src/Util/HTTPSignature.php

   1 <?php
   2 /**
   3  * @copyright Copyright (C) 2010-2022, 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\Logger;
  25 use Friendica\Database\Database;
  26 use Friendica\Database\DBA;
  27 use Friendica\DI;
  28 use Friendica\Model\APContact;
  29 use Friendica\Model\Contact;
  30 use Friendica\Model\ItemURI;
  31 use Friendica\Model\User;
  32 use Friendica\Network\HTTPClient\Capability\ICanHandleHttpResponses;
  33 use Friendica\Network\HTTPClient\Client\HttpClientAccept;
  34 use Friendica\Network\HTTPClient\Client\HttpClientOptions;
  35
  36 /**
  37  * Implements HTTP Signatures per draft-cavage-http-signatures-07.
  38  *
  39  * Ported from Hubzilla: https://framagit.org/hubzilla/core/blob/master/Zotlabs/Web/HTTPSig.php
  40  *
  41  * Other parts of the code for HTTP signing are taken from the Osada project.
  42  * https://framagit.org/macgirvin/osada
  43  *
  44  * @see https://tools.ietf.org/html/draft-cavage-http-signatures-07
  45  */
  46
  47 class HTTPSignature
  48 {
  49         // See draft-cavage-http-signatures-08
  50         /**
  51          * Verifies a magic request
  52          *
  53          * @param $key
  54          *
  55          * @return array with verification data
  56          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
  57          */
  58         public static function verifyMagic($key)
  59         {
  60                 $headers   = null;
  61                 $spoofable = false;
  62                 $result = [
  63                         'signer'         => '',
  64                         'header_signed'  => false,
  65                         'header_valid'   => false
  66                 ];
  67
  68                 // Decide if $data arrived via controller submission or curl.
  69                 $headers = [];
  70                 $headers['(request-target)'] = strtolower(DI::args()->getMethod()).' '.$_SERVER['REQUEST_URI'];
  71
  72                 foreach ($_SERVER as $k => $v) {
  73                         if (strpos($k, 'HTTP_') === 0) {
  74                                 $field = str_replace('_', '-', strtolower(substr($k, 5)));
  75                                 $headers[$field] = $v;
  76                         }
  77                 }
  78
  79                 $sig_block = null;
  80
  81                 $sig_block = self::parseSigheader($headers['authorization']);
  82
  83                 if (!$sig_block) {
  84                         Logger::notice('no signature provided.');
  85                         return $result;
  86                 }
  87
  88                 $result['header_signed'] = true;
  89
  90                 $signed_headers = $sig_block['headers'];
  91                 if (!$signed_headers) {
  92                         $signed_headers = ['date'];
  93                 }
  94
  95                 $signed_data = '';
  96                 foreach ($signed_headers as $h) {
  97                         if (array_key_exists($h, $headers)) {
  98                                 $signed_data .= $h . ': ' . $headers[$h] . "\n";
  99                         }
 100                         if (strpos($h, '.')) {
 101                                 $spoofable = true;
 102                         }
 103                 }
 104
 105                 $signed_data = rtrim($signed_data, "\n");
 106
 107                 $algorithm = 'sha512';
 108
 109                 if ($key && function_exists($key)) {
 110                         $result['signer'] = $sig_block['keyId'];
 111                         $key = $key($sig_block['keyId']);
 112                 }
 113
 114                 Logger::info('Got keyID ' . $sig_block['keyId']);
 115
 116                 if (!$key) {
 117                         return $result;
 118                 }
 119
 120                 $x = Crypto::rsaVerify($signed_data, $sig_block['signature'], $key, $algorithm);
 121
 122                 Logger::info('verified: ' . $x);
 123
 124                 if (!$x) {
 125                         return $result;
 126                 }
 127
 128                 if (!$spoofable) {
 129                         $result['header_valid'] = true;
 130                 }
 131
 132                 return $result;
 133         }
 134
 135         /**
 136          * @param array   $head
 137          * @param string  $prvkey
 138          * @param string  $keyid (optional, default 'Key')
 139          *
 140          * @return array
 141          */
 142         public static function createSig($head, $prvkey, $keyid = 'Key')
 143         {
 144                 $return_headers = [];
 145                 if (!empty($head)) {
 146                         $return_headers = $head;
 147                 }
 148
 149                 $alg = 'sha512';
 150                 $algorithm = 'rsa-sha512';
 151
 152                 $x = self::sign($head, $prvkey, $alg);
 153
 154                 $headerval = 'keyId="' . $keyid . '",algorithm="' . $algorithm
 155                         . '",headers="' . $x['headers'] . '",signature="' . $x['signature'] . '"';
 156
 157                 $return_headers['Authorization'] = ['Signature ' . $headerval];
 158
 159                 return $return_headers;
 160         }
