make versions of shared files downloadable

5 files changed, 131 insertions, 80 deletions

diff --git a/apps/files_encryption/lib/crypt.php b/apps/files_encryption/lib/crypt.php
index 38993ba65b0..cdc2df4cdd8 100644
--- a/apps/files_encryption/lib/crypt.php
+++ b/apps/files_encryption/lib/crypt.php
@@ -148,9 +148,6 @@ class Crypt {
 		// Fetch encryption metadata from end of file

 		$meta = substr($noPadding, -22);

 

-		// Fetch IV from end of file

-		$iv = substr($meta, -16);

-

 		// Fetch identifier from start of metadata

 		$identifier = substr($meta, 0, 6);

 

diff --git a/apps/files_encryption/lib/helper.php b/apps/files_encryption/lib/helper.php
index b9d45f67363..553c52e72fe 100644
--- a/apps/files_encryption/lib/helper.php
+++ b/apps/files_encryption/lib/helper.php
@@ -250,15 +250,14 @@ class Helper {
 	 * @return string e.g. turns '/admin/files/test.txt' into 'test.txt'
 	 */
 	public static function stripUserFilesPath($path) {
-		$trimmed = ltrim($path, '/');
-		$split = explode('/', $trimmed);
+		$split = self::splitPath($path);
 
 		// it is not a file relative to data/user/files
-		if (count($split) < 3 || $split[1] !== 'files') {
+		if (count($split) < 4 || $split[2] !== 'files') {
 			return false;
 		}
 
-		$sliced = array_slice($split, 2);
+		$sliced = array_slice($split, 3);
 		$relPath = implode('/', $sliced);
 
 		return $relPath;
@@ -267,7 +266,7 @@ class Helper {
 	/**
 	 * try to get the user from the path if no user is logged in
 	 * @param string $path
-	 * @return mixed user or false if we couldn't determine a user
+	 * @return string user
 	 */
 	public static function getUser($path) {
 
@@ -281,65 +280,85 @@ class Helper {
 
 		// if no user is logged in we try to access a publicly shared files.
 		// In this case we need to try to get the user from the path
+		return self::getUserFromPath($path);
+	}
 
-		$trimmed = ltrim($path, '/');
-		$split = explode('/', $trimmed);
+	/**
+	 * extract user from path
+	 *
+	 * @param string $path
+	 * @return string user id
+	 * @throws Exception\EncryptionException
+	 */
+	public static function getUserFromPath($path) {
+		$split = self::splitPath($path);
 
-		// it is not a file relative to data/user/files
-		if (count($split) < 2 || ($split[1] !== 'files' && $split[1] !== 'cache')) {
-			return false;
-		}
+		if (count($split) > 3 && (
+			$split[2] === 'files' || $split[2] === 'files_versions' || $split[2] === 'cache')) {
 
-		$user = $split[0];
+			$user = $split[1];
 
-		if (\OCP\User::userExists($user)) {
-			return $user;
+			if (\OCP\User::userExists($user)) {
+				return $user;
+			}
 		}
 
-		return false;
+		throw new Exception\EncryptionException('Could not determine user', Exception\EncryptionException::GENERIC);
 	}
 
 	/**
 	 * get path to the corresponding file in data/user/files if path points
-	 *        to a version or to a file in cache
-	 * @param string $path path to a version or a file in the trash
+	 * to a file in cache
+	 *
+	 * @param string $path path to a file in cache
 	 * @return string path to corresponding file relative to data/user/files
+	 * @throws Exception\EncryptionException
 	 */
-	public static function getPathToRealFile($path) {
-		$trimmed = ltrim($path, '/');
-		$split = explode('/', $trimmed);
-		$result = false;
-
-		if (count($split) >= 3 && ($split[1] === "files_versions" || $split[1] === 'cache')) {
-			$sliced = array_slice($split, 2);
-			$result = implode('/', $sliced);
-			if ($split[1] === "files_versions") {
-				// we skip user/files
-				$sliced = array_slice($split, 2);
-				$relPath = implode('/', $sliced);
-				//remove the last .v
-				$result = substr($relPath, 0, strrpos($relPath, '.v'));
-			}
-			if ($split[1] === "cache") {
-				// we skip /user/cache/transactionId
-				$sliced = array_slice($split, 3);
-				$result = implode('/', $sliced);
-				//prepare the folders
-				self::mkdirr($path, new \OC\Files\View('/'));
-			}
+	public static function getPathFromCachedFile($path) {
+		$split = self::splitPath($path);
+
+		if (count($split) < 5) {
+			throw new Exception\EncryptionException('no valid cache file path', Exception\EncryptionException::GENERIC);
 		}
 
-		return $result;
+		// we skip /user/cache/transactionId
+		$sliced = array_slice($split, 4);
+
+		return implode('/', $sliced);
+	}
+
+
+	/**
+	 * get path to the corresponding file in data/user/files for a version
+	 *
+	 * @param string $path path to a version
+	 * @return string path to corresponding file relative to data/user/files
+	 * @throws Exception\EncryptionException
+	 */
+	public static function getPathFromVersion($path) {
+		$split = self::splitPath($path);
+
+		if (count($split) < 4) {
+			throw new Exception\EncryptionException('no valid path to a version', Exception\EncryptionException::GENERIC);
+		}
+
+		// we skip user/files_versions
+		$sliced = array_slice($split, 3);
+		$relPath = implode('/', $sliced);
+		//remove the last .v
+		$realPath = substr($relPath, 0, strrpos($relPath, '.v'));
+
+		return $realPath;
 	}
 
