src/Util/JsonLD.php

   1 <?php
   2 /**
   3  * @copyright Copyright (C) 2010-2024, the Friendica project
   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\Util;
  23
  24 use Friendica\Core\Cache\Enum\Duration;
  25 use Friendica\Core\Logger;
  26 use Exception;
  27 use Friendica\Core\System;
  28 use Friendica\DI;
  29
  30 /**
  31  * This class contain methods to work with JsonLD data
  32  */
  33 class JsonLD
  34 {
  35         /**
  36          * Loader for LD-JSON validation
  37          *
  38          * @param $url
  39          *
  40          * @return mixed the loaded data
  41          * @throws \JsonLdException
  42          */
  43         public static function documentLoader($url)
  44         {
  45                 switch ($url) {
  46                         case 'https://w3id.org/security/v1':
  47                                 $url = DI::basePath() . '/static/security-v1.jsonld';
  48                                 break;
  49                         case 'https://w3id.org/security/data-integrity/v1':
  50                                 $url = DI::basePath() . '/static/security-data-integrity-v1.jsonld';
  51                                 break;
  52                         case 'https://w3id.org/security/multikey/v1':
  53                                 $url = DI::basePath() . '/static/security-multikey-v1.jsonld';
  54                                 break;
  55                         case 'https://w3id.org/identity/v1':
  56                                 $url = DI::basePath() . '/static/identity-v1.jsonld';
  57                                 break;
  58                         case 'https://www.w3.org/ns/activitystreams':
  59                                 $url = DI::basePath() . '/static/activitystreams.jsonld';
  60                                 break;
  61                         case 'https://www.w3.org/ns/did/v1':
  62                                 $url = DI::basePath() . '/static/did-v1.jsonld';
  63                                 break;
  64                         case 'https://funkwhale.audio/ns':
  65                                 $url = DI::basePath() . '/static/funkwhale.audio.jsonld';
  66                                 break;
  67                         case 'http://schema.org':
  68                                 $url = DI::basePath() . '/static/schema.jsonld';
  69                                 break;
  70                         case 'http://joinmastodon.org/ns':
  71                                 $url = DI::basePath() . '/static/joinmastodon.jsonld';
  72                                 break;
  73                         default:
  74                                 switch (parse_url($url, PHP_URL_PATH)) {
  75                                         case '/schemas/litepub-0.1.jsonld';
  76                                                 $url = DI::basePath() . '/static/litepub-0.1.jsonld';
  77                                                 break;
  78                                         case '/apschema/v1.2':
  79                                         case '/apschema/v1.9':
  80                                         case '/apschema/v1.10':
  81                                                 $url = DI::basePath() . '/static/apschema.jsonld';
  82                                                 break;
  83                                         default:
  84                                                 Logger::info('Got url', ['url' =>$url]);
  85                                                 break;
  86                                 }
  87                 }
  88
  89                 $recursion = 0;
  90
  91                 $x = debug_backtrace();
  92                 if ($x) {
  93                         foreach ($x as $n) {
  94                                 if ($n['function'] === __FUNCTION__)  {
  95                                         $recursion ++;
  96                                 }
  97                         }
  98                 }
  99
 100                 if ($recursion > 5) {
 101                         Logger::error('jsonld bomb detected at: ' . $url);
 102                         System::exit();
 103                 }
 104
 105                 $result = DI::cache()->get('documentLoader:' . $url);
 106                 if (!is_null($result)) {
 107                         return $result;
 108                 }
 109
 110                 $data = jsonld_default_document_loader($url);
 111                 DI::cache()->set('documentLoader:' . $url, $data, Duration::DAY);
 112                 return $data;
 113         }
 114
 115         /**
 116          * Normalises a given JSON array
 117          *
 118          * @param array $json
