Add an occ command to scan files for legacy file key in use and get rid of those

apps/encryption/appinfo/info.xml

@@ -42,6 +42,7 @@ Please read the documentation to know all implications before you decide to enab
 		<command>OCA\Encryption\Command\ScanLegacyFormat</command>
 		<command>OCA\Encryption\Command\FixEncryptedVersion</command>
 		<command>OCA\Encryption\Command\FixKeyLocation</command>
+		<command>OCA\Encryption\Command\DropLegacyFileKey</command>
 	</commands>
 
 	<settings>

apps/encryption/composer/composer/autoload_classmap.php

@@ -9,6 +9,7 @@
     'Composer\\InstalledVersions' => $vendorDir . '/composer/InstalledVersions.php',
     'OCA\\Encryption\\AppInfo\\Application' => $baseDir . '/../lib/AppInfo/Application.php',
     'OCA\\Encryption\\Command\\DisableMasterKey' => $baseDir . '/../lib/Command/DisableMasterKey.php',
+    'OCA\\Encryption\\Command\\DropLegacyFileKey' => $baseDir . '/../lib/Command/DropLegacyFileKey.php',
     'OCA\\Encryption\\Command\\EnableMasterKey' => $baseDir . '/../lib/Command/EnableMasterKey.php',
     'OCA\\Encryption\\Command\\FixEncryptedVersion' => $baseDir . '/../lib/Command/FixEncryptedVersion.php',
     'OCA\\Encryption\\Command\\FixKeyLocation' => $baseDir . '/../lib/Command/FixKeyLocation.php',

apps/encryption/composer/composer/autoload_static.php

@@ -24,6 +24,7 @@ class ComposerStaticInitEncryption
         'Composer\\InstalledVersions' => __DIR__ . '/..' . '/composer/InstalledVersions.php',
         'OCA\\Encryption\\AppInfo\\Application' => __DIR__ . '/..' . '/../lib/AppInfo/Application.php',
         'OCA\\Encryption\\Command\\DisableMasterKey' => __DIR__ . '/..' . '/../lib/Command/DisableMasterKey.php',
+        'OCA\\Encryption\\Command\\DropLegacyFileKey' => __DIR__ . '/..' . '/../lib/Command/DropLegacyFileKey.php',
         'OCA\\Encryption\\Command\\EnableMasterKey' => __DIR__ . '/..' . '/../lib/Command/EnableMasterKey.php',
         'OCA\\Encryption\\Command\\FixEncryptedVersion' => __DIR__ . '/..' . '/../lib/Command/FixEncryptedVersion.php',
         'OCA\\Encryption\\Command\\FixKeyLocation' => __DIR__ . '/..' . '/../lib/Command/FixKeyLocation.php',

apps/encryption/composer/composer/installed.php

@@ -3,7 +3,7 @@
         'name' => '__root__',
         'pretty_version' => 'dev-master',
         'version' => 'dev-master',
-        'reference' => 'dd3d689e04a5e1d558da937ca72980e0e2c7c404',
+        'reference' => 'ffa8d21f37c8ccf968974b6aeb828e3e84287b94',
         'type' => 'library',
         'install_path' => __DIR__ . '/../',
         'aliases' => array(),
@@ -13,7 +13,7 @@
         '__root__' => array(
             'pretty_version' => 'dev-master',
             'version' => 'dev-master',
-            'reference' => 'dd3d689e04a5e1d558da937ca72980e0e2c7c404',
+            'reference' => 'ffa8d21f37c8ccf968974b6aeb828e3e84287b94',
             'type' => 'library',
             'install_path' => __DIR__ . '/../',
             'aliases' => array(),