 	/**
 	 * create directory recursively
+	 *
 	 * @param string $path
 	 * @param \OC\Files\View $view
 	 */
 	public static function mkdirr($path, \OC\Files\View $view) {
-		$dirname = \OC\Files\Filesystem::normalizePath(dirname($path));
-		$dirParts = explode('/', $dirname);
+		$dirParts = self::splitPath(dirname($path));
 		$dir = "";
 		foreach ($dirParts as $part) {
 			$dir = $dir . '/' . $part;
@@ -454,6 +473,32 @@ class Helper {
 	}
 
 	/**
+	 * detect file type, encryption can read/write regular files, versions
+	 * and cached files
+	 *
+	 * @param string $path
+	 * @return int
+	 * @throws Exception\EncryptionException
+	 */
+	public static function detectFileType($path) {
+	    $parts = self::splitPath($path);
+
+		if (count($parts) > 2) {
+			switch ($parts[2]) {
+				case 'files':
+					return Util::FILE_TYPE_FILE;
+				case 'files_versions':
+					return Util::FILE_TYPE_VERSION;
+				case 'cache':
+					return Util::FILE_TYPE_CACHE;
+			}
+		}
+
+		// thow exception if we couldn't detect a valid file type
+		throw new Exception\EncryptionException('Could not detect file type', Exception\EncryptionException::GENERIC);
+	}
+
+	/**
 	 * read the cipher used for encryption from the config.php
 	 *
 	 * @return string
@@ -472,5 +517,11 @@ class Helper {
 
 		return $cipher;
 	}
+
+	public static function splitPath($path) {
+		$normalized = \OC\Files\Filesystem::normalizePath($path);
+		return explode('/', $normalized);
+	}
+
 }
 
diff --git a/apps/files_encryption/lib/proxy.php b/apps/files_encryption/lib/proxy.php
index ba78c81aa35..3ee7d83f04c 100644
--- a/apps/files_encryption/lib/proxy.php
+++ b/apps/files_encryption/lib/proxy.php
@@ -56,10 +56,12 @@ class Proxy extends \OC_FileProxy {
 
 		$path = \OC\Files\Filesystem::normalizePath($path);
 
+		$parts = explode('/', $path);
+
 		// we only encrypt/decrypt files in the files and files_versions folder
 		if(
 			strpos($path, '/' . $uid . '/files/') !== 0 &&
-			strpos($path, '/' . $uid . '/files_versions/') !== 0) {
+			!($parts[2] === 'files_versions' && \OCP\User::userExists($parts[1]))) {
 
 			return true;
 		}
diff --git a/apps/files_encryption/lib/stream.php b/apps/files_encryption/lib/stream.php
index 17da4eb1cdc..1bc0d54e1bc 100644
--- a/apps/files_encryption/lib/stream.php
+++ b/apps/files_encryption/lib/stream.php
@@ -75,6 +75,8 @@ class Stream {
 	private $headerWritten = false;
 	private $containHeader = false; // the file contain a header
 	private $cipher; // cipher used for encryption/decryption
+	/** @var \OCA\Files_Encryption\Util */
+	private $util;
 
 	/**
 	 * @var \OC\Files\View
@@ -103,9 +105,7 @@ class Stream {
 		// assume that the file already exist before we decide it finally in getKey()
 		$this->newFile = false;
 
-		if (!isset($this->rootView)) {
-			$this->rootView = new \OC\Files\View('/');
-		}
+		$this->rootView = new \OC\Files\View('/');
 
 		$this->session = new Session($this->rootView);
 
@@ -116,7 +116,8 @@ class Stream {
 		}
 
 		$normalizedPath = \OC\Files\Filesystem::normalizePath(str_replace('crypt://', '', $path));
-		if ($originalFile = Helper::getPathFromTmpFile($normalizedPath)) {
+		$originalFile = Helper::getPathFromTmpFile($normalizedPath);
+		if ($originalFile) {
 			$this->rawPath = $originalFile;
 			$this->isLocalTmpFile = true;
 			$this->localTmpFile = $normalizedPath;
@@ -124,24 +125,31 @@ class Stream {
 			$this->rawPath = $normalizedPath;
 		}
 
-		$this->userId = Helper::getUser($this->rawPath);
-
-		$util = new Util($this->rootView, $this->userId);
+		$this->util = new Util($this->rootView, Helper::getUser($this->rawPath));
 
 		// get the key ID which we want to use, can be the users key or the
 		// public share key
-		$this->keyId = $util->getKeyId();
+		$this->keyId = $this->util->getKeyId();
 
