mod/dfrn_poll.php

   1 <?php
   2
   3 /**
   4  * @file mod/dfrn_poll.php
   5  */
   6
   7 use Friendica\App;
   8 use Friendica\Core\Config;
   9 use Friendica\Core\L10n;
  10 use Friendica\Core\Logger;
  11 use Friendica\Core\System;
  12 use Friendica\Core\Session;
  13 use Friendica\Database\DBA;
  14 use Friendica\DI;
  15 use Friendica\Module\Security\Login;
  16 use Friendica\Protocol\DFRN;
  17 use Friendica\Protocol\OStatus;
  18 use Friendica\Util\Network;
  19 use Friendica\Util\Strings;
  20 use Friendica\Util\XML;
  21
  22 function dfrn_poll_init(App $a)
  23 {
  24         DI::auth()->withSession($a);
  25
  26         $dfrn_id         =  $_GET['dfrn_id']         ?? '';
  27         $type            = ($_GET['type']            ?? '') ?: 'data';
  28         $last_update     =  $_GET['last_update']     ?? '';
  29         $destination_url =  $_GET['destination_url'] ?? '';
  30         $challenge       =  $_GET['challenge']       ?? '';
  31         $sec             =  $_GET['sec']             ?? '';
  32         $dfrn_version    = floatval(($_GET['dfrn_version'] ?? 0.0) ?: 2.0);
  33         $quiet                   = !empty($_GET['quiet']);
  34
  35         // Possibly it is an OStatus compatible server that requests a user feed
  36         $user_agent = $_SERVER['HTTP_USER_AGENT'] ?? '';
  37         if (($a->argc > 1) && ($dfrn_id == '') && !strstr($user_agent, 'Friendica')) {
  38                 $nickname = $a->argv[1];
  39                 header("Content-type: application/atom+xml");
  40                 echo OStatus::feed($nickname, $last_update, 10);
  41                 exit();
  42         }
  43
  44         $direction = -1;
  45
  46         if (strpos($dfrn_id, ':') == 1) {
  47                 $direction = intval(substr($dfrn_id, 0, 1));
  48                 $dfrn_id = substr($dfrn_id, 2);
  49         }
  50
  51         $hidewall = false;
  52
  53         if (($dfrn_id === '') && empty($_POST['dfrn_id'])) {
  54                 if (Config::get('system', 'block_public') && !Session::isAuthenticated()) {
  55                         throw new \Friendica\Network\HTTPException\ForbiddenException();
  56                 }
  57
  58                 $user = '';
  59                 if ($a->argc > 1) {
  60                         $r = q("SELECT `hidewall`,`nickname` FROM `user` WHERE `user`.`nickname` = '%s' LIMIT 1",
  61                                 DBA::escape($a->argv[1])
  62                         );
  63                         if (!$r) {
  64                                 throw new \Friendica\Network\HTTPException\NotFoundException();
  65                         }
  66
  67                         $hidewall = ($r[0]['hidewall'] && !local_user());
  68
  69                         $user = $r[0]['nickname'];
  70                 }
  71
  72                 Logger::log('dfrn_poll: public feed request from ' . $_SERVER['REMOTE_ADDR'] . ' for ' . $user);
  73                 header("Content-type: application/atom+xml");
  74                 echo DFRN::feed('', $user, $last_update, 0, $hidewall);
  75                 exit();
  76         }
  77
  78         if (($type === 'profile') && (!strlen($sec))) {
  79                 $sql_extra = '';
  80                 switch ($direction) {
  81                         case -1:
  82                                 $sql_extra = sprintf(" AND ( `dfrn-id` = '%s' OR `issued-id` = '%s' ) ", DBA::escape($dfrn_id), DBA::escape($dfrn_id));
  83                                 $my_id = $dfrn_id;
  84                                 break;
  85                         case 0:
  86                                 $sql_extra = sprintf(" AND `issued-id` = '%s' AND `duplex` = 1 ", DBA::escape($dfrn_id));
  87                                 $my_id = '1:' . $dfrn_id;
  88                                 break;
  89                         case 1:
  90                                 $sql_extra = sprintf(" AND `dfrn-id` = '%s' AND `duplex` = 1 ", DBA::escape($dfrn_id));
  91                                 $my_id = '0:' . $dfrn_id;
  92                                 break;
  93                         default:
  94                                 DI::baseUrl()->redirect();
