owncloud/core

<?php
/**
 * @author Joas Schilling <coding@schilljs.com>
 * @author Lukas Reschke <lukas@statuscode.ch>
 * @author Thomas Müller <thomas.mueller@tmit.eu>
 * @author Vincent Petry <pvince81@owncloud.com>
 *
 * @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\FederatedFileSharing;

use GuzzleHttp\Exception\ClientException;
use GuzzleHttp\Exception\ConnectException;
use OCP\Http\Client\IClient;
use OCP\Http\Client\IClientService;
use OCP\ICache;
use OCP\ICacheFactory;

/**
 * Class DiscoveryManager handles the discovery of endpoints used by Federated
 * Cloud Sharing.
 *
 * @package OCA\FederatedFileSharing
 */
class DiscoveryManager {
    /** @var ICache */
    private $cache;
    /** @var IClient */
    private $client;
    /** @var bool */
    public $underTest = false;

    /**
     * @param ICacheFactory $cacheFactory
     * @param IClientService $clientService
     */
    public function __construct(
        ICacheFactory $cacheFactory,
        IClientService $clientService
    ) {
        $this->cache = $cacheFactory->create('ocs-discovery');
        $this->client = $clientService->newClient();
    }

    /**
     * Returns whether the specified URL includes only safe characters, if not
     * returns false
     *
     * @param string $url
     * @return bool
     */
    private function isSafeUrl($url) {
        return (bool)\preg_match('/^[\/\.A-Za-z0-9]+$/', $url);
    }

    /**
     * Discover the actual data and do some naive caching to ensure that the data
     * is not requested multiple times.
     *
     * If no valid discovery data is found the ownCloud defaults are returned.
     *
     * @param string $remote
     * @return array
     */
    private function discover($remote) {
        // Check if something is in the cache
        if ($cacheData = $this->cache->get($remote)) {
            return \json_decode($cacheData, true);
        }

        // Default response body
        $discoveredServices = [
            'webdav' => '/public.php/webdav',
            'share' => '/ocs/v1.php/cloud/shares',
        ];

        if (\defined('PHPUNIT_RUN') && !$this->underTest) {
            return $discoveredServices;
        }

        $decodedService = $this->makeRequest($remote . '/ocs-provider/');
        if (!empty($decodedService)) {
            $endpoints = [
                'webdav',
                'share',
            ];

            foreach ($endpoints as $endpoint) {
                if (isset($decodedService['services']['FEDERATED_SHARING']['endpoints'][$endpoint])) {
                    $endpointUrl = (string)$decodedService['services']['FEDERATED_SHARING']['endpoints'][$endpoint];
                    if ($this->isSafeUrl($endpointUrl)) {
                        $discoveredServices[$endpoint] = $endpointUrl;
                    }
                }
            }
        }

        // Write into cache
        $this->cache->set($remote, \json_encode($discoveredServices));
        return $discoveredServices;
    }

    /**
     * Discover the actual data and do some naive caching to ensure that the data
     * is not requested multiple times.
     *
     * If no valid discovery data is found the ownCloud defaults are returned.
     *
     * @param string $remote
     * @return array
     */
    private function ocmDiscover($remote) {
        // Check if something is in the cache
        if ($cacheData = $this->cache->get('OCM' . $remote)) {
            return \json_decode($cacheData, true);
        }

        // Default response body
        $discoveredServices = [
            'webdav' => '/public.php/webdav',
            'ocm' => '/index.php/apps/federatedfilesharing',
        ];

        if (\defined('PHPUNIT_RUN') && !$this->underTest) {
            return $discoveredServices;
        }

        $decodedService = $this->makeRequest($remote . '/ocm-provider/');
        if (!empty($decodedService) && $decodedService['enabled'] === true) {
            $discoveredServices['ocm'] = $decodedService['endPoint'];
            $types = [];
            if (isset($decodedService['shareTypes'])) {
                $types = $decodedService['shareTypes'];
            } elseif (isset($decodedService['resourceTypes'])) {
                $types = $decodedService['resourceTypes'];
            }
            foreach ($types as $type) {
                if ($type['name'] == 'file') {
                    $discoveredServices['webdav'] = $type['protocols']['webdav'];
                }
            }

            // Write into cache
            $this->cache->set('OCM' . $remote, \json_encode($discoveredServices));
            return $discoveredServices;
        }
        return [
            'webdav' => false,
            'ocm' => false,
        ];
    }

    /**
     * Send GET request and return decoded body of response on success
     *
     * @param $url
     *
     * @return array
     */
    private function makeRequest($url) {
        $decodedService = [];
        try {
            // make timeout configurable?
            $response = $this->client->get(
                $url,
                [
                    'timeout' => 10,
                    'connect_timeout' => 10,
                ]
            );
            if ($response->getStatusCode() === 200) {
                $decodedService = \json_decode($response->getBody(), true);
            }
            if (\is_array($decodedService) === false) {
                $decodedService = [];
            }
        } catch (ClientException $e) {
            // Don't throw any exception since exceptions are handled before
        } catch (ConnectException $e) {
            // Don't throw any exception since exceptions are handled before
        }
        return $decodedService;
    }

    /**
     * Return the public WebDAV endpoint used by the specified remote
     *
     * @param string $host
     * @return string
     */
    public function getWebDavEndpoint($host) {
        $ocmWebDavEndpoint = $this->ocmDiscover($host)['webdav'];
        return ($ocmWebDavEndpoint !== false)
            ? $ocmWebDavEndpoint
            : $this->discover($host)['webdav'];
    }

    /**
     * Return the sharing endpoint used by the specified remote
     *
     * @param string $host
     * @return string
     */
    public function getShareEndpoint($host) {
        return $this->discover($host)['share'];
    }

    public function getOcmShareEndPoint($host) {
        return $this->ocmDiscover($host)['ocm'];
    }
}