-		// Strip identifier text from path, this gives us the path relative to data/<user>/files
-		$this->relPath = Helper::stripUserFilesPath($this->rawPath);
-		// if raw path doesn't point to a real file, check if it is a version or a file in the trash bin
-		if ($this->relPath === false) {
-			$this->relPath = Helper::getPathToRealFile($this->rawPath);
-		}
+		$fileType = Helper::detectFileType($this->rawPath);
 
-		if($this->relPath === false) {
-			\OCP\Util::writeLog('Encryption library', 'failed to open file "' . $this->rawPath . '" expecting a path to "files", "files_versions" or "cache"', \OCP\Util::ERROR);
-			return false;
+		switch ($fileType) {
+			case Util::FILE_TYPE_FILE:
+				$this->relPath = Helper::stripUserFilesPath($this->rawPath);
+				$this->userId = \OC::$server->getUserSession()->getUser()->getUID();
+				break;
+			case Util::FILE_TYPE_VERSION:
+				$this->relPath = Helper::getPathFromVersion($this->rawPath);
+				$this->userId = Helper::getUserFromPath($this->rawPath);
+				break;
+			case Util::FILE_TYPE_CACHE:
+				$this->relPath = Helper::getPathFromCachedFile($this->rawPath);
+				Helper::mkdirr($this->rawPath, new \OC\Files\View('/'));
+				$this->userId = \OC::$server->getUserSession()->getUser()->getUID();
+				break;
+			default:
+				\OCP\Util::writeLog('Encryption library', 'failed to open file "' . $this->rawPath . '" expecting a path to "files", "files_versions" or "cache"', \OCP\Util::ERROR);
+				return false;
 		}
 
 		// Disable fileproxies so we can get the file size and open the source file without recursive encryption
@@ -154,22 +162,12 @@ class Stream {
 			or $mode === 'wb'
 			or $mode === 'wb+'
 		) {
-
 			// We're writing a new file so start write counter with 0 bytes
 			$this->size = 0;
 			$this->unencryptedSize = 0;
-
 		} else {
-
-			if($this->privateKey === false) {
-				// if private key is not valid redirect user to a error page
-				Helper::redirectToErrorPage($this->session);
-			}
-
 			$this->size = $this->rootView->filesize($this->rawPath);
-
 			$this->readHeader();
-
 		}
 
 		if ($this->isLocalTmpFile) {
@@ -328,9 +326,10 @@ class Stream {
 
 		}
 
+		$util = new Util($this->rootView, $this->userId);
+
 		// Fetch and decrypt keyfile
 		// Fetch existing keyfile
-		$util = new Util($this->rootView, $this->userId);
 		$this->encKeyfile = Keymanager::getFileKey($this->rootView, $util, $this->relPath);
 
 		// If a keyfile already exists
@@ -614,11 +613,9 @@ class Stream {
 				// Check if OC sharing api is enabled
 				$sharingEnabled = \OCP\Share::isEnabled();
 
-				$util = new Util($this->rootView, $this->userId);
-
 				// Get all users sharing the file includes current user
-				$uniqueUserIds = $util->getSharingUsersArray($sharingEnabled, $this->relPath);
-				$checkedUserIds = $util->filterShareReadyUsers($uniqueUserIds);
+				$uniqueUserIds = $this->util->getSharingUsersArray($sharingEnabled, $this->relPath);
+				$checkedUserIds = $this->util->filterShareReadyUsers($uniqueUserIds);
 
 				// Fetch public keys for all sharing users
 				$publicKeys = Keymanager::getPublicKeys($this->rootView, $checkedUserIds['ready']);
@@ -627,10 +624,10 @@ class Stream {
 				$this->encKeyfiles = Crypt::multiKeyEncrypt($this->plainKey, $publicKeys);
 
 				// Save the new encrypted file key
-				Keymanager::setFileKey($this->rootView, $util, $this->relPath, $this->encKeyfiles['data']);
+				Keymanager::setFileKey($this->rootView, $this->util, $this->relPath, $this->encKeyfiles['data']);
 
 				// Save the sharekeys
-				Keymanager::setShareKeys($this->rootView, $util, $this->relPath, $this->encKeyfiles['keys']);
+				Keymanager::setShareKeys($this->rootView, $this->util, $this->relPath, $this->encKeyfiles['keys']);
 
 				// Re-enable proxy - our work is done
 				\OC_FileProxy::$enabled = $proxyStatus;
diff --git a/apps/files_encryption/lib/util.php b/apps/files_encryption/lib/util.php
index 4aaf7aa2571..1b140822724 100644
--- a/apps/files_encryption/lib/util.php
+++ b/apps/files_encryption/lib/util.php
@@ -39,6 +39,10 @@ class Util {
 	const MIGRATION_IN_PROGRESS = -1; // migration is running
 	const MIGRATION_OPEN = 0;         // user still needs to be migrated
 
+	const FILE_TYPE_FILE = 0;
+	const FILE_TYPE_VERSION = 1;
+	const FILE_TYPE_CACHE = 2;
+
 	private $view; // OC\Files\View object for filesystem operations
 	private $userId; // ID of the user we use to encrypt/decrypt files
 	private $keyId; // ID of the key we want to manipulate