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>

2 files changed, 24 insertions, 9 deletions

diff --git a/apps/workflowengine/lib/Entity/File.php b/apps/workflowengine/lib/Entity/File.php
index 5a2549b1f65..0f47928eb22 100644
--- a/apps/workflowengine/lib/Entity/File.php
+++ b/apps/workflowengine/lib/Entity/File.php
@@ -26,6 +26,7 @@ declare(strict_types=1);
  */
 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\IURLGenerator;
 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 @@ class File implements IEntity, IDisplayText, IUrl, IIcon, IContextPortation {
 			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;
 		}
diff --git a/apps/workflowengine/tests/ManagerTest.php b/apps/workflowengine/tests/ManagerTest.php
index fd95f024acd..7d25bdc1e5b 100644
--- a/apps/workflowengine/tests/ManagerTest.php
+++ b/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 @@ class ManagerTest extends TestCase {
 							$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();