src/Protocol/ActivityPub.php

   1 <?php
   2 /**
   3  * @file src/Protocol/ActivityPub.php
   4  */
   5 namespace Friendica\Protocol;
   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\Item;
  16 use Friendica\Model\Term;
  17 use Friendica\Model\User;
  18 use Friendica\Util\DateTimeFormat;
  19 use Friendica\Util\Crypto;
  20 use Friendica\Content\Text\BBCode;
  21 use Friendica\Content\Text\HTML;
  22
  23 /**
  24  * @brief ActivityPub Protocol class
  25  * The ActivityPub Protocol is a message exchange protocol defined by the W3C.
  26  * https://www.w3.org/TR/activitypub/
  27  * https://www.w3.org/TR/activitystreams-core/
  28  * https://www.w3.org/TR/activitystreams-vocabulary/
  29  *
  30  * https://blog.joinmastodon.org/2018/06/how-to-implement-a-basic-activitypub-server/
  31  * https://blog.joinmastodon.org/2018/07/how-to-make-friends-and-verify-requests/
  32  *
  33  * Digest: https://tools.ietf.org/html/rfc5843
  34  * https://tools.ietf.org/html/draft-cavage-http-signatures-10#ref-15
  35  * https://github.com/digitalbazaar/php-json-ld
  36  *
  37  * Part of the code for HTTP signing is taken from the Osada project.
  38  * https://framagit.org/macgirvin/osada
  39  *
  40  * To-do:
  41  *
  42  * Receiver:
  43  * - Activities: Dislike, Update, Delete
  44  * - Object Types: Person, Tombstome
  45  *
  46  * Transmitter:
  47  * - Activities: Like, Dislike, Update, Delete
  48  * - Object Tyoes: Article, Announce, Person, Tombstone
  49  *
  50  * General:
  51  * - Message distribution
  52  * - Endpoints: Outbox, Object, Follower, Following
  53  * - General cleanup
  54  */
  55 class ActivityPub
  56 {
  57         const PUBLIC = 'https://www.w3.org/ns/activitystreams#Public';
  58
  59         public static function isRequest()
  60         {
  61                 return stristr(defaults($_SERVER, 'HTTP_ACCEPT', ''), 'application/activity+json') ||
  62                         stristr(defaults($_SERVER, 'HTTP_ACCEPT', ''), 'application/ld+json');
  63         }
  64
  65         public static function transmit($data, $target, $uid)
  66         {
  67                 $owner = User::getOwnerDataById($uid);
  68
  69                 if (!$owner) {
  70                         return;
  71                 }
  72
  73                 $content = json_encode($data);
  74
  75                 // Header data that is about to be signed.
  76                 $host = parse_url($target, PHP_URL_HOST);
  77                 $path = parse_url($target, PHP_URL_PATH);
  78                 $digest = 'SHA-256=' . base64_encode(hash('sha256', $content, true));
  79                 $content_length = strlen($content);
  80
  81                 $headers = ['Content-Length: ' . $content_length, 'Digest: ' . $digest, 'Host: ' . $host];
  82
  83                 $signed_data = "(request-target): post " . $path . "\ncontent-length: " . $content_length . "\ndigest: " . $digest . "\nhost: " . $host;
  84
  85                 $signature = base64_encode(Crypto::rsaSign($signed_data, $owner['uprvkey'], 'sha256'));
  86
  87                 $headers[] = 'Signature: keyId="' . $owner['url'] . '#main-key' . '",algorithm="rsa-sha256",headers="(request-target) content-length digest host",signature="' . $signature . '"';
  88
  89                 $headers[] = 'Content-Type: application/activity+json';
  90
  91                 Network::post($target, $content, $headers);
  92                 $return_code = BaseObject::getApp()->get_curl_code();
  93
  94                 logger('Transmit to ' . $target . ' returned ' . $return_code);
  95         }
  96
  97         /**
  98          * Return the ActivityPub profile of the given user
  99          *
 100          * @param integer $uid User ID
 101          * @return array
 102          */
 103         public static function profile($uid)
 104         {
 105                 $accounttype = ['Person', 'Organization', 'Service', 'Group', 'Application', 'page-flags'];
 106                 $condition = ['uid' => $uid, 'blocked' => false, 'account_expired' => false,
 107                         'account_removed' => false, 'verified' => true];
 108                 $fields = ['guid', 'nickname', 'pubkey', 'account-type'];
 109                 $user = DBA::selectFirst('user', $fields, $condition);
 110                 if (!DBA::isResult($user)) {
 111                         return [];
 112                 }
 113
 114                 $fields = ['locality', 'region', 'country-name'];
 115                 $profile = DBA::selectFirst('profile', $fields, ['uid' => $uid, 'is-default' => true]);
 116                 if (!DBA::isResult($profile)) {
 117                         return [];
 118                 }
 119
 120                 $fields = ['name', 'url', 'location', 'about', 'avatar'];
 121                 $contact = DBA::selectFirst('contact', $fields, ['uid' => $uid, 'self' => true]);
 122                 if (!DBA::isResult($contact)) {
 123                         return [];
 124                 }
 125
 126                 $data = ['@context' => ['https://www.w3.org/ns/activitystreams', 'https://w3id.org/security/v1',
 127                         ['vcard' => 'http://www.w3.org/2006/vcard/ns#', 'uuid' => 'http://schema.org/identifier',
 128                         'sensitive' => 'as:sensitive', 'manuallyApprovesFollowers' => 'as:manuallyApprovesFollowers']]];
 129
 130                 $data['id'] = $contact['url'];
 131                 $data['uuid'] = $user['guid'];
 132                 $data['type'] = $accounttype[$user['account-type']];
 133                 $data['following'] = System::baseUrl() . '/following/' . $user['nickname'];
 134                 $data['followers'] = System::baseUrl() . '/followers/' . $user['nickname'];
 135                 $data['inbox'] = System::baseUrl() . '/inbox/' . $user['nickname'];
 136                 $data['outbox'] = System::baseUrl() . '/outbox/' . $user['nickname'];
 137                 $data['preferredUsername'] = $user['nickname'];
 138                 $data['name'] = $contact['name'];
 139                 $data['vcard:hasAddress'] = ['@type' => 'vcard:Home', 'vcard:country-name' => $profile['country-name'],
 140                         'vcard:region' => $profile['region'], 'vcard:locality' => $profile['locality']];
 141                 $data['summary'] = $contact['about'];
 142                 $data['url'] = $contact['url'];
 143                 $data['manuallyApprovesFollowers'] = in_array($profile['page-flags'], [Contact::PAGE_NORMAL, Contact::PAGE_PRVGROUP]);
 144                 $data['publicKey'] = ['id' => $contact['url'] . '#main-key',
 145                         'owner' => $contact['url'],
 146                         'publicKeyPem' => $user['pubkey']];
 147                 $data['endpoints'] = ['sharedInbox' => System::baseUrl() . '/inbox'];
 148                 $data['icon'] = ['type' => 'Image',
 149                         'url' => $contact['avatar']];
 150
 151                 // tags: https://kitty.town/@inmysocks/100656097926961126.json
 152                 return $data;
 153         }
 154
 155         public static function createPermissionBlockForItem($item)
 156         {
 157                 $data = ['to' => [], 'cc' => []];
 158
 159                 $terms = Term::tagArrayFromItemId($item['id']);
 160
 161                 if (!$item['private']) {
 162                         $data['to'][] = self::PUBLIC;
 163                         $data['cc'][] = System::baseUrl() . '/followers/' . $item['author-nick'];
 164
 165                         foreach ($terms as $term) {
 166                                 if ($term['type'] != TERM_MENTION) {
 167                                         continue;
 168                                 }
 169                                 $profile = self::fetchprofile($term['url']);
 170                                 if (!empty($profile)) {
 171                                         $data['cc'][] = $profile['url'];
 172                                 }
 173                         }
 174                 } else {
 175                         //$data['cc'][] = System::baseUrl() . '/followers/' . $item['author-nick'];
 176                         $receiver_list = Item::enumeratePermissions($item);
 177
 178                         $mentioned = [];
 179
 180                         foreach ($terms as $term) {
 181                                 if ($term['type'] != TERM_MENTION) {
 182                                         continue;
 183                                 }
 184                                 $cid = Contact::getIdForURL($term['url'], $item['uid']);
 185                                 if (!empty($cid) && in_array($cid, $receiver_list)) {