  95                                 break; // NOTREACHED
  96                 }
  97
  98                 $r = q("SELECT `contact`.*, `user`.`username`, `user`.`nickname`
  99                         FROM `contact` LEFT JOIN `user` ON `contact`.`uid` = `user`.`uid`
 100                         WHERE `contact`.`blocked` = 0 AND `contact`.`pending` = 0
 101                         AND `user`.`nickname` = '%s' $sql_extra LIMIT 1",
 102                         DBA::escape($a->argv[1])
 103                 );
 104
 105                 if (DBA::isResult($r)) {
 106                         $s = Network::fetchUrl($r[0]['poll'] . '?dfrn_id=' . $my_id . '&type=profile-check');
 107
 108                         Logger::log("dfrn_poll: old profile returns " . $s, Logger::DATA);
 109
 110                         if (strlen($s)) {
 111                                 $xml = XML::parseString($s);
 112
 113                                 if ((int)$xml->status === 1) {
 114                                         $_SESSION['authenticated'] = 1;
 115                                         $_SESSION['visitor_id'] = $r[0]['id'];
 116                                         $_SESSION['visitor_home'] = $r[0]['url'];
 117                                         $_SESSION['visitor_handle'] = $r[0]['addr'];
 118                                         $_SESSION['visitor_visiting'] = $r[0]['uid'];
 119                                         $_SESSION['my_url'] = $r[0]['url'];
 120
 121                                         Session::setVisitorsContacts();
 122
 123                                         if (!$quiet) {
 124                                                 info(L10n::t('%1$s welcomes %2$s', $r[0]['username'], $r[0]['name']) . EOL);
 125                                         }
 126
 127                                         // Visitors get 1 day session.
 128                                         $session_id = session_id();
 129                                         $expire = time() + 86400;
 130                                         q("UPDATE `session` SET `expire` = '%s' WHERE `sid` = '%s'",
 131                                                 DBA::escape($expire),
 132                                                 DBA::escape($session_id)
 133                                         );
 134                                 }
 135                         }
 136
 137                         $profile = (count($r) > 0 && isset($r[0]['nickname']) ? $r[0]['nickname'] : '');
 138                         if (!empty($destination_url)) {
 139                                 System::externalRedirect($destination_url);
 140                         } else {
 141                                 DI::baseUrl()->redirect('profile/' . $profile);
 142                         }
 143                 }
 144                 DI::baseUrl()->redirect();
 145         }
 146
 147         if ($type === 'profile-check' && $dfrn_version < 2.2) {
 148                 if ((strlen($challenge)) && (strlen($sec))) {
 149                         DBA::delete('profile_check', ["`expire` < ?", time()]);
 150                         $r = q("SELECT * FROM `profile_check` WHERE `sec` = '%s' ORDER BY `expire` DESC LIMIT 1",
 151                                 DBA::escape($sec)
 152                         );
 153                         if (!DBA::isResult($r)) {
 154                                 System::xmlExit(3, 'No ticket');
 155                                 // NOTREACHED
 156                         }
 157
 158                         $orig_id = $r[0]['dfrn_id'];
 159                         if (strpos($orig_id, ':')) {
 160                                 $orig_id = substr($orig_id, 2);
 161                         }
 162
 163                         $c = q("SELECT * FROM `contact` WHERE `id` = %d LIMIT 1",
 164                                 intval($r[0]['cid'])
 165                         );
 166                         if (!DBA::isResult($c)) {
 167                                 System::xmlExit(3, 'No profile');
 168                         }
 169
 170                         $contact = $c[0];
 171
 172                         $sent_dfrn_id = hex2bin($dfrn_id);
 173                         $challenge = hex2bin($challenge);