apps/encryption/lib/Command/DropLegacyFileKey.php

@@ -0,0 +1,167 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2023, Côme Chilliet <[email protected]>
+ *
+ * @author Côme Chilliet <[email protected]>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * 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
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OCA\Encryption\Command;
+
+use OC\Encryption\Exceptions\DecryptionFailedException;
+use OC\Files\FileInfo;
+use OC\Files\View;
+use OCA\Encryption\KeyManager;
+use OCP\Encryption\Exceptions\GenericEncryptionException;
+use OCP\IUserManager;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+
+class DropLegacyFileKey extends Command {
+	private View $rootView;
+
+	public function __construct(
+		private IUserManager $userManager,
+		private KeyManager $keyManager,
+	) {
+		parent::__construct();
+
+		$this->rootView = new View();
+	}
+
+	protected function configure(): void {
+		$this
+			->setName('encryption:drop-legacy-filekey')
+			->setDescription('Scan the files for the legacy filekey format using RC4 and get rid of it (if master key is enabled)');
+	}
+
+	protected function execute(InputInterface $input, OutputInterface $output): int {
+		$result = true;
+
+		$output->writeln('<info>Scanning all files for legacy filekey</info>');
+
+		foreach ($this->userManager->getBackends() as $backend) {
+			$limit = 500;
+			$offset = 0;
+			do {
+				$users = $backend->getUsers('', $limit, $offset);
+				foreach ($users as $user) {
+					$output->writeln('Scanning all files for ' . $user);
+					$this->setupUserFS($user);
+					$result = $result && $this->scanFolder($output, '/' . $user);
+				}
+				$offset += $limit;
+			} while (count($users) >= $limit);
+		}
+
+		if ($result) {
+			$output->writeln('All scanned files are properly encrypted.');
+			return 0;
+		}
+
+		return 1;
+	}
+
+	private function scanFolder(OutputInterface $output, string $folder): bool {
+		$clean = true;
+
+		foreach ($this->rootView->getDirectoryContent($folder) as $item) {
+			$path = $folder . '/' . $item['name'];
+			if ($this->rootView->is_dir($path)) {
+				if ($this->scanFolder($output, $path) === false) {
+					$clean = false;
+				}
+			} else {
+				if (!$item->isEncrypted()) {
+					// ignore
+					continue;
+				}
+
+				$stats = $this->rootView->stat($path);
+				if (!isset($stats['hasHeader']) || $stats['hasHeader'] === false) {
+					$clean = false;
+					$output->writeln('<error>' . $path . ' does not have a proper header</error>');
+				} else {
+					try {
+						$legacyFileKey = $this->keyManager->getFileKey($path, null, true);
+						if ($legacyFileKey === '') {
+							$output->writeln('Got an empty legacy filekey for ' . $path . ', continuing', OutputInterface::VERBOSITY_VERBOSE);
+							continue;
+						}
+					} catch (GenericEncryptionException $e) {
+						$output->writeln('Got a decryption error for legacy filekey for ' . $path . ', continuing', OutputInterface::VERBOSITY_VERBOSE);
+						continue;
+					}
+					/* If that did not throw and filekey is not empty, a legacy filekey is used */
+					$clean = false;
+					$output->writeln($path . ' is using a legacy filekey, migrating');
+					$this->migrateSinglefile($path, $item, $output);
+				}
+			}
+		}
+
+		return $clean;
+	}
+
+	private function migrateSinglefile(string $path, FileInfo $fileInfo, OutputInterface $output): void {
+		$source = $path;
+		$target = $path . '.reencrypted.' . time();
+
+		try {
+			$this->rootView->copy($source, $target);
+			$copyResource = $this->rootView->fopen($target, 'r');
+			$sourceResource = $this->rootView->fopen($source, 'w');
+			if ($copyResource === false || $sourceResource === false) {
+				throw new DecryptionFailedException('Failed to open '.$source.' or '.$target);
+			}
+			if (stream_copy_to_stream($copyResource, $sourceResource) === false) {
+				$output->writeln('<error>Failed to copy '.$target.' data into '.$source.'</error>');
+				$output->writeln('<error>Leaving both files in there to avoid data loss</error>');
+				return;
+			}
+			$this->rootView->touch($source, $fileInfo->getMTime());
+			$this->rootView->unlink($target);
+			$output->writeln('<info>Migrated ' . $source . '</info>', OutputInterface::VERBOSITY_VERBOSE);
+		} catch (DecryptionFailedException $e) {
+			if ($this->rootView->file_exists($target)) {
+				$this->rootView->unlink($target);
+			}
+			$output->writeln('<error>Failed to migrate ' . $path . '</error>');
+			$output->writeln('<error>' . $e . '</error>', OutputInterface::VERBOSITY_VERBOSE);
+		} finally {
+			if (is_resource($copyResource)) {
+				fclose($copyResource);
+			}
+			if (is_resource($sourceResource)) {
+				fclose($sourceResource);
+			}
+		}
+	}
+
+	/**
+	 * setup user file system
+	 */
+	protected function setupUserFS(string $uid): void {
+		\OC_Util::tearDownFS();
+		\OC_Util::setupFS($uid);
+	}
+}

apps/encryption/lib/Command/ScanLegacyFormat.php

@@ -36,7 +36,6 @@
 use Symfony\Component\Console\Output\OutputInterface;
 
 class ScanLegacyFormat extends Command {
-
 	/** @var Util */
 	protected $util;
 
@@ -89,7 +88,7 @@ protected function execute(InputInterface $input, OutputInterface $output): int
 				foreach ($users as $user) {
 					$output->writeln('Scanning all files for ' . $user);
 					$this->setupUserFS($user);
-					$result &= $this->scanFolder($output, '/' . $user);
+					$result = $result && $this->scanFolder($output, '/' . $user);
 				}
 				$offset += $limit;
 			} while (count($users) >= $limit);

apps/encryption/lib/Crypto/Encryption.php

@@ -309,7 +309,12 @@ public function end($path, $position = '0') {
 
 			$publicKeys = $this->keyManager->addSystemKeys($this->accessList, $publicKeys, $this->getOwner($path));
 			$shareKeys = $this->crypt->multiKeyEncrypt($this->fileKey, $publicKeys);
-			$this->keyManager->deleteLegacyFileKey($this->path);
+			if (!$this->keyManager->deleteLegacyFileKey($this->path)) {
+				$this->logger->warning(
+					'Failed to delete legacy filekey for {path}',
+					['app' => 'encryption', 'path' => $path]
+				);
+			}
 			foreach ($shareKeys as $uid => $keyFile) {
 				$this->keyManager->setShareKey($this->path, $uid, $keyFile);
 			}