owncloud/core

<?php
/**
 * @author Georg Ehrke <georg@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\DAV\CardDAV;

use OCP\ILogger;
use Sabre\CardDAV\Card;
use Sabre\DAV\Server;
use Sabre\DAV\ServerPlugin;
use Sabre\HTTP\RequestInterface;
use Sabre\HTTP\ResponseInterface;
use Sabre\VObject\Parameter;
use Sabre\VObject\Property\Binary;
use Sabre\VObject\Reader;

class ImageExportPlugin extends ServerPlugin {
    /** @var Server */
    protected $server;
    /** @var ILogger */
    private $logger;

    public function __construct(ILogger $logger) {
        $this->logger = $logger;
    }

    /**
     * Initializes the plugin and registers event handlers
     *
     * @param Server $server
     * @return void
     */
    public function initialize(Server $server) {
        $this->server = $server;
        $this->server->on('method:GET', [$this, 'httpGet'], 90);
    }

    /**
     * Intercepts GET requests on addressbook urls ending with ?photo.
     *
     * @param RequestInterface $request
     * @param ResponseInterface $response
     * @return bool|void
     */
    public function httpGet(RequestInterface $request, ResponseInterface $response) {
        $queryParams = $request->getQueryParameters();
        // TODO: in addition to photo we should also add logo some point in time
        if (!\array_key_exists('photo', $queryParams)) {
            return true;
        }

        $path = $request->getPath();
        $node = $this->server->tree->getNodeForPath($path);

        if (!($node instanceof Card)) {
            return true;
        }

        $this->server->transactionType = 'carddav-image-export';

        // Checking ACL, if available.
        if ($aclPlugin = $this->server->getPlugin('acl')) {
            /** @var \Sabre\DAVACL\Plugin $aclPlugin */
            '@phan-var \Sabre\DAVACL\Plugin $aclPlugin';
            $aclPlugin->checkPrivileges($path, '{DAV:}read');
        }

        if ($result = $this->getPhoto($node)) {
            $response->setHeader('Content-Type', $result['Content-Type']);
            $response->setHeader('Content-Disposition', 'attachment');
            $response->setStatus(200);

            $response->setBody($result['body']);

            // Returning false to break the event chain
            return false;
        }
        return true;
    }

    public function getPhoto(Card $node) {
        // TODO: this is kind of expensive - load carddav data from database and parse it
        //       we might want to build up a cache one day
        try {
            $vObject = $this->readCard($node->get());
            if (!$vObject->PHOTO) {
                return false;
            }

            $photo = $vObject->PHOTO;
            $type = $this->getType($photo);

            $val = $photo->getValue();
            if ($photo->getValueType() === 'URI') {
                $parsed = \Sabre\Uri\parse($val);
                //only allow data://
                if ($parsed['scheme'] !== 'data') {
                    return false;
                }
                if (\substr_count($parsed['path'], ';') === 1) {
                    list($type, ) = \explode(';', $parsed['path']);
                }
                $val = \file_get_contents($val);
            }

            if (!\in_array($type, ['image/png', 'image/jpeg', 'image/gif'])) {
                $type = 'application/octet-stream';
            }

            return [
                'Content-Type' => $type,
                'body' => $val
            ];
        } catch (\Exception $ex) {
            $this->logger->logException($ex);
        }
        return false;
    }

    private function readCard($cardData) {
        return Reader::read($cardData);
    }

    /**
     * @param Binary $photo
     * @return string
     */
    private function getType($photo) {
        $params = $photo->parameters();
        if (isset($params['TYPE']) || isset($params['MEDIATYPE'])) {
            /** @var Parameter $typeParam */
            $typeParam = isset($params['TYPE']) ? $params['TYPE'] : $params['MEDIATYPE'];
            $type = $typeParam->getValue();

            if (\strpos($type, 'image/') === 0) {
                return $type;
            } else {
                return 'image/' . \strtolower($type);
            }
        }
        return 'application/octet-stream';
    }
}