isEncrypted = $this->encryptionManager->isEnabled() && $this->shouldEncrypt($targetInternalPath);
+        $cacheInformation = [
+            'encrypted' => $isEncrypted,
+        ];
+        if ($isEncrypted) {
+            $encryptedVersion = $sourceStorage->getCache()->get($sourceInternalPath)['encryptedVersion'];
+
+            // In case of a move operation from an unencrypted to an encrypted
+            // storage the old encrypted version would stay with "0" while the
+            // correct value would be "1". Thus we manually set the value to "1"
+            // for those cases.
+            // See also https://github.com/owncloud/core/issues/23078
+            if ($encryptedVersion === 0 || !$keepEncryptionVersion) {
+                $encryptedVersion = 1;
+            }
+
+            $cacheInformation['encryptedVersion'] = $encryptedVersion;
+        }
+
+        // in case of a rename we need to manipulate the source cache because
+        // this information will be kept for the new target
+        if ($isRename) {
+            $sourceStorage->getCache()->put($sourceInternalPath, $cacheInformation);
+        } else {
+            $this->getCache()->put($targetInternalPath, $cacheInformation);
+        }
+    }
+
+    /**
+     * copy file between two storages
+     *
+     * @param Storage\IStorage $sourceStorage
+     * @param string $sourceInternalPath
+     * @param string $targetInternalPath
+     * @param bool $preserveMtime
+     * @param bool $isRename
+     * @return bool
+     * @throws \Exception
+     */
+    private function copyBetweenStorage(Storage\IStorage $sourceStorage, $sourceInternalPath, $targetInternalPath, $preserveMtime, $isRename) {
+
+        // for versions we have nothing to do, because versions should always use the
+        // key from the original file. Just create a 1:1 copy and done
+        if ($this->isVersion($targetInternalPath) ||
+            $this->isVersion($sourceInternalPath)) {
+            // remember that we try to create a version so that we can detect it during
+            // fopen($sourceInternalPath) and by-pass the encryption in order to
+            // create a 1:1 copy of the file
+            $this->arrayCache->set('encryption_copy_version_' . $sourceInternalPath, true);
+            $result = $this->storage->copyFromStorage($sourceStorage, $sourceInternalPath, $targetInternalPath);
+            $this->arrayCache->remove('encryption_copy_version_' . $sourceInternalPath);
+            if ($result) {
+                $info = $this->getCache('', $sourceStorage)->get($sourceInternalPath);
+                // make sure that we update the unencrypted size for the version
+                if (isset($info['encrypted']) && $info['encrypted'] === true) {
+                    $this->updateUnencryptedSize(
+                        $this->getFullPath($targetInternalPath),
+                        $info['size']
+                    );
+                }
+                $this->updateEncryptedVersion($sourceStorage, $sourceInternalPath, $targetInternalPath, $isRename, true);
+            }
+            return $result;
+        }
+
+        // first copy the keys that we reuse the existing file key on the target location
+        // and don't create a new one which would break versions for example.
+        $mount = $this->mountManager->findByStorageId($sourceStorage->getId());
+        if (count($mount) === 1) {
+            $mountPoint = $mount[0]->getMountPoint();
+            $source = $mountPoint . '/' . $sourceInternalPath;
+            $target = $this->getFullPath($targetInternalPath);
+            $this->copyKeys($source, $target);
+        } else {
+            $this->logger->error('Could not find mount point, can\'t keep encryption keys');
+        }
+
+        if ($sourceStorage->is_dir($sourceInternalPath)) {
+            $dh = $sourceStorage->opendir($sourceInternalPath);
+            $result = $this->mkdir($targetInternalPath);
+            if (is_resource($dh)) {
+                while ($result and ($file = readdir($dh)) !== false) {
+                    if (!Filesystem::isIgnoredDir($file)) {
+                        $result &= $this->copyFromStorage($sourceStorage, $sourceInternalPath . '/' . $file, $targetInternalPath . '/' . $file, false, $isRename);
+                    }
+                }
+            }
+        } else {
+            try {
+                $source = $sourceStorage->fopen($sourceInternalPath, 'r');
+                $target = $this->fopen($targetInternalPath, 'w');
+                [, $result] = \OC_Helper::streamCopy($source, $target);
+                fclose($source);
+                fclose($target);
+            } catch (\Exception $e) {
+                fclose($source);
+                fclose($target);
+                throw $e;
+            }
+            if ($result) {
+                if ($preserveMtime) {
+                    $this->touch($targetInternalPath, $sourceStorage->filemtime($sourceInternalPath));
+                }
+                $this->updateEncryptedVersion($sourceStorage, $sourceInternalPath, $targetInternalPath, $isRename, false);
+            } else {
+                // delete partially written target file
+                $this->unlink($targetInternalPath);
+                // delete cache entry that was created by fopen
+                $this->getCache()->remove($targetInternalPath);
+            }
+        }
+        return (bool)$result;
+    }
+
+    /**
+     * get the path to a local version of the file.
