gnu-social/plugins/ActivityPub/Controller/Inbox.php

241 lines
8.8 KiB
PHP

<?php
declare(strict_types = 1);
// {{{ License
// This file is part of GNU social - https://www.gnu.org/software/social
//
// GNU social 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.
//
// GNU social 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 GNU social. If not, see <http://www.gnu.org/licenses/>.
// }}}
/**
* ActivityPub implementation for GNU social
*
* @package GNUsocial
* @category ActivityPub
*
* @author Diogo Peralta Cordeiro <@diogo.site>
* @copyright 2018-2019, 2021 Free Software Foundation, Inc http://www.fsf.org
* @license https://www.gnu.org/licenses/agpl.html GNU AGPL v3 or later
*/
namespace Plugin\ActivityPub\Controller;
use ActivityPhp\Type\AbstractObject;
use App\Core\Controller;
use App\Core\DB;
use function App\Core\I18n\_m;
use App\Core\Log;
use App\Core\Queue;
use App\Core\Router;
use App\Entity\Actor;
use App\Util\Common;
use App\Util\Exception\ClientException;
use Exception;
use Plugin\ActivityPub\Entity\ActivitypubActor;
use Plugin\ActivityPub\Entity\ActivitypubRsa;
use Plugin\ActivityPub\Util\Explorer;
use Plugin\ActivityPub\Util\HTTPSignature;
use Plugin\ActivityPub\Util\Model;
use Plugin\ActivityPub\Util\TypeResponse;
use Symfony\Component\HttpFoundation\Request;
/**
* ActivityPub Inbox Handler
*
* @copyright 2018-2019, 2021 Free Software Foundation, Inc http://www.fsf.org
* @license https://www.gnu.org/licenses/agpl.html GNU AGPL v3 or later
*/
class Inbox extends Controller
{
public function onGet(Request $request, ?int $gsactor_id = null): TypeResponse
{
return new TypeResponse(json_encode(['error' => 'No AP C2S inbox yet.']), 400);
}
/**
* Create an Inbox Handler to receive something from someone.
*/
public function onPost(Request $request, ?int $gsactor_id = null): TypeResponse
{
$error = function (string $m, ?Exception $e = null): TypeResponse {
Log::error('ActivityPub Error Answer: ' . ($json = json_encode(['error' => $m, 'exception' => var_export($e, true)])));
if (\is_null($e)) {
return new TypeResponse($json, 400);
} else {
throw $e;
}
};
$path = Router::url('activitypub_inbox', type: Router::ABSOLUTE_PATH);
if (!\is_null($gsactor_id)) {
try {
$user = DB::findOneBy('local_user', ['id' => $gsactor_id]);
$path = Router::url('activitypub_actor_inbox', ['gsactor_id' => $user->getId()], type: Router::ABSOLUTE_PATH);
} catch (Exception $e) {
throw new ClientException(_m('No such actor.'), 404, previous: $e);
}
}
Log::debug('ActivityPub Inbox: Received a POST request.');
$body = (string) $this->request->getContent();
Log::debug('ActivityPub Inbox: Request Body content: ' . $body);
$type = Model::jsonToType($body);
if ($type->has('actor') === false) {
return $error('Actor not found in the request.');
}
$to_actor = $this->deriveActivityTo($type);
try {
$resource_parts = parse_url($type->get('actor'));
if ($resource_parts['host'] !== Common::config('site', 'server')) {
$actor = DB::wrapInTransaction(fn () => Explorer::getOneFromUri($type->get('actor'), try_online: true, on_behalf_of: $to_actor));
$ap_actor = DB::findOneBy(ActivitypubActor::class, ['actor_id' => $actor->getId()]);
} else {
throw new Exception('Only remote actors can use this endpoint.');
}
unset($resource_parts);
} catch (Exception $e) {
return $error('Invalid actor.', $e);
}
$activitypub_rsa = ActivitypubRsa::getByActor($actor);
$actor_public_key = $activitypub_rsa->getPublicKey();
$headers = $this->request->headers->all();
Log::debug('ActivityPub Inbox: Request Headers.', [$headers]);