 186                                         $contact = DBA::selectFirst('contact', ['url'], ['id' => $cid, 'network' => Protocol::ACTIVITYPUB]);
 187                                         $data['to'][] = $contact['url'];
 188                                 }
 189                         }
 190
 191                         foreach ($receiver_list as $receiver) {
 192                                 $contact = DBA::selectFirst('contact', ['url'], ['id' => $receiver, 'network' => Protocol::ACTIVITYPUB]);
 193                                 $data['cc'][] = $contact['url'];
 194                         }
 195
 196                         if (empty($data['to'])) {
 197                                 $data['to'] = $data['cc'];
 198                                 $data['cc'] = [];
 199                         }
 200                 }
 201
 202                 return $data;
 203         }
 204
 205         public static function fetchTargetInboxes($item)
 206         {
 207                 $inboxes = [];
 208
 209                 $terms = Term::tagArrayFromItemId($item['id']);
 210                 if (!$item['private']) {
 211                         $contacts = DBA::select('contact', ['notify', 'batch'], ['uid' => $item['uid'],
 212                                         'rel' => [Contact::FOLLOWER, Contact::FRIEND], 'network' => Protocol::ACTIVITYPUB]);
 213                         while ($contact = DBA::fetch($contacts)) {
 214                                 $contact = defaults($contact, 'batch', $contact['notify']);
 215                                 $inboxes[$contact] = $contact;
 216                         }
 217                         DBA::close($contacts);
 218
 219                         foreach ($terms as $term) {
 220                                 if ($term['type'] != TERM_MENTION) {
 221                                         continue;
 222                                 }
 223                                 $profile = self::fetchprofile($term['url']);
 224                                 if (!empty($profile)) {
 225                                         $target = defaults($profile, 'sharedinbox', $profile['inbox']);
 226                                         $inboxes[$target] = $target;
 227                                 }
 228                         }
 229                 } else {
 230                         $receiver_list = Item::enumeratePermissions($item);
 231
 232                         $mentioned = [];
 233
 234                         foreach ($terms as $term) {
 235                                 if ($term['type'] != TERM_MENTION) {
 236                                         continue;
 237                                 }
 238                                 $cid = Contact::getIdForURL($term['url'], $item['uid']);
 239                                 if (!empty($cid) && in_array($cid, $receiver_list)) {
 240                                         $contact = DBA::selectFirst('contact', ['url'], ['id' => $cid, 'network' => Protocol::ACTIVITYPUB]);
 241                                         $profile = self::fetchprofile($contact['url']);
 242                                         if (!empty($profile['network'])) {
 243                                                 $target = defaults($profile, 'sharedinbox', $profile['inbox']);
 244                                                 $inboxes[$target] = $target;
 245                                         }
 246                                 }
 247                         }
 248
 249                         foreach ($receiver_list as $receiver) {
 250                                 $contact = DBA::selectFirst('contact', ['url'], ['id' => $receiver, 'network' => Protocol::ACTIVITYPUB]);
 251                                 $profile = self::fetchprofile($contact['url']);
 252                                 if (!empty($profile['network'])) {
 253                                         $target = defaults($profile, 'sharedinbox', $profile['inbox']);
 254                                         $inboxes[$target] = $target;
 255                                 }
 256                         }
 257                 }
 258
 259                 $profile = self::fetchprofile($item['author-link']);
 260                 if (!empty($profile['sharedinbox'])) {
 261                         unset($inboxes[$profile['sharedinbox']]);
 262                 }
 263
 264                 if (!empty($profile['inbox'])) {
 265                         unset($inboxes[$profile['inbox']]);
 266                 }
 267
 268                 return $inboxes;
 269         }
 270
 271         public static function createActivityFromItem($item_id)
 272         {
 273                 $item = Item::selectFirst([], ['id' => $item_id]);
 274
 275                 if (!DBA::isResult($item)) {
 276                         return false;
 277                 }
 278
 279                 $condition = ['item-uri' => $item['uri'], 'protocol' => Conversation::PARCEL_ACTIVITYPUB];
 280                 $conversation = DBA::selectFirst('conversation', ['source'], $condition);
 281                 if (DBA::isResult($conversation)) {
 282                         $data = json_decode($conversation['source']);
 283                         if (!empty($data)) {
 284                                 return $data;
 285                         }
 286                 }
 287
 288                 $data = ['@context' => ['https://www.w3.org/ns/activitystreams', 'https://w3id.org/security/v1',
 289                         ['ostatus' => 'http://ostatus.org#', 'sensitive' => 'as:sensitive',
 290                         'Hashtag' => 'as:Hashtag', 'atomUri' => 'ostatus:atomUri',
 291                         'conversation' => 'ostatus:conversation',
 292                         'inReplyToAtomUri' => 'ostatus:inReplyToAtomUri']]];
 293
 294                 $data['type'] = 'Create';
 295                 $data['id'] = $item['uri'] . '#activity';
 296                 $data['actor'] = $item['author-link'];
 297
 298                 $data['published'] = DateTimeFormat::utc($item["created"]."+00:00", DateTimeFormat::ATOM);
 299
 300                 if ($item["created"] != $item["edited"]) {
 301                         $data['updated'] = DateTimeFormat::utc($item["edited"]."+00:00", DateTimeFormat::ATOM);
 302                 }
 303
 304                 $data = array_merge($data, ActivityPub::createPermissionBlockForItem($item));
 305
 306                 $data['object'] = self::createNote($item);
 307                 return $data;
 308         }
 309
 310         public static function createObjectFromItemID($item_id)
 311         {
 312                 $item = Item::selectFirst([], ['id' => $item_id]);
 313
 314                 if (!DBA::isResult($item)) {
 315                         return false;
 316                 }
 317
 318                 $data = ['@context' => ['https://www.w3.org/ns/activitystreams', 'https://w3id.org/security/v1',
 319                         ['ostatus' => 'http://ostatus.org#', 'sensitive' => 'as:sensitive',
 320                         'Hashtag' => 'as:Hashtag', 'atomUri' => 'ostatus:atomUri',
 321                         'conversation' => 'ostatus:conversation',
 322                         'inReplyToAtomUri' => 'ostatus:inReplyToAtomUri']]];
 323
 324                 $data = array_merge($data, self::createNote($item));
 325
 326
 327                 return $data;
 328         }
 329
 330         private static function createTagList($item)
 331         {
 332                 $tags = [];
 333
 334                 $terms = Term::tagArrayFromItemId($item['id']);
 335                 foreach ($terms as $term) {
 336                         if ($term['type'] == TERM_MENTION) {
 337                                 $contact = Contact::getDetailsByURL($term['url']);
 338                                 if (!empty($contact['addr'])) {
 339                                         $mention = '@' . $contact['addr'];
 340                                 } else {
 341                                         $mention = '@' . $term['url'];
 342                                 }
 343
 344                                 $tags[] = ['type' => 'Mention', 'href' => $term['url'], 'name' => $mention];
 345                         }
 346                 }
 347
 348                 return $tags;
 349         }
 350
 351         public static function createNote($item)
 352         {
 353                 $data = [];
 354                 $data['type'] = 'Note';
 355                 $data['id'] = $item['uri'];
 356
 357                 if ($item['uri'] != $item['thr-parent']) {
 358                         $data['inReplyTo'] = $item['thr-parent'];
