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  * To-do:
  28  * - Polling the outboxes for missing content?
  29  */
  30 class ActivityPub
  31 {
  32         const PUBLIC_COLLECTION = 'https://www.w3.org/ns/activitystreams#Public';
  33         const CONTEXT = ['https://www.w3.org/ns/activitystreams', 'https://w3id.org/security/v1',
  34                 ['vcard' => 'http://www.w3.org/2006/vcard/ns#',
  35                 'diaspora' => 'https://diasporafoundation.org/ns/',
  36                 'manuallyApprovesFollowers' => 'as:manuallyApprovesFollowers',
  37                 'sensitive' => 'as:sensitive', 'Hashtag' => 'as:Hashtag']];
  38         const ACCOUNT_TYPES = ['Person', 'Organization', 'Service', 'Group', 'Application'];
  39         const CONTENT_TYPES = ['Note', 'Article', 'Video', 'Image'];
  40         const ACTIVITY_TYPES = ['Like', 'Dislike', 'Accept', 'Reject', 'TentativeAccept'];
  41         /**
  42          * @brief Checks if the web request is done for the AP protocol
  43          *
  44          * @return is it AP?
  45          */
  46         public static function isRequest()
  47         {
  48                 return stristr(defaults($_SERVER, 'HTTP_ACCEPT', ''), 'application/activity+json') ||
  49                         stristr(defaults($_SERVER, 'HTTP_ACCEPT', ''), 'application/ld+json');
  50         }
  51
  52         /**
  53          * Fetches ActivityPub content from the given url
  54          *
  55          * @param string $url content url
  56          * @return array
  57          */
  58         public static function fetchContent($url)
  59         {
  60                 $ret = Network::curl($url, false, $redirects, ['accept_content' => 'application/activity+json, application/ld+json']);
  61                 if (!$ret['success'] || empty($ret['body'])) {
  62                         return false;
  63                 }
  64
  65                 return json_decode($ret['body'], true);
  66         }
  67
  68         /**
  69          * Fetches a profile from the given url into an array that is compatible to Probe::uri
  70          *
  71          * @param string $url profile url
  72          * @return array
  73          */
  74         public static function probeProfile($url)
  75         {
  76                 $apcontact = APContact::getByURL($url, true);
  77                 if (empty($apcontact)) {
  78                         return false;
  79                 }
  80
  81                 $profile = ['network' => Protocol::ACTIVITYPUB];
  82                 $profile['nick'] = $apcontact['nick'];
  83                 $profile['name'] = $apcontact['name'];
  84                 $profile['guid'] = $apcontact['uuid'];
  85                 $profile['url'] = $apcontact['url'];
  86                 $profile['addr'] = $apcontact['addr'];
  87                 $profile['alias'] = $apcontact['alias'];
  88                 $profile['photo'] = $apcontact['photo'];
  89                 // $profile['community']
  90                 // $profile['keywords']
  91                 // $profile['location']
  92                 $profile['about'] = $apcontact['about'];
  93                 $profile['batch'] = $apcontact['sharedinbox'];
  94                 $profile['notify'] = $apcontact['inbox'];
  95                 $profile['poll'] = $apcontact['outbox'];
  96                 $profile['pubkey'] = $apcontact['pubkey'];
  97                 $profile['baseurl'] = $apcontact['baseurl'];
  98
  99                 // Remove all "null" fields
 100                 foreach ($profile as $field => $content) {
 101                         if (is_null($content)) {
 102                                 unset($profile[$field]);
 103                         }
 104                 }
 105
 106                 return $profile;
 107         }
 108
 109         /**
 110          * @brief
 111          *
 112          * @param $url
 113          * @param integer $uid User ID
 114          */
 115         public static function fetchOutbox($url, $uid)
 116         {
 117                 $data = self::fetchContent($url);
 118                 if (empty($data)) {
 119                         return;
 120                 }
 121
 122                 if (!empty($data['orderedItems'])) {
 123                         $items = $data['orderedItems'];
 124                 } elseif (!empty($data['first']['orderedItems'])) {
 125                         $items = $data['first']['orderedItems'];
 126                 } elseif (!empty($data['first'])) {
 127                         self::fetchOutbox($data['first'], $uid);
 128                         return;
 129                 } else {
 130                         $items = [];
 131                 }
 132
 133                 foreach ($items as $activity) {
 134                         ActivityPub\Receiver::processActivity($activity, '', $uid, true);
 135                 }
 136         }
 137 }