+<?php
+/**
+ * @copyright Copyright (C) 2010-2021, the Friendica project
+ *
+ * @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 <https://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace Friendica\Module\ActivityPub;
+
+use Friendica\BaseModule;
+use Friendica\Core\Logger;
+use Friendica\Core\System;
+use Friendica\Database\DBA;
+use Friendica\DI;
+use Friendica\Model\Contact;
+use Friendica\Model\Item;
+use Friendica\Model\Post;
+use Friendica\Network\HTTPException;
+use Friendica\Protocol\ActivityPub;
+use Friendica\Util\HTTPSignature;
+use Friendica\Util\Network;
+use Friendica\Util\Strings;
+
+/**
+ * ActivityPub Objects
+ */
+class Objects extends BaseModule
+{
+ public static function rawContent(array $parameters = [])
+ {
+ if (empty($parameters['guid'])) {
+ throw new HTTPException\BadRequestException();
+ }
+
+ if (!ActivityPub::isRequest()) {
+ DI::baseUrl()->redirect(str_replace('objects/', 'display/', DI::args()->getQueryString()));
+ }
+
+ $itemuri = DBA::selectFirst('item-uri', ['id'], ['guid' => $parameters['guid']]);
+
+ if (DBA::isResult($itemuri)) {
+ Logger::info('Provided GUID found.', ['guid' => $parameters['guid'], 'uri-id' => $itemuri['id']]);
+ } else {
+ // The item URI does not always contain the GUID. This means that we have to search the URL instead
+ $url = DI::baseUrl()->get() . '/' . DI::args()->getQueryString();
+ $nurl = Strings::normaliseLink($url);
+ $ssl_url = str_replace('http://', 'https://', $nurl);
+
+ $itemuri = DBA::selectFirst('item-uri', ['guid', 'id'], ['uri' => [$url, $nurl, $ssl_url]]);
+ if (DBA::isResult($itemuri)) {
+ Logger::info('URL found.', ['url' => $url, 'guid' => $itemuri['guid'], 'uri-id' => $itemuri['id']]);
+ } else {
+ Logger::info('URL not found.', ['url' => $url]);
+ throw new HTTPException\NotFoundException();
+ }
+ }
+
+ $item = Post::selectFirst(['id', 'uid', 'origin', 'author-link', 'changed', 'private', 'psid', 'gravity', 'deleted', 'parent-uri-id'],
+ ['uri-id' => $itemuri['id']], ['order' => ['origin' => true]]);
+
+ if (!DBA::isResult($item)) {
+ throw new HTTPException\NotFoundException();
+ }
+
+ $validated = in_array($item['private'], [Item::PUBLIC, Item::UNLISTED]);
+
+ if (!$validated) {
+ $requester = HTTPSignature::getSigner('', $_SERVER);
+ if (!empty($requester) && $item['origin']) {
+ $requester_id = Contact::getIdForURL($requester, $item['uid']);
+ if (!empty($requester_id)) {
+ $permissionSets = DI::permissionSet()->selectByContactId($requester_id, $item['uid']);
+ if (!empty($permissionSets)) {
+ $psid = array_merge($permissionSets->column('id'),
+ [DI::permissionSet()->getIdFromACL($item['uid'], '', '', '', '')]);
+ $validated = in_array($item['psid'], $psid);
+ }
+ }
+ }
+ }
+
+ if ($validated) {
+ // Valid items are original post or posted from this node (including in the case of a forum)
+ $validated = ($item['origin'] || (parse_url($item['author-link'], PHP_URL_HOST) == parse_url(DI::baseUrl()->get(), PHP_URL_HOST)));
+
+ if (!$validated && $item['deleted']) {
+ $validated = Post::exists(['origin' => true, 'uri-id' => $item['parent-uri-id']]);
+ }
+ }
+
+ if (!$validated) {
+ throw new HTTPException\NotFoundException();
+ }
+
+ $etag = md5($parameters['guid'] . '-' . $item['changed']);
+ $last_modified = $item['changed'];
+ Network::checkEtagModified($etag, $last_modified);
+
+ if (empty($parameters['activity']) && ($item['gravity'] != GRAVITY_ACTIVITY)) {
+ $activity = ActivityPub\Transmitter::createActivityFromItem($item['id'], true);
+ if (empty($activity['type'])) {
+ throw new HTTPException\NotFoundException();
+ }
+
+ $activity['type'] = $activity['type'] == 'Update' ? 'Create' : $activity['type'];
+
+ // Only display "Create" activity objects here, no reshares or anything else
+ if (empty($activity['object']) || ($activity['type'] != 'Create')) {
+ throw new HTTPException\NotFoundException();
+ }
+
+ $data = ['@context' => ActivityPub::CONTEXT];
+ $data = array_merge($data, $activity['object']);
+ } elseif (empty($parameters['activity']) || in_array($parameters['activity'],
+ ['Create', 'Announce', 'Update', 'Like', 'Dislike', 'Accept', 'Reject',
+ 'TentativeAccept', 'Follow', 'Add'])) {
+ $data = ActivityPub\Transmitter::createActivityFromItem($item['id']);
+ if (empty($data)) {
+ throw new HTTPException\NotFoundException();
+ }
+ if (!empty($parameters['activity']) && ($parameters['activity'] != 'Create')) {
+ $data['type'] = $parameters['activity'];
+ $data['id'] = str_replace('/Create', '/' . $parameters['activity'], $data['id']);
+ }
+ } else {
+ throw new HTTPException\NotFoundException();
+ }
+
+ // Relaxed CORS header for public items
+ header('Access-Control-Allow-Origin: *');
+ System::jsonExit($data, 'application/activity+json');
+ }
+}