Add share attributes + prevent download permission

Makes it possible to store download permission

Signed-off-by: Vincent Petry <vincent@nextcloud.com>

10 files changed, 591 insertions, 46 deletions

diff --git a/apps/files_sharing/composer/composer/autoload_classmap.php b/apps/files_sharing/composer/composer/autoload_classmap.php
index 2810910c8c9..e4a493cadfb 100644
--- a/apps/files_sharing/composer/composer/autoload_classmap.php
+++ b/apps/files_sharing/composer/composer/autoload_classmap.php
@@ -80,4 +80,5 @@ return array(
     'OCA\\Files_Sharing\\SharedMount' => $baseDir . '/../lib/SharedMount.php',
     'OCA\\Files_Sharing\\SharedStorage' => $baseDir . '/../lib/SharedStorage.php',
     'OCA\\Files_Sharing\\Updater' => $baseDir . '/../lib/Updater.php',
+    'OCA\\Files_Sharing\\ViewOnly' => $baseDir . '/../lib/ViewOnly.php',
 );
diff --git a/apps/files_sharing/composer/composer/autoload_static.php b/apps/files_sharing/composer/composer/autoload_static.php
index 70149b1cdc0..3c92a46fc82 100644
--- a/apps/files_sharing/composer/composer/autoload_static.php
+++ b/apps/files_sharing/composer/composer/autoload_static.php
@@ -95,6 +95,7 @@ class ComposerStaticInitFiles_Sharing
         'OCA\\Files_Sharing\\SharedMount' => __DIR__ . '/..' . '/../lib/SharedMount.php',
         'OCA\\Files_Sharing\\SharedStorage' => __DIR__ . '/..' . '/../lib/SharedStorage.php',
         'OCA\\Files_Sharing\\Updater' => __DIR__ . '/..' . '/../lib/Updater.php',
+        'OCA\\Files_Sharing\\ViewOnly' => __DIR__ . '/..' . '/../lib/ViewOnly.php',
     );
 
     public static function getInitializer(ClassLoader $loader)
diff --git a/apps/files_sharing/lib/AppInfo/Application.php b/apps/files_sharing/lib/AppInfo/Application.php
index 6f1d72f9115..fef579a11c0 100644
--- a/apps/files_sharing/lib/AppInfo/Application.php
+++ b/apps/files_sharing/lib/AppInfo/Application.php
@@ -52,14 +52,17 @@ use OCA\Files\Event\LoadAdditionalScriptsEvent;
 use OCA\Files\Event\LoadSidebar;
 use OCA\Files_Sharing\ShareBackend\File;
 use OCA\Files_Sharing\ShareBackend\Folder;
+use OCA\Files_Sharing\ViewOnly;
 use OCP\AppFramework\App;
 use OCP\AppFramework\Bootstrap\IBootContext;
 use OCP\AppFramework\Bootstrap\IBootstrap;
 use OCP\AppFramework\Bootstrap\IRegistrationContext;
 use OCP\Collaboration\Resources\LoadAdditionalScriptsEvent as ResourcesLoadAdditionalScriptsEvent;
 use OCP\EventDispatcher\IEventDispatcher;
+use OCP\EventDispatcher\GenericEvent;
 use OCP\Federation\ICloudIdManager;
 use OCP\Files\Config\IMountProviderCollection;
+use OCP\Files\IRootFolder;
 use OCP\Group\Events\UserAddedEvent;
 use OCP\IDBConnection;
 use OCP\IGroup;
@@ -71,7 +74,7 @@ use OCP\User\Events\UserChangedEvent;
 use OCP\Util;
 use Psr\Container\ContainerInterface;
 use Symfony\Component\EventDispatcher\EventDispatcherInterface;
-use Symfony\Component\EventDispatcher\GenericEvent;
+use Symfony\Component\EventDispatcher\GenericEvent as OldGenericEvent;
 
 class Application extends App implements IBootstrap {
 	public const APP_ID = 'files_sharing';
@@ -107,6 +110,7 @@ class Application extends App implements IBootstrap {
 	public function boot(IBootContext $context): void {
 		$context->injectFn([$this, 'registerMountProviders']);
 		$context->injectFn([$this, 'registerEventsScripts']);
+		$context->injectFn([$this, 'registerDownloadEvents']);
 		$context->injectFn([$this, 'setupSharingMenus']);
 
 		Helper::registerHooks();
@@ -139,18 +143,76 @@ class Application extends App implements IBootstrap {
 		});
 
 		// notifications api to accept incoming user shares
-		$oldDispatcher->addListener('OCP\Share::postShare', function (GenericEvent $event) {
+		$oldDispatcher->addListener('OCP\Share::postShare', function (OldGenericEvent $event) {
 			/** @var Listener $listener */
 			$listener = $this->getContainer()->query(Listener::class);
 			$listener->shareNotification($event);
 		});
-		$oldDispatcher->addListener(IGroup::class . '::postAddUser', function (GenericEvent $event) {
+		$oldDispatcher->addListener(IGroup::class . '::postAddUser', function (OldGenericEvent $event) {
 			/** @var Listener $listener */
 			$listener = $this->getContainer()->query(Listener::class);
 			$listener->userAddedToGroup($event);
 		});
 	}
 
