src/Protocol/ActivityPub/Receiver.php

   1 <?php
   2 /**
   3  * @file src/Protocol/ActivityPub.php
   4  */
   5 namespace Friendica\Protocol\ActivityPub;
   6
   7 use Friendica\Database\DBA;
   8 use Friendica\Core\System;
   9 use Friendica\BaseObject;
  10 use Friendica\Util\Network;
  11 use Friendica\Util\HTTPSignature;
  12 use Friendica\Core\Protocol;
  13 use Friendica\Model\Conversation;
  14 use Friendica\Model\Contact;
  15 use Friendica\Model\APContact;
  16 use Friendica\Model\Item;
  17 use Friendica\Model\Profile;
  18 use Friendica\Model\Term;
  19 use Friendica\Model\User;
  20 use Friendica\Util\DateTimeFormat;
  21 use Friendica\Util\Crypto;
  22 use Friendica\Content\Text\BBCode;
  23 use Friendica\Content\Text\HTML;
  24 use Friendica\Util\JsonLD;
  25 use Friendica\Util\LDSignature;
  26 use Friendica\Core\Config;
  27 use Friendica\Protocol\ActivityPub;
  28
  29 /**
  30  * @brief ActivityPub Protocol class
  31  */
  32 class Receiver
  33 {
  34         /**
  35          * @brief Checks if the web request is done for the AP protocol
  36          *
  37          * @return is it AP?
  38          */
  39         public static function isRequest()
  40         {
  41                 return stristr(defaults($_SERVER, 'HTTP_ACCEPT', ''), 'application/activity+json') ||
  42                         stristr(defaults($_SERVER, 'HTTP_ACCEPT', ''), 'application/ld+json');
  43         }
  44
  45         /**
  46          * @brief
  47          *
  48          * @param $body
  49          * @param $header
  50          * @param integer $uid User ID
  51          */
  52         public static function processInbox($body, $header, $uid)
  53         {
  54                 $http_signer = HTTPSignature::getSigner($body, $header);
  55                 if (empty($http_signer)) {
  56                         logger('Invalid HTTP signature, message will be discarded.', LOGGER_DEBUG);
  57                         return;
  58                 } else {
  59                         logger('HTTP signature is signed by ' . $http_signer, LOGGER_DEBUG);
  60                 }
  61
  62                 $activity = json_decode($body, true);
  63
  64                 $actor = JsonLD::fetchElement($activity, 'actor', 'id');
  65                 logger('Message for user ' . $uid . ' is from actor ' . $actor, LOGGER_DEBUG);
  66
  67                 if (empty($activity)) {
  68                         logger('Invalid body.', LOGGER_DEBUG);
  69                         return;
  70                 }
  71
  72                 if (LDSignature::isSigned($activity)) {
  73                         $ld_signer = LDSignature::getSigner($activity);
  74                         if (empty($ld_signer)) {
  75                                 logger('Invalid JSON-LD signature from ' . $actor, LOGGER_DEBUG);
  76                         }
  77                         if (!empty($ld_signer && ($actor == $http_signer))) {
  78                                 logger('The HTTP and the JSON-LD signature belong to ' . $ld_signer, LOGGER_DEBUG);
  79                                 $trust_source = true;
  80                         } elseif (!empty($ld_signer)) {
  81                                 logger('JSON-LD signature is signed by ' . $ld_signer, LOGGER_DEBUG);
  82                                 $trust_source = true;
  83                         } elseif ($actor == $http_signer) {
  84                                 logger('Bad JSON-LD signature, but HTTP signer fits the actor.', LOGGER_DEBUG);
  85                                 $trust_source = true;
  86                         } else {
  87                                 logger('Invalid JSON-LD signature and the HTTP signer is different.', LOGGER_DEBUG);
  88                                 $trust_source = false;
  89                         }
  90                 } elseif ($actor == $http_signer) {
  91                         logger('Trusting post without JSON-LD signature, The actor fits the HTTP signer.', LOGGER_DEBUG);
  92                         $trust_source = true;
  93                 } else {
  94                         logger('No JSON-LD signature, different actor.', LOGGER_DEBUG);
  95                         $trust_source = false;
  96                 }
  97
  98                 self::processActivity($activity, $body, $uid, $trust_source);
  99         }
 100
 101         /**
 102          * @brief
 103          *
 104          * @param array $activity
 105          * @param integer $uid User ID
 106          * @param $trust_source
 107          *
 108          * @return
 109          */
 110         private static function prepareObjectData($activity, $uid, &$trust_source)
 111         {
 112                 $actor = JsonLD::fetchElement($activity, 'actor', 'id');
 113                 if (empty($actor)) {
 114                         logger('Empty actor', LOGGER_DEBUG);
 115                         return [];
 116                 }
 117
 118                 // Fetch all receivers from to, cc, bto and bcc
 119                 $receivers = self::getReceivers($activity, $actor);
 120
 121                 // When it is a delivery to a personal inbox we add that user to the receivers
 122                 if (!empty($uid)) {
 123                         $owner = User::getOwnerDataById($uid);
 124                         $additional = ['uid:' . $uid => $uid];
 125                         $receivers = array_merge($receivers, $additional);
