Unify the permission checking in one place only

Signed-off-by: Joas Schilling <coding@schilljs.com>

apps/files_sharing/lib/Controller/ShareAPIController.php

@@ -971,41 +971,13 @@ class ShareAPIController extends OCSController {
 				}
 				$share->setExpirationDate($expireDate);
 			}
-
 		}
 
-		if ($permissions !== null && $share->getShareOwner() !== $this->currentUser) {
-
-			// Get the root mount point for the user and check the share permissions there
-			$userFolder = $this->rootFolder->getUserFolder($this->currentUser);
-			$userNodes = $userFolder->getById($share->getNodeId());
-			$userNode = array_shift($userNodes);
-
-			$userMountPointId = $userNode->getMountPoint()->getStorageRootId();
-			$userMountPoints = $userFolder->getById($userMountPointId);
-			$userMountPoint = array_shift($userMountPoints);
-
-			/* Check if this is an incoming share */
-			$incomingShares = $this->shareManager->getSharedWith($this->currentUser, Share::SHARE_TYPE_USER, $userMountPoint, -1, 0);
-			$incomingShares = array_merge($incomingShares, $this->shareManager->getSharedWith($this->currentUser, Share::SHARE_TYPE_GROUP, $userMountPoint, -1, 0));
-			$incomingShares = array_merge($incomingShares, $this->shareManager->getSharedWith($this->currentUser, Share::SHARE_TYPE_ROOM, $userMountPoint, -1, 0));
-
-			/** @var \OCP\Share\IShare[] $incomingShares */
-			if (!empty($incomingShares)) {
-				$maxPermissions = 0;
-				foreach ($incomingShares as $incomingShare) {
-					$maxPermissions |= $incomingShare->getPermissions();
-				}
-
-				if ($share->getPermissions() & ~$maxPermissions) {
-					throw new OCSNotFoundException($this->l->t('Cannot increase permissions'));
-				}
-			}
-		}
-
-
 		try {
 			$share = $this->shareManager->updateShare($share);
+		} catch (GenericShareException $e) {
+			$code = $e->getCode() === 0 ? 403 : $e->getCode();
+			throw new OCSException($e->getHint(), $code);
 		} catch (\Exception $e) {
 			throw new OCSBadRequestException($e->getMessage(), $e);
 		}

apps/files_sharing/tests/Controller/ShareAPIControllerTest.php

@@ -28,6 +28,7 @@ namespace OCA\Files_Sharing\Tests\Controller;
 
 use OCP\App\IAppManager;
 use OCP\AppFramework\Http\DataResponse;
+use OCP\AppFramework\OCS\OCSException;
 use OCP\AppFramework\OCS\OCSNotFoundException;
 use OCP\Files\File;
 use OCP\Files\Folder;
@@ -45,6 +46,7 @@ use OCP\IURLGenerator;
 use OCP\IUser;
 use OCP\Files\IRootFolder;
 use OCP\Lock\LockedException;
+use OCP\Share\Exceptions\GenericShareException;
 use OCP\Share\IManager;
 use OCP\Share;
 use Test\TestCase;
@@ -2418,13 +2420,16 @@ class ShareAPIControllerTest extends TestCase {
 		$mountPoint->method('getStorageRootId')
 			->willReturn(42);
 
-		$this->shareManager->expects($this->never())->method('updateShare');
+		$this->shareManager->expects($this->once())
+			->method('updateShare')
+			->with($share)
+			->willThrowException(new GenericShareException('Can’t increase permissions of path/file', 'Can’t increase permissions of path/file', 404));
 
 		try {
 			$ocs->updateShare(42, 31);
 			$this->fail();
-		} catch (OCSNotFoundException $e) {
-			$this->assertEquals('Cannot increase permissions', $e->getMessage());
+		} catch (OCSException $e) {
+			$this->assertEquals('Can’t increase permissions of path/file', $e->getMessage());
 		}
 	}
 

lib/private/Share20/Manager.php

@@ -290,16 +290,9 @@ class Manager implements IManager {
 			throw new \InvalidArgumentException('A share requires permissions');
 		}
 