 359                 }
 360
 361                 $conversation = DBA::selectFirst('conversation', ['conversation-uri'], ['item-uri' => $item['parent-uri']]);
 362                 if (DBA::isResult($conversation) && !empty($conversation['conversation-uri'])) {
 363                         $conversation_uri = $conversation['conversation-uri'];
 364                 } else {
 365                         $conversation_uri = $item['parent-uri'];
 366                 }
 367
 368                 $data['context'] = $data['conversation'] = $conversation_uri;
 369                 $data['actor'] = $item['author-link'];
 370                 $data = array_merge($data, ActivityPub::createPermissionBlockForItem($item));
 371                 $data['published'] = DateTimeFormat::utc($item["created"]."+00:00", DateTimeFormat::ATOM);
 372
 373                 if ($item["created"] != $item["edited"]) {
 374                         $data['updated'] = DateTimeFormat::utc($item["edited"]."+00:00", DateTimeFormat::ATOM);
 375                 }
 376
 377                 $data['attributedTo'] = $item['author-link'];
 378                 $data['name'] = BBCode::convert($item['title'], false, 7);
 379                 $data['content'] = BBCode::convert($item['body'], false, 7);
 380                 $data['source'] = ['content' => $item['body'], 'mediaType' => "text/bbcode"];
 381                 $data['summary'] = ''; // Ignore by now
 382                 $data['sensitive'] = false; // - Query NSFW
 383                 //$data['emoji'] = []; // Ignore by now
 384                 $data['tag'] = self::createTagList($item);
 385                 $data['attachment'] = []; // @ToDo
 386                 return $data;
 387         }
 388
 389         public static function transmitActivity($activity, $target, $uid)
 390         {
 391                 $profile = self::fetchprofile($target);
 392
 393                 $owner = User::getOwnerDataById($uid);
 394
 395                 $data = ['@context' => 'https://www.w3.org/ns/activitystreams',
 396                         'id' => System::baseUrl() . '/activity/' . System::createGUID(),
 397                         'type' => $activity,
 398                         'actor' => $owner['url'],
 399                         'object' => $profile['url'],
 400                         'to' => $profile['url']];
 401
 402                 logger('Sending activity ' . $activity . ' to ' . $target . ' for user ' . $uid, LOGGER_DEBUG);
 403                 return self::transmit($data,  $profile['inbox'], $uid);
 404         }
 405
 406         public static function transmitContactAccept($target, $id, $uid)
 407         {
 408                 $profile = self::fetchprofile($target);
 409
 410                 $owner = User::getOwnerDataById($uid);
 411                 $data = ['@context' => 'https://www.w3.org/ns/activitystreams',
 412                         'id' => System::baseUrl() . '/activity/' . System::createGUID(),
 413                         'type' => 'Accept',
 414                         'actor' => $owner['url'],
 415                         'object' => ['id' => $id, 'type' => 'Follow',
 416                                 'actor' => $profile['url'],
 417                                 'object' => $owner['url']],
 418                         'to' => $profile['url']];
 419
 420                 logger('Sending accept to ' . $target . ' for user ' . $uid . ' with id ' . $id, LOGGER_DEBUG);
 421                 return self::transmit($data,  $profile['inbox'], $uid);
 422         }
 423
 424         public static function transmitContactReject($target, $id, $uid)
 425         {
 426                 $profile = self::fetchprofile($target);
 427
 428                 $owner = User::getOwnerDataById($uid);
 429                 $data = ['@context' => 'https://www.w3.org/ns/activitystreams',
 430                         'id' => System::baseUrl() . '/activity/' . System::createGUID(),
 431                         'type' => 'Reject',
 432                         'actor' => $owner['url'],
 433                         'object' => ['id' => $id, 'type' => 'Follow',
 434                                 'actor' => $profile['url'],
 435                                 'object' => $owner['url']],
 436                         'to' => $profile['url']];
 437
 438                 logger('Sending reject to ' . $target . ' for user ' . $uid . ' with id ' . $id, LOGGER_DEBUG);
 439                 return self::transmit($data,  $profile['inbox'], $uid);
 440         }
 441
 442         public static function transmitContactUndo($target, $uid)
 443         {
 444                 $profile = self::fetchprofile($target);
 445
 446                 $id = System::baseUrl() . '/activity/' . System::createGUID();
 447
 448                 $owner = User::getOwnerDataById($uid);
 449                 $data = ['@context' => 'https://www.w3.org/ns/activitystreams',
 450                         'id' => $id,
 451                         'type' => 'Undo',
 452                         'actor' => $owner['url'],
 453                         'object' => ['id' => $id, 'type' => 'Follow',
 454                                 'actor' => $owner['url'],
 455                                 'object' => $profile['url']],
 456                         'to' => $profile['url']];
 457
 458                 logger('Sending undo to ' . $target . ' for user ' . $uid . ' with id ' . $id, LOGGER_DEBUG);
 459                 return self::transmit($data,  $profile['inbox'], $uid);
 460         }
 461
 462         /**
 463          * Fetches ActivityPub content from the given url
 464          *
 465          * @param string $url content url
 466          * @return array
 467          */
 468         public static function fetchContent($url)
 469         {
 470                 $ret = Network::curl($url, false, $redirects, ['accept_content' => 'application/activity+json, application/ld+json']);
 471                 if (!$ret['success'] || empty($ret['body'])) {
 472                         return;
 473                 }
 474
 475                 return json_decode($ret['body'], true);
 476         }
 477
 478         /**
 479          * Resolves the profile url from the address by using webfinger
 480          *
 481          * @param string $addr profile address (user@domain.tld)
 482          * @return string url
 483          */
 484         private static function addrToUrl($addr)
 485         {
 486                 $addr_parts = explode('@', $addr);
 487                 if (count($addr_parts) != 2) {
 488                         return false;
 489                 }
 490
 491                 $webfinger = 'https://' . $addr_parts[1] . '/.well-known/webfinger?resource=acct:' . urlencode($addr);
 492
 493                 $ret = Network::curl($webfinger, false, $redirects, ['accept_content' => 'application/jrd+json,application/json']);
 494                 if (!$ret['success'] || empty($ret['body'])) {
 495                         return false;
 496                 }
 497
 498                 $data = json_decode($ret['body'], true);
 499
 500                 if (empty($data['links'])) {
 501                         return false;
 502                 }
 503
 504                 foreach ($data['links'] as $link) {
 505                         if (empty($link['href']) || empty($link['rel']) || empty($link['type'])) {
 506                                 continue;
 507                         }
 508
 509                         if (($link['rel'] == 'self') && ($link['type'] == 'application/activity+json')) {
 510                                 return $link['href'];
 511                         }
 512                 }
 513
 514                 return false;
 515         }
 516
 517         public static function verifySignature($content, $http_headers)
 518         {
 519                 $object = json_decode($content, true);
 520
 521                 if (empty($object)) {
 522                         return false;
 523                 }
 524
 525                 $actor = self::processElement($object, 'actor', 'id');
 526
 527                 $headers = [];
 528                 $headers['(request-target)'] = strtolower($http_headers['REQUEST_METHOD']) . ' ' . $http_headers['REQUEST_URI'];
 529
 530                 // First take every header
 531                 foreach ($http_headers as $k => $v) {
 532                         $field = str_replace('_', '-', strtolower($k));
 533                         $headers[$field] = $v;
 534                 }
 535
 536                 // Now add every http header
 537                 foreach ($http_headers as $k => $v) {
 538                         if (strpos($k, 'HTTP_') === 0) {
