src/Util/JsonLD.php

   1 <?php
   2 /**
   3  * @copyright Copyright (C) 2010-2023, 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://funkwhale.audio/ns':
  62                                 $url = DI::basePath() . '/static/funkwhale.audio.jsonld';
  63                                 break;
  64                         case 'http://schema.org':
  65                                 $url = DI::basePath() . '/static/schema.jsonld';
  66                                 break;
  67                         case 'http://joinmastodon.org/ns':
  68                                 $url = DI::basePath() . '/static/joinmastodon.jsonld';
  69                                 break;
  70                         default:
  71                                 switch (parse_url($url, PHP_URL_PATH)) {
  72                                         case '/schemas/litepub-0.1.jsonld';
  73                                                 $url = DI::basePath() . '/static/litepub-0.1.jsonld';
  74                                                 break;
  75                                         case '/apschema/v1.2':
  76                                         case '/apschema/v1.9':
  77                                         case '/apschema/v1.10':
  78                                                 $url = DI::basePath() . '/static/apschema.jsonld';
  79                                                 break;
  80                                         default:
  81                                                 Logger::info('Got url', ['url' =>$url]);
  82                                                 break;
  83                                 }
  84                 }
  85
  86                 $recursion = 0;
  87
  88                 $x = debug_backtrace();
  89                 if ($x) {
  90                         foreach ($x as $n) {
  91                                 if ($n['function'] === __FUNCTION__)  {
  92                                         $recursion ++;
  93                                 }
  94                         }
  95                 }
  96
  97                 if ($recursion > 5) {
  98                         Logger::error('jsonld bomb detected at: ' . $url);
  99                         System::exit();
 100                 }
 101
 102                 $result = DI::cache()->get('documentLoader:' . $url);
 103                 if (!is_null($result)) {
 104                         return $result;
 105                 }
 106
 107                 $data = jsonld_default_document_loader($url);
 108                 DI::cache()->set('documentLoader:' . $url, $data, Duration::DAY);
 109                 return $data;
 110         }
 111
 112         /**
 113          * Normalises a given JSON array
 114          *
 115          * @param array $json
 116          *
 117          * @return mixed|bool normalized JSON string
 118          * @throws Exception
 119          */
 120         public static function normalize($json)
 121         {
 122                 jsonld_set_document_loader('Friendica\Util\JsonLD::documentLoader');
 123
 124                 $jsonobj = json_decode(json_encode($json, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE));
 125
 126                 try {
 127                         $normalized = jsonld_normalize($jsonobj, array('algorithm' => 'URDNA2015', 'format' => 'application/nquads'));
 128                 }
 129                 catch (Exception $e) {
 130                         $normalized = false;
 131                         $messages = [];
 132                         $currentException = $e;
 133                         do {
 134                                 $messages[] = $currentException->getMessage();
 135                         } while($currentException = $currentException->getPrevious());
 136
 137                         Logger::warning('JsonLD normalize error');
 138                         Logger::notice('JsonLD normalize error', ['messages' => $messages]);
 139                         Logger::info('JsonLD normalize error', ['trace' => $e->getTraceAsString()]);
 140                         Logger::debug('JsonLD normalize error', ['jsonobj' => $jsonobj]);
 141                 }
 142
 143                 return $normalized;
 144         }
 145
 146         /**
 147          * Compacts a given JSON array
 148          *
 149          * @param array $json
 150          * @param bool  $logfailed
 151          *
 152          * @return array Compacted JSON array
 153          * @throws Exception
 154          */
 155         public static function compact($json, bool $logfailed = true): array
 156         {
 157                 jsonld_set_document_loader('Friendica\Util\JsonLD::documentLoader');
 158
 159                 $context = (object)['as' => 'https://www.w3.org/ns/activitystreams#',
 160                         'w3id' => 'https://w3id.org/security#',
 161                         'ldp' => (object)['@id' => 'http://www.w3.org/ns/ldp#', '@type' => '@id'],
 162                         'vcard' => (object)['@id' => 'http://www.w3.org/2006/vcard/ns#', '@type' => '@id'],
 163                         'dfrn' => (object)['@id' => 'http://purl.org/macgirvin/dfrn/1.0/', '@type' => '@id'],
 164                         'diaspora' => (object)['@id' => 'https://diasporafoundation.org/ns/', '@type' => '@id'],
 165                         'ostatus' => (object)['@id' => 'http://ostatus.org#', '@type' => '@id'],
 166                         'dc' => (object)['@id' => 'http://purl.org/dc/terms/', '@type' => '@id'],
 167                         'toot' => (object)['@id' => 'http://joinmastodon.org/ns#', '@type' => '@id'],
 168                         'litepub' => (object)['@id' => 'http://litepub.social/ns#', '@type' => '@id'],
 169                         'sc' => (object)['@id' => 'http://schema.org#', '@type' => '@id'],
 170                         'pt' => (object)['@id' => 'https://joinpeertube.org/ns#', '@type' => '@id'],
 171                         'mobilizon' => (object)['@id' => 'https://joinmobilizon.org/ns#', '@type' => '@id'],
 172                         'fedibird' => (object)['@id' => 'http://fedibird.com/ns#', '@type' => '@id'],
 173                         'misskey' => (object)['@id' => 'https://misskey-hub.net/ns#', '@type' => '@id'],
 174                         'pixelfed' => (object)['@id' => 'http://pixelfed.org/ns#', '@type' => '@id'],
 175                 ];
 176
 177                 $orig_json = $json;
 178
 179                 // Preparation for adding possibly missing content to the context
 180                 if (!empty($json['@context']) && is_string($json['@context'])) {
 181                         $json['@context'] = [$json['@context']];
 182                 }
 183
 184                 if (!empty($json['@context']) && is_array($json['@context'])) {
 185                         // Remove empty entries from the context (a problem with WriteFreely)
 186                         $json['@context'] = array_filter($json['@context']);
 187
 188                         // Workaround for servers with missing context
 189                         // See issue https://github.com/nextcloud/social/issues/330
 190                         if (!in_array('https://w3id.org/security/v1', $json['@context'])) {
 191                                 $json['@context'][] = 'https://w3id.org/security/v1';
 192                         }
 193                 }
 194
 195                 // Bookwyrm transmits "id" fields with "null", which isn't allowed.