 161
 162         /**
 163          * @param array  $head
 164          * @param string $prvkey
 165          * @param string $alg (optional) default 'sha256'
 166          *
 167          * @return array
 168          */
 169         private static function sign($head, $prvkey, $alg = 'sha256')
 170         {
 171                 $ret = [];
 172                 $headers = '';
 173                 $fields  = '';
 174
 175                 foreach ($head as $k => $v) {
 176                         if (is_array($v)) {
 177                                 $v = implode(', ', $v);
 178                         }
 179                         $headers .= strtolower($k) . ': ' . trim($v) . "\n";
 180                         if ($fields) {
 181                                 $fields .= ' ';
 182                         }
 183                         $fields .= strtolower($k);
 184                 }
 185                 // strip the trailing linefeed
 186                 $headers = rtrim($headers, "\n");
 187
 188                 $sig = base64_encode(Crypto::rsaSign($headers, $prvkey, $alg));
 189
 190                 $ret['headers']   = $fields;
 191                 $ret['signature'] = $sig;
 192
 193                 return $ret;
 194         }
 195
 196         /**
 197          * @param string $header
 198          * @return array associative array with
 199          *   - \e string \b keyID
 200          *   - \e string \b created
 201          *   - \e string \b expires
 202          *   - \e string \b algorithm
 203          *   - \e array  \b headers
 204          *   - \e string \b signature
 205          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 206          */
 207         public static function parseSigheader($header)
 208         {
 209                 // Remove obsolete folds
 210                 $header = preg_replace('/\n\s+/', ' ', $header);
 211
 212                 $token = "[!#$%&'*+.^_`|~0-9A-Za-z-]";
 213
 214                 $quotedString = '"(?:\\\\.|[^"\\\\])*"';
 215
 216                 $regex = "/($token+)=($quotedString|$token+)/ism";
 217
 218                 $matches = [];
 219                 preg_match_all($regex, $header, $matches, PREG_SET_ORDER);
 220
 221                 $headers = [];
 222                 foreach ($matches as $match) {
 223                         $headers[$match[1]] = trim($match[2] ?: $match[3], '"');
 224                 }
 225
 226                 // if the header is encrypted, decrypt with (default) site private key and continue
 227                 if (!empty($headers['iv'])) {
 228                         $header = self::decryptSigheader($headers, DI::config()->get('system', 'prvkey'));
 229                         return self::parseSigheader($header);
 230                 }
 231
 232                 $return = [
 233                         'keyId'     => $headers['keyId'] ?? '',
 234                         'algorithm' => $headers['algorithm'] ?? 'rsa-sha256',
 235                         'created'   => $headers['created'] ?? null,
 236                         'expires'   => $headers['expires'] ?? null,
 237                         'headers'   => explode(' ', $headers['headers'] ?? ''),
 238                         'signature' => base64_decode(preg_replace('/\s+/', '', $headers['signature'] ?? '')),
 239                 ];
 240
 241                 if (!empty($return['signature']) && !empty($return['algorithm']) && empty($return['headers'])) {
 242                         $return['headers'] = ['date'];
 243                 }
 244
 245                 return $return;
 246         }
 247
 248         /**
 249          * @param array  $headers Signature headers
 250          * @param string $prvkey  The site private key
 251          * @return string Decrypted signature string
 252          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 253          */
 254         private static function decryptSigheader(array $headers, string $prvkey)
 255         {
 256                 if (!empty($headers['iv']) && !empty($headers['key']) && !empty($headers['data'])) {
 257                         return Crypto::unencapsulate($headers, $prvkey);
 258                 }
 259
 260                 return '';
 261         }
 262
 263         /*
 264          * Functions for ActivityPub
 265          */
 266
 267         /**
 268          * Post given data to a target for a user, returns the result class
 269          *
 270          * @param array   $data   Data that is about to be send
 271          * @param string  $target The URL of the inbox
 272          * @param integer $uid    User id of the sender
 273          *
 274          * @return ICanHandleHttpResponses
 275          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 276          */
 277         public static function post(array $data, string $target, int $uid): ICanHandleHttpResponses
 278         {
 279                 $owner = User::getOwnerDataById($uid);
 280
 281                 if (!$owner) {
 282                         return null;
 283                 }
 284
 285                 $content = json_encode($data, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE);
 286
 287                 // Header data that is about to be signed.