 539                                 $field = str_replace('_', '-', strtolower(substr($k, 5)));
 540                                 $headers[$field] = $v;
 541                         }
 542                 }
 543
 544                 $sig_block = ActivityPub::parseSigHeader($http_headers['HTTP_SIGNATURE']);
 545
 546                 if (empty($sig_block) || empty($sig_block['headers']) || empty($sig_block['keyId'])) {
 547                         return false;
 548                 }
 549
 550                 $signed_data = '';
 551                 foreach ($sig_block['headers'] as $h) {
 552                         if (array_key_exists($h, $headers)) {
 553                                 $signed_data .= $h . ': ' . $headers[$h] . "\n";
 554                         }
 555                 }
 556                 $signed_data = rtrim($signed_data, "\n");
 557
 558                 if (empty($signed_data)) {
 559                         return false;
 560                 }
 561
 562                 $algorithm = null;
 563
 564                 if ($sig_block['algorithm'] === 'rsa-sha256') {
 565                         $algorithm = 'sha256';
 566                 }
 567
 568                 if ($sig_block['algorithm'] === 'rsa-sha512') {
 569                         $algorithm = 'sha512';
 570                 }
 571
 572                 if (empty($algorithm)) {
 573                         return false;
 574                 }
 575
 576                 $key = self::fetchKey($sig_block['keyId'], $actor);
 577
 578                 if (empty($key)) {
 579                         return false;
 580                 }
 581
 582                 if (!Crypto::rsaVerify($signed_data, $sig_block['signature'], $key, $algorithm)) {
 583                         return false;
 584                 }
 585
 586                 // Check the digest when it is part of the signed data
 587                 if (in_array('digest', $sig_block['headers'])) {
 588                         $digest = explode('=', $headers['digest'], 2);
 589                         if ($digest[0] === 'SHA-256') {
 590                                 $hashalg = 'sha256';
 591                         }
 592                         if ($digest[0] === 'SHA-512') {
 593                                 $hashalg = 'sha512';
 594                         }
 595
 596                         /// @todo add all hashes from the rfc
 597
 598                         if (!empty($hashalg) && base64_encode(hash($hashalg, $content, true)) != $digest[1]) {
 599                                 return false;
 600                         }
 601                 }
 602
 603                 // Check the content-length when it is part of the signed data
 604                 if (in_array('content-length', $sig_block['headers'])) {
 605                         if (strlen($content) != $headers['content-length']) {
 606                                 return false;
 607                         }
 608                 }
 609
 610                 return true;
 611
 612         }
 613
 614         private static function fetchKey($id, $actor)
 615         {
 616                 $url = (strpos($id, '#') ? substr($id, 0, strpos($id, '#')) : $id);
 617
 618                 $profile = self::fetchprofile($url);
 619                 if (!empty($profile)) {
 620                         return $profile['pubkey'];
 621                 } elseif ($url != $actor) {
 622                         $profile = self::fetchprofile($actor);
 623                         if (!empty($profile)) {
 624                                 return $profile['pubkey'];
 625                         }
 626                 }
 627
 628                 return false;
 629         }
 630
 631         /**
 632          * @brief
 633          *
 634          * @param string $header
 635          * @return array associate array with
 636          *   - \e string \b keyID
 637          *   - \e string \b algorithm
 638          *   - \e array  \b headers
 639          *   - \e string \b signature
 640          */
 641         private static function parseSigHeader($header)
 642         {
 643                 $ret = [];
 644                 $matches = [];
 645
 646                 if (preg_match('/keyId="(.*?)"/ism',$header,$matches)) {
 647                         $ret['keyId'] = $matches[1];
 648                 }
 649
 650                 if (preg_match('/algorithm="(.*?)"/ism',$header,$matches)) {
 651                         $ret['algorithm'] = $matches[1];
 652                 }
 653
 654                 if (preg_match('/headers="(.*?)"/ism',$header,$matches)) {
 655                         $ret['headers'] = explode(' ', $matches[1]);
 656                 }
 657
 658                 if (preg_match('/signature="(.*?)"/ism',$header,$matches)) {
 659                         $ret['signature'] = base64_decode(preg_replace('/\s+/','',$matches[1]));
 660                 }
 661
 662                 return $ret;
 663         }
 664
 665         public static function fetchprofile($url, $update = false)
 666         {
 667                 if (empty($url)) {
 668                         return false;
 669                 }
 670
 671                 if (!$update) {
 672                         $apcontact = DBA::selectFirst('apcontact', [], ['url' => $url]);
 673                         if (DBA::isResult($apcontact)) {
 674                                 return $apcontact;
 675                         }
 676
 677                         $apcontact = DBA::selectFirst('apcontact', [], ['alias' => $url]);
 678                         if (DBA::isResult($apcontact)) {
 679                                 return $apcontact;
 680                         }
 681
 682                         $apcontact = DBA::selectFirst('apcontact', [], ['addr' => $url]);
 683                         if (DBA::isResult($apcontact)) {
 684                                 return $apcontact;
 685                         }
 686                 }
 687
 688                 if (empty(parse_url($url, PHP_URL_SCHEME))) {
 689                         $url = self::addrToUrl($url);
 690                         if (empty($url)) {
 691                                 return false;
 692                         }
 693                 }
 694
 695                 $data = self::fetchContent($url);
 696
 697                 if (empty($data) || empty($data['id']) || empty($data['inbox'])) {
 698                         return false;
 699                 }
 700
 701                 $apcontact = [];
 702                 $apcontact['url'] = $data['id'];
 703                 $apcontact['uuid'] = defaults($data, 'uuid', null);
 704                 $apcontact['type'] = defaults($data, 'type', null);
 705                 $apcontact['following'] = defaults($data, 'following', null);
 706                 $apcontact['followers'] = defaults($data, 'followers', null);
 707                 $apcontact['inbox'] = defaults($data, 'inbox', null);
 708                 $apcontact['outbox'] = defaults($data, 'outbox', null);
 709                 $apcontact['sharedinbox'] = self::processElement($data, 'endpoints', 'sharedInbox');
 710                 $apcontact['nick'] = defaults($data, 'preferredUsername', null);
 711                 $apcontact['name'] = defaults($data, 'name', $apcontact['nick']);
 712                 $apcontact['about'] = defaults($data, 'summary', '');
 713                 $apcontact['photo'] = self::processElement($data, 'icon', 'url');
 714                 $apcontact['alias'] = self::processElement($data, 'url', 'href');
 715
 716                 $parts = parse_url($apcontact['url']);
 717                 unset($parts['scheme']);
 718                 unset($parts['path']);
 719                 $apcontact['addr'] = $apcontact['nick'] . '@' . str_replace('//', '', Network::unparseURL($parts));
 720
 721                 $apcontact['pubkey'] = trim(self::processElement($data, 'publicKey', 'publicKeyPem'));
 722
 723                 // To-Do
 724                 // manuallyApprovesFollowers
 725
 726                 // Unhandled
 727                 // @context, tag, attachment, image, nomadicLocations, signature, following, followers, featured, movedTo, liked
 728
 729                 // Unhandled from Misskey
 730                 // sharedInbox, isCat
 731
 732                 // Unhandled from Kroeg
 733                 // kroeg:blocks, updated
 734
 735                 // Check if the address is resolvable
 736                 if (self::addrToUrl($apcontact['addr']) == $apcontact['url']) {
 737                         $parts = parse_url($apcontact['url']);
 738                         unset($parts['path']);
 739                         $apcontact['baseurl'] = Network::unparseURL($parts);