+	public function registerDownloadEvents(
+		IEventDispatcher $dispatcher,
+		?IUserSession $userSession,
+		IRootFolder $rootFolder
+	) {
+
+		$dispatcher->addListener(
+			'file.beforeGetDirect',
+			function (GenericEvent $event) use ($userSession, $rootFolder) {
+				$pathsToCheck[] = $event->getArgument('path');
+
+				// Check only for user/group shares. Don't restrict e.g. share links
+				if ($userSession && $userSession->isLoggedIn()) {
+					$uid = $userSession->getUser()->getUID();
+					$viewOnlyHandler = new ViewOnly(
+						$rootFolder->getUserFolder($uid)
+					);
+					if (!$viewOnlyHandler->check($pathsToCheck)) {
+						$event->setArgument('errorMessage', 'Access to this resource or one of its sub-items has been denied.');
+					}
+				}
+			}
+		);
+
+		$dispatcher->addListener(
+			'file.beforeCreateZip',
+			function (GenericEvent $event) use ($userSession, $rootFolder) {
+				$dir = $event->getArgument('dir');
+				$files = $event->getArgument('files');
+
+				$pathsToCheck = [];
+				if (\is_array($files)) {
+					foreach ($files as $file) {
+						$pathsToCheck[] = $dir . '/' . $file;
+					}
+				} elseif (\is_string($files)) {
+					$pathsToCheck[] = $dir . '/' . $files;
+				}
+
+				// Check only for user/group shares. Don't restrict e.g. share links
+				if ($userSession && $userSession->isLoggedIn()) {
+					$uid = $userSession->getUser()->getUID();
+					$viewOnlyHandler = new ViewOnly(
+						$rootFolder->getUserFolder($uid)
+					);
+					if (!$viewOnlyHandler->check($pathsToCheck)) {
+						$event->setArgument('errorMessage', 'Access to this resource or one of its sub-items has been denied.');
+						$event->setArgument('run', false);
+					} else {
+						$event->setArgument('run', true);
+					}
+				} else {
+					$event->setArgument('run', true);
+				}
+			}
+		);
+	}
+
 	public function setupSharingMenus(IManager $shareManager, IFactory $l10nFactory, IUserSession $userSession) {
 		if (!$shareManager->shareApiEnabled() || !class_exists('\OCA\Files\App')) {
 			return;
diff --git a/apps/files_sharing/lib/Controller/ShareAPIController.php b/apps/files_sharing/lib/Controller/ShareAPIController.php
index fafdb1a64cd..e40aed0da70 100644
--- a/apps/files_sharing/lib/Controller/ShareAPIController.php
+++ b/apps/files_sharing/lib/Controller/ShareAPIController.php
@@ -45,6 +45,7 @@ declare(strict_types=1);
 namespace OCA\Files_Sharing\Controller;
 
 use OC\Files\FileInfo;
+use OCA\DAV\DAV\ViewOnlyPlugin;
 use OCA\Files_Sharing\Exceptions\SharingRightsException;
 use OCA\Files_Sharing\External\Storage;
 use OCA\Files\Helper;
@@ -324,6 +325,11 @@ class ShareAPIController extends OCSController {
 		$result['mail_send'] = $share->getMailSend() ? 1 : 0;
 		$result['hide_download'] = $share->getHideDownload() ? 1 : 0;
 
+		$result['attributes'] = null;
+		if ($attributes = $share->getAttributes()) {
+			$result['attributes'] =  \json_encode($attributes->toArray());
+		}
+
 		return $result;
 	}
 
@@ -674,6 +680,8 @@ class ShareAPIController extends OCSController {
 			$share->setNote($note);
 		}
 
+		$share = $this->setShareAttributes($share, $this->request->getParam('attributes', null));
+
 		try {
 			$share = $this->shareManager->createShare($share);
 		} catch (GenericShareException $e) {
@@ -1216,6 +1224,8 @@ class ShareAPIController extends OCSController {
 			}
 		}
 
+		$share = $this->setShareAttributes($share, $this->request->getParam('attributes', null));
+
 		try {
 			$share = $this->shareManager->updateShare($share);
 		} catch (GenericShareException $e) {
@@ -1832,4 +1842,25 @@ class ShareAPIController extends OCSController {
 			}
 		}
 	}
+
+	/**
+	 * @param IShare $share
+	 * @param string[][]|null $formattedShareAttributes
+	 * @return IShare modified share
+	 */
+	private function setShareAttributes(IShare $share, $formattedShareAttributes) {
+		$newShareAttributes = $this->shareManager->newShare()->newAttributes();
+		if ($formattedShareAttributes !== null) {
+			foreach ($formattedShareAttributes as $formattedAttr) {
+				$newShareAttributes->setAttribute(
+					$formattedAttr['scope'],
+					$formattedAttr['key'],
+					(bool) \json_decode($formattedAttr['enabled'])
+				);
+			}
+		}
+		$share->setAttributes($newShareAttributes);
+
+		return $share;
+	}
 }
diff --git a/apps/files_sharing/lib/MountProvider.php b/apps/files_sharing/lib/MountProvider.php
index 5817ece6809..30e398d663b 100644
--- a/apps/files_sharing/lib/MountProvider.php
+++ b/apps/files_sharing/lib/MountProvider.php
@@ -38,6 +38,7 @@ use OCP\ICacheFactory;
 use OCP\IConfig;
 use OCP\ILogger;
 use OCP\IUser;
+use OCP\Share\IAttributes;
 use OCP\Share\IManager;
 use OCP\Share\IShare;
 
@@ -229,14 +230,31 @@ class MountProvider implements IMountProvider {
 				->setTarget($shares[0]->getTarget());
 
 			// use most permissive permissions
-			$permissions = 0;
+			// this covers the case where there are multiple shares for the same
+			// file e.g. from different groups and different permissions
+			$superPermissions = 0;
+			$superAttributes = $this->shareManager->newShare()->newAttributes();
 			$status = IShare::STATUS_PENDING;
 			foreach ($shares as $share) {
-				$permissions |= $share->getPermissions();
+				$superPermissions |= $share->getPermissions();
 				$status = max($status, $share->getStatus());
+				// update permissions
+				$superPermissions |= $share->getPermissions();
+
+				// update share permission attributes
+				if ($share->getAttributes() !== null) {
+					foreach ($share->getAttributes()->toArray() as $attribute) {
+						if ($superAttributes->getAttribute($attribute['scope'], $attribute['key']) === true) {
+							// if super share attribute is already enabled, it is most permissive
+							continue;
+						}
+						// update supershare attributes with subshare attribute
+						$superAttributes->setAttribute($attribute['scope'], $attribute['key'], $attribute['enabled']);
+					}
+				}
 
