src/Protocol/ActivityPub.php

   1 <?php
   2 /**
   3  * @copyright Copyright (C) 2010-2023, the Friendica project
   4  *
   5  * @license GNU AGPL version 3 or any later version
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU Affero General Public License as
   9  * published by the Free Software Foundation, either version 3 of the
  10  * License, or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU Affero General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Affero General Public License
  18  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  19  *
  20  */
  21
  22 namespace Friendica\Protocol;
  23
  24 use Friendica\Core\Logger;
  25 use Friendica\Core\Protocol;
  26 use Friendica\Core\System;
  27 use Friendica\DI;
  28 use Friendica\Model\APContact;
  29 use Friendica\Model\Contact;
  30 use Friendica\Model\User;
  31 use Friendica\Util\HTTPSignature;
  32 use Friendica\Util\JsonLD;
  33
  34 /**
  35  * ActivityPub Protocol class
  36  *
  37  * The ActivityPub Protocol is a message exchange protocol defined by the W3C.
  38  * https://www.w3.org/TR/activitypub/
  39  * https://www.w3.org/TR/activitystreams-core/
  40  * https://www.w3.org/TR/activitystreams-vocabulary/
  41  *
  42  * https://blog.joinmastodon.org/2018/06/how-to-implement-a-basic-activitypub-server/
  43  * https://blog.joinmastodon.org/2018/07/how-to-make-friends-and-verify-requests/
  44  *
  45  * Digest: https://tools.ietf.org/html/rfc5843
  46  * https://tools.ietf.org/html/draft-cavage-http-signatures-10#ref-15
  47  *
  48  * Mastodon implementation of supported activities:
  49  * https://github.com/tootsuite/mastodon/blob/master/app/lib/activitypub/activity.rb#L26
  50  *
  51  * Funkwhale:
  52  * http://docs-funkwhale-funkwhale-549-music-federation-documentation.preview.funkwhale.audio/federation/index.html
  53  *
  54  * To-do:
  55  * - Polling the outboxes for missing content?
  56  *
  57  * Missing parts from DFRN:
  58  * - Public Group
  59  * - Private Group
  60  * - Relocation
  61  */
  62 class ActivityPub
  63 {
  64         const PUBLIC_COLLECTION = 'https://www.w3.org/ns/activitystreams#Public';
  65         const CONTEXT = [
  66                 'https://www.w3.org/ns/activitystreams', 'https://w3id.org/security/v1',
  67                 [
  68                         'vcard' => 'http://www.w3.org/2006/vcard/ns#',
  69                         'dfrn' => 'http://purl.org/macgirvin/dfrn/1.0/',
  70                         'diaspora' => 'https://diasporafoundation.org/ns/',
  71                         'litepub' => 'http://litepub.social/ns#',
  72                         'toot' => 'http://joinmastodon.org/ns#',
  73                         'featured' => [
  74                                 "@id" => "toot:featured",
  75                                 "@type" => "@id",
  76                         ],
  77                         'schema' => 'http://schema.org#',
  78                         'manuallyApprovesFollowers' => 'as:manuallyApprovesFollowers',
  79                         'sensitive' => 'as:sensitive', 'Hashtag' => 'as:Hashtag',
  80                         'quoteUrl' => 'as:quoteUrl',
  81                         'conversation' => 'ostatus:conversation',
  82                         'directMessage' => 'litepub:directMessage',
  83                         'discoverable' => 'toot:discoverable',
  84                         'PropertyValue' => 'schema:PropertyValue',
  85                         'value' => 'schema:value',
  86                 ]
  87         ];
  88         const ACCOUNT_TYPES = ['Person', 'Organization', 'Service', 'Group', 'Application', 'Tombstone'];
  89         /**
  90          * Checks if the web request is done for the AP protocol
  91          *
  92          * @return bool is it AP?