 119          *
 120          * @return mixed|bool normalized JSON string
 121          * @throws Exception
 122          */
 123         public static function normalize($json)
 124         {
 125                 jsonld_set_document_loader('Friendica\Util\JsonLD::documentLoader');
 126
 127                 $jsonobj = json_decode(json_encode($json, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE));
 128
 129                 try {
 130                         $normalized = jsonld_normalize($jsonobj, array('algorithm' => 'URDNA2015', 'format' => 'application/nquads'));
 131                 }
 132                 catch (Exception $e) {
 133                         $normalized = false;
 134                         $messages = [];
 135                         $currentException = $e;
 136                         do {
 137                                 $messages[] = $currentException->getMessage();
 138                         } while($currentException = $currentException->getPrevious());
 139
 140                         Logger::warning('JsonLD normalize error');
 141                         Logger::notice('JsonLD normalize error', ['messages' => $messages]);
 142                         Logger::info('JsonLD normalize error', ['trace' => $e->getTraceAsString()]);
 143                         Logger::debug('JsonLD normalize error', ['jsonobj' => $jsonobj]);
 144                 }
 145
 146                 return $normalized;
 147         }
 148
 149         /**
 150          * Compacts a given JSON array
 151          *
 152          * @param array $json
 153          * @param bool  $logfailed
 154          *
 155          * @return array Compacted JSON array
 156          * @throws Exception
 157          */
 158         public static function compact($json, bool $logfailed = true): array
 159         {
 160                 jsonld_set_document_loader('Friendica\Util\JsonLD::documentLoader');
 161
 162                 $context = (object)['as' => 'https://www.w3.org/ns/activitystreams#',
 163                         'w3id' => 'https://w3id.org/security#',
 164                         'ldp' => (object)['@id' => 'http://www.w3.org/ns/ldp#', '@type' => '@id'],
 165                         'vcard' => (object)['@id' => 'http://www.w3.org/2006/vcard/ns#', '@type' => '@id'],
 166                         'dfrn' => (object)['@id' => 'http://purl.org/macgirvin/dfrn/1.0/', '@type' => '@id'],
 167                         'diaspora' => (object)['@id' => 'https://diasporafoundation.org/ns/', '@type' => '@id'],
 168                         'ostatus' => (object)['@id' => 'http://ostatus.org#', '@type' => '@id'],
 169                         'dc' => (object)['@id' => 'http://purl.org/dc/terms/', '@type' => '@id'],
 170                         'toot' => (object)['@id' => 'http://joinmastodon.org/ns#', '@type' => '@id'],
 171                         'litepub' => (object)['@id' => 'http://litepub.social/ns#', '@type' => '@id'],
 172                         'sc' => (object)['@id' => 'http://schema.org#', '@type' => '@id'],
 173                         'pt' => (object)['@id' => 'https://joinpeertube.org/ns#', '@type' => '@id'],
 174                         'mobilizon' => (object)['@id' => 'https://joinmobilizon.org/ns#', '@type' => '@id'],
 175                         'fedibird' => (object)['@id' => 'http://fedibird.com/ns#', '@type' => '@id'],
 176                         'misskey' => (object)['@id' => 'https://misskey-hub.net/ns#', '@type' => '@id'],
 177                         'pixelfed' => (object)['@id' => 'http://pixelfed.org/ns#', '@type' => '@id'],
 178                 ];
 179
 180                 $orig_json = $json;
 181
 182                 // Preparation for adding possibly missing content to the context
 183                 if (!empty($json['@context']) && is_string($json['@context'])) {
 184                         $json['@context'] = [$json['@context']];
 185                 }
 186
 187                 if (!empty($json['@context']) && is_array($json['@context'])) {
 188                         // Remove empty entries from the context (a problem with WriteFreely)
 189                         $json['@context'] = array_filter($json['@context']);
 190
 191                         // Workaround for servers with missing context
 192                         // See issue https://github.com/nextcloud/social/issues/330
 193                         if (!in_array('https://w3id.org/security/v1', $json['@context'])) {
 194                                 $json['@context'][] = 'https://w3id.org/security/v1';
 195                         }
 196                 }
 197
 198                 // Bookwyrm transmits "id" fields with "null", which isn't allowed.