+				// adjust target, for database consistency if needed
 				if ($share->getTarget() !== $superShare->getTarget()) {
-					// adjust target, for database consistency
 					$share->setTarget($superShare->getTarget());
 					try {
 						$this->shareManager->moveShare($share, $user->getUID());
@@ -261,8 +279,9 @@ class MountProvider implements IMountProvider {
 				}
 			}
 
-			$superShare->setPermissions($permissions)
-				->setStatus($status);
+			$superShare->setPermissions($superPermissions);
+			$superShare->setStatus($status);
+			$superShare->setAttributes($superAttributes);
 
 			$result[] = [$superShare, $shares];
 		}
diff --git a/apps/files_sharing/lib/ViewOnly.php b/apps/files_sharing/lib/ViewOnly.php
new file mode 100644
index 00000000000..58ff2e7f2b4
--- /dev/null
+++ b/apps/files_sharing/lib/ViewOnly.php
@@ -0,0 +1,116 @@
+<?php
+/**
+ * @author Piotr Mrowczynski piotr@owncloud.com
+ *
+ * @copyright Copyright (c) 2019, ownCloud GmbH
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OCA\Files_Sharing;
+
+use OCP\Files\File;
+use OCP\Files\Folder;
+use OCP\Files\Node;
+use OCP\Files\NotFoundException;
+
+/**
+ * Handles restricting for download of files
+ */
+class ViewOnly {
+
+	/** @var Folder */
+	private $userFolder;
+
+	public function __construct(Folder $userFolder) {
+		$this->userFolder = $userFolder;
+	}
+
+	/**
+	 * @param string[] $pathsToCheck
+	 * @return bool
+	 */
+	public function check($pathsToCheck) {
+		// If any of elements cannot be downloaded, prevent whole download
+		foreach ($pathsToCheck as $file) {
+			try {
+				$info = $this->userFolder->get($file);
+				if ($info instanceof File) {
+					// access to filecache is expensive in the loop
+					if (!$this->checkFileInfo($info)) {
+						return false;
+					}
+				} elseif ($info instanceof Folder) {
+					// get directory content is rather cheap query
+					if (!$this->dirRecursiveCheck($info)) {
+						return false;
+					}
+				}
+			} catch (NotFoundException $e) {
+				continue;
+			}
+		}
+		return true;
+	}
+
+	/**
+	 * @param Folder $dirInfo
+	 * @return bool
+	 * @throws NotFoundException
+	 */
+	private function dirRecursiveCheck(Folder $dirInfo) {
+		if (!$this->checkFileInfo($dirInfo)) {
+			return false;
+		}
+		// If any of elements cannot be downloaded, prevent whole download
+		$files = $dirInfo->getDirectoryListing();
+		foreach ($files as $file) {
+			if ($file instanceof File) {
+				if (!$this->checkFileInfo($file)) {
+					return false;
+				}
+			} elseif ($file instanceof Folder) {
+				return $this->dirRecursiveCheck($file);
+			}
+		}
+
+		return true;
+	}
+
+	/**
+	 * @param Node $fileInfo
+	 * @return bool
+	 * @throws NotFoundException
+	 */
+	private function checkFileInfo(Node $fileInfo) {
+		// Restrict view-only to nodes which are shared
+		$storage = $fileInfo->getStorage();
+		if (!$storage->instanceOfStorage(SharedStorage::class)) {
+			return true;
+		}
+
+		// Extract extra permissions
+		/** @var \OCA\Files_Sharing\SharedStorage $storage */
+		$share = $storage->getShare();
+
+		// Check if read-only and on whether permission can download is both set and disabled.
+
+		$canDownload = $share->getAttributes()->getAttribute('permissions', 'download');
+		if ($canDownload !== null && !$canDownload) {
+			return false;
+		}
+		return true;
+	}
+}
diff --git a/apps/files_sharing/tests/ApiTest.php b/apps/files_sharing/tests/ApiTest.php
index a16a1aaf383..50869b7a9f8 100644
--- a/apps/files_sharing/tests/ApiTest.php
+++ b/apps/files_sharing/tests/ApiTest.php
@@ -948,8 +948,11 @@ class ApiTest extends TestCase {
 			->setSharedBy(self::TEST_FILES_SHARING_API_USER1)
 			->setSharedWith(self::TEST_FILES_SHARING_API_USER2)
 			->setShareType(IShare::TYPE_USER)
-			->setPermissions(19);
+			->setPermissions(19)
+			->setAttributes($this->shareManager->newShare()->newAttributes());
 		$share1 = $this->shareManager->createShare($share1);
+		$this->assertEquals(19, $share1->getPermissions());
+		$this->assertEquals(null, $share1->getAttributes());
 
 		$share2 = $this->shareManager->newShare();
 		$share2->setNode($node1)
@@ -957,6 +960,7 @@ class ApiTest extends TestCase {
 			->setShareType(IShare::TYPE_LINK)
 			->setPermissions(1);
 		$share2 = $this->shareManager->createShare($share2);
+		$this->assertEquals(1, $share2->getPermissions());
 
 		// update permissions
 		$ocs = $this->createOCS(self::TEST_FILES_SHARING_API_USER1);
@@ -965,6 +969,7 @@ class ApiTest extends TestCase {
 
 		$share1 = $this->shareManager->getShareById('ocinternal:' . $share1->getId());
 		$this->assertEquals(1, $share1->getPermissions());
+		$this->assertEquals(true, $share1->getAttributes()->getAttribute('app1', 'attr1'));
 
