src/Protocol/ActivityPub.php

   1 <?php
   2 /**
   3  * @copyright Copyright (C) 2020, Friendica
   4  *
   5  * @license GNU AGPL version 3 or any later version
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU Affero General Public License as
   9  * published by the Free Software Foundation, either version 3 of the
  10  * License, or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU Affero General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Affero General Public License
  18  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  19  *
  20  */
  21
  22 namespace Friendica\Protocol;
  23
  24 use Friendica\Core\Protocol;
  25 use Friendica\Model\APContact;
  26 use Friendica\Model\User;
  27 use Friendica\Util\HTTPSignature;
  28 use Friendica\Util\JsonLD;
  29
  30 /**
  31  * ActivityPub Protocol class
  32  *
  33  * The ActivityPub Protocol is a message exchange protocol defined by the W3C.
  34  * https://www.w3.org/TR/activitypub/
  35  * https://www.w3.org/TR/activitystreams-core/
  36  * https://www.w3.org/TR/activitystreams-vocabulary/
  37  *
  38  * https://blog.joinmastodon.org/2018/06/how-to-implement-a-basic-activitypub-server/
  39  * https://blog.joinmastodon.org/2018/07/how-to-make-friends-and-verify-requests/
  40  *
  41  * Digest: https://tools.ietf.org/html/rfc5843
  42  * https://tools.ietf.org/html/draft-cavage-http-signatures-10#ref-15
  43  *
  44  * Mastodon implementation of supported activities:
  45  * https://github.com/tootsuite/mastodon/blob/master/app/lib/activitypub/activity.rb#L26
  46  *
  47  * Funkwhale:
  48  * http://docs-funkwhale-funkwhale-549-music-federation-documentation.preview.funkwhale.audio/federation/index.html
  49  *
  50  * To-do:
  51  * - Polling the outboxes for missing content?
  52  *
  53  * Missing parts from DFRN:
  54  * - Public Forum
  55  * - Private Forum
  56  * - Relocation
  57  */
  58 class ActivityPub
  59 {
  60         const PUBLIC_COLLECTION = 'https://www.w3.org/ns/activitystreams#Public';
  61         const CONTEXT = ['https://www.w3.org/ns/activitystreams', 'https://w3id.org/security/v1',
  62                 ['vcard' => 'http://www.w3.org/2006/vcard/ns#',
  63                 'dfrn' => 'http://purl.org/macgirvin/dfrn/1.0/',
  64                 'diaspora' => 'https://diasporafoundation.org/ns/',
  65                 'litepub' => 'http://litepub.social/ns#',
  66                 'manuallyApprovesFollowers' => 'as:manuallyApprovesFollowers',
  67                 'sensitive' => 'as:sensitive', 'Hashtag' => 'as:Hashtag',
  68                 'directMessage' => 'litepub:directMessage']];
  69         const ACCOUNT_TYPES = ['Person', 'Organization', 'Service', 'Group', 'Application'];
  70         /**
  71          * Checks if the web request is done for the AP protocol
  72          *
  73          * @return bool is it AP?
  74          */
  75         public static function isRequest()
  76         {
  77                 return stristr($_SERVER['HTTP_ACCEPT'] ?? '', 'application/activity+json') ||
  78                         stristr($_SERVER['HTTP_ACCEPT'] ?? '', 'application/ld+json');
  79         }
  80
  81         /**
  82          * Fetches ActivityPub content from the given url
  83          *
  84          * @param string  $url content url
  85          * @param integer $uid User ID for the signature
  86          * @return array
  87          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
  88          */
  89         public static function fetchContent($url, $uid = 0)
  90         {
  91                 if (!empty($uid)) {
  92                         return HTTPSignature::fetch($url, $uid);
  93                 }
  94
  95                 $curlResult = DI::httpRequest()->curl($url, false, ['accept_content' => 'application/activity+json, application/ld+json']);
  96                 if (!$curlResult->isSuccess() || empty($curlResult->getBody())) {
  97                         return false;
  98                 }
  99
 100                 $content = json_decode($curlResult->getBody(), true);
 101
 102                 if (empty($content) || !is_array($content)) {
 103                         return false;
 104                 }
 105
 106                 return $content;
 107         }
 108
 109         private static function getAccountType($apcontact)
 110         {
 111                 $accounttype = -1;
 112
 113                 switch($apcontact['type']) {
 114                         case 'Person':
 115                                 $accounttype = User::ACCOUNT_TYPE_PERSON;
 116                                 break;
 117                         case 'Organization':
 118                                 $accounttype = User::ACCOUNT_TYPE_ORGANISATION;
 119                                 break;
 120                         case 'Service':
 121                                 $accounttype = User::ACCOUNT_TYPE_NEWS;
 122                                 break;
 123                         case 'Group':
 124                                 $accounttype = User::ACCOUNT_TYPE_COMMUNITY;
 125                                 break;
 126                         case 'Application':
 127                                 $accounttype = User::ACCOUNT_TYPE_RELAY;
 128                                 break;
 129                 }
 130
 131                 return $accounttype;
 132         }
 133
 134         /**
 135          * Fetches a profile from the given url into an array that is compatible to Probe::uri
 136          *
 137          * @param string  $url    profile url
 138          * @param boolean $update Update the profile