 740                 } else {
 741                         $apcontact['addr'] = null;
 742                 }
 743
 744                 if ($apcontact['url'] == $apcontact['alias']) {
 745                         $apcontact['alias'] = null;
 746                 }
 747
 748                 $apcontact['updated'] = DateTimeFormat::utcNow();
 749
 750                 DBA::update('apcontact', $apcontact, ['url' => $url], true);
 751
 752                 return $apcontact;
 753         }
 754
 755         /**
 756          * Fetches a profile from the given url into an array that is compatible to Probe::uri
 757          *
 758          * @param string $url profile url
 759          * @return array
 760          */
 761         public static function probeProfile($url)
 762         {
 763                 $apcontact = self::fetchprofile($url, true);
 764                 if (empty($apcontact)) {
 765                         return false;
 766                 }
 767
 768                 $profile = ['network' => Protocol::ACTIVITYPUB];
 769                 $profile['nick'] = $apcontact['nick'];
 770                 $profile['name'] = $apcontact['name'];
 771                 $profile['guid'] = $apcontact['uuid'];
 772                 $profile['url'] = $apcontact['url'];
 773                 $profile['addr'] = $apcontact['addr'];
 774                 $profile['alias'] = $apcontact['alias'];
 775                 $profile['photo'] = $apcontact['photo'];
 776                 // $profile['community']
 777                 // $profile['keywords']
 778                 // $profile['location']
 779                 $profile['about'] = $apcontact['about'];
 780                 $profile['batch'] = $apcontact['sharedinbox'];
 781                 $profile['notify'] = $apcontact['inbox'];
 782                 $profile['poll'] = $apcontact['outbox'];
 783                 $profile['pubkey'] = $apcontact['pubkey'];
 784                 $profile['baseurl'] = $apcontact['baseurl'];
 785
 786                 // Remove all "null" fields
 787                 foreach ($profile as $field => $content) {
 788                         if (is_null($content)) {
 789                                 unset($profile[$field]);
 790                         }
 791                 }
 792
 793                 return $profile;
 794         }
 795
 796         public static function processInbox($body, $header, $uid)
 797         {
 798                 logger('Incoming message for user ' . $uid, LOGGER_DEBUG);
 799
 800                 if (!self::verifySignature($body, $header)) {
 801                         logger('Invalid signature, message will be discarded.', LOGGER_DEBUG);
 802                         return;
 803                 }
 804
 805                 $activity = json_decode($body, true);
 806
 807                 if (!is_array($activity)) {
 808                         logger('Invalid body.', LOGGER_DEBUG);
 809                         return;
 810                 }
 811
 812                 self::processActivity($activity, $body, $uid);
 813         }
 814
 815         public static function fetchOutbox($url)
 816         {
 817                 $data = self::fetchContent($url);
 818                 if (empty($data)) {
 819                         return;
 820                 }
 821
 822                 if (!empty($data['orderedItems'])) {
 823                         $items = $data['orderedItems'];
 824                 } elseif (!empty($data['first']['orderedItems'])) {
 825                         $items = $data['first']['orderedItems'];
 826                 } elseif (!empty($data['first'])) {
 827                         self::fetchOutbox($data['first']);
 828                         return;
 829                 } else {
 830                         $items = [];
 831                 }
 832
 833                 foreach ($items as $activity) {
 834                         self::processActivity($activity);
 835                 }
 836         }
 837
 838         private static function prepareObjectData($activity, $uid)
 839         {
 840                 $actor = self::processElement($activity, 'actor', 'id');
 841                 if (empty($actor)) {
 842                         logger('Empty actor', LOGGER_DEBUG);
 843                         return [];
 844                 }
 845
 846                 // Fetch all receivers from to, cc, bto and bcc
 847                 $receivers = self::getReceivers($activity, $actor);
 848
 849                 // When it is a delivery to a personal inbox we add that user to the receivers
 850                 if (!empty($uid)) {
 851                         $owner = User::getOwnerDataById($uid);
 852                         $additional = ['uid:' . $uid => $uid];
 853                         $receivers = array_merge($receivers, $additional);
 854                 }
 855
 856                 logger('Receivers: ' . json_encode($receivers), LOGGER_DEBUG);
 857
 858                 $public = in_array(0, $receivers);
 859
 860                 if (is_string($activity['object'])) {
 861                         $object_url = $activity['object'];
 862                 } elseif (!empty($activity['object']['id'])) {
 863                         $object_url = $activity['object']['id'];
 864                 } else {
 865                         logger('No object found', LOGGER_DEBUG);
 866                         return [];
 867                 }
 868
 869                 // Fetch the content only on activities where this matters
 870                 if (in_array($activity['type'], ['Create', 'Update', 'Announce'])) {
 871                         $object_data = self::fetchObject($object_url, $activity['object']);
 872                         if (empty($object_data)) {
 873                                 logger("Object data couldn't be processed", LOGGER_DEBUG);
 874                                 return [];
 875                         }
 876                 } elseif ($activity['type'] == 'Accept') {
 877                         $object_data = [];
 878                         $object_data['object_type'] = self::processElement($activity, 'object', 'type');
 879                         $object_data['object'] = self::processElement($activity, 'object', 'actor');
 880                 } elseif ($activity['type'] == 'Undo') {
 881                         $object_data = [];
 882                         $object_data['object_type'] = self::processElement($activity, 'object', 'type');
 883                         $object_data['object'] = self::processElement($activity, 'object', 'object');
 884                 } elseif (in_array($activity['type'], ['Like', 'Dislike'])) {
 885                         // Create a mostly empty array out of the activity data (instead of the object).
 886                         // This way we later don't have to check for the existence of ech individual array element.
 887                         $object_data = self::processCommonData($activity);
 888                         $object_data['name'] = $activity['type'];
 889                         $object_data['author'] = $activity['actor'];
 890                         $object_data['object'] = $object_url;
 891                 } elseif ($activity['type'] == 'Follow') {
 892                         $object_data['id'] = $activity['id'];
 893                         $object_data['object'] = $object_url;
 894                 } else {
 895                         $object_data = [];
 896                 }
 897
 898                 $object_data = self::addActivityFields($object_data, $activity);
 899
 900                 $object_data['type'] = $activity['type'];
 901                 $object_data['owner'] = $actor;
 902                 $object_data['receiver'] = array_merge(defaults($object_data, 'receiver', []), $receivers);
 903
 904                 return $object_data;
 905         }
 906
 907         private static function processActivity($activity, $body = '', $uid = null)
 908         {
 909                 if (empty($activity['type'])) {
 910                         logger('Empty type', LOGGER_DEBUG);
 911                         return;
 912                 }
 913
 914                 if (empty($activity['object'])) {
 915                         logger('Empty object', LOGGER_DEBUG);
 916                         return;
 917                 }
 918
 919                 if (empty($activity['actor'])) {
 920                         logger('Empty actor', LOGGER_DEBUG);
 921                         return;
 922
 923                 }
 924
 925                 // Non standard
 926                 // title, atomUri, context_id, statusnetConversationId
 927
 928                 // To-Do?