 		// update password for link share
 		$this->assertNull($share2->getPassword());
diff --git a/apps/files_sharing/tests/ApplicationTest.php b/apps/files_sharing/tests/ApplicationTest.php
new file mode 100644
index 00000000000..3f3164b233e
--- /dev/null
+++ b/apps/files_sharing/tests/ApplicationTest.php
@@ -0,0 +1,238 @@
+<?php
+/**
+ * @copyright 2022, Vincent Petry <vincent@nextcloud.com>
+ *
+ * @author Vincent Petry <vincent@nextcloud.com>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+namespace OCA\Files_Sharing\Tests;
+
+use Psr\Log\LoggerInterface;
+use OC\Share20\LegacyHooks;
+use OC\Share20\Manager;
+use OC\EventDispatcher\EventDispatcher;
+use OCA\Files_Sharing\AppInfo\Application;
+use OCA\Files_Sharing\SharedStorage;
+use OCP\Constants;
+use OCP\EventDispatcher\GenericEvent;
+use OCP\EventDispatcher\IEventDispatcher;
+use OCP\Files\Cache\ICacheEntry;
+use OCP\Files\File;
+use OCP\Files\Folder;
+use OCP\Files\IRootFolder;
+use OCP\Files\Storage\IStorage;
+use OCP\IServerContainer;
+use OCP\IUser;
+use OCP\IUserSession;
+use OCP\Share\IAttributes;
+use OCP\Share\IShare;
+use Symfony\Component\EventDispatcher\EventDispatcher as SymfonyDispatcher;
+use Test\TestCase;
+
+class ApplicationTest extends TestCase {
+
+	/** @var Application */
+	private $application;
+
+	/** @var IEventDispatcher */
+	private $eventDispatcher;
+
+	/** @var IUserSession */
+	private $userSession;
+
+	/** @var IRootFolder */
+	private $rootFolder;
+
+	/** @var Manager */ private $manager;
+
+	protected function setUp(): void {
+		parent::setUp();
+
+		$this->application = new Application([]);
+
+		// FIXME: how to mock this one ??
+		$symfonyDispatcher = $this->createMock(SymfonyDispatcher::class);
+		$this->eventDispatcher = new EventDispatcher(
+			$symfonyDispatcher,
+			$this->createMock(IServerContainer::class),
+			$this->createMock(LoggerInterface::class)
+		);
+		$this->userSession = $this->createMock(IUserSession::class);
+		$this->rootFolder = $this->createMock(IRootFolder::class);
+
+		$this->application->registerDownloadEvents(
+			$this->eventDispatcher,
+			$this->userSession,
+			$this->rootFolder
+		);
+	}
+
+	public function providesDataForCanGet() {
+		// normal file (sender) - can download directly
+		$senderFileStorage = $this->createMock(IStorage::class);
+		$senderFileStorage->method('instanceOfStorage')->with(SharedStorage::class)->willReturn(false);
+		$senderFile = $this->createMock(File::class);
+		$senderFile->method('getStorage')->willReturn($senderFileStorage);
+		$senderUserFolder = $this->createMock(Folder::class);
+		$senderUserFolder->method('get')->willReturn($senderFile);
+
+		$result[] = [ '/bar.txt', $senderUserFolder, true ];
+
+		// shared file (receiver) with attribute secure-view-enabled set false -
+		// can download directly
+		$receiverFileShareAttributes = $this->createMock(IAttributes::class);
+		$receiverFileShareAttributes->method('getAttribute')->with('permissions', 'download')->willReturn(true);
+		$receiverFileShare = $this->createMock(IShare::class);
+		$receiverFileShare->method('getAttributes')->willReturn($receiverFileShareAttributes);
+		$receiverFileStorage = $this->createMock(SharedStorage::class);
+		$receiverFileStorage->method('instanceOfStorage')->with(SharedStorage::class)->willReturn(true);
+		$receiverFileStorage->method('getShare')->willReturn($receiverFileShare);
+		$receiverFile = $this->createMock(File::class);
+		$receiverFile->method('getStorage')->willReturn($receiverFileStorage);
+		$receiverUserFolder = $this->createMock(Folder::class);
+		$receiverUserFolder->method('get')->willReturn($receiverFile);
+
+		$result[] = [ '/share-bar.txt', $receiverUserFolder, true ];
+
+		// shared file (receiver) with attribute secure-view-enabled set true -
+		// cannot download directly
+		$secureReceiverFileShareAttributes = $this->createMock(IAttributes::class);
+		$secureReceiverFileShareAttributes->method('getAttribute')->with('permissions', 'download')->willReturn(false);
+		$secureReceiverFileShare = $this->createMock(IShare::class);
+		$secureReceiverFileShare->method('getAttributes')->willReturn($secureReceiverFileShareAttributes);
+		$secureReceiverFileStorage = $this->createMock(SharedStorage::class);
+		$secureReceiverFileStorage->method('instanceOfStorage')->with(SharedStorage::class)->willReturn(true);
+		$secureReceiverFileStorage->method('getShare')->willReturn($secureReceiverFileShare);
+		$secureReceiverFile = $this->createMock(File::class);
+		$secureReceiverFile->method('getStorage')->willReturn($secureReceiverFileStorage);
+		$secureReceiverUserFolder = $this->createMock(Folder::class);
+		$secureReceiverUserFolder->method('get')->willReturn($secureReceiverFile);
+
+		$result[] = [ '/secure-share-bar.txt', $secureReceiverUserFolder, false ];
+
+		return $result;
+	}
+
+	/**
+	 * @dataProvider providesDataForCanGet
+	 */
+	public function testCheckDirectCanBeDownloaded($path, $userFolder, $run) {
+		$user = $this->createMock(IUser::class);
+		$user->method("getUID")->willReturn("test");
+		$this->userSession->method("getUser")->willReturn($user);
+		$this->userSession->method("isLoggedIn")->willReturn(true);
+		$this->rootFolder->method('getUserFolder')->willReturn($userFolder);
+
+		// Simulate direct download of file
+		$event = new GenericEvent(null, [ 'path' => $path ]);
+		$this->eventDispatcher->dispatch('file.beforeGetDirect', $event);
+
+		$this->assertEquals($run, !$event->hasArgument('errorMessage'));
+	}
+
+	public function providesDataForCanZip() {
+		// Mock: Normal file/folder storage
+		$nonSharedStorage = $this->createMock(IStorage::class);
