fix(isLegitimatedForUserId): Setup mountpoints to check file access

This fixes workflows on groupfolders, as it will consider access to
files in groupfolders.

It also fixes false positives where access to files was limited by other
means not taken into account before, e.g. access control.

For postDelete events, check for permissions of the parent folder
instead, as the file itself no longer exists.

Fixes: nextcloud/flow_notifications#71

Signed-off-by: Jonas <jonas@freesources.org>

apps/workflowengine/lib/Entity/File.php

@@ -26,6 +26,7 @@
  */
 namespace OCA\WorkflowEngine\Entity;
 
+use OC\Files\Config\UserMountCache;
 use OCP\EventDispatcher\Event;
 use OCP\EventDispatcher\GenericEvent;
 use OCP\Files\InvalidPathException;
@@ -37,7 +38,6 @@
 use OCP\IUser;
 use OCP\IUserManager;
 use OCP\IUserSession;
-use OCP\Share\IManager as ShareManager;
 use OCP\SystemTag\ISystemTag;
 use OCP\SystemTag\ISystemTagManager;
 use OCP\SystemTag\MapperEvent;
@@ -62,8 +62,6 @@ class File implements IEntity, IDisplayText, IUrl, IIcon, IContextPortation {
 	protected $eventName;
 	/** @var Event */
 	protected $event;
-	/** @var ShareManager */
-	private $shareManager;
 	/** @var IUserSession */
 	private $userSession;
 	/** @var ISystemTagManager */
@@ -74,23 +72,25 @@ class File implements IEntity, IDisplayText, IUrl, IIcon, IContextPortation {
 	private $actingUser = null;
 	/** @var IUserManager */
 	private $userManager;
+	/** @var UserMountCache */
+	private $userMountCache;
 
 	public function __construct(
 		IL10N $l10n,
 		IURLGenerator $urlGenerator,
 		IRootFolder $root,
-		ShareManager $shareManager,
 		IUserSession $userSession,
 		ISystemTagManager $tagManager,
-		IUserManager $userManager
+		IUserManager $userManager,
+		UserMountCache $userMountCache
 	) {
 		$this->l10n = $l10n;
 		$this->urlGenerator = $urlGenerator;
 		$this->root = $root;
-		$this->shareManager = $shareManager;
 		$this->userSession = $userSession;
 		$this->tagManager = $tagManager;
 		$this->userManager = $userManager;
+		$this->userMountCache = $userMountCache;
 	}
 
 	public function getName(): string {
@@ -135,8 +135,22 @@ public function isLegitimatedForUserId(string $uid): bool {
 			if ($node->getOwner()->getUID() === $uid) {
 				return true;
 			}
-			$acl = $this->shareManager->getAccessList($node, true, true);
-			return isset($acl['users']) && array_key_exists($uid, $acl['users']);
+
+			if ($this->eventName === self::EVENT_NAMESPACE . 'postDelete') {
+				// At postDelete, the file no longer exists. Check for parent folder instead.
+				$fileId = $node->getParentId();
+			} else {
+				$fileId = $node->getId();
+			}
+
+			$mounts = $this->userMountCache->getMountsForFileId($fileId, $uid);
+			foreach ($mounts as $mount) {
+				$userFolder = $this->root->getUserFolder($uid);
+				if (!empty($userFolder->getById($fileId))) {
+					return true;
+				}
+			}
+			return false;
 		} catch (NotFoundException $e) {
 			return false;
 		}

apps/workflowengine/tests/ManagerTest.php

@@ -26,6 +26,7 @@
  */
 namespace OCA\WorkflowEngine\Tests;
 
+use OC\Files\Config\UserMountCache;
 use OC\L10N\L10N;
 use OCA\WorkflowEngine\Entity\File;
 use OCA\WorkflowEngine\Helper\ScopeContext;
@@ -403,10 +404,10 @@ public function testUpdateOperation() {
 							$this->l,
 							$this->createMock(IURLGenerator::class),
 							$this->createMock(IRootFolder::class),
-							$this->createMock(\OCP\Share\IManager::class),
 							$this->createMock(IUserSession::class),
 							$this->createMock(ISystemTagManager::class),
 							$this->createMock(IUserManager::class),
+							$this->createMock(UserMountCache::class),
 						])
 						->setMethodsExcept(['getEvents'])
 						->getMock();