 288                 $host = parse_url($target, PHP_URL_HOST);
 289                 $path = parse_url($target, PHP_URL_PATH);
 290                 $digest = 'SHA-256=' . base64_encode(hash('sha256', $content, true));
 291                 $content_length = strlen($content);
 292                 $date = DateTimeFormat::utcNow(DateTimeFormat::HTTP);
 293
 294                 $headers = [
 295                         'Date' => $date,
 296                         'Content-Length' => $content_length,
 297                         'Digest' => $digest,
 298                         'Host' => $host
 299                 ];
 300
 301                 $signed_data = "(request-target): post " . $path . "\ndate: ". $date . "\ncontent-length: " . $content_length . "\ndigest: " . $digest . "\nhost: " . $host;
 302
 303                 $signature = base64_encode(Crypto::rsaSign($signed_data, $owner['uprvkey'], 'sha256'));
 304
 305                 $headers['Signature'] = 'keyId="' . $owner['url'] . '#main-key' . '",algorithm="rsa-sha256",headers="(request-target) date content-length digest host",signature="' . $signature . '"';
 306
 307                 $headers['Content-Type'] = 'application/activity+json';
 308
 309                 $postResult = DI::httpClient()->post($target, $content, $headers, DI::config()->get('system', 'curl_timeout'));
 310                 $return_code = $postResult->getReturnCode();
 311
 312                 Logger::info('Transmit to ' . $target . ' returned ' . $return_code);
 313
 314                 self::setInboxStatus($target, ($return_code >= 200) && ($return_code <= 299));
 315
 316                 return $postResult;
 317         }
 318
 319         /**
 320          * Transmit given data to a target for a user
 321          *
 322          * @param array   $data   Data that is about to be send
 323          * @param string  $target The URL of the inbox
 324          * @param integer $uid    User id of the sender
 325          *
 326          * @return boolean Was the transmission successful?
 327          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 328          */
 329         public static function transmit(array $data, string $target, int $uid): bool
 330         {
 331                 $postResult = self::post($data, $target, $uid);
 332                 $return_code = $postResult->getReturnCode();
 333
 334                 return ($return_code >= 200) && ($return_code <= 299);
 335         }
 336
 337         /**
 338          * Set the delivery status for a given inbox
 339          *
 340          * @param string  $url     The URL of the inbox
 341          * @param boolean $success Transmission status
 342          * @param boolean $shared  The inbox is a shared inbox
 343          */
 344         static public function setInboxStatus($url, $success, $shared = false)
 345         {
 346                 $now = DateTimeFormat::utcNow();
 347
 348                 $status = DBA::selectFirst('inbox-status', [], ['url' => $url]);
 349                 if (!DBA::isResult($status)) {
 350                         DBA::insert('inbox-status', ['url' => $url, 'uri-id' => ItemURI::getIdByURI($url), 'created' => $now, 'shared' => $shared], Database::INSERT_IGNORE);
 351                         $status = DBA::selectFirst('inbox-status', [], ['url' => $url]);
 352                 }
 353
 354                 if ($success) {
 355                         $fields = ['success' => $now];
 356                 } else {
 357                         $fields = ['failure' => $now];
 358                 }
 359
 360                 if ($status['failure'] > DBA::NULL_DATETIME) {
 361                         $new_previous_stamp = strtotime($status['failure']);
 362                         $old_previous_stamp = strtotime($status['previous']);
 363
 364                         // Only set "previous" with at least one day difference.
 365                         // We use this to assure to not accidentally archive too soon.
 366                         if (($new_previous_stamp - $old_previous_stamp) >= 86400) {
 367                                 $fields['previous'] = $status['failure'];
 368                         }
 369                 }
 370
 371                 if (!$success) {
 372                         if ($status['success'] <= DBA::NULL_DATETIME) {
 373                                 $stamp1 = strtotime($status['created']);
 374                         } else {
 375                                 $stamp1 = strtotime($status['success']);
 376                         }
 377
 378                         $stamp2 = strtotime($now);
 379                         $previous_stamp = strtotime($status['previous']);
 380
 381                         // Archive the inbox when there had been failures for five days.
 382                         // Additionally ensure that at least one previous attempt has to be in between.
