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\Database\DBA;
  26 use Friendica\DI;
  27 use Friendica\Model\APContact;
  28 use Friendica\Model\User;
  29 use Friendica\Util\HTTPSignature;
  30 use Friendica\Util\JsonLD;
  31
  32 /**
  33  * ActivityPub Protocol class
  34  *
  35  * The ActivityPub Protocol is a message exchange protocol defined by the W3C.
  36  * https://www.w3.org/TR/activitypub/
  37  * https://www.w3.org/TR/activitystreams-core/
  38  * https://www.w3.org/TR/activitystreams-vocabulary/
  39  *
  40  * https://blog.joinmastodon.org/2018/06/how-to-implement-a-basic-activitypub-server/
  41  * https://blog.joinmastodon.org/2018/07/how-to-make-friends-and-verify-requests/
  42  *
  43  * Digest: https://tools.ietf.org/html/rfc5843
  44  * https://tools.ietf.org/html/draft-cavage-http-signatures-10#ref-15
  45  *
  46  * Mastodon implementation of supported activities:
  47  * https://github.com/tootsuite/mastodon/blob/master/app/lib/activitypub/activity.rb#L26
  48  *
  49  * Funkwhale:
  50  * http://docs-funkwhale-funkwhale-549-music-federation-documentation.preview.funkwhale.audio/federation/index.html
  51  *
  52  * To-do:
  53  * - Polling the outboxes for missing content?
  54  *
  55  * Missing parts from DFRN:
  56  * - Public Forum
  57  * - Private Forum
  58  * - Relocation
  59  */
  60 class ActivityPub
  61 {
  62         const PUBLIC_COLLECTION = 'https://www.w3.org/ns/activitystreams#Public';
  63         const CONTEXT = ['https://www.w3.org/ns/activitystreams', 'https://w3id.org/security/v1',
  64                 ['vcard' => 'http://www.w3.org/2006/vcard/ns#',
  65                 'dfrn' => 'http://purl.org/macgirvin/dfrn/1.0/',
  66                 'diaspora' => 'https://diasporafoundation.org/ns/',
  67                 'litepub' => 'http://litepub.social/ns#',
  68                 'manuallyApprovesFollowers' => 'as:manuallyApprovesFollowers',
  69                 'sensitive' => 'as:sensitive', 'Hashtag' => 'as:Hashtag',
  70                 'directMessage' => 'litepub:directMessage']];
  71         const ACCOUNT_TYPES = ['Person', 'Organization', 'Service', 'Group', 'Application'];
  72         /**
  73          * Checks if the web request is done for the AP protocol
  74          *
  75          * @return bool is it AP?
  76          */
  77         public static function isRequest()
  78         {
  79                 return stristr($_SERVER['HTTP_ACCEPT'] ?? '', 'application/activity+json') ||
  80                         stristr($_SERVER['HTTP_ACCEPT'] ?? '', 'application/ld+json');
  81         }
  82
  83         /**
  84          * Fetches ActivityPub content from the given url
  85          *
  86          * @param string  $url content url
  87          * @param integer $uid User ID for the signature
  88          * @return array
  89          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
  90          */
  91         public static function fetchContent(string $url, int $uid = 0)
  92         {
  93                 if (empty($uid)) {
  94                         $user = User::getFirstAdmin(['uid']);
  95
  96                         if (empty($user['uid'])) {
  97                                 // When the system setup is missing an admin we just take the first user
  98                                 $condition = ['verified' => true, 'blocked' => false, 'account_removed' => false, 'account_expired' => false];
  99                                 $user = DBA::selectFirst('user', ['uid'], $condition);
 100                         }
 101
 102                         if (!empty($user['uid'])) {
 103                                 $uid = $user['uid'];
 104                         }
 105                 }
 106
 107                 return HTTPSignature::fetch($url, $uid);
 108         }
 109
 110         private static function getAccountType($apcontact)
 111         {
 112                 $accounttype = -1;
 113
 114                 switch($apcontact['type']) {
 115                         case 'Person':
 116                                 $accounttype = User::ACCOUNT_TYPE_PERSON;
 117                                 break;
 118                         case 'Organization':
 119                                 $accounttype = User::ACCOUNT_TYPE_ORGANISATION;
 120                                 break;
 121                         case 'Service':
 122                                 $accounttype = User::ACCOUNT_TYPE_NEWS;
 123                                 break;
 124                         case 'Group':
 125                                 $accounttype = User::ACCOUNT_TYPE_COMMUNITY;
 126                                 break;
 127                         case 'Application':
 128                                 $accounttype = User::ACCOUNT_TYPE_RELAY;
 129                                 break;
 130                 }
 131
 132                 return $accounttype;
 133         }
 134
 135         /**
 136          * Fetches a profile from the given url into an array that is compatible to Probe::uri
 137          *
 138          * @param string  $url    profile url
 139          * @param boolean $update Update the profile
 140          * @return array
 141          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 142          * @throws \ImagickException
 143          */
 144         public static function probeProfile($url, $update = true)
 145         {