 929                 // context, location, signature;
 930
 931                 logger('Processing activity: ' . $activity['type'], LOGGER_DEBUG);
 932
 933                 $object_data = self::prepareObjectData($activity, $uid);
 934                 if (empty($object_data)) {
 935                         logger('No object data found', LOGGER_DEBUG);
 936                         return;
 937                 }
 938
 939                 switch ($activity['type']) {
 940                         case 'Create':
 941                         case 'Announce':
 942                                 self::createItem($object_data, $body);
 943                                 break;
 944
 945                         case 'Like':
 946                                 self::likeItem($object_data, $body);
 947                                 break;
 948
 949                         case 'Dislike':
 950                                 break;
 951
 952                         case 'Update':
 953                                 break;
 954
 955                         case 'Delete':
 956                                 break;
 957
 958                         case 'Follow':
 959                                 self::followUser($object_data);
 960                                 break;
 961
 962                         case 'Accept':
 963                                 if ($object_data['object_type'] == 'Follow') {
 964                                         self::acceptFollowUser($object_data);
 965                                 }
 966                                 break;
 967
 968                         case 'Undo':
 969                                 if ($object_data['object_type'] == 'Follow') {
 970                                         self::undoFollowUser($object_data);
 971                                 }
 972                                 break;
 973
 974                         default:
 975                                 logger('Unknown activity: ' . $activity['type'], LOGGER_DEBUG);
 976                                 break;
 977                 }
 978         }
 979
 980         private static function getReceivers($activity, $actor)
 981         {
 982                 $receivers = [];
 983
 984                 if (!empty($actor)) {
 985                         $profile = self::fetchprofile($actor);
 986                         $followers = defaults($profile, 'followers', '');
 987
 988                         logger('Actor: ' . $actor . ' - Followers: ' . $followers, LOGGER_DEBUG);
 989                 } else {
 990                         logger('Empty actor', LOGGER_DEBUG);
 991                         $followers = '';
 992                 }
 993
 994                 $elements = ['to', 'cc', 'bto', 'bcc'];
 995                 foreach ($elements as $element) {
 996                         if (empty($activity[$element])) {
 997                                 continue;
 998                         }
 999
1000                         // The receiver can be an arror or a string
1001                         if (is_string($activity[$element])) {
1002                                 $activity[$element] = [$activity[$element]];
1003                         }
1004
1005                         foreach ($activity[$element] as $receiver) {
1006                                 if ($receiver == self::PUBLIC) {
1007                                         $receivers['uid:0'] = 0;
1008                                 }
1009
1010                                 if (($receiver == self::PUBLIC) && !empty($actor)) {
1011                                         // This will most likely catch all OStatus connections to Mastodon
1012                                         $condition = ['alias' => [$actor, normalise_link($actor)], 'rel' => [Contact::SHARING, Contact::FRIEND]];
1013                                         $contacts = DBA::select('contact', ['uid'], $condition);
1014                                         while ($contact = DBA::fetch($contacts)) {
1015                                                 if ($contact['uid'] != 0) {
1016                                                         $receivers['uid:' . $contact['uid']] = $contact['uid'];
1017                                                 }
1018                                         }
1019                                         DBA::close($contacts);
1020                                 }
1021
1022                                 if (in_array($receiver, [$followers, self::PUBLIC]) && !empty($actor)) {
1023                                         $condition = ['nurl' => normalise_link($actor), 'rel' => [Contact::SHARING, Contact::FRIEND],
1024                                                 'network' => Protocol::ACTIVITYPUB];
1025                                         $contacts = DBA::select('contact', ['uid'], $condition);
1026                                         while ($contact = DBA::fetch($contacts)) {
1027                                                 if ($contact['uid'] != 0) {
1028                                                         $receivers['uid:' . $contact['uid']] = $contact['uid'];
1029                                                 }
1030                                         }
1031                                         DBA::close($contacts);
1032                                         continue;
1033                                 }
1034
1035                                 $condition = ['self' => true, 'nurl' => normalise_link($receiver)];
1036                                 $contact = DBA::selectFirst('contact', ['uid'], $condition);
1037                                 if (!DBA::isResult($contact)) {
1038                                         continue;
1039                                 }
1040                                 $receivers['uid:' . $contact['uid']] = $contact['uid'];
1041                         }
1042                 }
1043                 return $receivers;
1044         }
1045
1046         private static function addActivityFields($object_data, $activity)
1047         {
1048                 if (!empty($activity['published']) && empty($object_data['published'])) {
1049                         $object_data['published'] = $activity['published'];
1050                 }
1051
1052                 if (!empty($activity['updated']) && empty($object_data['updated'])) {
1053                         $object_data['updated'] = $activity['updated'];
1054                 }
1055
1056                 if (!empty($activity['inReplyTo']) && empty($object_data['parent-uri'])) {
1057                         $object_data['parent-uri'] = self::processElement($activity, 'inReplyTo', 'id');
1058                 }
1059
1060                 if (!empty($activity['instrument'])) {
1061                         $object_data['service'] = self::processElement($activity, 'instrument', 'name', 'type', 'Service');
1062                 }
1063                 return $object_data;
1064         }
1065
1066         private static function fetchObject($object_url, $object = [], $public = true)
1067         {
1068                 if ($public) {
1069                         $data = self::fetchContent($object_url);
1070                         if (empty($data)) {
1071                                 logger('Empty content for ' . $object_url . ', check if content is available locally.', LOGGER_DEBUG);
1072                                 $data = $object_url;
1073                                 $data = $object;
1074                         }
1075                 } else {
1076                         logger('Using original object for url ' . $object_url, LOGGER_DEBUG);
1077                         $data = $object;
1078                 }
1079
1080                 if (is_string($data)) {
1081                         $item = Item::selectFirst([], ['uri' => $data]);
1082                         if (!DBA::isResult($item)) {
1083                                 logger('Object with url ' . $data . ' was not found locally.', LOGGER_DEBUG);
1084                                 return false;
1085                         }
1086                         logger('Using already stored item for url ' . $object_url, LOGGER_DEBUG);
1087                         $data = self::createNote($item);
1088                 }
1089
1090                 if (empty($data['type'])) {
1091                         logger('Empty type', LOGGER_DEBUG);
1092                         return false;
1093                 } else {
1094                         $type = $data['type'];
1095                         logger('Type ' . $type, LOGGER_DEBUG);
1096                 }
1097
1098                 if (in_array($type, ['Note', 'Article', 'Video'])) {
1099                         $common = self::processCommonData($data);
1100                 }
1101
1102                 switch ($type) {
1103                         case 'Note':
1104                                 return array_merge($common, self::processNote($data));
1105                         case 'Article':
1106                                 return array_merge($common, self::processArticle($data));
1107                         case 'Video':
1108                                 return array_merge($common, self::processVideo($data));
1109
1110                         case 'Announce':
1111                                 if (empty($data['object'])) {
1112                                         return false;
1113                                 }
1114                                 return self::fetchObject($data['object']);
1115
1116                         case 'Person':
1117                         case 'Tombstone':
1118                                 break;
1119
1120                         default:
1121                                 logger('Unknown object type: ' . $data['type'], LOGGER_DEBUG);