 383                         if ((($stamp2 - $stamp1) >= 86400 * 5) && ($previous_stamp > $stamp1)) {
 384                                 $fields['archive'] = true;
 385                         }
 386                 } else {
 387                         $fields['archive'] = false;
 388                 }
 389
 390                 if (empty($status['uri-id'])) {
 391                         $fields['uri-id'] = ItemURI::getIdByURI($url);
 392                 }
 393
 394                 DBA::update('inbox-status', $fields, ['url' => $url]);
 395         }
 396
 397         /**
 398          * Fetches JSON data for a user
 399          *
 400          * @param string  $request request url
 401          * @param integer $uid     User id of the requester
 402          *
 403          * @return array JSON array
 404          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 405          */
 406         public static function fetch($request, $uid)
 407         {
 408                 $curlResult = self::fetchRaw($request, $uid);
 409
 410                 if (empty($curlResult)) {
 411                         return false;
 412                 }
 413
 414                 if (!$curlResult->isSuccess() || empty($curlResult->getBody())) {
 415                         return false;
 416                 }
 417
 418                 $content = json_decode($curlResult->getBody(), true);
 419                 if (empty($content) || !is_array($content)) {
 420                         return false;
 421                 }
 422
 423                 return $content;
 424         }
 425
 426         /**
 427          * Fetches raw data for a user
 428          *
 429          * @param string  $request request url
 430          * @param integer $uid     User id of the requester
 431          * @param boolean $binary  TRUE if asked to return binary results (file download) (default is "false")
 432          * @param array   $opts    (optional parameters) assoziative array with:
 433          *                         'accept_content' => supply Accept: header with 'accept_content' as the value
 434          *                         'timeout' => int Timeout in seconds, default system config value or 60 seconds
 435          *                         'nobody' => only return the header
 436          *                         'cookiejar' => path to cookie jar file
 437          *
 438          * @return \Friendica\Network\HTTPClient\Capability\ICanHandleHttpResponses CurlResult
 439          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 440          */
 441         public static function fetchRaw($request, $uid = 0, $opts = [HttpClientOptions::ACCEPT_CONTENT => [HttpClientAccept::JSON_AS]])
 442         {
 443                 $header = [];
 444
 445                 if (!empty($uid)) {
 446                         $owner = User::getOwnerDataById($uid);
 447                         if (!$owner) {
 448                                 return;
 449                         }
 450                 } else {
 451                         $owner = User::getSystemAccount();
 452                         if (!$owner) {
 453                                 return;
 454                         }
 455                 }
 456
 457                 if (!empty($owner['uprvkey'])) {
 458                         // Header data that is about to be signed.
 459                         $host = parse_url($request, PHP_URL_HOST);
 460                         $path = parse_url($request, PHP_URL_PATH);
 461                         $date = DateTimeFormat::utcNow(DateTimeFormat::HTTP);
 462
 463                         $header['Date'] = $date;
 464                         $header['Host'] = $host;
 465
 466                         $signed_data = "(request-target): get " . $path . "\ndate: ". $date . "\nhost: " . $host;
 467
 468                         $signature = base64_encode(Crypto::rsaSign($signed_data, $owner['uprvkey'], 'sha256'));
 469
 470                         $header['Signature'] = 'keyId="' . $owner['url'] . '#main-key' . '",algorithm="rsa-sha256",headers="(request-target) date host",signature="' . $signature . '"';
 471                 }
 472
 473                 $curl_opts                             = $opts;
 474                 $curl_opts[HttpClientOptions::HEADERS] = $header;
 475
 476                 if (!empty($opts['nobody'])) {
 477                         $curlResult = DI::httpClient()->head($request, $curl_opts);
 478                 } else {
 479                         $curlResult = DI::httpClient()->get($request, HttpClientAccept::JSON_AS, $curl_opts);
 480                 }
 481                 $return_code = $curlResult->getReturnCode();
 482
 483                 Logger::info('Fetched for user ' . $uid . ' from ' . $request . ' returned ' . $return_code);
 484
 485                 return $curlResult;
 486         }
 487
 488         /**
 489          * Gets a signer from a given HTTP request
 490          *
 491          * @param $content
 492          * @param $http_headers
 493          *
 494          * @return string Signer
 495          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 496          */
 497         public static function getSigner($content, $http_headers)
 498         {
 499                 if (empty($http_headers['HTTP_SIGNATURE'])) {
 500                         Logger::debug('No HTTP_SIGNATURE header');
