owncloud/core

<?php
/**
 * @author Björn Schießle <bjoern@schiessle.org>
 * @author Jan-Christoph Borchardt <hey@jancborchardt.net>
 * @author Joas Schilling <coding@schilljs.com>
 * @author Thomas Müller <thomas.mueller@tmit.eu>
 *
 * @copyright Copyright (c) 2018, ownCloud GmbH
 * @license AGPL-3.0
 *
 * This code is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License, version 3,
 * as published by the Free Software Foundation.
 *
 * 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, version 3,
 * along with this program.  If not, see <http://www.gnu.org/licenses/>
 *
 */

namespace OC\Encryption;

use OC\Encryption\Keys\Storage;
use OC\Files\Filesystem;
use OC\Files\View;
use OC\Memcache\ArrayCache;
use OC\ServiceUnavailableException;
use OCP\Encryption\IEncryptionModule;
use OCP\Encryption\IManager;
use OCP\IConfig;
use OCP\IL10N;
use OCP\ILogger;

class Manager implements IManager {
    /** @var array */
    protected $encryptionModules;

    /** @var IConfig */
    protected $config;

    /** @var ILogger */
    protected $logger;

    /** @var Il10n */
    protected $l;

    /** @var View  */
    protected $rootView;

    /** @var Util  */
    protected $util;

    /** @var ArrayCache  */
    protected $arrayCache;

    /**
     * @param IConfig $config
     * @param ILogger $logger
     * @param IL10N $l10n
     * @param View $rootView
     * @param Util $util
     * @param ArrayCache $arrayCache
     */
    public function __construct(IConfig $config, ILogger $logger, IL10N $l10n, View $rootView, Util $util, ArrayCache $arrayCache) {
        $this->encryptionModules = [];
        $this->config = $config;
        $this->logger = $logger;
        $this->l = $l10n;
        $this->rootView = $rootView;
        $this->util = $util;
        $this->arrayCache = $arrayCache;
    }

    /**
     * Check if encryption is enabled
     *
     * @return bool true if enabled, false if not
     */
    public function isEnabled() {
        $installed = $this->config->getSystemValue('installed', false);
        if (!$installed) {
            return false;
        }

        $enabled = $this->config->getAppValue('core', 'encryption_enabled', 'no');
        $masterKeyEnabled = $this->config->getAppValue('encryption', 'useMasterKey', 0);
        return ($enabled === 'yes' or (bool)$masterKeyEnabled);
    }

    /**
     * check if new encryption is ready
     *
     * @return bool
     * @throws ServiceUnavailableException
     */
    public function isReady() {
        // check if we are still in transit between the old and the new encryption
        $oldEncryption = $this->config->getAppValue('files_encryption', 'installed_version');
        if (!empty($oldEncryption)) {
            $warning = 'Installation is in transit between the old Encryption (ownCloud <= 8.0)
            and the new encryption. Please enable the "Default encryption module"
            and run \'occ encryption:migrate\'';
            $this->logger->warning($warning);
            return false;
        }

        if ($this->isKeyStorageReady() === false) {
            throw new ServiceUnavailableException('Key Storage is not ready');
        }

        return true;
    }

    /**
     * @param string $user
     * @return bool
     */
    public function isReadyForUser($user) {
        if (!$this->isReady()) {
            return false;
        }

        foreach ($this->getEncryptionModules() as $module) {
            /** @var IEncryptionModule $m */
            $m = \call_user_func($module['callback']);
            if (!$m->isReadyForUser($user)) {
                return false;
            }
        }

        return true;
    }

    /**
     * Registers an callback function which must return an encryption module instance
     *
     * @param string $id
     * @param string $displayName
     * @param callable $callback
     * @throws Exceptions\ModuleAlreadyExistsException
     */
    public function registerEncryptionModule($id, $displayName, callable $callback) {
        if (isset($this->encryptionModules[$id])) {
            throw new Exceptions\ModuleAlreadyExistsException($id, $displayName);
        }

        $this->encryptionModules[$id] = [
            'id' => $id,
            'displayName' => $displayName,
            'callback' => $callback,
        ];

        $defaultEncryptionModuleId = $this->getDefaultEncryptionModuleId();

        if (empty($defaultEncryptionModuleId)) {
            $this->setDefaultEncryptionModule($id);
        }
    }

    /**
     * Unregisters an encryption module
     *
     * @param string $moduleId
     */
    public function unregisterEncryptionModule($moduleId) {
        unset($this->encryptionModules[$moduleId]);
    }

    /**
     * get a list of all encryption modules
     *
     * @return array [id => ['id' => $id, 'displayName' => $displayName, 'callback' => callback]]
     */
    public function getEncryptionModules() {
        return $this->encryptionModules;
    }

    /**
     * get a specific encryption module
     *
     * @param string $moduleId
     * @return IEncryptionModule
     * @throws Exceptions\ModuleDoesNotExistsException
     */
    public function getEncryptionModule($moduleId = '') {
        if (!empty($moduleId)) {
            if (isset($this->encryptionModules[$moduleId])) {
                return \call_user_func($this->encryptionModules[$moduleId]['callback']);
            } else {
                $message = "Module with id: $moduleId does not exist.";
                $hint = $this->l->t('Module with id: %s does not exist. Please enable it in your apps settings or contact your administrator.', [$moduleId]);
                throw new Exceptions\ModuleDoesNotExistsException($message, $hint);
            }
        } else {
            return $this->getDefaultEncryptionModule();
        }
    }

    /**
     * get default encryption module
     *
     * @return \OCP\Encryption\IEncryptionModule
     * @throws Exceptions\ModuleDoesNotExistsException
     */
    protected function getDefaultEncryptionModule() {
        $defaultModuleId = $this->getDefaultEncryptionModuleId();
        if (!empty($defaultModuleId)) {
            if (isset($this->encryptionModules[$defaultModuleId])) {
                return \call_user_func($this->encryptionModules[$defaultModuleId]['callback']);
            } else {
                $message = 'Default encryption module not loaded';
                throw new Exceptions\ModuleDoesNotExistsException($message);
            }
        } else {
            $message = 'No default encryption module defined';
            throw new Exceptions\ModuleDoesNotExistsException($message);
        }
    }

    /**
     * set default encryption module Id
     *
     * @param string $moduleId
     * @return bool
     */
    public function setDefaultEncryptionModule($moduleId) {
        try {
            $this->getEncryptionModule($moduleId);
        } catch (\Exception $e) {
            return false;
        }

        $this->config->setAppValue('core', 'default_encryption_module', $moduleId);
        return true;
    }

    /**
     * get default encryption module Id
     *
     * @return string
     */
    public function getDefaultEncryptionModuleId() {
        return $this->config->getAppValue('core', 'default_encryption_module');
    }

    /**
     * Add storage wrapper
     */
    public function setupStorage() {
        $encryptionWrapper = new EncryptionWrapper($this->arrayCache, $this, $this->logger);
        Filesystem::addStorageWrapper('oc_encryption', [$encryptionWrapper, 'wrapStorage'], 2);
    }

    /**
     * check if key storage is ready
     *
     * @return bool
     */
    protected function isKeyStorageReady() {
        $rootDir = $this->util->getKeyStorageRoot();

        // the default root is always valid
        if ($rootDir === '') {
            return true;
        }

        // check if key storage is mounted correctly
        if ($this->rootView->file_exists($rootDir . '/' . Storage::KEY_STORAGE_MARKER)) {
            return true;
        }

        return false;
    }
}