 126                 }
 127
 128                 logger('Receivers: ' . json_encode($receivers), LOGGER_DEBUG);
 129
 130                 $object_id = JsonLD::fetchElement($activity, 'object', 'id');
 131                 if (empty($object_id)) {
 132                         logger('No object found', LOGGER_DEBUG);
 133                         return [];
 134                 }
 135
 136                 // Fetch the content only on activities where this matters
 137                 if (in_array($activity['type'], ['Create', 'Announce'])) {
 138                         $object_data = self::fetchObject($object_id, $activity['object'], $trust_source);
 139                         if (empty($object_data)) {
 140                                 logger("Object data couldn't be processed", LOGGER_DEBUG);
 141                                 return [];
 142                         }
 143                         // We had been able to retrieve the object data - so we can trust the source
 144                         $trust_source = true;
 145                 } elseif (in_array($activity['type'], ['Like', 'Dislike'])) {
 146                         // Create a mostly empty array out of the activity data (instead of the object).
 147                         // This way we later don't have to check for the existence of ech individual array element.
 148                         $object_data = self::processObject($activity);
 149                         $object_data['name'] = $activity['type'];
 150                         $object_data['author'] = $activity['actor'];
 151                         $object_data['object'] = $object_id;
 152                         $object_data['object_type'] = ''; // Since we don't fetch the object, we don't know the type
 153                 } else {
 154                         $object_data = [];
 155                         $object_data['id'] = $activity['id'];
 156                         $object_data['object'] = $activity['object'];
 157                         $object_data['object_type'] = JsonLD::fetchElement($activity, 'object', 'type');
 158                 }
 159
 160                 $object_data = self::addActivityFields($object_data, $activity);
 161
 162                 $object_data['type'] = $activity['type'];
 163                 $object_data['owner'] = $actor;
 164                 $object_data['receiver'] = array_merge(defaults($object_data, 'receiver', []), $receivers);
 165
 166                 logger('Processing ' . $object_data['type'] . ' ' . $object_data['object_type'] . ' ' . $object_data['id'], LOGGER_DEBUG);
 167
 168                 return $object_data;
 169         }
 170
 171         /**
 172          * @brief
 173          *
 174          * @param array $activity
 175          * @param $body
 176          * @param integer $uid User ID
 177          * @param $trust_source
 178          */
 179         public static function processActivity($activity, $body = '', $uid = null, $trust_source = false)
 180         {
 181                 if (empty($activity['type'])) {
 182                         logger('Empty type', LOGGER_DEBUG);
 183                         return;
 184                 }
 185
 186                 if (empty($activity['object'])) {
 187                         logger('Empty object', LOGGER_DEBUG);
 188                         return;
 189                 }
 190
 191                 if (empty($activity['actor'])) {
 192                         logger('Empty actor', LOGGER_DEBUG);
 193                         return;
 194
 195                 }
 196
 197                 // $trust_source is called by reference and is set to true if the content was retrieved successfully
 198                 $object_data = self::prepareObjectData($activity, $uid, $trust_source);
 199                 if (empty($object_data)) {
 200                         logger('No object data found', LOGGER_DEBUG);
 201                         return;
 202                 }
 203
 204                 if (!$trust_source) {
 205                         logger('No trust for activity type "' . $activity['type'] . '", so we quit now.', LOGGER_DEBUG);
 206                 }
 207
 208                 switch ($activity['type']) {
 209                         case 'Create':
 210                         case 'Announce':
 211                                 ActivityPub\Processor::createItem($object_data, $body);
 212                                 break;
 213
 214                         case 'Like':
 215                                 ActivityPub\Processor::likeItem($object_data, $body);
 216                                 break;
 217
 218                         case 'Dislike':
 219                                 ActivityPub\Processor::dislikeItem($object_data, $body);
 220                                 break;
 221
 222                         case 'Update':
 223                                 if (in_array($object_data['object_type'], ActivityPub::CONTENT_TYPES)) {
 224                                         /// @todo
 225                                 } elseif (in_array($object_data['object_type'], ActivityPub::ACCOUNT_TYPES)) {
 226                                         ActivityPub\Processor::updatePerson($object_data, $body);
 227                                 }
 228                                 break;
 229
 230                         case 'Delete':
 231                                 if ($object_data['object_type'] == 'Tombstone') {
