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/identity/v1':
  50                                 $url = DI::basePath() . '/static/identity-v1.jsonld';
  51                                 break;
  52                         case 'https://w3id.org/security/data-integrity/v1':
  53                                 $url = DI::basePath() . '/static/security-data-integrity-v1.jsonld';
  54                                 break;
  55                         case 'https://www.w3.org/ns/activitystreams':
  56                                 $url = DI::basePath() . '/static/activitystreams.jsonld';
  57                                 break;
  58                         case 'https://funkwhale.audio/ns':
  59                                 $url = DI::basePath() . '/static/funkwhale.audio.jsonld';
  60                                 break;
  61                         case 'http://schema.org':
  62                                 $url = DI::basePath() . '/static/schema.jsonld';
  63                                 break;
  64                         case 'http://joinmastodon.org/ns':
  65                                 $url = DI::basePath() . '/static/joinmastodon.jsonld';
  66                                 break;
  67                         default:
  68                                 switch (parse_url($url, PHP_URL_PATH)) {
  69                                         case '/schemas/litepub-0.1.jsonld';
  70                                                 $url = DI::basePath() . '/static/litepub-0.1.jsonld';
  71                                                 break;
  72                                         case '/apschema/v1.2':
  73                                         case '/apschema/v1.9':
  74                                         case '/apschema/v1.10':
  75                                                 $url = DI::basePath() . '/static/apschema.jsonld';
  76                                                 break;
  77                                         default:
  78                                                 Logger::info('Got url', ['url' =>$url]);
  79                                                 break;
  80                                 }
  81                 }
  82
  83                 $recursion = 0;
  84
  85                 $x = debug_backtrace();
  86                 if ($x) {
  87                         foreach ($x as $n) {
  88                                 if ($n['function'] === __FUNCTION__)  {
  89                                         $recursion ++;
  90                                 }
  91                         }
  92                 }
  93
  94                 if ($recursion > 5) {
  95                         Logger::error('jsonld bomb detected at: ' . $url);
  96                         System::exit();
  97                 }
  98
  99                 $result = DI::cache()->get('documentLoader:' . $url);
 100                 if (!is_null($result)) {
 101                         return $result;
 102                 }
 103
 104                 $data = jsonld_default_document_loader($url);
 105                 DI::cache()->set('documentLoader:' . $url, $data, Duration::DAY);
 106                 return $data;
 107         }
 108
 109         /**
 110          * Normalises a given JSON array
 111          *
 112          * @param array $json
 113          *
 114          * @return mixed|bool normalized JSON string
 115          * @throws Exception
 116          */
 117         public static function normalize($json)
 118         {
 119                 jsonld_set_document_loader('Friendica\Util\JsonLD::documentLoader');
 120
 121                 $jsonobj = json_decode(json_encode($json, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE));
 122
 123                 try {
 124                         $normalized = jsonld_normalize($jsonobj, array('algorithm' => 'URDNA2015', 'format' => 'application/nquads'));
 125                 }
 126                 catch (Exception $e) {
 127                         $normalized = false;
 128                         $messages = [];
 129                         $currentException = $e;
 130                         do {
 131                                 $messages[] = $currentException->getMessage();
 132                         } while($currentException = $currentException->getPrevious());
 133
 134                         Logger::warning('JsonLD normalize error');
 135                         Logger::notice('JsonLD normalize error', ['messages' => $messages]);
 136                         Logger::info('JsonLD normalize error', ['trace' => $e->getTraceAsString()]);
 137                         Logger::debug('JsonLD normalize error', ['jsonobj' => $jsonobj]);
 138                 }
 139
 140                 return $normalized;
 141         }
 142
 143         /**
 144          * Compacts a given JSON array
 145          *
 146          * @param array $json
 147          * @param bool  $logfailed
 148          *
 149          * @return array Compacted JSON array
 150          * @throws Exception
 151          */
 152         public static function compact($json, bool $logfailed = true): array
 153         {
 154                 jsonld_set_document_loader('Friendica\Util\JsonLD::documentLoader');
 155
 156                 $context = (object)['as' => 'https://www.w3.org/ns/activitystreams#',
 157                         'w3id' => 'https://w3id.org/security#',
 158                         'ldp' => (object)['@id' => 'http://www.w3.org/ns/ldp#', '@type' => '@id'],
 159                         'vcard' => (object)['@id' => 'http://www.w3.org/2006/vcard/ns#', '@type' => '@id'],
 160                         'dfrn' => (object)['@id' => 'http://purl.org/macgirvin/dfrn/1.0/', '@type' => '@id'],
 161                         'diaspora' => (object)['@id' => 'https://diasporafoundation.org/ns/', '@type' => '@id'],
 162                         'ostatus' => (object)['@id' => 'http://ostatus.org#', '@type' => '@id'],
 163                         'dc' => (object)['@id' => 'http://purl.org/dc/terms/', '@type' => '@id'],
 164                         'toot' => (object)['@id' => 'http://joinmastodon.org/ns#', '@type' => '@id'],
 165                         'litepub' => (object)['@id' => 'http://litepub.social/ns#', '@type' => '@id'],
 166                         'sc' => (object)['@id' => 'http://schema.org#', '@type' => '@id'],
 167                         'pt' => (object)['@id' => 'https://joinpeertube.org/ns#', '@type' => '@id'],
 168                         'mobilizon' => (object)['@id' => 'https://joinmobilizon.org/ns#', '@type' => '@id'],
 169                         'fedibird' => (object)['@id' => 'http://fedibird.com/ns#', '@type' => '@id'],
 170                         'misskey' => (object)['@id' => 'https://misskey-hub.net/ns#', '@type' => '@id'],
 171                 ];
 172
 173                 $orig_json = $json;
 174
 175                 // Preparation for adding possibly missing content to the context
 176                 if (!empty($json['@context']) && is_string($json['@context'])) {
 177                         $json['@context'] = [$json['@context']];
 178                 }
 179
 180                 if (!empty($json['@context']) && is_array($json['@context'])) {
 181                         // Remove empty entries from the context (a problem with WriteFreely)
 182                         $json['@context'] = array_filter($json['@context']);
 183
 184                         // Workaround for servers with missing context
 185                         // See issue https://github.com/nextcloud/social/issues/330
 186                         if (!in_array('https://w3id.org/security/v1', $json['@context'])) {
 187                                 $json['@context'][] = 'https://w3id.org/security/v1';
 188                         }
 189                 }
 190
 191                 // Bookwyrm transmits "id" fields with "null", which isn't allowed.
