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  * Missing parts from DFRN:
  34  * - Public Forum
  35  * - Private Forum
  36  * - Relocation
  37  */
  38 class ActivityPub
  39 {
  40         const PUBLIC_COLLECTION = 'https://www.w3.org/ns/activitystreams#Public';
  41         const CONTEXT = ['https://www.w3.org/ns/activitystreams', 'https://w3id.org/security/v1',
  42                 ['vcard' => 'http://www.w3.org/2006/vcard/ns#',
  43                 'diaspora' => 'https://diasporafoundation.org/ns/',
  44                 'manuallyApprovesFollowers' => 'as:manuallyApprovesFollowers',
  45                 'sensitive' => 'as:sensitive', 'Hashtag' => 'as:Hashtag']];
  46         const ACCOUNT_TYPES = ['Person', 'Organization', 'Service', 'Group', 'Application'];
  47         /**
  48          * Checks if the web request is done for the AP protocol
  49          *
  50          * @return is it AP?
  51          */
  52         public static function isRequest()
  53         {
  54                 return stristr(defaults($_SERVER, 'HTTP_ACCEPT', ''), 'application/activity+json') ||
  55                         stristr(defaults($_SERVER, 'HTTP_ACCEPT', ''), 'application/ld+json');
  56         }
  57
  58         /**
  59          * Fetches ActivityPub content from the given url
  60          *
  61          * @param string $url content url
  62          * @return array
  63          */
  64         public static function fetchContent($url)
  65         {
  66                 $curlResult = Network::curl($url, false, $redirects, ['accept_content' => 'application/activity+json, application/ld+json']);
  67                 if (!$curlResult->isSuccess() || empty($curlResult->getBody())) {
  68                         return false;
  69                 }
  70
  71                 $content = json_decode($curlResult->getBody(), true);
  72
  73                 if (empty($content) || !is_array($content)) {
  74                         return false;
  75                 }
  76
  77                 return $content;
  78         }
  79
  80         /**
  81          * Fetches a profile from the given url into an array that is compatible to Probe::uri
  82          *
  83          * @param string $url profile url
  84          * @return array
  85          */
  86         public static function probeProfile($url)
  87         {
  88                 $apcontact = APContact::getByURL($url, true);
  89                 if (empty($apcontact)) {
  90                         return false;
  91                 }
  92
  93                 $profile = ['network' => Protocol::ACTIVITYPUB];
  94                 $profile['nick'] = $apcontact['nick'];
  95                 $profile['name'] = $apcontact['name'];
  96                 $profile['guid'] = $apcontact['uuid'];
  97                 $profile['url'] = $apcontact['url'];
  98                 $profile['addr'] = $apcontact['addr'];
  99                 $profile['alias'] = $apcontact['alias'];
 100                 $profile['photo'] = $apcontact['photo'];
 101                 // $profile['community']
 102                 // $profile['keywords']
 103                 // $profile['location']
 104                 $profile['about'] = $apcontact['about'];
 105                 $profile['batch'] = $apcontact['sharedinbox'];
 106                 $profile['notify'] = $apcontact['inbox'];
 107                 $profile['poll'] = $apcontact['outbox'];
 108                 $profile['pubkey'] = $apcontact['pubkey'];
 109                 $profile['baseurl'] = $apcontact['baseurl'];
 110
 111                 // Remove all "null" fields
 112                 foreach ($profile as $field => $content) {
 113                         if (is_null($content)) {
 114                                 unset($profile[$field]);
 115                         }
 116                 }
 117
 118                 return $profile;
 119         }
 120
 121         /**
 122          * Fetches activities from the outbox of a given profile and processes it
 123          *
 124          * @param string $url
 125          * @param integer $uid User ID
 126          */
 127         public static function fetchOutbox($url, $uid)
 128         {
 129                 $data = self::fetchContent($url);
 130                 if (empty($data)) {
 131                         return;
 132                 }
 133
 134                 if (!empty($data['orderedItems'])) {
 135                         $items = $data['orderedItems'];
 136                 } elseif (!empty($data['first']['orderedItems'])) {
 137                         $items = $data['first']['orderedItems'];
 138                 } elseif (!empty($data['first'])) {
 139                         self::fetchOutbox($data['first'], $uid);
 140                         return;
 141                 } else {
 142                         $items = [];
 143                 }
 144
 145                 foreach ($items as $activity) {
 146                         $ldactivity = JsonLD::compact($activity);
 147                         ActivityPub\Receiver::processActivity($ldactivity, '', $uid, true);
 148                 }
 149         }
 150 }