 232                                         ActivityPub\Processor::deleteItem($object_data, $body);
 233                                 } elseif (in_array($object_data['object_type'], ActivityPub::ACCOUNT_TYPES)) {
 234                                         ActivityPub\Processor::deletePerson($object_data, $body);
 235                                 }
 236                                 break;
 237
 238                         case 'Follow':
 239                                 ActivityPub\Processor::followUser($object_data);
 240                                 break;
 241
 242                         case 'Accept':
 243                                 if ($object_data['object_type'] == 'Follow') {
 244                                         ActivityPub\Processor::acceptFollowUser($object_data);
 245                                 }
 246                                 break;
 247
 248                         case 'Reject':
 249                                 if ($object_data['object_type'] == 'Follow') {
 250                                         ActivityPub\Processor::rejectFollowUser($object_data);
 251                                 }
 252                                 break;
 253
 254                         case 'Undo':
 255                                 if ($object_data['object_type'] == 'Follow') {
 256                                         ActivityPub\Processor::undoFollowUser($object_data);
 257                                 } elseif (in_array($object_data['object_type'], ActivityPub::ACTIVITY_TYPES)) {
 258                                         ActivityPub\Processor::undoActivity($object_data);
 259                                 }
 260                                 break;
 261
 262                         default:
 263                                 logger('Unknown activity: ' . $activity['type'], LOGGER_DEBUG);
 264                                 break;
 265                 }
 266         }
 267
 268         /**
 269          * @brief
 270          *
 271          * @param array $activity
 272          * @param $actor
 273          *
 274          * @return
 275          */
 276         private static function getReceivers($activity, $actor)
 277         {
 278                 $receivers = [];
 279
 280                 // When it is an answer, we inherite the receivers from the parent
 281                 $replyto = JsonLD::fetchElement($activity, 'inReplyTo', 'id');
 282                 if (!empty($replyto)) {
 283                         $parents = Item::select(['uid'], ['uri' => $replyto]);
 284                         while ($parent = Item::fetch($parents)) {
 285                                 $receivers['uid:' . $parent['uid']] = $parent['uid'];
 286                         }
 287                 }
 288
 289                 if (!empty($actor)) {
 290                         $profile = APContact::getByURL($actor);
 291                         $followers = defaults($profile, 'followers', '');
 292
 293                         logger('Actor: ' . $actor . ' - Followers: ' . $followers, LOGGER_DEBUG);
 294                 } else {
 295                         logger('Empty actor', LOGGER_DEBUG);
 296                         $followers = '';
 297                 }
 298
 299                 foreach (['to', 'cc', 'bto', 'bcc'] as $element) {
 300                         if (empty($activity[$element])) {
 301                                 continue;
 302                         }
 303
 304                         // The receiver can be an array or a string
 305                         if (is_string($activity[$element])) {
 306                                 $activity[$element] = [$activity[$element]];
 307                         }
 308
 309                         foreach ($activity[$element] as $receiver) {
 310                                 if ($receiver == ActivityPub::PUBLIC_COLLECTION) {
 311                                         $receivers['uid:0'] = 0;
 312                                 }
 313
 314                                 if (($receiver == ActivityPub::PUBLIC_COLLECTION) && !empty($actor)) {
 315                                         // This will most likely catch all OStatus connections to Mastodon
 316                                         $condition = ['alias' => [$actor, normalise_link($actor)], 'rel' => [Contact::SHARING, Contact::FRIEND]
 317                                                 , 'archive' => false, 'pending' => false];
 318                                         $contacts = DBA::select('contact', ['uid'], $condition);
 319                                         while ($contact = DBA::fetch($contacts)) {
 320                                                 if ($contact['uid'] != 0) {
 321                                                         $receivers['uid:' . $contact['uid']] = $contact['uid'];
 322                                                 }
 323                                         }
 324                                         DBA::close($contacts);
 325                                 }
 326
 327                                 if (in_array($receiver, [$followers, ActivityPub::PUBLIC_COLLECTION]) && !empty($actor)) {
 328                                         $condition = ['nurl' => normalise_link($actor), 'rel' => [Contact::SHARING, Contact::FRIEND],
 329                                                 'network' => Protocol::ACTIVITYPUB, 'archive' => false, 'pending' => false];