  93          */
  94         public static function isRequest(): bool
  95         {
  96                 header('Vary: Accept', false);
  97
  98                 $isrequest = stristr($_SERVER['HTTP_ACCEPT'] ?? '', 'application/activity+json') ||
  99                         stristr($_SERVER['HTTP_ACCEPT'] ?? '', 'application/json') ||
 100                         stristr($_SERVER['HTTP_ACCEPT'] ?? '', 'application/ld+json');
 101
 102                 if ($isrequest) {
 103                         Logger::debug('Is AP request', ['accept' => $_SERVER['HTTP_ACCEPT'], 'agent' => $_SERVER['HTTP_USER_AGENT'] ?? '']);
 104                 }
 105
 106                 return $isrequest;
 107         }
 108
 109         private static function getAccountType(array $apcontact): int
 110         {
 111                 $accounttype = -1;
 112
 113                 switch ($apcontact['type']) {
 114                         case 'Person':
 115                                 $accounttype = User::ACCOUNT_TYPE_PERSON;
 116                                 break;
 117                         case 'Organization':
 118                                 $accounttype = User::ACCOUNT_TYPE_ORGANISATION;
 119                                 break;
 120                         case 'Service':
 121                                 $accounttype = User::ACCOUNT_TYPE_NEWS;
 122                                 break;
 123                         case 'Group':
 124                                 $accounttype = User::ACCOUNT_TYPE_COMMUNITY;
 125                                 break;
 126                         case 'Application':
 127                                 $accounttype = User::ACCOUNT_TYPE_RELAY;
 128                                 break;
 129                         case 'Tombstone':
 130                                 $accounttype = User::ACCOUNT_TYPE_DELETED;
 131                                 break;
 132                 }
 133
 134                 return $accounttype;
 135         }
 136
 137         /**
 138          * Fetches a profile from the given url into an array that is compatible to Probe::uri
 139          *
 140          * @param string  $url    profile url
 141          * @param boolean $update Update the profile
 142          * @return array
 143          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 144          * @throws \ImagickException
 145          */
 146         public static function probeProfile(string $url, bool $update = true): array
 147         {
 148                 $apcontact = APContact::getByURL($url, $update);
 149                 if (empty($apcontact)) {
 150                         return [];
 151                 }
 152
 153                 $profile = ['network' => Protocol::ACTIVITYPUB];
 154                 $profile['nick'] = $apcontact['nick'];
 155                 $profile['name'] = $apcontact['name'];
 156                 $profile['guid'] = $apcontact['uuid'];
 157                 $profile['url'] = $apcontact['url'];
 158                 $profile['addr'] = $apcontact['addr'];
 159                 $profile['alias'] = $apcontact['alias'];
 160                 $profile['following'] = $apcontact['following'];
 161                 $profile['followers'] = $apcontact['followers'];
 162                 $profile['inbox'] = $apcontact['inbox'];
 163                 $profile['outbox'] = $apcontact['outbox'];
 164                 $profile['sharedinbox'] = $apcontact['sharedinbox'];
 165                 $profile['photo'] = $apcontact['photo'];
 166                 $profile['header'] = $apcontact['header'];
 167                 $profile['account-type'] = self::getAccountType($apcontact);
 168                 $profile['community'] = ($profile['account-type'] == User::ACCOUNT_TYPE_COMMUNITY);
 169                 // $profile['keywords']
 170                 // $profile['location']
 171                 $profile['about'] = $apcontact['about'];
 172                 $profile['xmpp'] = $apcontact['xmpp'];
 173                 $profile['matrix'] = $apcontact['matrix'];
 174                 $profile['batch'] = $apcontact['sharedinbox'];
 175                 $profile['notify'] = $apcontact['inbox'];
 176                 $profile['poll'] = $apcontact['outbox'];
 177                 $profile['pubkey'] = $apcontact['pubkey'];
 178                 $profile['subscribe'] = $apcontact['subscribe'];
 179                 $profile['manually-approve'] = $apcontact['manually-approve'];
 180                 $profile['baseurl'] = $apcontact['baseurl'];
 181                 $profile['gsid'] = $apcontact['gsid'];
 182
 183                 if (!is_null($apcontact['discoverable'])) {
 184                         $profile['hide'] = !$apcontact['discoverable'];
 185                 }
 186
 187                 // Remove all "null" fields
 188                 foreach ($profile as $field => $content) {
 189                         if (is_null($content)) {
 190                                 unset($profile[$field]);
 191                         }
 192                 }
 193
 194                 return $profile;
 195         }
 196
 197         /**
 198          * Fetches activities from the outbox of a given profile and processes it
 199          *
 200          * @param string  $url
 201          * @param integer $uid User ID
 202          * @return void
 203          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 204          */
 205         public static function fetchOutbox(string $url, int $uid)
 206         {
 207                 $data = HTTPSignature::fetch($url, $uid);
 208                 if (empty($data)) {
 209                         return;
 210                 }
 211