+     * The local version of the file can be temporary and doesn't have to be persistent across requests
+     *
+     * @param string $path
+     * @return string
+     */
+    public function getLocalFile($path) {
+        if ($this->encryptionManager->isEnabled()) {
+            $cachedFile = $this->getCachedFile($path);
+            if (is_string($cachedFile)) {
+                return $cachedFile;
+            }
+        }
+        return $this->storage->getLocalFile($path);
+    }
+
+    /**
+     * Returns the wrapped storage's value for isLocal()
+     *
+     * @return bool wrapped storage's isLocal() value
+     */
+    public function isLocal() {
+        if ($this->encryptionManager->isEnabled()) {
+            return false;
+        }
+        return $this->storage->isLocal();
+    }
+
+    /**
+     * see http://php.net/manual/en/function.stat.php
+     * only the following keys are required in the result: size and mtime
+     *
+     * @param string $path
+     * @return array
+     */
+    public function stat($path) {
+        $stat = $this->storage->stat($path);
+        $fileSize = $this->filesize($path);
+        $stat['size'] = $fileSize;
+        $stat[7] = $fileSize;
+        $stat['hasHeader'] = $this->getHeaderSize($path) > 0;
+        return $stat;
+    }
+
+    /**
+     * see http://php.net/manual/en/function.hash.php
+     *
+     * @param string $type
+     * @param string $path
+     * @param bool $raw
+     * @return string
+     */
+    public function hash($type, $path, $raw = false) {
+        $fh = $this->fopen($path, 'rb');
+        $ctx = hash_init($type);
+        hash_update_stream($ctx, $fh);
+        fclose($fh);
+        return hash_final($ctx, $raw);
+    }
+
+    /**
+     * return full path, including mount point
+     *
+     * @param string $path relative to mount point
+     * @return string full path including mount point
+     */
+    protected function getFullPath($path) {
+        return Filesystem::normalizePath($this->mountPoint . '/' . $path);
+    }
+
+    /**
+     * read first block of encrypted file, typically this will contain the
+     * encryption header
+     *
+     * @param string $path
+     * @return string
+     */
+    protected function readFirstBlock($path) {
+        $firstBlock = '';
+        if ($this->storage->file_exists($path)) {
+            $handle = $this->storage->fopen($path, 'r');
+            $firstBlock = fread($handle, $this->util->getHeaderSize());
+            fclose($handle);
+        }
+        return $firstBlock;
+    }
+
+    /**
+     * return header size of given file
+     *
+     * @param string $path
+     * @return int
+     */
+    protected function getHeaderSize($path) {
+        $headerSize = 0;
+        $realFile = $this->util->stripPartialFileExtension($path);
+        if ($this->storage->file_exists($realFile)) {
+            $path = $realFile;
+        }
+        $firstBlock = $this->readFirstBlock($path);
+
+        if (substr($firstBlock, 0, strlen(Util::HEADER_START)) === Util::HEADER_START) {
+            $headerSize = $this->util->getHeaderSize();
+        }
+
+        return $headerSize;
+    }
+
+    /**
+     * parse raw header to array
+     *
+     * @param string $rawHeader
+     * @return array
+     */
+    protected function parseRawHeader($rawHeader) {
+        $result = [];
+        if (substr($rawHeader, 0, strlen(Util::HEADER_START)) === Util::HEADER_START) {
+            $header = $rawHeader;
+            $endAt = strpos($header, Util::HEADER_END);
+            if ($endAt !== false) {
+                $header = substr($header, 0, $endAt + strlen(Util::HEADER_END));
+
+                // +1 to not start with an ':' which would result in empty element at the beginning
+                $exploded = explode(':', substr($header, strlen(Util::HEADER_START) + 1));
+
+                $element = array_shift($exploded);
+                while ($element !== Util::HEADER_END) {
+                    $result[$element] = array_shift($exploded);
+                    $element = array_shift($exploded);
+                }
+            }
+        }
+
+        return $result;
+    }
+
+    /**
+     * read header from file