// Flattify headers
foreach ($headers as $key => $val) {
$headers[$key] = $val[0];
}
if (!isset($headers['signature'])) {
Log::debug('ActivityPub Inbox: HTTP Signature: Missing Signature header.');
return $error('Missing Signature header.');
// TODO: support other methods beyond HTTP Signatures
}
// Extract the signature properties
$signatureData = HTTPSignature::parseSignatureHeader($headers['signature']);
Log::debug('ActivityPub Inbox: HTTP Signature Data.', [$signatureData]);
if (isset($signatureData['error'])) {
return $error(json_encode($signatureData, \JSON_PRETTY_PRINT));
}
[$verified, /*$headers*/] = HTTPSignature::verify($actor_public_key, $signatureData, $headers, $path, $body);
// If the signature fails verification the first time, update profile as it might have changed public key
if ($verified !== 1) {
try {
$res = Explorer::getRemoteActorActivity($ap_actor->getUri(), $to_actor);
if (\is_null($res)) {
return $error('Invalid remote actor (null response).');
}
} catch (Exception $e) {
return $error('Invalid remote actor.', $e);
}
try {
ActivitypubActor::update_profile($ap_actor, $actor, $activitypub_rsa, $res);
} catch (Exception $e) {
return $error('Failed to update remote actor information.', $e);
}
[$verified, /*$headers*/] = HTTPSignature::verify($actor_public_key, $signatureData, $headers, $path, $body);
}
// If it still failed despite profile update
if ($verified !== 1) {
Log::debug('ActivityPub Inbox: HTTP Signature: Invalid signature.');
return $error('Invalid signature.');
}
// HTTP signature checked out, make sure the "actor" of the activity matches that of the signature
Log::debug('ActivityPub Inbox: HTTP Signature: Authorised request. Will now start the inbox handler.');
Queue::enqueue(
payload: [$ap_actor, $actor, $type],
queue: 'ActivitypubInbox',
priority: false,
);
return new TypeResponse($type, status: 202);
}
/**
* Poke at the given AbstractObject to find out who it is 'to'.
* Function will check through the 'to', 'cc', and 'object' fields
* of the given type (in that order) to check if if points to anyone
* on our instance. The first found candidate will be returned.
*
* @param AbstractObject $type
*
* @return Actor|null The discovered actor, if found. null otherwise.
*
* @throws Exception
*/
private function deriveActivityTo(AbstractObject $type): Actor|null
{
foreach (['to', 'cc'] as $field) {
foreach ((array) $type->get($field) as $uri) {
$actor = self::uriToMaybeLocalActor($uri);
if (!\is_null($actor)) {
return $actor;
}
}
}
// if it's not to or cc anyone we have to dive deeper
if ($type->has('object')) {
// the 'object' field might just be a uri of one
// of our Actors, if this is a follow or block
$object = $type->get('object');
if (\is_string($object)) {
$actor = self::uriToMaybeLocalActor($object);
if (!\is_null($actor)) {
return $actor;
}
} else if ($object instanceof AbstractObject) {
// if the inner object is also a Type, repeat the process
return $this->deriveActivityTo($object);
}
}
return null;
}
/**
* Get local actor that owns or corresponds to given uri.
*
* @param string $uri
*
* @return Actor|null
*/
private static function uriToMaybeLocalActor(string $uri): Actor|null
{
$parsed = parse_url($uri);
// check if this uri belongs to us
if ($parsed['host'] === Common::config('site', 'server')) {
// it is our uri so we should be able to get
// the actor without making any remote calls
$actor = Explorer::getLocalActorForPath($parsed['path']);
if (!\is_null($actor)) {
return $actor;
}
}
return null;
}
}