owncloud/core

<?php
/**
 * @author Lukas Reschke <lukas@statuscode.ch>
 * @author Morris Jobke <hey@morrisjobke.de>
 * @author Roeland Jago Douma <rullzer@owncloud.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 OCA\Files_Sharing\Middleware;

use OCA\Files_Sharing\Exceptions\S2SException;
use OCP\App\IAppManager;
use OCP\AppFramework\Http\JSONResponse;
use OCP\AppFramework\Http\NotFoundResponse;
use OCP\AppFramework\Middleware;
use OCP\AppFramework\Utility\IControllerMethodReflector;
use OCP\Files\NotFoundException;
use OCP\IConfig;

/**
 * Checks whether the "sharing check" is enabled
 *
 * @package OCA\Files_Sharing\Middleware
 */
class SharingCheckMiddleware extends Middleware {
    /** @var string */
    protected $appName;
    /** @var IConfig */
    protected $config;
    /** @var IAppManager */
    protected $appManager;
    /** @var IControllerMethodReflector */
    protected $reflector;

    /***
     * @param string $appName
     * @param IConfig $config
     * @param IAppManager $appManager
     */
    public function __construct(
        $appName,
        IConfig $config,
        IAppManager $appManager,
        IControllerMethodReflector $reflector
    ) {
        $this->appName = $appName;
        $this->config = $config;
        $this->appManager = $appManager;
        $this->reflector = $reflector;
    }

    /**
     * Check if sharing is enabled before the controllers is executed
     *
     * @param \OCP\AppFramework\Controller $controller
     * @param string $methodName
     * @throws NotFoundException
     */
    public function beforeController($controller, $methodName) {
        if (!$this->isSharingEnabled()) {
            throw new NotFoundException('Sharing is disabled.');
        }

        if ($controller instanceof \OCA\Files_Sharing\Controllers\ExternalSharesController &&
            !$this->externalSharesChecks()) {
            throw new S2SException('Federated sharing not allowed');
        } elseif ($controller instanceof \OCA\Files_Sharing\Controllers\ShareController &&
            !$this->isLinkSharingEnabled()) {
            throw new NotFoundException('Link sharing is disabled');
        }
    }

    /**
     * Return 404 page in case of a not found exception
     *
     * @param \OCP\AppFramework\Controller $controller
     * @param string $methodName
     * @param \Exception $exception
     * @return NotFoundResponse
     * @throws \Exception
     */
    public function afterException($controller, $methodName, \Exception $exception) {
        if (\is_a($exception, '\OCP\Files\NotFoundException')) {
            return new NotFoundResponse();
        }

        if (\is_a($exception, '\OCA\Files_Sharing\Exceptions\S2SException')) {
            return new JSONResponse($exception->getMessage(), 405);
        }

        throw $exception;
    }

    /**
     * Checks for externalshares controller
     * @return bool
     */
    private function externalSharesChecks() {
        if (!$this->reflector->hasAnnotation('NoIncomingFederatedSharingRequired') &&
            $this->config->getAppValue('files_sharing', 'incoming_server2server_share_enabled', 'yes') !== 'yes') {
            return false;
        }

        if (!$this->reflector->hasAnnotation('NoOutgoingFederatedSharingRequired') &&
            $this->config->getAppValue('files_sharing', 'outgoing_server2server_share_enabled', 'yes') !== 'yes') {
            return false;
        }

        return true;
    }

    /**
     * Check whether sharing is enabled
     * @return bool
     */
    private function isSharingEnabled() {
        // FIXME: This check is done here since the route is globally defined and not inside the files_sharing app
        // Check whether the sharing application is enabled
        if (!$this->appManager->isEnabledForUser($this->appName)) {
            return false;
        }

        return true;
    }

    /**
     * Check if link sharing is allowed
     * @return bool
     */
    private function isLinkSharingEnabled() {
        // Check if the shareAPI is enabled
        if ($this->config->getAppValue('core', 'shareapi_enabled', 'yes') !== 'yes') {
            return false;
        }

        // Check whether public sharing is enabled
        if ($this->config->getAppValue('core', 'shareapi_allow_links', 'yes') !== 'yes') {
            return false;
        }

        return true;
    }
}