src/Protocol/ActivityPub.php

   1 <?php
   2 /**
   3  * @file src/Protocol/ActivityPub.php
   4  */
   5 namespace Friendica\Protocol;
   6
   7 use Friendica\Util\Network;
   8 use Friendica\Core\Protocol;
   9 use Friendica\Model\APContact;
  10
  11 /**
  12  * @brief ActivityPub Protocol class
  13  * The ActivityPub Protocol is a message exchange protocol defined by the W3C.
  14  * https://www.w3.org/TR/activitypub/
  15  * https://www.w3.org/TR/activitystreams-core/
  16  * https://www.w3.org/TR/activitystreams-vocabulary/
  17  *
  18  * https://blog.joinmastodon.org/2018/06/how-to-implement-a-basic-activitypub-server/
  19  * https://blog.joinmastodon.org/2018/07/how-to-make-friends-and-verify-requests/
  20  *
  21  * Digest: https://tools.ietf.org/html/rfc5843
  22  * https://tools.ietf.org/html/draft-cavage-http-signatures-10#ref-15
  23  *
  24  * Mastodon implementation of supported activities:
  25  * https://github.com/tootsuite/mastodon/blob/master/app/lib/activitypub/activity.rb#L26
  26  *
  27  * Funkwhale:
  28  * http://docs-funkwhale-funkwhale-549-music-federation-documentation.preview.funkwhale.audio/federation/index.html
  29  *
  30  * To-do:
  31  * - Polling the outboxes for missing content?
  32  */
  33 class ActivityPub
  34 {
  35         const PUBLIC_COLLECTION = 'https://www.w3.org/ns/activitystreams#Public';
  36         const CONTEXT = ['https://www.w3.org/ns/activitystreams', 'https://w3id.org/security/v1',
  37                 ['vcard' => 'http://www.w3.org/2006/vcard/ns#',
  38                 'diaspora' => 'https://diasporafoundation.org/ns/',
  39                 'manuallyApprovesFollowers' => 'as:manuallyApprovesFollowers',
  40                 'sensitive' => 'as:sensitive', 'Hashtag' => 'as:Hashtag']];
  41         const ACCOUNT_TYPES = ['Person', 'Organization', 'Service', 'Group', 'Application'];
  42         /**
  43          * Checks if the web request is done for the AP protocol
  44          *
  45          * @return is it AP?
  46          */
  47         public static function isRequest()
  48         {
  49                 return stristr(defaults($_SERVER, 'HTTP_ACCEPT', ''), 'application/activity+json') ||
  50                         stristr(defaults($_SERVER, 'HTTP_ACCEPT', ''), 'application/ld+json');
  51         }
  52
  53         /**
  54          * Fetches ActivityPub content from the given url
  55          *
  56          * @param string $url content url
  57          * @return array
  58          */
  59         public static function fetchContent($url)
  60         {
  61                 $ret = Network::curl($url, false, $redirects, ['accept_content' => 'application/activity+json, application/ld+json']);
  62                 if (!$ret['success'] || empty($ret['body'])) {
  63                         return false;
  64                 }
  65
  66                 return json_decode($ret['body'], true);
  67         }
  68
  69         /**
  70          * Fetches a profile from the given url into an array that is compatible to Probe::uri
  71          *
  72          * @param string $url profile url
  73          * @return array
  74          */
  75         public static function probeProfile($url)
  76         {
  77                 $apcontact = APContact::getByURL($url, true);
  78                 if (empty($apcontact)) {
  79                         return false;
  80                 }
  81
  82                 $profile = ['network' => Protocol::ACTIVITYPUB];
  83                 $profile['nick'] = $apcontact['nick'];
  84                 $profile['name'] = $apcontact['name'];
  85                 $profile['guid'] = $apcontact['uuid'];
  86                 $profile['url'] = $apcontact['url'];
  87                 $profile['addr'] = $apcontact['addr'];
  88                 $profile['alias'] = $apcontact['alias'];
  89                 $profile['photo'] = $apcontact['photo'];
  90                 // $profile['community']
  91                 // $profile['keywords']
  92                 // $profile['location']
  93                 $profile['about'] = $apcontact['about'];
  94                 $profile['batch'] = $apcontact['sharedinbox'];
  95                 $profile['notify'] = $apcontact['inbox'];
  96                 $profile['poll'] = $apcontact['outbox'];
  97                 $profile['pubkey'] = $apcontact['pubkey'];
  98                 $profile['baseurl'] = $apcontact['baseurl'];
  99
 100                 // Remove all "null" fields
 101                 foreach ($profile as $field => $content) {
 102                         if (is_null($content)) {
 103                                 unset($profile[$field]);
 104                         }
 105                 }
 106
 107                 return $profile;
 108         }
 109
 110         /**
 111          * Fetches activities from the outbox of a given profile and processes it
 112          *
 113          * @param string $url
 114          * @param integer $uid User ID
 115          */
 116         public static function fetchOutbox($url, $uid)
 117         {
 118                 $data = self::fetchContent($url);
 119                 if (empty($data)) {
 120                         return;
 121                 }
 122
 123                 if (!empty($data['orderedItems'])) {
 124                         $items = $data['orderedItems'];
 125                 } elseif (!empty($data['first']['orderedItems'])) {
 126                         $items = $data['first']['orderedItems'];
 127                 } elseif (!empty($data['first'])) {
 128                         self::fetchOutbox($data['first'], $uid);
 129                         return;
 130                 } else {
 131                         $items = [];
 132                 }
 133
 134                 foreach ($items as $activity) {
 135                         $ldactivity = JsonLD::compact($activity);
 136                         ActivityPub\Receiver::processActivity($ldactivity, '', $uid, true);
 137                 }
 138         }
 139 }