-		/*
-		 * Quick fix for #23536
-		 * Non moveable mount points do not have update and delete permissions
-		 * while we 'most likely' do have that on the storage.
-		 */
-		$permissions = $share->getNode()->getPermissions();
 		$mount = $share->getNode()->getMountPoint();
-		if (!($mount instanceof MoveableMount)) {
-			$permissions |= \OCP\Constants::PERMISSION_DELETE | \OCP\Constants::PERMISSION_UPDATE;
-		} else if ($share->getNode()->getOwner()->getUID() !== $share->getSharedBy()) {
+		if ($share->getNode()->getOwner()->getUID() !== $share->getSharedBy()) {
+			// When it's a reshare use the parent share permissions as maximum
 			$userMountPointId = $mount->getStorageRootId();
 			$userMountPoints = $userFolder->getById($userMountPointId);
 			$userMountPoint = array_shift($userMountPoints);
@@ -316,6 +309,16 @@ class Manager implements IManager {
 					$permissions |= $incomingShare->getPermissions();
 				}
 			}
+		} else {
+			/*
+			 * Quick fix for #23536
+			 * Non moveable mount points do not have update and delete permissions
+			 * while we 'most likely' do have that on the storage.
+			 */
+			$permissions = $share->getNode()->getPermissions();
+			if (!($mount instanceof MoveableMount)) {
+				$permissions |= \OCP\Constants::PERMISSION_DELETE | \OCP\Constants::PERMISSION_UPDATE;
+			}
 		}
 
 		// Check that we do not share with more permissions than we have

tests/lib/Share20/ManagerTest.php

@@ -546,6 +546,9 @@ class ManagerTest extends \Test\TestCase {
 		$user0 = 'user0';
 		$user2 = 'user1';
 		$group0 = 'group0';
+		$owner = $this->createMock(IUser::class);
+		$owner->method('getUID')
+			->willReturn($user0);
 
 		$file = $this->createMock(File::class);
 		$node = $this->createMock(Node::class);
@@ -580,6 +583,8 @@ class ManagerTest extends \Test\TestCase {
 		$nonShareAble = $this->createMock(Folder::class);
 		$nonShareAble->method('isShareable')->willReturn(false);
 		$nonShareAble->method('getPath')->willReturn('path');
+		$nonShareAble->method('getOwner')
+			->willReturn($owner);
 
 		$data[] = [$this->createShare(null, \OCP\Share::SHARE_TYPE_USER,  $nonShareAble, $user2, $user0, $user0, 31, null, null), 'You are not allowed to share path', true];
 		$data[] = [$this->createShare(null, \OCP\Share::SHARE_TYPE_GROUP, $nonShareAble, $group0, $user0, $user0, 31, null, null), 'You are not allowed to share path', true];
@@ -589,10 +594,6 @@ class ManagerTest extends \Test\TestCase {
 		$limitedPermssions->method('isShareable')->willReturn(true);
 		$limitedPermssions->method('getPermissions')->willReturn(\OCP\Constants::PERMISSION_READ);
 		$limitedPermssions->method('getPath')->willReturn('path');
-
-		$owner = $this->createMock(IUser::class);
-		$owner->method('getUID')
-			->willReturn($user0);
 		$limitedPermssions->method('getOwner')
 			->willReturn($owner);
 
@@ -611,6 +612,8 @@ class ManagerTest extends \Test\TestCase {
 		$nonMoveableMountPermssions->method('isShareable')->willReturn(true);
 		$nonMoveableMountPermssions->method('getPermissions')->willReturn(\OCP\Constants::PERMISSION_READ);
 		$nonMoveableMountPermssions->method('getPath')->willReturn('path');
+		$nonMoveableMountPermssions->method('getOwner')
+			->willReturn($owner);
 
 		$data[] = [$this->createShare(null, \OCP\Share::SHARE_TYPE_USER,  $nonMoveableMountPermssions, $user2, $user0, $user0, 11, null, null), 'Can’t increase permissions of path', false];
 		$data[] = [$this->createShare(null, \OCP\Share::SHARE_TYPE_GROUP, $nonMoveableMountPermssions, $group0, $user0, $user0, 11, null, null), 'Can’t increase permissions of path', false];
@@ -627,6 +630,8 @@ class ManagerTest extends \Test\TestCase {
 		$allPermssions = $this->createMock(Folder::class);
 		$allPermssions->method('isShareable')->willReturn(true);
 		$allPermssions->method('getPermissions')->willReturn(\OCP\Constants::PERMISSION_ALL);
+		$allPermssions->method('getOwner')
+			->willReturn($owner);
 
 		$data[] = [$this->createShare(null, \OCP\Share::SHARE_TYPE_USER,  $allPermssions, $user2, $user0, $user0, 30, null, null), 'Shares need at least read permissions', true];
 		$data[] = [$this->createShare(null, \OCP\Share::SHARE_TYPE_GROUP, $allPermssions, $group0, $user0, $user0, 2, null, null), 'Shares need at least read permissions', true];