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 = ['https://www.w3.org/ns/activitystreams', 'https://w3id.org/security/v1',
  65                 ['vcard' => 'http://www.w3.org/2006/vcard/ns#',
  66                 'dfrn' => 'http://purl.org/macgirvin/dfrn/1.0/',
  67                 'diaspora' => 'https://diasporafoundation.org/ns/',
  68                 'litepub' => 'http://litepub.social/ns#',
  69                 'toot' => 'http://joinmastodon.org/ns#',
  70                 'featured' => [
  71                         "@id" => "toot:featured",
  72                         "@type" => "@id",
  73                 ],
  74                 'schema' => 'http://schema.org#',
  75                 'manuallyApprovesFollowers' => 'as:manuallyApprovesFollowers',
  76                 'sensitive' => 'as:sensitive', 'Hashtag' => 'as:Hashtag',
  77                 'quoteUrl' => 'as:quoteUrl',
  78                 'conversation' => 'ostatus:conversation',
  79                 'directMessage' => 'litepub:directMessage',
  80                 'discoverable' => 'toot:discoverable',
  81                 'PropertyValue' => 'schema:PropertyValue',
  82                 'value' => 'schema:value',
  83         ]];
  84         const ACCOUNT_TYPES = ['Person', 'Organization', 'Service', 'Group', 'Application', 'Tombstone'];
  85         /**
  86          * Checks if the web request is done for the AP protocol
  87          *
  88          * @return bool is it AP?
  89          */
  90         public static function isRequest(): bool
  91         {
  92                 header('Vary: Accept', false);
  93
  94                 $isrequest = stristr($_SERVER['HTTP_ACCEPT'] ?? '', 'application/activity+json') ||
  95                         stristr($_SERVER['HTTP_ACCEPT'] ?? '', 'application/json') ||
  96                         stristr($_SERVER['HTTP_ACCEPT'] ?? '', 'application/ld+json');
  97
  98                 if ($isrequest) {
  99                         Logger::debug('Is AP request', ['accept' => $_SERVER['HTTP_ACCEPT'], 'agent' => $_SERVER['HTTP_USER_AGENT'] ?? '']);
 100                 }
 101
 102                 return $isrequest;
 103         }
 104
 105         /**
 106          * Fetches ActivityPub content from the given url
 107          *
 108          * @param string  $url content url
 109          * @param integer $uid User ID for the signature
 110          * @return array
 111          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 112          */
 113         public static function fetchContent(string $url, int $uid = 0): array
 114         {
 115                 return HTTPSignature::fetch($url, $uid);
 116         }
 117
 118         private static function getAccountType(array $apcontact): int
 119         {
 120                 $accounttype = -1;
 121
 122                 switch($apcontact['type']) {
 123                         case 'Person':
 124                                 $accounttype = User::ACCOUNT_TYPE_PERSON;
 125                                 break;
 126                         case 'Organization':
 127                                 $accounttype = User::ACCOUNT_TYPE_ORGANISATION;
 128                                 break;
 129                         case 'Service':
 130                                 $accounttype = User::ACCOUNT_TYPE_NEWS;
 131                                 break;
 132                         case 'Group':
 133                                 $accounttype = User::ACCOUNT_TYPE_COMMUNITY;
 134                                 break;
 135                         case 'Application':
 136                                 $accounttype = User::ACCOUNT_TYPE_RELAY;
 137                                 break;
 138                         case 'Tombstone':
 139                                 $accounttype = User::ACCOUNT_TYPE_DELETED;
 140                                 break;
 141                 }
 142
 143                 return $accounttype;
 144         }
 145
 146         /**
 147          * Fetches a profile from the given url into an array that is compatible to Probe::uri
 148          *
 149          * @param string  $url    profile url
 150          * @param boolean $update Update the profile
 151          * @return array
 152          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 153          * @throws \ImagickException
 154          */
 155         public static function probeProfile(string $url, bool $update = true): array
 156         {
 157                 $apcontact = APContact::getByURL($url, $update);
 158                 if (empty($apcontact)) {
 159                         return [];
 160                 }
 161
 162                 $profile = ['network' => Protocol::ACTIVITYPUB];
 163                 $profile['nick'] = $apcontact['nick'];
 164                 $profile['name'] = $apcontact['name'];
 165                 $profile['guid'] = $apcontact['uuid'];
 166                 $profile['url'] = $apcontact['url'];
 167                 $profile['addr'] = $apcontact['addr'];
 168                 $profile['alias'] = $apcontact['alias'];
 169                 $profile['following'] = $apcontact['following'];
 170                 $profile['followers'] = $apcontact['followers'];
 171                 $profile['inbox'] = $apcontact['inbox'];
 172                 $profile['outbox'] = $apcontact['outbox'];
 173                 $profile['sharedinbox'] = $apcontact['sharedinbox'];
 174                 $profile['photo'] = $apcontact['photo'];
 175                 $profile['header'] = $apcontact['header'];
 176                 $profile['account-type'] = self::getAccountType($apcontact);
 177                 $profile['community'] = ($profile['account-type'] == User::ACCOUNT_TYPE_COMMUNITY);
 178                 // $profile['keywords']
 179                 // $profile['location']
 180                 $profile['about'] = $apcontact['about'];
 181                 $profile['xmpp'] = $apcontact['xmpp'];
 182                 $profile['matrix'] = $apcontact['matrix'];
 183                 $profile['batch'] = $apcontact['sharedinbox'];
 184                 $profile['notify'] = $apcontact['inbox'];
