src/Protocol/ActivityPub.php

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