+		$nonSharedStorage->method('instanceOfStorage')->with(SharedStorage::class)->willReturn(false);
+
+		// Mock: Secure-view file/folder shared storage
+		$secureReceiverFileShareAttributes = $this->createMock(IAttributes::class);
+		$secureReceiverFileShareAttributes->method('getAttribute')->with('permissions', 'download')->willReturn(false);
+		$secureReceiverFileShare = $this->createMock(IShare::class);
+		$secureReceiverFileShare->method('getAttributes')->willReturn($secureReceiverFileShareAttributes);
+		$secureSharedStorage = $this->createMock(SharedStorage::class);
+		$secureSharedStorage->method('instanceOfStorage')->with(SharedStorage::class)->willReturn(true);
+		$secureSharedStorage->method('getShare')->willReturn($secureReceiverFileShare);
+
+		// 1. can download zipped 2 non-shared files inside non-shared folder
+		// 2. can download zipped non-shared folder
+		$sender1File = $this->createMock(File::class);
+		$sender1File->method('getStorage')->willReturn($nonSharedStorage);
+		$sender1Folder = $this->createMock(Folder::class);
+		$sender1Folder->method('getStorage')->willReturn($nonSharedStorage);
+		$sender1Folder->method('getDirectoryListing')->willReturn([$sender1File, $sender1File]);
+		$sender1RootFolder = $this->createMock(Folder::class);
+		$sender1RootFolder->method('getStorage')->willReturn($nonSharedStorage);
+		$sender1RootFolder->method('getDirectoryListing')->willReturn([$sender1Folder]);
+		$sender1UserFolder = $this->createMock(Folder::class);
+		$sender1UserFolder->method('get')->willReturn($sender1RootFolder);
+
+		$return[] = [ '/folder', ['bar1.txt', 'bar2.txt'], $sender1UserFolder, true ];
+		$return[] = [ '/', 'folder', $sender1UserFolder, true ];
+
+		// 3. cannot download zipped 1 non-shared file and 1 secure-shared inside non-shared folder
+		$receiver1File = $this->createMock(File::class);
+		$receiver1File->method('getStorage')->willReturn($nonSharedStorage);
+		$receiver1SecureFile = $this->createMock(File::class);
+		$receiver1SecureFile->method('getStorage')->willReturn($secureSharedStorage);
+		$receiver1Folder = $this->createMock(Folder::class);
+		$receiver1Folder->method('getStorage')->willReturn($nonSharedStorage);
+		$receiver1Folder->method('getDirectoryListing')->willReturn([$receiver1File, $receiver1SecureFile]);
+		$receiver1RootFolder = $this->createMock(Folder::class);
+		$receiver1RootFolder->method('getStorage')->willReturn($nonSharedStorage);
+		$receiver1RootFolder->method('getDirectoryListing')->willReturn([$receiver1Folder]);
+		$receiver1UserFolder = $this->createMock(Folder::class);
+		$receiver1UserFolder->method('get')->willReturn($receiver1RootFolder);
+
+		$return[] = [ '/folder', ['secured-bar1.txt', 'bar2.txt'], $receiver1UserFolder, false ];
+
+		// 4. cannot download zipped secure-shared folder
+		$receiver2Folder = $this->createMock(Folder::class);
+		$receiver2Folder->method('getStorage')->willReturn($secureSharedStorage);
+		$receiver2RootFolder = $this->createMock(Folder::class);
+		$receiver2RootFolder->method('getStorage')->willReturn($nonSharedStorage);
+		$receiver2RootFolder->method('getDirectoryListing')->willReturn([$receiver2Folder]);
+		$receiver2UserFolder = $this->createMock(Folder::class);
+		$receiver2UserFolder->method('get')->willReturn($receiver2RootFolder);
+
+		$return[] = [ '/', 'secured-folder', $receiver2UserFolder, false ];
+
+		return $return;
+	}
+
+	/**
+	 * @dataProvider providesDataForCanZip
+	 */
+	public function testCheckZipCanBeDownloaded($dir, $files, $userFolder, $run) {
+		$user = $this->createMock(IUser::class);
+		$user->method("getUID")->willReturn("test");
+		$this->userSession->method("getUser")->willReturn($user);
+		$this->userSession->method("isLoggedIn")->willReturn(true);
+
+		$this->rootFolder->method('getUserFolder')->with("test")->willReturn($userFolder);
+
+		// Simulate zip download of folder folder
+		$event = new GenericEvent(null, ['dir' => $dir, 'files' => $files, 'run' => true]);
+		$this->eventDispatcher->dispatch('file.beforeCreateZip', $event);
+
+		$this->assertEquals($run, $event->getArgument('run'));
+		$this->assertEquals($run, !$event->hasArgument('errorMessage'));
+	}
+
+	public function testCheckFileUserNotFound() {
+		$this->userSession->method("isLoggedIn")->willReturn(false);
+
+		// Simulate zip download of folder folder
+		$event = new GenericEvent(null, ['dir' => '/test', 'files' => ['test.txt'], 'run' => true]);
+		$this->eventDispatcher->dispatch('file.beforeCreateZip', $event);
+
+		// It should run as this would restrict e.g. share links otherwise
+		$this->assertTrue($event->getArgument('run'));
+		$this->assertFalse($event->hasArgument('errorMessage'));
+	}
+}
diff --git a/apps/files_sharing/tests/Controller/ShareAPIControllerTest.php b/apps/files_sharing/tests/Controller/ShareAPIControllerTest.php
index fd5580f19a7..f6568415727 100644
--- a/apps/files_sharing/tests/Controller/ShareAPIControllerTest.php
+++ b/apps/files_sharing/tests/Controller/ShareAPIControllerTest.php
@@ -124,7 +124,11 @@ class ShareAPIControllerTest extends TestCase {
 			->willReturn(true);
 		$this->shareManager
 			->expects($this->any())
-		->method('shareProviderExists')->willReturn(true);
+			->method('shareProviderExists')->willReturn(true);
+		$this->shareManager
+			->expects($this->any())
+			->method('newShare')
+			->willReturn($this->newShare());
 		$this->groupManager = $this->createMock(IGroupManager::class);
 		$this->userManager = $this->createMock(IUserManager::class);
 		$this->request = $this->createMock(IRequest::class);
@@ -194,6 +198,25 @@ class ShareAPIControllerTest extends TestCase {
 	}
 
