Restore encrypted version to original if no fix was found

CHANGELOG.md

@@ -6,8 +6,12 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 
 ## [Unreleased] - XXXX-XX-XX
 
+### Fixed
+
 - Use legacy-encoding setting for HSM also [#269](https://github.com/owncloud/encryption/issues/269)
 
+- `fix-encrypted-version` command restores value to original if no fix is found  [#269](https://github.com/owncloud/encryption/issues/269)
+
 ## [1.5.0] - 2021-03-11
 
 ### Added

lib/Command/FixEncryptedVersion.php

@@ -1,6 +1,7 @@
 <?php
 /**
  * @author Sujith Haridasan <[email protected]>
+ * @author Ilja Neumann <[email protected]>
  *
  * @copyright Copyright (c) 2019, ownCloud GmbH
  * @license AGPL-3.0
@@ -185,6 +186,8 @@ private function correctEncryptedVersion($path, OutputInterface $output) {
 			return true;
 		}
 
+		// Save original encrypted version so we can restore it if decryption fails with all version
+		$originalEncryptedVersion = $encryptedVersion;
 		if ($encryptedVersion >= 0) {
 			//test by decrementing the value till 1 and if nothing works try incrementing
 			$encryptedVersion--;
@@ -222,6 +225,11 @@ private function correctEncryptedVersion($path, OutputInterface $output) {
 				$increment++;
 			}
 		}
+
+		$cacheInfo = ['encryptedVersion' => $originalEncryptedVersion, 'encrypted' => $originalEncryptedVersion];
+		$cache->put($fileCache->getPath(), $cacheInfo);
+		$output->writeln("<info>No fix found for $path, restored version to original: $originalEncryptedVersion</info>");
+
 		return false;
 	}
 

tests/unit/Command/FixEncryptedVersionTest.php

@@ -273,6 +273,34 @@ public function testEncryptedVersionGreaterThanOriginalValue() {
 Fixed the file: /test_enc_version_affected_user1/files/world.txt with version 9", $output);
 	}
 
+	public function testVersionIsRestoredToOriginalIfNoFixIsFound() {
+		\OC::$server->getUserSession()->login(self::TEST_ENCRYPTION_VERSION_AFFECTED_USER, 'foo');
+		$view = new View("/" . self::TEST_ENCRYPTION_VERSION_AFFECTED_USER . "/files");
+
+		$view->touch('bar.txt');
+		for ($i=0; $i < 40; $i++) {
+			$view->file_put_contents('bar.txt', 'a test string for hello ' . $i);
+		}
+
+		$fileInfo = $view->getFileInfo('bar.txt');
+
+		$storage = $fileInfo->getStorage();
+		$cache = $storage->getCache();
+		$fileCache = $cache->get($fileInfo->getId());
+
+		$cacheInfo = ['encryptedVersion' => 15, 'encrypted' => 15];
+		$cache->put($fileCache->getPath(), $cacheInfo);
+
+		$this->commandTester->execute([
+			'user' => self::TEST_ENCRYPTION_VERSION_AFFECTED_USER
+		]);
+
+		$cacheInfo = $cache->get($fileInfo->getId());
+		$encryptedVersion = $cacheInfo["encryptedVersion"];
+
+		$this->assertEquals(15, $encryptedVersion);
+	}
+
 	/**
 	 * Test commands with a file path
 	 */