 199                 array_walk_recursive($json, function (&$value, $key) {
 200                         if ($key == 'id' && is_null($value)) {
 201                                 $value = '';
 202                         }
 203                 });
 204
 205                 $jsonobj = json_decode(json_encode($json, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE));
 206
 207                 try {
 208                         $compacted = jsonld_compact($jsonobj, $context);
 209                 }
 210                 catch (Exception $e) {
 211                         $compacted = false;
 212                         Logger::notice('compacting error', ['msg' => $e->getMessage(), 'previous' => $e->getPrevious(), 'line' => $e->getLine()]);
 213                         if ($logfailed && DI::config()->get('debug', 'ap_log_failure')) {
 214                                 $tempfile = tempnam(System::getTempPath(), 'failed-jsonld');
 215                                 file_put_contents($tempfile, json_encode(['json' => $orig_json, 'msg' => $e->getMessage(), 'previous' => $e->getPrevious()], JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE | JSON_PRETTY_PRINT));
 216                                 Logger::notice('Failed message stored', ['file' => $tempfile]);
 217                         }
 218                 }
 219
 220                 $json = json_decode(json_encode($compacted, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE), true);
 221
 222                 if ($json === false) {
 223                         Logger::notice('JSON encode->decode failed', ['orig_json' => $orig_json, 'compacted' => $compacted]);
 224                         $json = [];
 225                 }
 226
 227                 return $json;
 228         }
 229
 230         /**
 231          * Fetches an element array from a JSON array
 232          *
 233          * @param $array
 234          * @param $element
 235          * @param $key
 236          *
 237          * @return array fetched element
 238          */
 239         public static function fetchElementArray($array, $element, $key = null, $type = null, $type_value = null)
 240         {
 241                 if (!isset($array[$element])) {
 242                         return null;
 243                 }
 244
 245                 // If it isn't an array yet, make it to one
 246                 if (!is_array($array[$element]) || !is_int(key($array[$element]))) {
 247                         $array[$element] = [$array[$element]];
 248                 }
 249
 250                 $elements = [];
 251
 252                 foreach ($array[$element] as $entry) {
 253                         if (!is_array($entry) || is_null($key)) {
 254                                 $item = $entry;
 255                         } elseif (isset($entry[$key])) {
 256                                 $item = $entry[$key];
 257                         }
 258
 259                         if (isset($item) && (is_null($type) || is_null($type_value) || isset($item[$type]) && $item[$type] == $type_value)) {
 260                                 $elements[] = $item;
 261                         }
 262                 }
 263
 264                 return $elements;
 265         }
 266
 267         /**
 268          * Fetches an element from a JSON array
 269          *
 270          * @param $array
 271          * @param $element
 272          * @param $key
 273          * @param $type
 274          * @param $type_value
 275          *
 276          * @return string fetched element
 277          */
 278         public static function fetchElement($array, $element, $key = '@id', $type = null, $type_value = null)
 279         {
 280                 if (empty($array)) {
 281                         return null;
 282                 }
 283
 284                 if (!isset($array[$element])) {
 285                         return null;
 286                 }
 287
 288                 if (!is_array($array[$element])) {
 289                         return $array[$element];
 290                 }
 291
 292                 if (is_null($type) || is_null($type_value)) {
 293                         $element_array = self::fetchElementArray($array, $element, $key);
 294                         if (is_null($element_array)) {
 295                                 return null;
 296                         }
 297
 298                         return array_shift($element_array);
 299                 }
 300
 301                 $element_array = self::fetchElementArray($array, $element);
 302                 if (is_null($element_array)) {
 303                         return null;
 304                 }
 305
 306                 foreach ($element_array as $entry) {
 307                         if (isset($entry[$key]) && isset($entry[$type]) && ($entry[$type] == $type_value)) {
 308                                 return $entry[$key];
 309                         }
 310                 }
 311
 312                 return null;
 313         }
 314 }