remove encryption keys if user unshares a file

apps/files_encryption/hooks/hooks.php

@@ -34,6 +34,8 @@ class Hooks {
 	private static $renamedFiles = array();
 	// file for which we want to delete the keys after the delete operation was successful
 	private static $deleteFiles = array();
+	// file for which we want to delete the keys after the delete operation was successful
+	private static $umountedFiles = array();
 
 	/**
 	 * Startup encryption backend upon user login
@@ -610,4 +612,57 @@ class Hooks {
 			'path' => $ownerPath);
 	}
 
+	/**
+	 * remember files/folders which get unmounted
+	 */
+	public static function preUmount($params) {
+		$path = $params[\OC\Files\Filesystem::signal_param_path];
+		$user = \OCP\USER::getUser();
+
+		$view = new \OC\Files\View();
+		$itemType = $view->is_dir('/' . $user . '/files' . $path) ? 'folder' : 'file';
+
+		$util = new Util($view, $user);
+		list($owner, $ownerPath) = $util->getUidAndFilename($path);
+
+		self::$umountedFiles[$params[\OC\Files\Filesystem::signal_param_path]] = array(
+			'uid' => $owner,
+			'path' => $ownerPath,
+			'itemType' => $itemType);
+	}
+
+	public static function postUmount($params) {
+
+		if (!isset(self::$umountedFiles[$params[\OC\Files\Filesystem::signal_param_path]])) {
+			return true;
+		}
+
+		$umountedFile = self::$umountedFiles[$params[\OC\Files\Filesystem::signal_param_path]];
+		$path = $umountedFile['path'];
+		$user = $umountedFile['uid'];
+		$itemType = $umountedFile['itemType'];
+
+		$view = new \OC\Files\View();
+		$util = new Util($view, $user);
+
+		// we don't need to remember the file any longer
+		unset(self::$umountedFiles[$params[\OC\Files\Filesystem::signal_param_path]]);
+
+		// if we unshare a folder we need a list of all (sub-)files
+		if ($itemType === 'folder') {
+			$allFiles = $util->getAllFiles($path);
+		} else {
+			$allFiles = array($path);
+		}
+
+		foreach ($allFiles as $path) {
+
+			// check if the user still has access to the file, otherwise delete share key
+			$sharingUsers = $result = \OCP\Share::getUsersSharingFile($path, $user);
+			if (!in_array(\OCP\User::getUser(), $sharingUsers['users'])) {
+				Keymanager::delShareKey($view, array(\OCP\User::getUser()), $path);
+			}
+		}
+	}
+
 }

apps/files_encryption/lib/helper.php

@@ -65,6 +65,8 @@ class Helper {
 		\OCP\Util::connectHook('OC_Filesystem', 'post_rename', 'OCA\Encryption\Hooks', 'postRename');
 		\OCP\Util::connectHook('OC_Filesystem', 'post_delete', 'OCA\Encryption\Hooks', 'postDelete');
 		\OCP\Util::connectHook('OC_Filesystem', 'delete', 'OCA\Encryption\Hooks', 'preDelete');
+		\OCP\Util::connectHook('OC_Filesystem', 'post_umount', 'OCA\Encryption\Hooks', 'postUmount');
+		\OCP\Util::connectHook('OC_Filesystem', 'umount', 'OCA\Encryption\Hooks', 'preUmount');
 	}
 
 	/**

apps/files_encryption/tests/hooks.php

@@ -257,14 +257,14 @@ class Test_Encryption_Hooks extends \PHPUnit_Framework_TestCase {
 
 		$this->assertTrue($result);
 
-		// now keys from user1s home should be gone
-		$this->assertFalse($this->rootView->file_exists(
+		// share key for user2 from user1s home should be gone, all other keys should still exists
+		$this->assertTrue($this->rootView->file_exists(
 			self::TEST_ENCRYPTION_HOOKS_USER1 . '/files_encryption/share-keys/'
 			. $this->filename . '.' . \Test_Encryption_Hooks::TEST_ENCRYPTION_HOOKS_USER1 . '.shareKey'));
 		$this->assertFalse($this->rootView->file_exists(
 				self::TEST_ENCRYPTION_HOOKS_USER1 . '/files_encryption/share-keys/'
 				. $this->filename . '.' . \Test_Encryption_Hooks::TEST_ENCRYPTION_HOOKS_USER2 . '.shareKey'));
-		$this->assertFalse($this->rootView->file_exists(
+		$this->assertTrue($this->rootView->file_exists(
 			self::TEST_ENCRYPTION_HOOKS_USER1 . '/files_encryption/keyfiles/' . $this->filename . '.key'));
 
 		// cleanup

lib/private/files/view.php

@@ -361,7 +361,18 @@ class View {
 		$mount = Filesystem::getMountManager()->find($absolutePath . $postFix);
 		if ($mount->getInternalPath($absolutePath) === '') {
 			if ($mount instanceof MoveableMount) {
-				return $mount->removeMount();
+				\OC_Hook::emit(
+						Filesystem::CLASSNAME, "umount",
+						array(Filesystem::signal_param_path => $path)
+						);
+				$result = $mount->removeMount();
+				if ($result) {
+					\OC_Hook::emit(
+							Filesystem::CLASSNAME, "post_umount",
+							array(Filesystem::signal_param_path => $path)
+							);
+				}
+				return $result;
 			} else {
 				// do not allow deleting the storage's root / the mount point
 				// because for some storages it might delete the whole contents