+     *
+     * @param string $path
+     * @return array
+     */
+    protected function getHeader($path) {
+        $realFile = $this->util->stripPartialFileExtension($path);
+        $exists = $this->storage->file_exists($realFile);
+        if ($exists) {
+            $path = $realFile;
+        }
+
+        $firstBlock = $this->readFirstBlock($path);
+        $result = $this->parseRawHeader($firstBlock);
+
+        // if the header doesn't contain a encryption module we check if it is a
+        // legacy file. If true, we add the default encryption module
+        if (!isset($result[Util::HEADER_ENCRYPTION_MODULE_KEY])) {
+            if (!empty($result)) {
+                $result[Util::HEADER_ENCRYPTION_MODULE_KEY] = 'OC_DEFAULT_MODULE';
+            } elseif ($exists) {
+                // if the header was empty we have to check first if it is a encrypted file at all
+                // We would do query to filecache only if we know that entry in filecache exists
+                $info = $this->getCache()->get($path);
+                if (isset($info['encrypted']) && $info['encrypted'] === true) {
+                    $result[Util::HEADER_ENCRYPTION_MODULE_KEY] = 'OC_DEFAULT_MODULE';
+                }
+            }
+        }
+
+        return $result;
+    }
+
+    /**
+     * read encryption module needed to read/write the file located at $path
+     *
+     * @param string $path
+     * @return null|\OCP\Encryption\IEncryptionModule
+     * @throws ModuleDoesNotExistsException
+     * @throws \Exception
+     */
+    protected function getEncryptionModule($path) {
+        $encryptionModule = null;
+        $header = $this->getHeader($path);
+        $encryptionModuleId = $this->util->getEncryptionModuleId($header);
+        if (!empty($encryptionModuleId)) {
+            try {
+                $encryptionModule = $this->encryptionManager->getEncryptionModule($encryptionModuleId);
+            } catch (ModuleDoesNotExistsException $e) {
+                $this->logger->critical('Encryption module defined in "' . $path . '" not loaded!');
+                throw $e;
+            }
+        }
+
+        return $encryptionModule;
+    }
+
+    /**
+     * @param string $path
+     * @param int $unencryptedSize
+     */
+    public function updateUnencryptedSize($path, $unencryptedSize) {
+        $this->unencryptedSize[$path] = $unencryptedSize;
+    }
+
+    /**
+     * copy keys to new location
+     *
+     * @param string $source path relative to data/
+     * @param string $target path relative to data/
+     * @return bool
+     */
+    protected function copyKeys($source, $target) {
+        if (!$this->util->isExcluded($source)) {
+            return $this->keyStorage->copyKeys($source, $target);
+        }
+
+        return false;
+    }
+
+    /**
+     * check if path points to a files version
+     *
+     * @param $path
+     * @return bool
+     */
+    protected function isVersion($path) {
+        $normalized = Filesystem::normalizePath($path);
+        return substr($normalized, 0, strlen('/files_versions/')) === '/files_versions/';
+    }
+
+    /**
+     * check if the given storage should be encrypted or not
+     *
+     * @param $path
+     * @return bool
+     */
+    protected function shouldEncrypt($path) {
+        $fullPath = $this->getFullPath($path);
+        $mountPointConfig = $this->mount->getOption('encrypt', true);
+        if ($mountPointConfig === false) {
+            return false;
+        }
+
+        try {
+            $encryptionModule = $this->getEncryptionModule($fullPath);
+        } catch (ModuleDoesNotExistsException $e) {
+            return false;
+        }
+
+        if ($encryptionModule === null) {
+            $encryptionModule = $this->encryptionManager->getEncryptionModule();
+        }
+
+        return $encryptionModule->shouldEncrypt($fullPath);
+    }
+
+    public function writeStream(string $path, $stream, int $size = null): int {
+        // always fall back to fopen
+        $target = $this->fopen($path, 'w');
+        [$count, $result] = \OC_Helper::streamCopy($stream, $target);
+        fclose($target);
+        return $count;
+    }
 }