 501                         return false;
 502                 }
 503
 504                 if (!empty($content)) {
 505                         $object = json_decode($content, true);
 506                         if (empty($object)) {
 507                                 Logger::info('No object');
 508                                 return false;
 509                         }
 510
 511                         $actor = JsonLD::fetchElement($object, 'actor', 'id');
 512                 } else {
 513                         $actor = '';
 514                 }
 515
 516                 $headers = [];
 517                 $headers['(request-target)'] = strtolower(DI::args()->getMethod()) . ' ' . parse_url($http_headers['REQUEST_URI'], PHP_URL_PATH);
 518
 519                 // First take every header
 520                 foreach ($http_headers as $k => $v) {
 521                         $field = str_replace('_', '-', strtolower($k));
 522                         $headers[$field] = $v;
 523                 }
 524
 525                 // Now add every http header
 526                 foreach ($http_headers as $k => $v) {
 527                         if (strpos($k, 'HTTP_') === 0) {
 528                                 $field = str_replace('_', '-', strtolower(substr($k, 5)));
 529                                 $headers[$field] = $v;
 530                         }
 531                 }
 532
 533                 $sig_block = self::parseSigHeader($http_headers['HTTP_SIGNATURE']);
 534
 535                 // Add fields from the signature block to the header. See issue 8845
 536                 if (!empty($sig_block['created']) && empty($headers['(created)'])) {
 537                         $headers['(created)'] = $sig_block['created'];
 538                 }
 539
 540                 if (!empty($sig_block['expires']) && empty($headers['(expires)'])) {
 541                         $headers['(expires)'] = $sig_block['expires'];
 542                 }
 543
 544                 if (empty($sig_block) || empty($sig_block['headers']) || empty($sig_block['keyId'])) {
 545                         Logger::info('No headers or keyId');
 546                         return false;
 547                 }
 548
 549                 $signed_data = '';
 550                 foreach ($sig_block['headers'] as $h) {
 551                         if (array_key_exists($h, $headers)) {
 552                                 $signed_data .= $h . ': ' . $headers[$h] . "\n";
 553                         } else {
 554                                 Logger::info('Requested header field not found', ['field' => $h, 'header' => $headers]);
 555                         }
 556                 }
 557                 $signed_data = rtrim($signed_data, "\n");
 558
 559                 if (empty($signed_data)) {
 560                         Logger::info('Signed data is empty');
 561                         return false;
 562                 }
 563
 564                 $algorithm = null;
 565
 566                 // Wildcard value where signing algorithm should be derived from keyId
 567                 // @see https://tools.ietf.org/html/draft-ietf-httpbis-message-signatures-00#section-4.1
 568                 // Defaulting to SHA256 as it seems to be the prevalent implementation
 569                 // @see https://arewehs2019yet.vpzom.click
 570                 if ($sig_block['algorithm'] === 'hs2019') {
 571                         $algorithm = 'sha256';
 572                 }
 573
 574                 if ($sig_block['algorithm'] === 'rsa-sha256') {
 575                         $algorithm = 'sha256';
 576                 }
 577
 578                 if ($sig_block['algorithm'] === 'rsa-sha512') {
 579                         $algorithm = 'sha512';
 580                 }
 581
 582                 if (empty($algorithm)) {
 583                         Logger::info('No alagorithm');
 584                         return false;
 585                 }
 586
 587                 $key = self::fetchKey($sig_block['keyId'], $actor);
 588                 if (empty($key)) {
 589                         Logger::info('Empty key');
 590                         return false;
 591                 }
 592
 593                 if (!empty($key['url']) && !empty($key['type']) && ($key['type'] == 'Tombstone')) {
 594                         Logger::info('Actor is a tombstone', ['key' => $key]);
 595
 596                         if (!Contact::isLocal($key['url'])) {
 597                                 // We now delete everything that we possibly knew from this actor
 598                                 Contact::deleteContactByUrl($key['url']);
 599                         }
 600                         return null;
 601                 }
 602
 603                 if (empty($key['pubkey'])) {
 604                         Logger::info('Empty pubkey');
 605                         return false;
 606                 }
 607
 608                 if (!Crypto::rsaVerify($signed_data, $sig_block['signature'], $key['pubkey'], $algorithm)) {
 609                         Logger::info('Verification failed', ['signed_data' => $signed_data, 'algorithm' => $algorithm, 'header' => $sig_block['headers'], 'http_headers' => $http_headers]);
 610                         return false;
 611                 }
 612