 330                                         $contacts = DBA::select('contact', ['uid'], $condition);
 331                                         while ($contact = DBA::fetch($contacts)) {
 332                                                 if ($contact['uid'] != 0) {
 333                                                         $receivers['uid:' . $contact['uid']] = $contact['uid'];
 334                                                 }
 335                                         }
 336                                         DBA::close($contacts);
 337                                         continue;
 338                                 }
 339
 340                                 $condition = ['self' => true, 'nurl' => normalise_link($receiver)];
 341                                 $contact = DBA::selectFirst('contact', ['uid'], $condition);
 342                                 if (!DBA::isResult($contact)) {
 343                                         continue;
 344                                 }
 345                                 $receivers['uid:' . $contact['uid']] = $contact['uid'];
 346                         }
 347                 }
 348
 349                 self::switchContacts($receivers, $actor);
 350
 351                 return $receivers;
 352         }
 353
 354         /**
 355          * @brief
 356          *
 357          * @param $cid
 358          * @param integer $uid User ID
 359          * @param $url
 360          */
 361         private static function switchContact($cid, $uid, $url)
 362         {
 363                 $profile = ActivityPub::probeProfile($url);
 364                 if (empty($profile)) {
 365                         return;
 366                 }
 367
 368                 logger('Switch contact ' . $cid . ' (' . $profile['url'] . ') for user ' . $uid . ' from OStatus to ActivityPub');
 369
 370                 $photo = $profile['photo'];
 371                 unset($profile['photo']);
 372                 unset($profile['baseurl']);
 373
 374                 $profile['nurl'] = normalise_link($profile['url']);
 375                 DBA::update('contact', $profile, ['id' => $cid]);
 376
 377                 Contact::updateAvatar($photo, $uid, $cid);
 378         }
 379
 380         /**
 381          * @brief
 382          *
 383          * @param $receivers
 384          * @param $actor
 385          */
 386         private static function switchContacts($receivers, $actor)
 387         {
 388                 if (empty($actor)) {
 389                         return;
 390                 }
 391
 392                 foreach ($receivers as $receiver) {
 393                         $contact = DBA::selectFirst('contact', ['id'], ['uid' => $receiver, 'network' => Protocol::OSTATUS, 'nurl' => normalise_link($actor)]);
 394                         if (DBA::isResult($contact)) {
 395                                 self::switchContact($contact['id'], $receiver, $actor);
 396                         }
 397
 398                         $contact = DBA::selectFirst('contact', ['id'], ['uid' => $receiver, 'network' => Protocol::OSTATUS, 'alias' => [normalise_link($actor), $actor]]);
 399                         if (DBA::isResult($contact)) {
 400                                 self::switchContact($contact['id'], $receiver, $actor);
 401                         }
 402                 }
 403         }
 404
 405         /**
 406          * @brief
 407          *
 408          * @param $object_data
 409          * @param array $activity
 410          *
 411          * @return
 412          */
 413         private static function addActivityFields($object_data, $activity)
 414         {
 415                 if (!empty($activity['published']) && empty($object_data['published'])) {
 416                         $object_data['published'] = $activity['published'];
 417                 }
 418
 419                 if (!empty($activity['updated']) && empty($object_data['updated'])) {
 420                         $object_data['updated'] = $activity['updated'];
 421                 }
 422
 423                 if (!empty($activity['inReplyTo']) && empty($object_data['parent-uri'])) {
 424                         $object_data['parent-uri'] = JsonLD::fetchElement($activity, 'inReplyTo', 'id');
 425                 }
 426
 427                 if (!empty($activity['instrument'])) {
 428                         $object_data['service'] = JsonLD::fetchElement($activity, 'instrument', 'name', 'type', 'Service');
 429                 }
 430                 return $object_data;
 431         }
 432
 433         /**
 434          * @brief
 435          *
 436          * @param $object_id
 437          * @param $object
 438          * @param $trust_source
 439          *
 440          * @return
 441          */
 442         private static function fetchObject($object_id, $object = [], $trust_source = false)
 443         {
 444                 if (!$trust_source || is_string($object)) {
 445                         $data = ActivityPub::fetchContent($object_id);
 446                         if (empty($data)) {
 447                                 logger('Empty content for ' . $object_id . ', check if content is available locally.', LOGGER_DEBUG);
 448                                 $data = $object_id;
 449                         } else {
 450                                 logger('Fetched content for ' . $object_id, LOGGER_DEBUG);
 451                         }
