Make legacy cipher opt in

* Systems that upgrade have this enabled by default
* New systems disable it
* We'll have to add some wargning in the setup checks if this is enabled

Signed-off-by: Roeland Jago Douma <roeland@famdouma.nl>

Author: rullzer

apps/encryption/lib/Crypto/Crypt.php

@@ -32,6 +32,7 @@
 
 use OC\Encryption\Exceptions\DecryptionFailedException;
 use OC\Encryption\Exceptions\EncryptionFailedException;
+use OC\ServerNotAvailableException;
 use OCA\Encryption\Exceptions\MultiKeyDecryptException;
 use OCA\Encryption\Exceptions\MultiKeyEncryptException;
 use OCP\Encryption\Exceptions\GenericEncryptionException;
@@ -89,6 +90,9 @@ class Crypt {
 		'AES-128-CFB' => 16,
 	];
 
+	/** @var bool */
+	private $supportLegacy;
+
 	/**
 	 * @param ILogger $logger
 	 * @param IUserSession $userSession
@@ -101,6 +105,8 @@ public function __construct(ILogger $logger, IUserSession $userSession, IConfig
 		$this->config = $config;
 		$this->l = $l;
 		$this->supportedKeyFormats = ['hash', 'password'];
+
+		$this->supportLegacy = $this->config->getSystemValueBool('encryption.legacy_format_support', false);
 	}
 
 	/**
@@ -299,6 +305,10 @@ protected function getKeySize($cipher) {
 	 * @return string
 	 */
 	public function getLegacyCipher() {
+		if (!$this->supportLegacy) {
+			throw new ServerNotAvailableException('Legacy cipher is no longer supported!');
+		}
+
 		return self::LEGACY_CIPHER;
 	}
 
@@ -391,7 +401,7 @@ public function decryptPrivateKey($privateKey, $password = '', $uid = '') {
 		if (isset($header['cipher'])) {
 			$cipher = $header['cipher'];
 		} else {
-			$cipher = self::LEGACY_CIPHER;
+			$cipher = $this->getLegacyCipher();
 		}
 
 		if (isset($header['keyFormat'])) {
@@ -570,6 +580,11 @@ private function hasSignature($catFile, $cipher) {
 		$meta = substr($catFile, -93);
 		$signaturePosition = strpos($meta, '00sig00');
 
+		// If we no longer support the legacy format then everything needs a signature
+		if (!$skipSignatureCheck && !$this->supportLegacy && $signaturePosition === false) {
+			throw new GenericEncryptionException('Missing Signature', $this->l->t('Missing Signature'));
+		}
+
 		// enforce signature for the new 'CTR' ciphers
 		if (!$skipSignatureCheck && $signaturePosition === false && stripos($cipher, 'ctr') !== false) {
 			throw new GenericEncryptionException('Missing Signature', $this->l->t('Missing Signature'));

lib/composer/composer/autoload_classmap.php

@@ -1245,6 +1245,7 @@
     'OC\\Repair\\NC16\\CleanupCardDAVPhotoCache' => $baseDir . '/lib/private/Repair/NC16/CleanupCardDAVPhotoCache.php',
     'OC\\Repair\\NC16\\ClearCollectionsAccessCache' => $baseDir . '/lib/private/Repair/NC16/ClearCollectionsAccessCache.php',
     'OC\\Repair\\NC18\\ResetGeneratedAvatarFlag' => $baseDir . '/lib/private/Repair/NC18/ResetGeneratedAvatarFlag.php',
+    'OC\\Repair\\NC20\\EncryptionLegacyCipher' => $baseDir . '/lib/private/Repair/NC20/EncryptionLegacyCipher.php',
     'OC\\Repair\\OldGroupMembershipShares' => $baseDir . '/lib/private/Repair/OldGroupMembershipShares.php',
     'OC\\Repair\\Owncloud\\DropAccountTermsTable' => $baseDir . '/lib/private/Repair/Owncloud/DropAccountTermsTable.php',
     'OC\\Repair\\Owncloud\\SaveAccountsTableData' => $baseDir . '/lib/private/Repair/Owncloud/SaveAccountsTableData.php',