 212                 if (!empty($data['orderedItems'])) {
 213                         $items = $data['orderedItems'];
 214                 } elseif (!empty($data['first']['orderedItems'])) {
 215                         $items = $data['first']['orderedItems'];
 216                 } elseif (!empty($data['first'])) {
 217                         self::fetchOutbox($data['first'], $uid);
 218                         return;
 219                 } else {
 220                         $items = [];
 221                 }
 222
 223                 foreach ($items as $activity) {
 224                         $ldactivity = JsonLD::compact($activity);
 225                         ActivityPub\Receiver::processActivity($ldactivity, '', $uid, true);
 226                 }
 227         }
 228
 229         /**
 230          * Fetch items from AP endpoints
 231          *
 232          * @param string $url              Address of the endpoint
 233          * @param integer $uid             Optional user id
 234          * @param integer $start_timestamp Internally used parameter to stop fetching after some time
 235          * @return array Endpoint items
 236          */
 237         public static function fetchItems(string $url, int $uid = 0, int $start_timestamp = 0): array
 238         {
 239                 $start_timestamp = $start_timestamp ?: time();
 240
 241                 if ((time() - $start_timestamp) > 60) {
 242                         Logger::info('Fetch time limit reached', ['url' => $url, 'uid' => $uid]);
 243                         return [];
 244                 }
 245
 246                 $data = HTTPSignature::fetch($url, $uid);
 247                 if (empty($data)) {
 248                         return [];
 249                 }
 250
 251                 if (!empty($data['orderedItems'])) {
 252                         $items = $data['orderedItems'];
 253                 } elseif (!empty($data['first']['orderedItems'])) {
 254                         $items = $data['first']['orderedItems'];
 255                 } elseif (!empty($data['first']) && is_string($data['first']) && ($data['first'] != $url)) {
 256                         return self::fetchItems($data['first'], $uid, $start_timestamp);
 257                 } else {
 258                         return [];
 259                 }
 260
 261                 if (!empty($data['next']) && is_string($data['next'])) {
 262                         $items = array_merge($items, self::fetchItems($data['next'], $uid, $start_timestamp));
 263                 }
 264
 265                 return $items;
 266         }
 267
 268         /**
 269          * Checks if the given contact url does support ActivityPub
 270          *
 271          * @param string  $url    profile url
 272          * @param boolean $update true = always update, false = never update, null = update when not found or outdated
 273          * @return boolean
 274          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 275          * @throws \ImagickException
 276          */
 277         public static function isSupportedByContactUrl(string $url, $update = null): bool
 278         {
 279                 return !empty(APContact::getByURL($url, $update));
 280         }
 281
 282         public static function isAcceptedRequester(int $uid = 0): bool
 283         {
 284                 $called_by = System::callstack(1);
 285
 286                 $signer = HTTPSignature::getSigner('', $_SERVER);
 287                 if (!$signer) {
 288                         Logger::debug('No signer or invalid signature', ['uid' => $uid, 'agent' => $_SERVER['HTTP_USER_AGENT'] ?? '', 'called_by' => $called_by]);
 289                         return false;
 290                 }
 291
 292                 $apcontact = APContact::getByURL($signer);
 293                 if (empty($apcontact)) {
 294                         Logger::info('APContact not found', ['uid' => $uid, 'handle' => $signer, 'called_by' => $called_by]);
 295                         return false;
 296                 }
 297
 298                 if (empty($apcontact['gsid'] || empty($apcontact['baseurl']))) {
 299                         Logger::debug('No server found', ['uid' => $uid, 'signer' => $signer, 'called_by' => $called_by]);
 300                         return false;
 301                 }
 302
 303                 $contact = Contact::getByURL($signer, false, ['id', 'baseurl', 'gsid']);
 304                 if (!empty($contact) && Contact\User::isBlocked($contact['id'], $uid)) {
 305                         Logger::info('Requesting contact is blocked', ['uid' => $uid, 'id' => $contact['id'], 'signer' => $signer, 'baseurl' => $contact['baseurl'], 'called_by' => $called_by]);
 306                         return false;
 307                 }
 308
 309                 $limited = DI::config()->get('system', 'limited_servers');
 310                 if (!empty($limited)) {
 311                         $servers = explode(',', str_replace(' ', '', $limited));
 312                         $host = parse_url($apcontact['baseurl'], PHP_URL_HOST);
 313                         if (!empty($host) && in_array($host, $servers)) {
 314                                 return false;
 315                         }
 316                 }
 317
 318                 if (DI::userGServer()->isIgnoredByUser($uid, $apcontact['gsid'])) {
 319                         return false;
 320                 }
 321
 322                 Logger::debug('Server is an accepted requester', ['uid' => $uid, 'id' => $apcontact['gsid'], 'url' => $apcontact['baseurl'], 'signer' => $signer, 'called_by' => $called_by]);
 323
 324                 return true;
 325         }
 326 }