1122                                 break;
1123                 }
1124         }
1125
1126         private static function processCommonData(&$object)
1127         {
1128                 if (empty($object['id'])) {
1129                         return false;
1130                 }
1131
1132                 $object_data = [];
1133                 $object_data['type'] = $object['type'];
1134                 $object_data['uri'] = $object['id'];
1135
1136                 if (!empty($object['inReplyTo'])) {
1137                         $object_data['reply-to-uri'] = self::processElement($object, 'inReplyTo', 'id');
1138                 } else {
1139                         $object_data['reply-to-uri'] = $object_data['uri'];
1140                 }
1141
1142                 $object_data['published'] = defaults($object, 'published', null);
1143                 $object_data['updated'] = defaults($object, 'updated', $object_data['published']);
1144
1145                 if (empty($object_data['published']) && !empty($object_data['updated'])) {
1146                         $object_data['published'] = $object_data['updated'];
1147                 }
1148
1149                 $object_data['uuid'] = defaults($object, 'uuid', null);
1150                 $object_data['owner'] = $object_data['author'] = self::processElement($object, 'attributedTo', 'id');
1151                 $object_data['context'] = defaults($object, 'context', null);
1152                 $object_data['conversation'] = defaults($object, 'conversation', null);
1153                 $object_data['sensitive'] = defaults($object, 'sensitive', null);
1154                 $object_data['name'] = defaults($object, 'title', null);
1155                 $object_data['name'] = defaults($object, 'name', $object_data['name']);
1156                 $object_data['summary'] = defaults($object, 'summary', null);
1157                 $object_data['content'] = defaults($object, 'content', null);
1158                 $object_data['source'] = defaults($object, 'source', null);
1159                 $object_data['location'] = self::processElement($object, 'location', 'name', 'type', 'Place');
1160                 $object_data['attachments'] = defaults($object, 'attachment', null);
1161                 $object_data['tags'] = defaults($object, 'tag', null);
1162                 $object_data['service'] = self::processElement($object, 'instrument', 'name', 'type', 'Service');
1163                 $object_data['alternate-url'] = self::processElement($object, 'url', 'href');
1164                 $object_data['receiver'] = self::getReceivers($object, $object_data['owner']);
1165
1166                 // Unhandled
1167                 // @context, type, actor, signature, mediaType, duration, replies, icon
1168
1169                 // Also missing: (Defined in the standard, but currently unused)
1170                 // audience, preview, endTime, startTime, generator, image
1171
1172                 return $object_data;
1173         }
1174
1175         private static function processNote($object)
1176         {
1177                 $object_data = [];
1178
1179                 // To-Do?
1180                 // emoji, atomUri, inReplyToAtomUri
1181
1182                 // Unhandled
1183                 // contentMap, announcement_count, announcements, context_id, likes, like_count
1184                 // inReplyToStatusId, shares, quoteUrl, statusnetConversationId
1185
1186                 return $object_data;
1187         }
1188
1189         private static function processArticle($object)
1190         {
1191                 $object_data = [];
1192
1193                 return $object_data;
1194         }
1195
1196         private static function processVideo($object)
1197         {
1198                 $object_data = [];
1199
1200                 // To-Do?
1201                 // category, licence, language, commentsEnabled
1202
1203                 // Unhandled
1204                 // views, waitTranscoding, state, support, subtitleLanguage
1205                 // likes, dislikes, shares, comments
1206
1207                 return $object_data;
1208         }
1209
1210         private static function processElement($array, $element, $key, $type = null, $type_value = null)
1211         {
1212                 if (empty($array)) {
1213                         return false;
1214                 }
1215
1216                 if (empty($array[$element])) {
1217                         return false;
1218                 }
1219
1220                 if (is_string($array[$element])) {
1221                         return $array[$element];
1222                 }
1223
1224                 if (is_null($type_value)) {
1225                         if (!empty($array[$element][$key])) {
1226                                 return $array[$element][$key];
1227                         }
1228
1229                         if (!empty($array[$element][0][$key])) {
1230                                 return $array[$element][0][$key];
1231                         }
1232
1233                         return false;
1234                 }
1235
1236                 if (!empty($array[$element][$key]) && !empty($array[$element][$type]) && ($array[$element][$type] == $type_value)) {
1237                         return $array[$element][$key];
1238                 }
1239
1240                 /// @todo Add array search
1241
1242                 return false;
1243         }
1244
1245         private static function convertMentions($body)
1246         {
1247                 $URLSearchString = "^\[\]";
1248                 $body = preg_replace("/\[url\=([$URLSearchString]*)\]([#@!])(.*?)\[\/url\]/ism", '$2[url=$1]$3[/url]', $body);
1249
1250                 return $body;
1251         }
1252
1253         private static function constructTagList($tags, $sensitive)
1254         {
1255                 if (empty($tags)) {
1256                         return '';
1257                 }
1258
1259                 $tag_text = '';
1260                 foreach ($tags as $tag) {
1261                         if (in_array($tag['type'], ['Mention', 'Hashtag'])) {
1262                                 if (!empty($tag_text)) {
1263                                         $tag_text .= ',';
1264                                 }
1265
1266                                 if (empty($tag['href'])) {
1267                                         //$tag['href']
1268                                         logger('Blubb!');
1269                                 }
1270
1271                                 $tag_text .= substr($tag['name'], 0, 1) . '[url=' . $tag['href'] . ']' . substr($tag['name'], 1) . '[/url]';
1272                         }
1273                 }
1274
1275                 /// @todo add nsfw for $sensitive
1276
1277                 return $tag_text;
1278         }
1279
1280         private static function constructAttachList($attachments, $item)
1281         {
1282                 if (empty($attachments)) {
1283                         return $item;
1284                 }
1285
1286                 foreach ($attachments as $attach) {
1287                         $filetype = strtolower(substr($attach['mediaType'], 0, strpos($attach['mediaType'], '/')));
1288                         if ($filetype == 'image') {
1289                                 $item['body'] .= "\n[img]".$attach['url'].'[/img]';
1290                         } else {
1291                                 if (!empty($item["attach"])) {
1292                                         $item["attach"] .= ',';
1293                                 } else {
1294                                         $item["attach"] = '';
1295                                 }
1296                                 if (!isset($attach['length'])) {
1297                                         $attach['length'] = "0";
1298                                 }
1299                                 $item["attach"] .= '[attach]href="'.$attach['url'].'" length="'.$attach['length'].'" type="'.$attach['mediaType'].'" title="'.defaults($attach, 'name', '').'"[/attach]';
1300                         }
1301                 }
1302
1303                 return $item;
1304         }
1305
1306         private static function createItem($activity, $body)
1307         {
1308                 $item = [];
1309                 $item['verb'] = ACTIVITY_POST;
1310                 $item['parent-uri'] = $activity['reply-to-uri'];
1311
1312                 if ($activity['reply-to-uri'] == $activity['uri']) {
1313                         $item['gravity'] = GRAVITY_PARENT;
1314                         $item['object-type'] = ACTIVITY_OBJ_NOTE;
1315                 } else {
1316                         $item['gravity'] = GRAVITY_COMMENT;
1317                         $item['object-type'] = ACTIVITY_OBJ_COMMENT;
1318                 }
1319
1320                 if (($activity['uri'] != $activity['reply-to-uri']) && !Item::exists(['uri' => $activity['reply-to-uri']])) {
1321                         logger('Parent ' . $activity['reply-to-uri'] . ' not found. Try to refetch it.');
1322                         self::fetchMissingActivity($activity['reply-to-uri'], $activity);
1323                 }
1324
1325                 self::postItem($activity, $item, $body);
1326         }
1327
1328         private static function likeItem($activity, $body)
1329         {
1330                 $item = [];
1331                 $item['verb'] = ACTIVITY_LIKE;
1332                 $item['parent-uri'] = $activity['object'];
1333                 $item['gravity'] = GRAVITY_ACTIVITY;
1334                 $item['object-type'] = ACTIVITY_OBJ_NOTE;
1335
1336                 self::postItem($activity, $item, $body);
1337         }
1338
1339         private static function postItem($activity, $item, $body)
1340         {
1341                 /// @todo What to do with $activity['context']?