 146                 $apcontact = APContact::getByURL($url, $update);
 147                 if (empty($apcontact)) {
 148                         return [];
 149                 }
 150
 151                 $profile = ['network' => Protocol::ACTIVITYPUB];
 152                 $profile['nick'] = $apcontact['nick'];
 153                 $profile['name'] = $apcontact['name'];
 154                 $profile['guid'] = $apcontact['uuid'];
 155                 $profile['url'] = $apcontact['url'];
 156                 $profile['addr'] = $apcontact['addr'];
 157                 $profile['alias'] = $apcontact['alias'];
 158                 $profile['following'] = $apcontact['following'];
 159                 $profile['followers'] = $apcontact['followers'];
 160                 $profile['inbox'] = $apcontact['inbox'];
 161                 $profile['outbox'] = $apcontact['outbox'];
 162                 $profile['sharedinbox'] = $apcontact['sharedinbox'];
 163                 $profile['photo'] = $apcontact['photo'];
 164                 $profile['account-type'] = self::getAccountType($apcontact);
 165                 $profile['community'] = ($profile['account-type'] == User::ACCOUNT_TYPE_COMMUNITY);
 166                 // $profile['keywords']
 167                 // $profile['location']
 168                 $profile['about'] = $apcontact['about'];
 169                 $profile['batch'] = $apcontact['sharedinbox'];
 170                 $profile['notify'] = $apcontact['inbox'];
 171                 $profile['poll'] = $apcontact['outbox'];
 172                 $profile['pubkey'] = $apcontact['pubkey'];
 173                 $profile['subscribe'] = $apcontact['subscribe'];
 174                 $profile['baseurl'] = $apcontact['baseurl'];
 175                 $profile['gsid'] = $apcontact['gsid'];
 176
 177                 // Remove all "null" fields
 178                 foreach ($profile as $field => $content) {
 179                         if (is_null($content)) {
 180                                 unset($profile[$field]);
 181                         }
 182                 }
 183
 184                 return $profile;
 185         }
 186
 187         /**
 188          * Fetches activities from the outbox of a given profile and processes it
 189          *
 190          * @param string  $url
 191          * @param integer $uid User ID
 192          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 193          */
 194         public static function fetchOutbox($url, $uid)
 195         {
 196                 $data = self::fetchContent($url, $uid);
 197                 if (empty($data)) {
 198                         return;
 199                 }
 200
 201                 if (!empty($data['orderedItems'])) {
 202                         $items = $data['orderedItems'];
 203                 } elseif (!empty($data['first']['orderedItems'])) {
 204                         $items = $data['first']['orderedItems'];
 205                 } elseif (!empty($data['first'])) {
 206                         self::fetchOutbox($data['first'], $uid);
 207                         return;
 208                 } else {
 209                         $items = [];
 210                 }
 211
 212                 foreach ($items as $activity) {
 213                         $ldactivity = JsonLD::compact($activity);
 214                         ActivityPub\Receiver::processActivity($ldactivity, '', $uid, true);
 215                 }
 216         }
 217
 218         /**
 219          * Fetch items from AP endpoints
 220          *
 221          * @param string $url  Address of the endpoint
 222          * @param integer $uid Optional user id
 223          * @return array Endpoint items
 224          */
 225         public static function fetchItems(string $url, int $uid = 0)
 226         {
 227                 $data = self::fetchContent($url, $uid);
 228                 if (empty($data)) {
 229                         return [];
 230                 }
 231
 232                 if (!empty($data['orderedItems'])) {
 233                         $items = $data['orderedItems'];
 234                 } elseif (!empty($data['first']['orderedItems'])) {
 235                         $items = $data['first']['orderedItems'];
 236                 } elseif (!empty($data['first']) && is_string($data['first']) && ($data['first'] != $url)) {
 237                         return self::fetchItems($data['first'], $uid);
 238                 } else {
 239                         return [];
 240                 }
 241
 242                 if (!empty($data['next']) && is_string($data['next'])) {
 243                         $items = array_merge($items, self::fetchItems($data['next'], $uid));
 244                 }
 245
 246                 return $items;
 247         }
 248
 249         /**
 250          * Checks if the given contact url does support ActivityPub
 251          *
 252          * @param string  $url    profile url
 253          * @param boolean $update true = always update, false = never update, null = update when not found or outdated
 254          * @return boolean
 255          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 256          * @throws \ImagickException
 257          */
 258         public static function isSupportedByContactUrl($url, $update = null)
 259         {
 260                 return !empty(APContact::getByURL($url, $update));
 261         }
 262 }