fix: always validate share token if provided

Signed-off-by: Benjamin Frueh <benjamin.frueh@gmail.com>

Author: benjaminfrueh

lib/Middleware/SessionMiddleware.php

@@ -116,13 +116,9 @@ private function assertDocumentSession(ISessionAwareController $controller): voi
 	 */
 	private function assertUserOrShareToken(ISessionAwareController $controller): void {
 		$documentId = (int)$this->request->getParam('documentId');
-		if (null !== $userId = $this->userSession->getUser()?->getUID()) {
-			// Check if user has access to document
-			if (count($this->rootFolder->getUserFolder($userId)->getById($documentId)) === 0) {
-				throw new InvalidSessionException();
-			}
-			$controller->setUserId($userId);
-		} elseif ('' !== $shareToken = (string)$this->request->getParam('shareToken')) {
+		$shareToken = (string)$this->request->getParam('shareToken');
+
+		if ($shareToken !== '') {
 			try {
 				$share = $this->shareManager->getShareByToken($shareToken);
 			} catch (ShareNotFound) {
@@ -136,8 +132,9 @@ private function assertUserOrShareToken(ISessionAwareController $controller): vo
 
 			/** @psalm-suppress RedundantConditionGivenDocblockType */
 			if ($share->getPassword() !== null) {
-				$shareId = $this->session->get('public_link_authenticated');
-				if ($share->getId() !== $shareId) {
+				$shareIds = $this->session->get('public_link_authenticated');
+				$shareIds = is_array($shareIds) ? $shareIds : [$shareIds];
+				if (!in_array($share->getId(), $shareIds, true)) {
 					throw new InvalidSessionException();
 				}
 			}
@@ -150,6 +147,12 @@ private function assertUserOrShareToken(ISessionAwareController $controller): vo
 			if ($attributes !== null && $attributes->getAttribute('permissions', 'download') === false) {
 				throw new InvalidSessionException();
 			}
+		} elseif (null !== $userId = $this->userSession->getUser()?->getUID()) {
+			// Check if user has access to document
+			if (count($this->rootFolder->getUserFolder($userId)->getById($documentId)) === 0) {
+				throw new InvalidSessionException();
+			}
+			$controller->setUserId($userId);
 		} else {
 			throw new InvalidSessionException();
 		}