1342
1343                 $item['network'] = Protocol::ACTIVITYPUB;
1344                 $item['private'] = !in_array(0, $activity['receiver']);
1345                 $item['author-id'] = Contact::getIdForURL($activity['author'], 0, true);
1346                 $item['owner-id'] = Contact::getIdForURL($activity['owner'], 0, true);
1347                 $item['uri'] = $activity['uri'];
1348                 $item['created'] = $activity['published'];
1349                 $item['edited'] = $activity['updated'];
1350                 $item['guid'] = $activity['uuid'];
1351                 $item['title'] = HTML::toBBCode($activity['name']);
1352                 $item['content-warning'] = HTML::toBBCode($activity['summary']);
1353                 $item['body'] = self::convertMentions(HTML::toBBCode($activity['content']));
1354                 $item['location'] = $activity['location'];
1355                 $item['tag'] = self::constructTagList($activity['tags'], $activity['sensitive']);
1356                 $item['app'] = $activity['service'];
1357                 $item['plink'] = defaults($activity, 'alternate-url', $item['uri']);
1358
1359                 $item = self::constructAttachList($activity['attachments'], $item);
1360
1361                 $source = self::processElement($activity, 'source', 'content', 'mediaType', 'text/bbcode');
1362                 if (!empty($source)) {
1363                         $item['body'] = $source;
1364                 }
1365
1366                 $item['protocol'] = Conversation::PARCEL_ACTIVITYPUB;
1367                 $item['source'] = $body;
1368                 $item['conversation-uri'] = $activity['conversation'];
1369
1370                 foreach ($activity['receiver'] as $receiver) {
1371                         $item['uid'] = $receiver;
1372                         $item['contact-id'] = Contact::getIdForURL($activity['author'], $receiver, true);
1373
1374                         if (($receiver != 0) && empty($item['contact-id'])) {
1375                                 $item['contact-id'] = Contact::getIdForURL($activity['author'], 0, true);
1376                         }
1377
1378                         $item_id = Item::insert($item);
1379                         logger('Storing for user ' . $item['uid'] . ': ' . $item_id);
1380                 }
1381         }
1382
1383         private static function fetchMissingActivity($url, $child)
1384         {
1385                 $object = ActivityPub::fetchContent($url);
1386                 if (empty($object)) {
1387                         logger('Activity ' . $url . ' was not fetchable, aborting.');
1388                         return;
1389                 }
1390
1391                 $activity = [];
1392                 $activity['@context'] = $object['@context'];
1393                 unset($object['@context']);
1394                 $activity['id'] = $object['id'];
1395                 $activity['to'] = defaults($object, 'to', []);
1396                 $activity['cc'] = defaults($object, 'cc', []);
1397                 $activity['actor'] = $child['author'];
1398                 $activity['object'] = $object;
1399                 $activity['published'] = $object['published'];
1400                 $activity['type'] = 'Create';
1401                 self::processActivity($activity);
1402                 logger('Activity ' . $url . ' had been fetched and processed.');
1403         }
1404
1405         private static function getUserOfObject($object)
1406         {
1407                 $self = DBA::selectFirst('contact', ['uid'], ['nurl' => normalise_link($object), 'self' => true]);
1408                 if (!DBA::isResult($self)) {
1409                         return false;
1410                 } else {
1411                         return $self['uid'];
1412                 }
1413         }
1414
1415         private static function followUser($activity)
1416         {
1417                 $uid = self::getUserOfObject($activity['object']);
1418                 if (empty($uid)) {
1419                         return;
1420                 }
1421
1422                 $owner = User::getOwnerDataById($uid);
1423
1424                 $cid = Contact::getIdForURL($activity['owner'], $uid);
1425                 if (!empty($cid)) {
1426                         $contact = DBA::selectFirst('contact', [], ['id' => $cid]);
1427                 } else {
1428                         $contact = false;
1429                 }
1430
1431                 $item = ['author-id' => Contact::getIdForURL($activity['owner']),
1432                         'author-link' => $activity['owner']];
1433
1434                 Contact::addRelationship($owner, $contact, $item);
1435                 $cid = Contact::getIdForURL($activity['owner'], $uid);
1436                 if (empty($cid)) {
1437                         return;
1438                 }
1439
1440                 $contact = DBA::selectFirst('contact', ['network'], ['id' => $cid]);
1441                 if ($contact['network'] != Protocol::ACTIVITYPUB) {
1442                         Contact::updateFromProbe($cid, Protocol::ACTIVITYPUB);
1443                 }
1444
1445                 DBA::update('contact', ['hub-verify' => $activity['id']], ['id' => $cid]);
1446                 logger('Follow user ' . $uid . ' from contact ' . $cid . ' with id ' . $activity['id']);
1447         }
1448
1449         private static function acceptFollowUser($activity)
1450         {
1451                 $uid = self::getUserOfObject($activity['object']);
1452                 if (empty($uid)) {
1453                         return;
1454                 }
1455
1456                 $owner = User::getOwnerDataById($uid);
1457
1458                 $cid = Contact::getIdForURL($activity['owner'], $uid);
1459                 if (empty($cid)) {
1460                         logger('No contact found for ' . $activity['owner'], LOGGER_DEBUG);
1461                         return;
1462                 }
1463
1464                 $fields = ['pending' => false];
1465
1466                 $contact = DBA::selectFirst('contact', ['rel'], ['id' => $cid]);
1467                 if ($contact['rel'] == Contact::FOLLOWER) {
1468                         $fields['rel'] = Contact::FRIEND;
1469                 }
1470
1471                 $condition = ['id' => $cid];
1472                 DBA::update('contact', $fields, $condition);
1473                 logger('Accept contact request from contact ' . $cid . ' for user ' . $uid, LOGGER_DEBUG);
1474         }
1475
1476         private static function undoFollowUser($activity)
1477         {
1478                 $uid = self::getUserOfObject($activity['object']);
1479                 if (empty($uid)) {
1480                         return;
1481                 }
1482
1483                 $owner = User::getOwnerDataById($uid);
1484
1485                 $cid = Contact::getIdForURL($activity['owner'], $uid);
1486                 if (empty($cid)) {
1487                         logger('No contact found for ' . $activity['owner'], LOGGER_DEBUG);
1488                         return;
1489                 }
1490
1491                 $contact = DBA::selectFirst('contact', [], ['id' => $cid]);
1492                 if (!DBA::isResult($contact)) {
1493                         return;
1494                 }
1495
1496                 Contact::removeFollower($owner, $contact);
1497                 logger('Undo following request from contact ' . $cid . ' for user ' . $uid, LOGGER_DEBUG);
1498         }
1499 }