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\Util\JsonLD;
  25 use Friendica\Util\Network;
  26 use Friendica\Core\Protocol;
  27 use Friendica\Model\APContact;
  28 use Friendica\Model\User;
  29 use Friendica\Util\HTTPSignature;
  30
  31 /**
  32  * ActivityPub Protocol class
  33  *
  34  * The ActivityPub Protocol is a message exchange protocol defined by the W3C.
  35  * https://www.w3.org/TR/activitypub/
  36  * https://www.w3.org/TR/activitystreams-core/
  37  * https://www.w3.org/TR/activitystreams-vocabulary/
  38  *
  39  * https://blog.joinmastodon.org/2018/06/how-to-implement-a-basic-activitypub-server/
  40  * https://blog.joinmastodon.org/2018/07/how-to-make-friends-and-verify-requests/
  41  *
  42  * Digest: https://tools.ietf.org/html/rfc5843
  43  * https://tools.ietf.org/html/draft-cavage-http-signatures-10#ref-15
  44  *
  45  * Mastodon implementation of supported activities:
  46  * https://github.com/tootsuite/mastodon/blob/master/app/lib/activitypub/activity.rb#L26
  47  *
  48  * Funkwhale:
  49  * http://docs-funkwhale-funkwhale-549-music-federation-documentation.preview.funkwhale.audio/federation/index.html
  50  *
  51  * To-do:
  52  * - Polling the outboxes for missing content?
  53  *
  54  * Missing parts from DFRN:
  55  * - Public Forum
  56  * - Private Forum
  57  * - Relocation
  58  */
  59 class ActivityPub
  60 {
  61         const PUBLIC_COLLECTION = 'https://www.w3.org/ns/activitystreams#Public';
  62         const CONTEXT = ['https://www.w3.org/ns/activitystreams', 'https://w3id.org/security/v1',
  63                 ['vcard' => 'http://www.w3.org/2006/vcard/ns#',
  64                 'dfrn' => 'http://purl.org/macgirvin/dfrn/1.0/',
  65                 'diaspora' => 'https://diasporafoundation.org/ns/',
  66                 'litepub' => 'http://litepub.social/ns#',
  67                 'manuallyApprovesFollowers' => 'as:manuallyApprovesFollowers',
  68                 'sensitive' => 'as:sensitive', 'Hashtag' => 'as:Hashtag',
  69                 'directMessage' => 'litepub:directMessage']];
  70         const ACCOUNT_TYPES = ['Person', 'Organization', 'Service', 'Group', 'Application'];
  71         /**
  72          * Checks if the web request is done for the AP protocol
  73          *
  74          * @return bool is it AP?
  75          */
  76         public static function isRequest()
  77         {
  78                 return stristr($_SERVER['HTTP_ACCEPT'] ?? '', 'application/activity+json') ||
  79                         stristr($_SERVER['HTTP_ACCEPT'] ?? '', 'application/ld+json');
  80         }
  81
  82         /**
  83          * Fetches ActivityPub content from the given url
  84          *
  85          * @param string  $url content url
  86          * @param integer $uid User ID for the signature
  87          * @return array
  88          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
  89          */
  90         public static function fetchContent($url, $uid = 0)
  91         {
  92                 if (!empty($uid)) {
  93                         return HTTPSignature::fetch($url, $uid);
  94                 }
  95
  96                 $curlResult = Network::curl($url, false, ['accept_content' => 'application/activity+json, application/ld+json']);
  97                 if (!$curlResult->isSuccess() || empty($curlResult->getBody())) {
  98                         return false;
  99                 }
 100
 101                 $content = json_decode($curlResult->getBody(), true);
 102
 103                 if (empty($content) || !is_array($content)) {
 104                         return false;
 105                 }
 106
 107                 return $content;
 108         }
 109
 110         private static function getAccountType($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 false;
 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['baseurl'] = $apcontact['baseurl'];
 174
 175                 // Remove all "null" fields
 176                 foreach ($profile as $field => $content) {
 177                         if (is_null($content)) {
 178                                 unset($profile[$field]);
 179                         }
 180                 }
 181
 182                 return $profile;
 183         }
 184
 185         /**
 186          * Fetches activities from the outbox of a given profile and processes it
 187          *
 188          * @param string  $url
 189          * @param integer $uid User ID
 190          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 191          */
 192         public static function fetchOutbox($url, $uid)
 193         {
 194                 $data = self::fetchContent($url, $uid);
 195                 if (empty($data)) {
 196                         return;
 197                 }
 198
 199                 if (!empty($data['orderedItems'])) {
 200                         $items = $data['orderedItems'];
 201                 } elseif (!empty($data['first']['orderedItems'])) {
 202                         $items = $data['first']['orderedItems'];
 203                 } elseif (!empty($data['first'])) {
 204                         self::fetchOutbox($data['first'], $uid);
 205                         return;
 206                 } else {
 207                         $items = [];
 208                 }
 209
 210                 foreach ($items as $activity) {
 211                         $ldactivity = JsonLD::compact($activity);
 212                         ActivityPub\Receiver::processActivity($ldactivity, '', $uid, true);
 213                 }
 214         }
 215
 216         /**
 217          * Fetch items from AP endpoints
 218          *
 219          * @param string $url  Address of the endpoint
 220          * @param integer $uid Optional user id
 221          * @return array Endpoint items
 222          */
 223         public static function fetchItems(string $url, int $uid = 0)
 224         {
 225                 $data = self::fetchContent($url, $uid);
 226                 if (empty($data)) {
 227                         return [];
 228                 }
 229
 230                 if (!empty($data['orderedItems'])) {
 231                         $items = $data['orderedItems'];
 232                 } elseif (!empty($data['first']['orderedItems'])) {
 233                         $items = $data['first']['orderedItems'];
 234                 } elseif (!empty($data['first']) && is_string($data['first']) && ($data['first'] != $url)) {
 235                         return self::fetchItems($data['first'], $uid);
 236                 } else {
 237                         return [];
 238                 }
 239
 240                 if (!empty($data['next']) && is_string($data['next'])) {
 241                         $items = array_merge($items, self::fetchItems($data['next'], $uid));
 242                 }
 243
 244                 return $items;
 245         }
 246
 247         /**
 248          * Checks if the given contact url does support ActivityPub
 249          *
 250          * @param string  $url    profile url
 251          * @param boolean $update true = always update, false = never update, null = update when not found or outdated
 252          * @return boolean
 253          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 254          * @throws \ImagickException
 255          */
 256         public static function isSupportedByContactUrl($url, $update = null)
 257         {
 258                 return !empty(APContact::getByURL($url, $update));
 259         }
 260 }