 139          * @return array
 140          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 141          * @throws \ImagickException
 142          */
 143         public static function probeProfile($url, $update = true)
 144         {
 145                 $apcontact = APContact::getByURL($url, $update);
 146                 if (empty($apcontact)) {
 147                         return [];
 148                 }
 149
 150                 $profile = ['network' => Protocol::ACTIVITYPUB];
 151                 $profile['nick'] = $apcontact['nick'];
 152                 $profile['name'] = $apcontact['name'];
 153                 $profile['guid'] = $apcontact['uuid'];
 154                 $profile['url'] = $apcontact['url'];
 155                 $profile['addr'] = $apcontact['addr'];
 156                 $profile['alias'] = $apcontact['alias'];
 157                 $profile['following'] = $apcontact['following'];
 158                 $profile['followers'] = $apcontact['followers'];
 159                 $profile['inbox'] = $apcontact['inbox'];
 160                 $profile['outbox'] = $apcontact['outbox'];
 161                 $profile['sharedinbox'] = $apcontact['sharedinbox'];
 162                 $profile['photo'] = $apcontact['photo'];
 163                 $profile['account-type'] = self::getAccountType($apcontact);
 164                 $profile['community'] = ($profile['account-type'] == User::ACCOUNT_TYPE_COMMUNITY);
 165                 // $profile['keywords']
 166                 // $profile['location']
 167                 $profile['about'] = $apcontact['about'];
 168                 $profile['batch'] = $apcontact['sharedinbox'];
 169                 $profile['notify'] = $apcontact['inbox'];
 170                 $profile['poll'] = $apcontact['outbox'];
 171                 $profile['pubkey'] = $apcontact['pubkey'];
 172                 $profile['subscribe'] = $apcontact['subscribe'];
 173                 $profile['baseurl'] = $apcontact['baseurl'];
 174                 $profile['gsid'] = $apcontact['gsid'];
 175
 176                 // Remove all "null" fields
 177                 foreach ($profile as $field => $content) {
 178                         if (is_null($content)) {
 179                                 unset($profile[$field]);
 180                         }
 181                 }
 182
 183                 return $profile;
 184         }
 185
 186         /**
 187          * Fetches activities from the outbox of a given profile and processes it
 188          *
 189          * @param string  $url
 190          * @param integer $uid User ID
 191          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 192          */
 193         public static function fetchOutbox($url, $uid)
 194         {
 195                 $data = self::fetchContent($url, $uid);
 196                 if (empty($data)) {
 197                         return;
 198                 }
 199
 200                 if (!empty($data['orderedItems'])) {
 201                         $items = $data['orderedItems'];
 202                 } elseif (!empty($data['first']['orderedItems'])) {
 203                         $items = $data['first']['orderedItems'];
 204                 } elseif (!empty($data['first'])) {
 205                         self::fetchOutbox($data['first'], $uid);
 206                         return;
 207                 } else {
 208                         $items = [];
 209                 }
 210
 211                 foreach ($items as $activity) {
 212                         $ldactivity = JsonLD::compact($activity);
 213                         ActivityPub\Receiver::processActivity($ldactivity, '', $uid, true);
 214                 }
 215         }
 216
 217         /**
 218          * Fetch items from AP endpoints
 219          *
 220          * @param string $url  Address of the endpoint
 221          * @param integer $uid Optional user id
 222          * @return array Endpoint items
 223          */
 224         public static function fetchItems(string $url, int $uid = 0)
 225         {
 226                 $data = self::fetchContent($url, $uid);
 227                 if (empty($data)) {
 228                         return [];
 229                 }
 230
 231                 if (!empty($data['orderedItems'])) {
 232                         $items = $data['orderedItems'];
 233                 } elseif (!empty($data['first']['orderedItems'])) {
 234                         $items = $data['first']['orderedItems'];
 235                 } elseif (!empty($data['first']) && is_string($data['first']) && ($data['first'] != $url)) {
 236                         return self::fetchItems($data['first'], $uid);
 237                 } else {
 238                         return [];
 239                 }
 240
 241                 if (!empty($data['next']) && is_string($data['next'])) {
 242                         $items = array_merge($items, self::fetchItems($data['next'], $uid));
 243                 }
 244
 245                 return $items;
 246         }
 247
 248         /**
 249          * Checks if the given contact url does support ActivityPub
 250          *
 251          * @param string  $url    profile url
 252          * @param boolean $update true = always update, false = never update, null = update when not found or outdated
 253          * @return boolean
 254          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 255          * @throws \ImagickException
 256          */
 257         public static function isSupportedByContactUrl($url, $update = null)
 258         {
 259                 return !empty(APContact::getByURL($url, $update));
 260         }
 261 }