add occ command to disable the master key again

Signed-off-by: Bjoern Schiessle <bjoern@schiessle.org>

apps/encryption/lib/Command/DisableMasterKey.php

@@ -0,0 +1,89 @@
+<?php
+/**
+ * @copyright Copyright (c) 2017 Bjoern Schiessle <bjoern@schiessle.org>
+ *
+ * @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 OCA\Encryption\Util;
+use OCP\IConfig;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Helper\QuestionHelper;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+use Symfony\Component\Console\Question\ConfirmationQuestion;
+
+class DisableMasterKey extends Command {
+
+	/** @var Util */
+	protected $util;
+
+	/** @var IConfig */
+	protected $config;
+
+	/** @var  QuestionHelper */
+	protected $questionHelper;
+
+	/**
+	 * @param Util $util
+	 * @param IConfig $config
+	 * @param QuestionHelper $questionHelper
+	 */
+	public function __construct(Util $util,
+								IConfig $config,
+								QuestionHelper $questionHelper) {
+
+		$this->util = $util;
+		$this->config = $config;
+		$this->questionHelper = $questionHelper;
+		parent::__construct();
+	}
+
+	protected function configure() {
+		$this
+			->setName('encryption:disable-master-key')
+			->setDescription('Disable the master key and use per-user keys instead. Only available for fresh installations with no existing encrypted data! There is no way to enable it again.');
+	}
+
+	protected function execute(InputInterface $input, OutputInterface $output) {
+
+		$isMasterKeyEnabled = $this->util->isMasterKeyEnabled();
+
+		if(!$isMasterKeyEnabled) {
+			$output->writeln('Master key already disabled');
+		} else {
+			$question = new ConfirmationQuestion(
+				'Warning: Only perform this operation for a fresh installations with no existing encrypted data! '
+				. 'There is no way to enable the master key again. '
+				. 'We strongly recommend to keep the master key, it provides significant performance improvements '
+				. 'and is easier to handle for both, users and administrators. '
+				. 'Do you really want to switch to per-user keys? (y/n) ', false);
+			if ($this->questionHelper->ask($input, $output, $question)) {
+				$this->config->setAppValue('encryption', 'useMasterKey', '0');
+				$output->writeln('Master key successfully disabled.');
+			} else {
+				$output->writeln('aborted.');
+			}
+		}
+
+	}
+
+}