 192                 array_walk_recursive($json, function (&$value, $key) {
 193                         if ($key == 'id' && is_null($value)) {
 194                                 $value = '';
 195                         }
 196                 });
 197
 198                 $jsonobj = json_decode(json_encode($json, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE));
 199
 200                 try {
 201                         $compacted = jsonld_compact($jsonobj, $context);
 202                 }
 203                 catch (Exception $e) {
 204                         $compacted = false;
 205                         Logger::notice('compacting error', ['msg' => $e->getMessage(), 'previous' => $e->getPrevious(), 'line' => $e->getLine()]);
 206                         if ($logfailed && DI::config()->get('debug', 'ap_log_failure')) {
 207                                 $tempfile = tempnam(System::getTempPath(), 'failed-jsonld');
 208                                 file_put_contents($tempfile, json_encode(['json' => $orig_json, 'callstack' => System::callstack(20), 'msg' => $e->getMessage(), 'previous' => $e->getPrevious()], JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE | JSON_PRETTY_PRINT));
 209                                 Logger::notice('Failed message stored', ['file' => $tempfile]);
 210                         }
 211                 }
 212
 213                 $json = json_decode(json_encode($compacted, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE), true);
 214
 215                 if ($json === false) {
 216                         Logger::notice('JSON encode->decode failed', ['orig_json' => $orig_json, 'compacted' => $compacted]);
 217                         $json = [];
 218                 }
 219
 220                 return $json;
 221         }
 222
 223         /**
 224          * Fetches an element array from a JSON array
 225          *
 226          * @param $array
 227          * @param $element
 228          * @param $key
 229          *
 230          * @return array fetched element
 231          */
 232         public static function fetchElementArray($array, $element, $key = null, $type = null, $type_value = null)
 233         {
 234                 if (!isset($array[$element])) {
 235                         return null;
 236                 }
 237
 238                 // If it isn't an array yet, make it to one
 239                 if (!is_array($array[$element]) || !is_int(key($array[$element]))) {
 240                         $array[$element] = [$array[$element]];
 241                 }
 242
 243                 $elements = [];
 244
 245                 foreach ($array[$element] as $entry) {
 246                         if (!is_array($entry) || is_null($key)) {
 247                                 $item = $entry;
 248                         } elseif (isset($entry[$key])) {
 249                                 $item = $entry[$key];
 250                         }
 251
 252                         if (isset($item) && (is_null($type) || is_null($type_value) || isset($item[$type]) && $item[$type] == $type_value)) {
 253                                 $elements[] = $item;
 254                         }
 255                 }
 256
 257                 return $elements;
 258         }
 259
 260         /**
 261          * Fetches an element from a JSON array
 262          *
 263          * @param $array
 264          * @param $element
 265          * @param $key
 266          * @param $type
 267          * @param $type_value
 268          *
 269          * @return string fetched element
 270          */
 271         public static function fetchElement($array, $element, $key = '@id', $type = null, $type_value = null)
 272         {
 273                 if (empty($array)) {
 274                         return null;
 275                 }
 276
 277                 if (!isset($array[$element])) {
 278                         return null;
 279                 }
 280
 281                 if (!is_array($array[$element])) {
 282                         return $array[$element];
 283                 }
 284
 285                 if (is_null($type) || is_null($type_value)) {
 286                         $element_array = self::fetchElementArray($array, $element, $key);
 287                         if (is_null($element_array)) {
 288                                 return null;
 289                         }
 290
 291                         return array_shift($element_array);
 292                 }
 293
 294                 $element_array = self::fetchElementArray($array, $element);
 295                 if (is_null($element_array)) {
 296                         return null;
 297                 }
 298
 299                 foreach ($element_array as $entry) {
 300                         if (isset($entry[$key]) && isset($entry[$type]) && ($entry[$type] == $type_value)) {
 301                                 return $entry[$key];
 302                         }
 303                 }
 304
 305                 return null;
 306         }
 307 }