 
+	private function mockShareAttributes() {
+		$formattedShareAttributes = [
+			[
+				[
+					'scope' => 'permissions',
+					'key' => 'download',
+					'enabled' => true
+				]
+			]
+		];
+
+		$shareAttributes = $this->createMock(IShareAttributes::class);
+		$shareAttributes->method('toArray')->willReturn($formattedShareAttributes);
+		$shareAttributes->method('getAttribute')->with('permissions', 'download')->willReturn(true);
+
+		// send both IShare attributes class and expected json string
+		return [$shareAttributes, \json_encode($formattedShareAttributes)];
+	}
+
 	public function testDeleteShareShareNotFound() {
 		$this->expectException(\OCP\AppFramework\OCS\OCSNotFoundException::class);
 		$this->expectExceptionMessage('Wrong share ID, share does not exist');
@@ -505,7 +528,7 @@ class ShareAPIControllerTest extends TestCase {
 
 	public function createShare($id, $shareType, $sharedWith, $sharedBy, $shareOwner, $path, $permissions,
 								$shareTime, $expiration, $parent, $target, $mail_send, $note = '', $token = null,
-								$password = null, $label = '') {
+								$password = null, $label = '', $attributes = null) {
 		$share = $this->getMockBuilder(IShare::class)->getMock();
 		$share->method('getId')->willReturn($id);
 		$share->method('getShareType')->willReturn($shareType);
@@ -516,6 +539,7 @@ class ShareAPIControllerTest extends TestCase {
 		$share->method('getPermissions')->willReturn($permissions);
 		$share->method('getNote')->willReturn($note);
 		$share->method('getLabel')->willReturn($label);
+		$share->method('getAttributes')->willReturn($attributes);
 		$time = new \DateTime();
 		$time->setTimestamp($shareTime);
 		$share->method('getShareTime')->willReturn($time);
@@ -565,6 +589,8 @@ class ShareAPIControllerTest extends TestCase {
 		$folder->method('getParent')->willReturn($parentFolder);
 		$folder->method('getMimeType')->willReturn('myFolderMimeType');
 
+		[$shareAttributes, $shareAttributesReturnJson] = $this->mockShareAttributes();
+
 		// File shared with user
 		$share = $this->createShare(
 			100,
@@ -579,7 +605,8 @@ class ShareAPIControllerTest extends TestCase {
 			6,
 			'target',
 			0,
-			'personal note'
+			'personal note',
+			$shareAttributes,
 		);
 		$expected = [
 			'id' => 100,
@@ -597,6 +624,7 @@ class ShareAPIControllerTest extends TestCase {
 			'token' => null,
 			'expiration' => null,
 			'permissions' => 4,
+			'attributes' => $shareAttributesReturnJson,
 			'stime' => 5,
 			'parent' => null,
 			'storage_id' => 'STORAGE',
@@ -630,7 +658,8 @@ class ShareAPIControllerTest extends TestCase {
 			6,
 			'target',
 			0,
-			'personal note'
+			'personal note',
+			$shareAttributes,
 		);
 		$expected = [
 			'id' => 101,
@@ -647,6 +676,7 @@ class ShareAPIControllerTest extends TestCase {
 			'token' => null,
 			'expiration' => null,
 			'permissions' => 4,
+			'attributes' => $shareAttributesReturnJson,
 			'stime' => 5,
 			'parent' => null,
 			'storage_id' => 'STORAGE',
@@ -702,6 +732,7 @@ class ShareAPIControllerTest extends TestCase {
 			'token' => 'token',
 			'expiration' => '2000-01-02 00:00:00',
 			'permissions' => 4,
+			'attributes' => null,
 			'stime' => 5,
 			'parent' => null,
 			'storage_id' => 'STORAGE',
@@ -3725,7 +3756,7 @@ class ShareAPIControllerTest extends TestCase {
 		$recipient = $this->getMockBuilder(IUser::class)->getMock();
 		$recipient->method('getDisplayName')->willReturn('recipientDN');
 		$recipient->method('getSystemEMailAddress')->willReturn('recipient');
-
+		[$shareAttributes, $shareAttributesReturnJson] = $this->mockShareAttributes();
 
 		$result = [];
 
@@ -3735,6 +3766,7 @@ class ShareAPIControllerTest extends TestCase {
 			->setSharedBy('initiator')
 			->setShareOwner('owner')
 			->setPermissions(\OCP\Constants::PERMISSION_READ)
+			->setAttributes($shareAttributes)
 			->setNode($file)
 			->setShareTime(new \DateTime('2000-01-01T00:01:02'))
 			->setTarget('myTarget')
@@ -3749,6 +3781,7 @@ class ShareAPIControllerTest extends TestCase {
 				'uid_owner' => 'initiator',
 				'displayname_owner' => 'initiator',
 				'permissions' => 1,
+				'attributes' => $shareAttributesReturnJson,
 				'stime' => 946684862,
 				'parent' => null,
 				'expiration' => null,
@@ -3785,6 +3818,7 @@ class ShareAPIControllerTest extends TestCase {
 				'uid_owner' => 'initiator',
 				'displayname_owner' => 'initiatorDN',
 				'permissions' => 1,
+				'attributes' => $shareAttributesReturnJson,
 				'stime' => 946684862,
 				'parent' => null,
 				'expiration' => null,
@@ -3837,6 +3871,7 @@ class ShareAPIControllerTest extends TestCase {
 				'uid_owner' => 'initiator',
 				'displayname_owner' => 'initiator',
 				'permissions' => 1,
+				'attributes' => null,
 				'stime' => 946684862,
 				'parent' => null,
 				'expiration' => null,
@@ -3885,6 +3920,7 @@ class ShareAPIControllerTest extends TestCase {
 				'uid_owner' => 'initiator',
 				'displayname_owner' => 'initiator',
 				'permissions' => 1,
+				'attributes' => null,
 				'stime' => 946684862,
 				'parent' => null,
 				'expiration' => null,
@@ -3935,6 +3971,7 @@ class ShareAPIControllerTest extends TestCase {
 				'uid_owner' => 'initiator',
 				'displayname_owner' => 'initiator',
 				'permissions' => 1,
+				'attributes' => null,
 				'stime' => 946684862,
 				'parent' => null,
 				'expiration' => null,
@@ -4030,6 +4067,7 @@ class ShareAPIControllerTest extends TestCase {
 				'uid_owner' => 'initiator',
 				'displayname_owner' => 'initiator',
 				'permissions' => 1,
+				'attributes' => null,
 				'stime' => 946684862,
 				'parent' => null,
 				'expiration' => '2001-01-02 00:00:00',
@@ -4228,6 +4266,7 @@ class ShareAPIControllerTest extends TestCase {
 				'uid_owner' => 'initiator',
 				'displayname_owner' => 'initiator',
 				'permissions' => 1,
+				'attributes' => null,
 				'stime' => 946684862,
 				'parent' => null,
 				'expiration' => null,
diff --git a/apps/files_sharing/tests/MountProviderTest.php b/apps/files_sharing/tests/MountProviderTest.php
index 53bea929def..740c7c89eb7 100644
--- a/apps/files_sharing/tests/MountProviderTest.php
+++ b/apps/files_sharing/tests/MountProviderTest.php
@@ -81,12 +81,36 @@ class MountProviderTest extends \Test\TestCase {
 		$this->provider = new MountProvider($this->config, $this->shareManager, $this->logger, $eventDispatcher, $cacheFactory);
 	}
 