 185                 $profile['poll'] = $apcontact['outbox'];
 186                 $profile['pubkey'] = $apcontact['pubkey'];
 187                 $profile['subscribe'] = $apcontact['subscribe'];
 188                 $profile['manually-approve'] = $apcontact['manually-approve'];
 189                 $profile['baseurl'] = $apcontact['baseurl'];
 190                 $profile['gsid'] = $apcontact['gsid'];
 191
 192                 if (!is_null($apcontact['discoverable'])) {
 193                         $profile['hide'] = !$apcontact['discoverable'];
 194                 }
 195
 196                 // Remove all "null" fields
 197                 foreach ($profile as $field => $content) {
 198                         if (is_null($content)) {
 199                                 unset($profile[$field]);
 200                         }
 201                 }
 202
 203                 return $profile;
 204         }
 205
 206         /**
 207          * Fetches activities from the outbox of a given profile and processes it
 208          *
 209          * @param string  $url
 210          * @param integer $uid User ID
 211          * @return void
 212          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 213          */
 214         public static function fetchOutbox(string $url, int $uid)
 215         {
 216                 $data = self::fetchContent($url, $uid);
 217                 if (empty($data)) {
 218                         return;
 219                 }
 220
 221                 if (!empty($data['orderedItems'])) {
 222                         $items = $data['orderedItems'];
 223                 } elseif (!empty($data['first']['orderedItems'])) {
 224                         $items = $data['first']['orderedItems'];
 225                 } elseif (!empty($data['first'])) {
 226                         self::fetchOutbox($data['first'], $uid);
 227                         return;
 228                 } else {
 229                         $items = [];
 230                 }
 231
 232                 foreach ($items as $activity) {
 233                         $ldactivity = JsonLD::compact($activity);
 234                         ActivityPub\Receiver::processActivity($ldactivity, '', $uid, true);
 235                 }
 236         }
 237
 238         /**
 239          * Fetch items from AP endpoints
 240          *
 241          * @param string $url  Address of the endpoint
 242          * @param integer $uid Optional user id
 243          * @return array Endpoint items
 244          */
 245         public static function fetchItems(string $url, int $uid = 0): array
 246         {
 247                 $data = self::fetchContent($url, $uid);
 248                 if (empty($data)) {
 249                         return [];
 250                 }
 251
 252                 if (!empty($data['orderedItems'])) {
 253                         $items = $data['orderedItems'];
 254                 } elseif (!empty($data['first']['orderedItems'])) {
 255                         $items = $data['first']['orderedItems'];
 256                 } elseif (!empty($data['first']) && is_string($data['first']) && ($data['first'] != $url)) {
 257                         return self::fetchItems($data['first'], $uid);
 258                 } else {
 259                         return [];
 260                 }
 261
 262                 if (!empty($data['next']) && is_string($data['next'])) {
 263                         $items = array_merge($items, self::fetchItems($data['next'], $uid));
 264                 }
 265
 266                 return $items;
 267         }
 268
 269         /**
 270          * Checks if the given contact url does support ActivityPub
 271          *
 272          * @param string  $url    profile url
 273          * @param boolean $update true = always update, false = never update, null = update when not found or outdated
 274          * @return boolean
 275          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 276          * @throws \ImagickException
 277          */
 278         public static function isSupportedByContactUrl(string $url, $update = null): bool
 279         {
 280                 return !empty(APContact::getByURL($url, $update));
 281         }
 282
 283         public static function isAcceptedRequester(int $uid = 0): bool
 284         {
 285                 $called_by = System::callstack(1);
 286
 287                 $signer = HTTPSignature::getSigner('', $_SERVER);
 288                 if (!$signer) {
 289                         Logger::debug('No signer or invalid signature', ['uid' => $uid, 'agent' => $_SERVER['HTTP_USER_AGENT'] ?? '', 'called_by' => $called_by]);
 290                         return false;
 291                 }
 292
 293                 $apcontact = APContact::getByURL($signer);
 294                 if (empty($apcontact)) {
 295                         Logger::info('APContact not found', ['uid' => $uid, 'handle' => $signer, 'called_by' => $called_by]);
 296                         return false;
 297                 }
 298
 299                 if (empty($apcontact['gsid'] || empty($apcontact['baseurl']))) {
 300                         Logger::debug('No server found', ['uid' => $uid, 'signer' => $signer, 'called_by' => $called_by]);
 301                         return false;
 302                 }
 303
 304                 $contact = Contact::getByURL($signer, false, ['id', 'baseurl', 'gsid']);
 305                 if (!empty($contact) && Contact\User::isBlocked($contact['id'], $uid)) {
 306                         Logger::info('Requesting contact is blocked', ['uid' => $uid, 'id' => $contact['id'], 'signer' => $signer, 'baseurl' => $contact['baseurl'], 'called_by' => $called_by]);
 307                         return false;
 308                 }
 309
 310                 // @todo Look for user blocked domains
 311
 312                 Logger::debug('Server is an accepted requester', ['uid' => $uid, 'id' => $apcontact['gsid'], 'url' => $apcontact['baseurl'], 'signer' => $signer, 'called_by' => $called_by]);
 313
 314                 return true;
 315         }
 316 }