1 files changed, 150 insertions, 0 deletions
diff --git a/apps/encryption/lib/Command/DropLegacyFileKey.php b/apps/encryption/lib/Command/DropLegacyFileKey.php
new file mode 100644
index 00000000000..a9add1ad93b
--- /dev/null
+++ b/apps/encryption/lib/Command/DropLegacyFileKey.php
@@ -0,0 +1,150 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2023 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+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 self::SUCCESS;
+		}
+
+		return self::FAILURE;
+	}
+
+	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);
+	}
+}