-	private function makeMockShare($id, $nodeId, $owner = 'user2', $target = null, $permissions = 31) {
+	private function makeMockShareAttributes($attrs) {
+		if ($attrs === null) {
+			return null;
+		}
+
+		$shareAttributes = $this->createMock(IShareAttributes::class);
+		$shareAttributes->method('toArray')->willReturn($attrs);
+		$shareAttributes->method('getAttribute')->will(
+			$this->returnCallback(function ($scope, $key) use ($attrs) {
+				$result = null;
+				foreach ($attrs as $attr) {
+					if ($attr['key'] === $key && $attr['scope'] === $scope) {
+						$result = $attr['enabled'];
+					}
+				}
+				return $result;
+			})
+		);
+		return $shareAttributes;
+	}
+
+	private function makeMockShare($id, $nodeId, $owner = 'user2', $target = null, $permissions = 31, $attributes) {
 		$share = $this->createMock(IShare::class);
 		$share->expects($this->any())
 			->method('getPermissions')
 			->willReturn($permissions);
 		$share->expects($this->any())
+			->method('getAttributes')
+			->will($this->returnValue($this->makeMockShareAttributes($attributes)));
+		$share->expects($this->any())
 			->method('getShareOwner')
 			->willReturn($owner);
 		$share->expects($this->any())
@@ -115,14 +139,16 @@ class MountProviderTest extends \Test\TestCase {
 	public function testExcludeShares() {
 		$rootFolder = $this->createMock(IRootFolder::class);
 		$userManager = $this->createMock(IUserManager::class);
+		$attr1 = [];
+		$attr2 = [['scope' => 'permission', 'key' => 'download', 'enabled' => true]];
 		$userShares = [
-			$this->makeMockShare(1, 100, 'user2', '/share2', 0),
-			$this->makeMockShare(2, 100, 'user2', '/share2', 31),
+			$this->makeMockShare(1, 100, 'user2', '/share2', 0, $attr1),
+			$this->makeMockShare(2, 100, 'user2', '/share2', 31, $attr2),
 		];
 		$groupShares = [
-			$this->makeMockShare(3, 100, 'user2', '/share2', 0),
-			$this->makeMockShare(4, 101, 'user2', '/share4', 31),
-			$this->makeMockShare(5, 100, 'user1', '/share4', 31),
+			$this->makeMockShare(3, 100, 'user2', '/share2', 0, $attr1),
+			$this->makeMockShare(4, 101, 'user2', '/share4', 31, $attr2),
+			$this->makeMockShare(5, 100, 'user1', '/share4', 31, $attr2),
 		];
 		$roomShares = [
 			$this->makeMockShare(6, 102, 'user2', '/share6', 0),
@@ -173,12 +199,14 @@ class MountProviderTest extends \Test\TestCase {
 		$this->assertEquals(100, $mountedShare1->getNodeId());
 		$this->assertEquals('/share2', $mountedShare1->getTarget());
 		$this->assertEquals(31, $mountedShare1->getPermissions());
+		$this->assertEquals(true, $mountedShare1->getAttributes()->getAttribute('permission', 'download'));
 		$mountedShare2 = $mounts[1]->getShare();
 		$this->assertEquals('4', $mountedShare2->getId());
 		$this->assertEquals('user2', $mountedShare2->getShareOwner());
 		$this->assertEquals(101, $mountedShare2->getNodeId());
 		$this->assertEquals('/share4', $mountedShare2->getTarget());
 		$this->assertEquals(31, $mountedShare2->getPermissions());
+		$this->assertEquals(true, $mountedShare2->getAttributes()->getAttribute('permission', 'download'));
 		$mountedShare3 = $mounts[2]->getShare();
 		$this->assertEquals('8', $mountedShare3->getId());
 		$this->assertEquals('user2', $mountedShare3->getShareOwner());
@@ -200,27 +228,27 @@ class MountProviderTest extends \Test\TestCase {
 			// #0: share as outsider with "group1" and "user1" with same permissions
 			[
 				[
-					[1, 100, 'user2', '/share2', 31],
+					[1, 100, 'user2', '/share2', 31, null],
 				],
 				[
-					[2, 100, 'user2', '/share2', 31],
+					[2, 100, 'user2', '/share2', 31, null],
 				],
 				[
 					// combined, user share has higher priority
-					['1', 100, 'user2', '/share2', 31],
+					['1', 100, 'user2', '/share2', 31, []],
 				],
 			],
 			// #1: share as outsider with "group1" and "user1" with different permissions
 			[
 				[
-					[1, 100, 'user2', '/share', 31],
+					[1, 100, 'user2', '/share', 31, [['scope' => 'permission', 'key' => 'download', 'enabled' => true], ['scope' => 'app', 'key' => 'attribute1', 'enabled' => true]]],
 				],
 				[
-					[2, 100, 'user2', '/share', 15],
+					[2, 100, 'user2', '/share', 15, [['scope' => 'permission', 'key' => 'download', 'enabled' => false], ['scope' => 'app', 'key' => 'attribute2', 'enabled' => false]]],
 				],
 				[
 					// use highest permissions
-					['1', 100, 'user2', '/share', 31],
