1 files changed, 29 insertions, 28 deletions

diff --git a/lib/private/Encryption/Util.php b/lib/private/Encryption/Util.php
index a828483265b..2d7bc28129b 100644
--- a/lib/private/Encryption/Util.php
+++ b/lib/private/Encryption/Util.php
@@ -1,29 +1,9 @@
 <?php
+
 /**
- * @copyright Copyright (c) 2016, ownCloud, Inc.
- *
- * @author Bjoern Schiessle <bjoern@schiessle.org>
- * @author Björn Schießle <bjoern@schiessle.org>
- * @author Christoph Wurst <christoph@winzerhof-wurst.at>
- * @author Jan-Christoph Borchardt <hey@jancborchardt.net>
- * @author Morris Jobke <hey@morrisjobke.de>
- * @author Roeland Jago Douma <roeland@famdouma.nl>
- * @author Thomas Müller <thomas.mueller@tmit.eu>
- *
- * @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/>
- *
+ * SPDX-FileCopyrightText: 2016-2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-FileCopyrightText: 2016 ownCloud, Inc.
+ * SPDX-License-Identifier: AGPL-3.0-only
  */
 namespace OC\Encryption;
 
@@ -105,7 +85,7 @@ class Util {
 	 * @return string
 	 * @throws ModuleDoesNotExistsException
 	 */
-	public function getEncryptionModuleId(array $header = null) {
+	public function getEncryptionModuleId(?array $header = null) {
 		$id = '';
 		$encryptionModuleKey = self::HEADER_ENCRYPTION_MODULE_KEY;
 
@@ -310,8 +290,8 @@ class Util {
 		if (count($root) > 1) {
 			// detect alternative key storage root
 			$rootDir = $this->getKeyStorageRoot();
-			if ($rootDir !== '' &&
-				str_starts_with(Filesystem::normalizePath($path), Filesystem::normalizePath($rootDir))
+			if ($rootDir !== ''
+				&& str_starts_with(Filesystem::normalizePath($path), Filesystem::normalizePath($rootDir))
 			) {
 				return true;
 			}
@@ -324,7 +304,7 @@ class Util {
 
 			// detect user specific folders
 			if ($this->userManager->userExists($root[1])
-				&& in_array($root[2], $this->excludedPaths)) {
+				&& in_array($root[2] ?? '', $this->excludedPaths)) {
 				return true;
 			}
 		}
@@ -385,4 +365,25 @@ class Util {
 
 		return $result;
 	}
+
+	/**
+	 * get path to key folder for a given file
+	 *
+	 * @param string $encryptionModuleId
+	 * @param string $path path to the file, relative to data/
+	 * @return string
+	 */
+	public function getFileKeyDir(string $encryptionModuleId, string $path): string {
+		[$owner, $filename] = $this->getUidAndFilename($path);
+		$root = $this->getKeyStorageRoot();
+
+		// in case of system-wide mount points the keys are stored directly in the data directory
+		if ($this->isSystemWideMountPoint($filename, $owner)) {
+			$keyPath = $root . '/' . '/files_encryption/keys' . $filename . '/';
+		} else {
+			$keyPath = $root . '/' . $owner . '/files_encryption/keys' . $filename . '/';
+		}
+
+		return Filesystem::normalizePath($keyPath . $encryptionModuleId . '/', false);
+	}
 }