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 use Friendica\Util\HTTPSignature;
  11
  12 /**
  13  * @brief ActivityPub Protocol class
  14  * The ActivityPub Protocol is a message exchange protocol defined by the W3C.
  15  * https://www.w3.org/TR/activitypub/
  16  * https://www.w3.org/TR/activitystreams-core/
  17  * https://www.w3.org/TR/activitystreams-vocabulary/
  18  *
  19  * https://blog.joinmastodon.org/2018/06/how-to-implement-a-basic-activitypub-server/
  20  * https://blog.joinmastodon.org/2018/07/how-to-make-friends-and-verify-requests/
  21  *
  22  * Digest: https://tools.ietf.org/html/rfc5843
  23  * https://tools.ietf.org/html/draft-cavage-http-signatures-10#ref-15
  24  *
  25  * Mastodon implementation of supported activities:
  26  * https://github.com/tootsuite/mastodon/blob/master/app/lib/activitypub/activity.rb#L26
  27  *
  28  * Funkwhale:
  29  * http://docs-funkwhale-funkwhale-549-music-federation-documentation.preview.funkwhale.audio/federation/index.html
  30  *
  31  * To-do:
  32  * - Polling the outboxes for missing content?
  33  *
  34  * Missing parts from DFRN:
  35  * - Public Forum
  36  * - Private Forum
  37  * - Relocation
  38  */
  39 class ActivityPub
  40 {
  41         const PUBLIC_COLLECTION = 'https://www.w3.org/ns/activitystreams#Public';
  42         const CONTEXT = ['https://www.w3.org/ns/activitystreams', 'https://w3id.org/security/v1',
  43                 ['vcard' => 'http://www.w3.org/2006/vcard/ns#',
  44                 'dfrn' => 'http://purl.org/macgirvin/dfrn/1.0/',
  45                 'diaspora' => 'https://diasporafoundation.org/ns/',
  46                 'manuallyApprovesFollowers' => 'as:manuallyApprovesFollowers',
  47                 'sensitive' => 'as:sensitive', 'Hashtag' => 'as:Hashtag']];
  48         const ACCOUNT_TYPES = ['Person', 'Organization', 'Service', 'Group', 'Application'];
  49         /**
  50          * Checks if the web request is done for the AP protocol
  51          *
  52          * @return is it AP?
  53          */
  54         public static function isRequest()
  55         {
  56                 return stristr(defaults($_SERVER, 'HTTP_ACCEPT', ''), 'application/activity+json') ||
  57                         stristr(defaults($_SERVER, 'HTTP_ACCEPT', ''), 'application/ld+json');
  58         }
  59
  60         /**
  61          * Fetches ActivityPub content from the given url
  62          *
  63          * @param string  $url content url
  64          * @param integer $uid User ID for the signature
  65          * @return array
  66          */
  67         public static function fetchContent($url, $uid = 0)
  68         {
  69                 if (!empty($uid)) {
  70                         return HTTPSignature::fetch($url, $uid);
  71                 }
  72
  73                 $curlResult = Network::curl($url, false, $redirects, ['accept_content' => 'application/activity+json, application/ld+json']);
  74                 if (!$curlResult->isSuccess() || empty($curlResult->getBody())) {
  75                         return false;
  76                 }
  77
  78                 $content = json_decode($curlResult->getBody(), true);
  79
  80                 if (empty($content) || !is_array($content)) {
  81                         return false;
  82                 }
  83
  84                 return $content;
  85         }
  86
  87         /**
  88          * Fetches a profile from the given url into an array that is compatible to Probe::uri
  89          *
  90          * @param string $url profile url
  91          * @return array
  92          */
  93         public static function probeProfile($url)
  94         {
  95                 $apcontact = APContact::getByURL($url, true);
  96                 if (empty($apcontact)) {
  97                         return false;
  98                 }
  99
 100                 $profile = ['network' => Protocol::ACTIVITYPUB];
 101                 $profile['nick'] = $apcontact['nick'];
 102                 $profile['name'] = $apcontact['name'];
 103                 $profile['guid'] = $apcontact['uuid'];
 104                 $profile['url'] = $apcontact['url'];
 105                 $profile['addr'] = $apcontact['addr'];
 106                 $profile['alias'] = $apcontact['alias'];
 107                 $profile['photo'] = $apcontact['photo'];
 108                 // $profile['community']
 109                 // $profile['keywords']
 110                 // $profile['location']
 111                 $profile['about'] = $apcontact['about'];
 112                 $profile['batch'] = $apcontact['sharedinbox'];
 113                 $profile['notify'] = $apcontact['inbox'];
 114                 $profile['poll'] = $apcontact['outbox'];
 115                 $profile['pubkey'] = $apcontact['pubkey'];
 116                 $profile['baseurl'] = $apcontact['baseurl'];
 117
 118                 // Remove all "null" fields
 119                 foreach ($profile as $field => $content) {
 120                         if (is_null($content)) {
 121                                 unset($profile[$field]);
 122                         }
 123                 }
 124
 125                 return $profile;
 126         }
 127
 128         /**
 129          * Fetches activities from the outbox of a given profile and processes it
 130          *
 131          * @param string $url
 132          * @param integer $uid User ID
 133          */
 134         public static function fetchOutbox($url, $uid)
 135         {
 136                 $data = self::fetchContent($url);
 137                 if (empty($data)) {
 138                         return;
 139                 }
 140
 141                 if (!empty($data['orderedItems'])) {
 142                         $items = $data['orderedItems'];
 143                 } elseif (!empty($data['first']['orderedItems'])) {
 144                         $items = $data['first']['orderedItems'];
 145                 } elseif (!empty($data['first'])) {
 146                         self::fetchOutbox($data['first'], $uid);
 147                         return;
 148                 } else {
 149                         $items = [];
 150                 }
 151
 152                 foreach ($items as $activity) {
 153                         $ldactivity = JsonLD::compact($activity);
 154                         ActivityPub\Receiver::processActivity($ldactivity, '', $uid, true);
 155                 }
 156         }
 157 }