+					['1', 100, 'user2', '/share', 31, [['scope' => 'permission', 'key' => 'download', 'enabled' => true], ['scope' => 'app', 'key' => 'attribute1', 'enabled' => true], ['scope' => 'app', 'key' => 'attribute2', 'enabled' => false]]],
 				],
 			],
 			// #2: share as outsider with "group1" and "group2" with same permissions
@@ -228,12 +256,12 @@ class MountProviderTest extends \Test\TestCase {
 				[
 				],
 				[
-					[1, 100, 'user2', '/share', 31],
-					[2, 100, 'user2', '/share', 31],
+					[1, 100, 'user2', '/share', 31, null],
+					[2, 100, 'user2', '/share', 31, []],
 				],
 				[
 					// combined, first group share has higher priority
-					['1', 100, 'user2', '/share', 31],
+					['1', 100, 'user2', '/share', 31, []],
 				],
 			],
 			// #3: share as outsider with "group1" and "group2" with different permissions
@@ -241,12 +269,12 @@ class MountProviderTest extends \Test\TestCase {
 				[
 				],
 				[
-					[1, 100, 'user2', '/share', 31],
-					[2, 100, 'user2', '/share', 15],
+					[1, 100, 'user2', '/share', 31, [['scope' => 'permission', 'key' => 'download', 'enabled' => false]]],
+					[2, 100, 'user2', '/share', 15, [['scope' => 'permission', 'key' => 'download', 'enabled' => true]]],
 				],
 				[
-					// use higher permissions
-					['1', 100, 'user2', '/share', 31],
+					// use higher permissions (most permissive)
+					['1', 100, 'user2', '/share', 31, [['scope' => 'permission', 'key' => 'download', 'enabled' => true]]],
 				],
 			],
 			// #4: share as insider with "group1"
@@ -254,7 +282,7 @@ class MountProviderTest extends \Test\TestCase {
 				[
 				],
 				[
-					[1, 100, 'user1', '/share', 31],
+					[1, 100, 'user1', '/share', 31, []],
 				],
 				[
 					// no received share since "user1" is the sharer/owner
@@ -265,8 +293,8 @@ class MountProviderTest extends \Test\TestCase {
 				[
 				],
 				[
-					[1, 100, 'user1', '/share', 31],
-					[2, 100, 'user1', '/share', 15],
+					[1, 100, 'user1', '/share', 31, [['scope' => 'permission', 'key' => 'download', 'enabled' => true]]],
+					[2, 100, 'user1', '/share', 15, [['scope' => 'permission', 'key' => 'download', 'enabled' => false]]],
 				],
 				[
 					// no received share since "user1" is the sharer/owner
@@ -277,7 +305,7 @@ class MountProviderTest extends \Test\TestCase {
 				[
 				],
 				[
-					[1, 100, 'user2', '/share', 0],
+					[1, 100, 'user2', '/share', 0, []],
 				],
 				[
 					// no received share since "user1" opted out
@@ -286,40 +314,40 @@ class MountProviderTest extends \Test\TestCase {
 			// #7: share as outsider with "group1" and "user1" where recipient renamed in between
 			[
 				[
-					[1, 100, 'user2', '/share2-renamed', 31],
+					[1, 100, 'user2', '/share2-renamed', 31, []],
 				],
 				[
-					[2, 100, 'user2', '/share2', 31],
+					[2, 100, 'user2', '/share2', 31, []],
 				],
 				[
 					// use target of least recent share
-					['1', 100, 'user2', '/share2-renamed', 31],
+					['1', 100, 'user2', '/share2-renamed', 31, []],
 				],
 			],
 			// #8: share as outsider with "group1" and "user1" where recipient renamed in between
 			[
 				[
-					[2, 100, 'user2', '/share2', 31],
+					[2, 100, 'user2', '/share2', 31, []],
 				],
 				[
-					[1, 100, 'user2', '/share2-renamed', 31],
+					[1, 100, 'user2', '/share2-renamed', 31, []],
 				],
 				[
 					// use target of least recent share
-					['1', 100, 'user2', '/share2-renamed', 31],
+					['1', 100, 'user2', '/share2-renamed', 31, []],
 				],
 			],
 			// #9: share as outsider with "nullgroup" and "user1" where recipient renamed in between
 			[
 				[
-					[2, 100, 'user2', '/share2', 31],
+					[2, 100, 'user2', '/share2', 31, []],
 				],
 				[
-					[1, 100, 'nullgroup', '/share2-renamed', 31],
+					[1, 100, 'nullgroup', '/share2-renamed', 31, []],
 				],
 				[
 					// use target of least recent share
-					['1', 100, 'nullgroup', '/share2-renamed', 31],
+					['1', 100, 'nullgroup', '/share2-renamed', 31, []],
 				],
 				true
 			],
@@ -400,6 +428,11 @@ class MountProviderTest extends \Test\TestCase {
 			$this->assertEquals($expectedShare[2], $share->getShareOwner());
 			$this->assertEquals($expectedShare[3], $share->getTarget());
 			$this->assertEquals($expectedShare[4], $share->getPermissions());
+			if ($expectedShare[5] === null) {
+				$this->assertNull($share->getAttributes());
+			} else {
+				$this->assertEquals($expectedShare[5], $share->getAttributes()->toArray());
+			}
 		}
 	}
 }