 196                 array_walk_recursive($json, function (&$value, $key) {
 197                         if ($key == 'id' && is_null($value)) {
 198                                 $value = '';
 199                         }
 200                 });
 201
 202                 $jsonobj = json_decode(json_encode($json, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE));
 203
 204                 try {
 205                         $compacted = jsonld_compact($jsonobj, $context);
 206                 }
 207                 catch (Exception $e) {
 208                         $compacted = false;
 209                         Logger::notice('compacting error', ['msg' => $e->getMessage(), 'previous' => $e->getPrevious(), 'line' => $e->getLine()]);
 210                         if ($logfailed && DI::config()->get('debug', 'ap_log_failure')) {
 211                                 $tempfile = tempnam(System::getTempPath(), 'failed-jsonld');
 212                                 file_put_contents($tempfile, json_encode(['json' => $orig_json, 'msg' => $e->getMessage(), 'previous' => $e->getPrevious()], JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE | JSON_PRETTY_PRINT));
 213                                 Logger::notice('Failed message stored', ['file' => $tempfile]);
 214                         }
 215                 }
 216
 217                 $json = json_decode(json_encode($compacted, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE), true);
 218
 219                 if ($json === false) {
 220                         Logger::notice('JSON encode->decode failed', ['orig_json' => $orig_json, 'compacted' => $compacted]);
 221                         $json = [];
 222                 }
 223
 224                 return $json;
 225         }
 226
 227         /**
 228          * Fetches an element array from a JSON array
 229          *
 230          * @param $array
 231          * @param $element
 232          * @param $key
 233          *
 234          * @return array fetched element
 235          */
 236         public static function fetchElementArray($array, $element, $key = null, $type = null, $type_value = null)
 237         {
 238                 if (!isset($array[$element])) {
 239                         return null;
 240                 }
 241
 242                 // If it isn't an array yet, make it to one
 243                 if (!is_array($array[$element]) || !is_int(key($array[$element]))) {
 244                         $array[$element] = [$array[$element]];
 245                 }
 246
 247                 $elements = [];
 248
 249                 foreach ($array[$element] as $entry) {
 250                         if (!is_array($entry) || is_null($key)) {
 251                                 $item = $entry;
 252                         } elseif (isset($entry[$key])) {
 253                                 $item = $entry[$key];
 254                         }
 255
 256                         if (isset($item) && (is_null($type) || is_null($type_value) || isset($item[$type]) && $item[$type] == $type_value)) {
 257                                 $elements[] = $item;
 258                         }
 259                 }
 260
 261                 return $elements;
 262         }
 263
 264         /**
 265          * Fetches an element from a JSON array
 266          *
 267          * @param $array
 268          * @param $element
 269          * @param $key
 270          * @param $type
 271          * @param $type_value
 272          *
 273          * @return string fetched element
 274          */
 275         public static function fetchElement($array, $element, $key = '@id', $type = null, $type_value = null)
 276         {
 277                 if (empty($array)) {
 278                         return null;
 279                 }
 280
 281                 if (!isset($array[$element])) {
 282                         return null;
 283                 }
 284
 285                 if (!is_array($array[$element])) {
 286                         return $array[$element];
 287                 }
 288
 289                 if (is_null($type) || is_null($type_value)) {
 290                         $element_array = self::fetchElementArray($array, $element, $key);
 291                         if (is_null($element_array)) {
 292                                 return null;
 293                         }
 294
 295                         return array_shift($element_array);
 296                 }
 297
 298                 $element_array = self::fetchElementArray($array, $element);
 299                 if (is_null($element_array)) {
 300                         return null;
 301                 }
 302
 303                 foreach ($element_array as $entry) {
 304                         if (isset($entry[$key]) && isset($entry[$type]) && ($entry[$type] == $type_value)) {
 305                                 return $entry[$key];
 306                         }
 307                 }
 308
 309                 return null;
 310         }
 311 }