lib/composer/composer/autoload_static.php

@@ -1274,6 +1274,7 @@ class ComposerStaticInit53792487c5a8370acc0b06b1a864ff4c
         'OC\\Repair\\NC16\\CleanupCardDAVPhotoCache' => __DIR__ . '/../../..' . '/lib/private/Repair/NC16/CleanupCardDAVPhotoCache.php',
         'OC\\Repair\\NC16\\ClearCollectionsAccessCache' => __DIR__ . '/../../..' . '/lib/private/Repair/NC16/ClearCollectionsAccessCache.php',
         'OC\\Repair\\NC18\\ResetGeneratedAvatarFlag' => __DIR__ . '/../../..' . '/lib/private/Repair/NC18/ResetGeneratedAvatarFlag.php',
+        'OC\\Repair\\NC20\\EncryptionLegacyCipher' => __DIR__ . '/../../..' . '/lib/private/Repair/NC20/EncryptionLegacyCipher.php',
         'OC\\Repair\\OldGroupMembershipShares' => __DIR__ . '/../../..' . '/lib/private/Repair/OldGroupMembershipShares.php',
         'OC\\Repair\\Owncloud\\DropAccountTermsTable' => __DIR__ . '/../../..' . '/lib/private/Repair/Owncloud/DropAccountTermsTable.php',
         'OC\\Repair\\Owncloud\\SaveAccountsTableData' => __DIR__ . '/../../..' . '/lib/private/Repair/Owncloud/SaveAccountsTableData.php',

lib/private/Repair.php

@@ -48,6 +48,7 @@
 use OC\Repair\NC16\CleanupCardDAVPhotoCache;
 use OC\Repair\NC16\ClearCollectionsAccessCache;
 use OC\Repair\NC18\ResetGeneratedAvatarFlag;
+use OC\Repair\NC20\EncryptionLegacyCipher;
 use OC\Repair\OldGroupMembershipShares;
 use OC\Repair\Owncloud\DropAccountTermsTable;
 use OC\Repair\Owncloud\SaveAccountsTableData;
@@ -156,6 +157,7 @@ public static function getRepairSteps() {
 			new RemoveLinkShares(\OC::$server->getDatabaseConnection(), \OC::$server->getConfig(), \OC::$server->getGroupManager(), \OC::$server->getNotificationManager(), \OC::$server->query(ITimeFactory::class)),
 			new ClearCollectionsAccessCache(\OC::$server->getConfig(), \OC::$server->query(IManager::class)),
 			\OC::$server->query(ResetGeneratedAvatarFlag::class),
+			\OC::$server->query(EncryptionLegacyCipher::class),
 		];
 	}
 

lib/private/Repair/NC20/EncryptionLegacyCipher.php

@@ -0,0 +1,62 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * @copyright Copyright (c) 2020, Roeland Jago Douma <roeland@famdouma.nl>
+ *
+ * @author Roeland Jago Douma <roeland@famdouma.nl>
+ *
+ * @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 OC\Repair\NC20;
+
+use OCP\Encryption\IManager;
+use OCP\IConfig;
+use OCP\Migration\IOutput;
+use OCP\Migration\IRepairStep;
+
+class EncryptionLegacyCipher implements IRepairStep {
+
+	/** @var IConfig */
+	private $config;
+	/** @var IManager */
+	private $manager;
+
+	public function __construct(IConfig $config,
+								IManager $manager) {
+		$this->config = $config;
+		$this->manager = $manager;
+	}
+
+	public function getName(): string {
+		return 'Keep legacy encryption enabled';
+	}
+
+	private function shouldRun(): bool {
+		$versionFromBeforeUpdate = $this->config->getSystemValue('version', '0.0.0.0');
+		return version_compare($versionFromBeforeUpdate, '20.0.0.0', '<=');
+	}
+
+	public function run(IOutput $output): void {
+		if ($this->manager->isEnabled()) {
+			if ($this->config->getSystemValue('encryption.legacy_format_support', '') === '') {
+				$this->config->setSystemValue('encryption.legacy_format_support', true);
+			}
+		}
+	}
+}

version.php

@@ -29,7 +29,7 @@
 // between betas, final and RCs. This is _not_ the public version number. Reset minor/patchlevel
 // when updating major/minor version number.
 
-$OC_Version = [20, 0, 0, 0];
+$OC_Version = [20, 0, 0, 1];
 
 // The human readable string
 $OC_VersionString = '20.0.0 alpha';