 452                 } else {
 453                         logger('Using original object for url ' . $object_id, LOGGER_DEBUG);
 454                         $data = $object;
 455                 }
 456
 457                 if (is_string($data)) {
 458                         $item = Item::selectFirst([], ['uri' => $data]);
 459                         if (!DBA::isResult($item)) {
 460                                 logger('Object with url ' . $data . ' was not found locally.', LOGGER_DEBUG);
 461                                 return false;
 462                         }
 463                         logger('Using already stored item for url ' . $object_id, LOGGER_DEBUG);
 464                         $data = ActivityPub\Transmitter::createNote($item);
 465                 }
 466
 467                 if (empty($data['type'])) {
 468                         logger('Empty type', LOGGER_DEBUG);
 469                         return false;
 470                 }
 471
 472                 if (in_array($data['type'], ActivityPub::CONTENT_TYPES)) {
 473                         return self::processObject($data);
 474                 }
 475
 476                 if ($data['type'] == 'Announce') {
 477                         if (empty($data['object'])) {
 478                                 return false;
 479                         }
 480                         return self::fetchObject($data['object']);
 481                 }
 482
 483                 logger('Unhandled object type: ' . $data['type'], LOGGER_DEBUG);
 484         }
 485
 486         /**
 487          * @brief
 488          *
 489          * @param $object
 490          *
 491          * @return
 492          */
 493         private static function processObject($object)
 494         {
 495                 if (empty($object['id'])) {
 496                         return false;
 497                 }
 498
 499                 $object_data = [];
 500                 $object_data['object_type'] = $object['type'];
 501                 $object_data['id'] = $object['id'];
 502
 503                 if (!empty($object['inReplyTo'])) {
 504                         $object_data['reply-to-id'] = JsonLD::fetchElement($object, 'inReplyTo', 'id');
 505                 } else {
 506                         $object_data['reply-to-id'] = $object_data['id'];
 507                 }
 508
 509                 $object_data['published'] = defaults($object, 'published', null);
 510                 $object_data['updated'] = defaults($object, 'updated', $object_data['published']);
 511
 512                 if (empty($object_data['published']) && !empty($object_data['updated'])) {
 513                         $object_data['published'] = $object_data['updated'];
 514                 }
 515
 516                 $actor = JsonLD::fetchElement($object, 'attributedTo', 'id');
 517                 if (empty($actor)) {
 518                         $actor = defaults($object, 'actor', null);
 519                 }
 520
 521                 $object_data['diaspora:guid'] = defaults($object, 'diaspora:guid', null);
 522                 $object_data['owner'] = $object_data['author'] = $actor;
 523                 $object_data['context'] = defaults($object, 'context', null);
 524                 $object_data['conversation'] = defaults($object, 'conversation', null);
 525                 $object_data['sensitive'] = defaults($object, 'sensitive', null);
 526                 $object_data['name'] = defaults($object, 'title', null);
 527                 $object_data['name'] = defaults($object, 'name', $object_data['name']);
 528                 $object_data['summary'] = defaults($object, 'summary', null);
 529                 $object_data['content'] = defaults($object, 'content', null);
 530                 $object_data['source'] = defaults($object, 'source', null);
 531                 $object_data['location'] = JsonLD::fetchElement($object, 'location', 'name', 'type', 'Place');
 532                 $object_data['attachments'] = defaults($object, 'attachment', null);
 533                 $object_data['tags'] = defaults($object, 'tag', null);
 534                 $object_data['service'] = JsonLD::fetchElement($object, 'instrument', 'name', 'type', 'Service');
 535                 $object_data['alternate-url'] = JsonLD::fetchElement($object, 'url', 'href');
 536                 $object_data['receiver'] = self::getReceivers($object, $object_data['owner']);
 537
 538                 // Common object data:
 539
 540                 // Unhandled
 541                 // @context, type, actor, signature, mediaType, duration, replies, icon
 542
 543                 // Also missing: (Defined in the standard, but currently unused)
 544                 // audience, preview, endTime, startTime, generator, image
 545
 546                 // Data in Notes:
 547
 548                 // Unhandled
 549                 // contentMap, announcement_count, announcements, context_id, likes, like_count
 550                 // inReplyToStatusId, shares, quoteUrl, statusnetConversationId
 551
 552                 // Data in video:
 553
 554                 // To-Do?
 555                 // category, licence, language, commentsEnabled
 556
 557                 // Unhandled
 558                 // views, waitTranscoding, state, support, subtitleLanguage
 559                 // likes, dislikes, shares, comments
 560
 561                 return $object_data;
 562         }
 563 }