 613                 $hasGoodSignedContent = false;
 614
 615                 // Check the digest when it is part of the signed data
 616                 if (!empty($content) && in_array('digest', $sig_block['headers'])) {
 617                         $digest = explode('=', $headers['digest'], 2);
 618                         if ($digest[0] === 'SHA-256') {
 619                                 $hashalg = 'sha256';
 620                         }
 621                         if ($digest[0] === 'SHA-512') {
 622                                 $hashalg = 'sha512';
 623                         }
 624
 625                         /// @todo add all hashes from the rfc
 626
 627                         if (!empty($hashalg) && base64_encode(hash($hashalg, $content, true)) != $digest[1]) {
 628                                 Logger::info('Digest does not match');
 629                                 return false;
 630                         }
 631
 632                         $hasGoodSignedContent = true;
 633                 }
 634
 635                 if (in_array('date', $sig_block['headers']) && !empty($headers['date'])) {
 636                         $created = strtotime($headers['date']);
 637                 } elseif (in_array('(created)', $sig_block['headers']) && !empty($sig_block['created'])) {
 638                         $created = $sig_block['created'];
 639                 } else {
 640                         $created = 0;
 641                 }
 642
 643                 if (in_array('(expires)', $sig_block['headers']) && !empty($sig_block['expires'])) {
 644                         $expired = min($sig_block['expires'], $created + 300);
 645                 } else {
 646                         $expired = $created + 300;
 647                 }
 648
 649                 //  Check if the signed date field is in an acceptable range
 650                 if (!empty($created)) {
 651                         $current = time();
 652
 653                         // Calculate with a grace period of 60 seconds to avoid slight time differences between the servers
 654                         if (($created - 60) > $current) {
 655                                 Logger::notice('Signature created in the future', ['created' => date(DateTimeFormat::MYSQL, $created), 'expired' => date(DateTimeFormat::MYSQL, $expired), 'current' => date(DateTimeFormat::MYSQL, $current)]);
 656                                 return false;
 657                         }
 658
 659                         if ($current > $expired) {
 660                                 Logger::notice('Signature expired', ['created' => date(DateTimeFormat::MYSQL, $created), 'expired' => date(DateTimeFormat::MYSQL, $expired), 'current' => date(DateTimeFormat::MYSQL, $current)]);
 661                                 return false;
 662                         }
 663
 664                         Logger::debug('Valid creation date', ['created' => date(DateTimeFormat::MYSQL, $created), 'expired' => date(DateTimeFormat::MYSQL, $expired), 'current' => date(DateTimeFormat::MYSQL, $current)]);
 665                         $hasGoodSignedContent = true;
 666                 }
 667
 668                 // Check the content-length when it is part of the signed data
 669                 if (in_array('content-length', $sig_block['headers'])) {
 670                         if (strlen($content) != $headers['content-length']) {
 671                                 Logger::info('Content length does not match');
 672                                 return false;
 673                         }
 674                 }
 675
 676                 // Ensure that the authentication had been done with some content
 677                 // Without this check someone could authenticate with fakeable data
 678                 if (!$hasGoodSignedContent) {
 679                         Logger::info('No good signed content');
 680                         return false;
 681                 }
 682
 683                 return $key['url'];
 684         }
 685
 686         /**
 687          * fetches a key for a given id and actor
 688          *
 689          * @param $id
 690          * @param $actor
 691          *
 692          * @return array with actor url and public key
 693          * @throws \Exception
 694          */
 695         private static function fetchKey($id, $actor)
 696         {
 697                 $url = (strpos($id, '#') ? substr($id, 0, strpos($id, '#')) : $id);
 698
 699                 $profile = APContact::getByURL($url);
 700                 if (!empty($profile)) {
 701                         Logger::info('Taking key from id', ['id' => $id]);
 702                         return ['url' => $url, 'pubkey' => $profile['pubkey'], 'type' => $profile['type']];
 703                 } elseif ($url != $actor) {
 704                         $profile = APContact::getByURL($actor);
 705                         if (!empty($profile)) {
 706                                 Logger::info('Taking key from actor', ['actor' => $actor]);
 707                                 return ['url' => $actor, 'pubkey' => $profile['pubkey'], 'type' => $profile['type']];
 708                         }
 709                 }
 710
 711                 Logger::notice('Key could not be fetched', ['url' => $url, 'actor' => $actor]);
 712                 return false;
 713         }
 714 }