src/Protocol/ActivityPub.php

   1 <?php
   2 /**
   3  * @file src/Protocol/ActivityPub.php
   4  */
   5 namespace Friendica\Protocol;
   6
   7 use Friendica\Util\JsonLD;
   8 use Friendica\Util\Network;
   9 use Friendica\Core\Protocol;
  10 use Friendica\Model\APContact;
  11 use Friendica\Util\HTTPSignature;
  12
  13 /**
  14  * @brief ActivityPub Protocol class
  15  * The ActivityPub Protocol is a message exchange protocol defined by the W3C.
  16  * https://www.w3.org/TR/activitypub/
  17  * https://www.w3.org/TR/activitystreams-core/
  18  * https://www.w3.org/TR/activitystreams-vocabulary/
  19  *
  20  * https://blog.joinmastodon.org/2018/06/how-to-implement-a-basic-activitypub-server/
  21  * https://blog.joinmastodon.org/2018/07/how-to-make-friends-and-verify-requests/
  22  *
  23  * Digest: https://tools.ietf.org/html/rfc5843
  24  * https://tools.ietf.org/html/draft-cavage-http-signatures-10#ref-15
  25  *
  26  * Mastodon implementation of supported activities:
  27  * https://github.com/tootsuite/mastodon/blob/master/app/lib/activitypub/activity.rb#L26
  28  *
  29  * Funkwhale:
  30  * http://docs-funkwhale-funkwhale-549-music-federation-documentation.preview.funkwhale.audio/federation/index.html
  31  *
  32  * To-do:
  33  * - Polling the outboxes for missing content?
  34  *
  35  * Missing parts from DFRN:
  36  * - Public Forum
  37  * - Private Forum
  38  * - Relocation
  39  */
  40 class ActivityPub
  41 {
  42         const PUBLIC_COLLECTION = 'https://www.w3.org/ns/activitystreams#Public';
  43         const CONTEXT = ['https://www.w3.org/ns/activitystreams', 'https://w3id.org/security/v1',
  44                 ['vcard' => 'http://www.w3.org/2006/vcard/ns#',
  45                 'dfrn' => 'http://purl.org/macgirvin/dfrn/1.0/',
  46                 'diaspora' => 'https://diasporafoundation.org/ns/',
  47                 'manuallyApprovesFollowers' => 'as:manuallyApprovesFollowers',
  48                 'sensitive' => 'as:sensitive', 'Hashtag' => 'as:Hashtag']];
  49         const ACCOUNT_TYPES = ['Person', 'Organization', 'Service', 'Group', 'Application'];
  50         /**
  51          * Checks if the web request is done for the AP protocol
  52          *
  53          * @return bool is it AP?
  54          */
  55         public static function isRequest()
  56         {
  57                 return stristr(defaults($_SERVER, 'HTTP_ACCEPT', ''), 'application/activity+json') ||
  58                         stristr(defaults($_SERVER, 'HTTP_ACCEPT', ''), 'application/ld+json');
  59         }
  60
  61         /**
  62          * Fetches ActivityPub content from the given url
  63          *
  64          * @param string  $url content url
  65          * @param integer $uid User ID for the signature
  66          * @return array
  67          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
  68          */
  69         public static function fetchContent($url, $uid = 0)
  70         {
  71                 if (!empty($uid)) {
  72                         return HTTPSignature::fetch($url, $uid);
  73                 }
  74
  75                 $curlResult = Network::curl($url, false, $redirects, ['accept_content' => 'application/activity+json, application/ld+json']);
  76                 if (!$curlResult->isSuccess() || empty($curlResult->getBody())) {
  77                         return false;
  78                 }
  79
  80                 $content = json_decode($curlResult->getBody(), true);
  81
  82                 if (empty($content) || !is_array($content)) {
  83                         return false;
  84                 }
  85
  86                 return $content;
  87         }
  88
  89         /**
  90          * Fetches a profile from the given url into an array that is compatible to Probe::uri
  91          *
  92          * @param string $url profile url
  93          * @return array
  94          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
  95          * @throws \ImagickException
  96          */
  97         public static function probeProfile($url)
  98         {
  99                 $apcontact = APContact::getByURL($url, true);
 100                 if (empty($apcontact)) {
 101                         return false;
 102                 }
 103
 104                 $profile = ['network' => Protocol::ACTIVITYPUB];
 105                 $profile['nick'] = $apcontact['nick'];
 106                 $profile['name'] = $apcontact['name'];
 107                 $profile['guid'] = $apcontact['uuid'];
 108                 $profile['url'] = $apcontact['url'];
 109                 $profile['addr'] = $apcontact['addr'];
 110                 $profile['alias'] = $apcontact['alias'];
 111                 $profile['photo'] = $apcontact['photo'];
 112                 // $profile['community']
 113                 // $profile['keywords']
 114                 // $profile['location']
 115                 $profile['about'] = $apcontact['about'];
 116                 $profile['batch'] = $apcontact['sharedinbox'];
 117                 $profile['notify'] = $apcontact['inbox'];
 118                 $profile['poll'] = $apcontact['outbox'];
 119                 $profile['pubkey'] = $apcontact['pubkey'];
 120                 $profile['baseurl'] = $apcontact['baseurl'];
 121
 122                 // Remove all "null" fields
 123                 foreach ($profile as $field => $content) {
 124                         if (is_null($content)) {
 125                                 unset($profile[$field]);
 126                         }
 127                 }
 128
 129                 return $profile;
 130         }
 131
 132         /**
 133          * Fetches activities from the outbox of a given profile and processes it
 134          *
 135          * @param string  $url
 136          * @param integer $uid User ID
 137          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 138          */
 139         public static function fetchOutbox($url, $uid)
 140         {
 141                 $data = self::fetchContent($url);
 142                 if (empty($data)) {
 143                         return;
 144                 }
 145
 146                 if (!empty($data['orderedItems'])) {
 147                         $items = $data['orderedItems'];
 148                 } elseif (!empty($data['first']['orderedItems'])) {
 149                         $items = $data['first']['orderedItems'];
 150                 } elseif (!empty($data['first'])) {
 151                         self::fetchOutbox($data['first'], $uid);
 152                         return;
 153                 } else {
 154                         $items = [];
 155                 }
 156
 157                 foreach ($items as $activity) {
 158                         $ldactivity = JsonLD::compact($activity);
 159                         ActivityPub\Receiver::processActivity($ldactivity, '', $uid, true);
 160                 }
 161         }
 162 }