 174
 175                         $final_dfrn_id = '';
 176
 177                         if (($contact['duplex']) && strlen($contact['prvkey'])) {
 178                                 openssl_private_decrypt($sent_dfrn_id, $final_dfrn_id, $contact['prvkey']);
 179                                 openssl_private_decrypt($challenge, $decoded_challenge, $contact['prvkey']);
 180                         } else {
 181                                 openssl_public_decrypt($sent_dfrn_id, $final_dfrn_id, $contact['pubkey']);
 182                                 openssl_public_decrypt($challenge, $decoded_challenge, $contact['pubkey']);
 183                         }
 184
 185                         $final_dfrn_id = substr($final_dfrn_id, 0, strpos($final_dfrn_id, '.'));
 186
 187                         if (strpos($final_dfrn_id, ':') == 1) {
 188                                 $final_dfrn_id = substr($final_dfrn_id, 2);
 189                         }
 190
 191                         if ($final_dfrn_id != $orig_id) {
 192                                 Logger::log('profile_check: ' . $final_dfrn_id . ' != ' . $orig_id, Logger::DEBUG);
 193                                 // did not decode properly - cannot trust this site
 194                                 System::xmlExit(3, 'Bad decryption');
 195                         }
 196
 197                         header("Content-type: text/xml");
 198                         echo "<?xml version=\"1.0\" encoding=\"UTF-8\"?><dfrn_poll><status>0</status><challenge>$decoded_challenge</challenge><sec>$sec</sec></dfrn_poll>";
 199                         exit();
 200                         // NOTREACHED
 201                 } else {
 202                         // old protocol
 203                         switch ($direction) {
 204                                 case 1:
 205                                         $dfrn_id = '0:' . $dfrn_id;
 206                                         break;
 207                                 case 0:
 208                                         $dfrn_id = '1:' . $dfrn_id;
 209                                         break;
 210                                 default:
 211                                         break;
 212                         }
 213
 214                         DBA::delete('profile_check', ["`expire` < ?", time()]);
 215                         $r = q("SELECT * FROM `profile_check` WHERE `dfrn_id` = '%s' ORDER BY `expire` DESC",
 216                                 DBA::escape($dfrn_id));
 217                         if (DBA::isResult($r)) {
 218                                 System::xmlExit(1);
 219                                 return; // NOTREACHED
 220                         }
 221                         System::xmlExit(0);
 222                         return; // NOTREACHED
 223                 }
 224         }
 225 }
 226
 227 function dfrn_poll_post(App $a)
 228 {
 229         $dfrn_id      =  $_POST['dfrn_id']   ?? '';
 230         $challenge    =  $_POST['challenge'] ?? '';
 231         $url          =  $_POST['url']       ?? '';
 232         $sec          =  $_POST['sec']       ?? '';
 233         $ptype        =  $_POST['type']      ?? '';
 234         $perm         = ($_POST['perm']      ?? '') ?: 'r';
 235         $dfrn_version = floatval(($_GET['dfrn_version'] ?? 0.0) ?: 2.0);
 236
 237         if ($ptype === 'profile-check') {
 238                 if (strlen($challenge) && strlen($sec)) {
 239                         Logger::log('dfrn_poll: POST: profile-check');
 240
 241                         DBA::delete('profile_check', ["`expire` < ?", time()]);
 242                         $r = q("SELECT * FROM `profile_check` WHERE `sec` = '%s' ORDER BY `expire` DESC LIMIT 1",
 243                                 DBA::escape($sec)
 244                         );
 245                         if (!DBA::isResult($r)) {
 246                                 System::xmlExit(3, 'No ticket');
 247                                 // NOTREACHED
 248                         }
 249
 250                         $orig_id = $r[0]['dfrn_id'];
 251                         if (strpos($orig_id, ':')) {
 252                                 $orig_id = substr($orig_id, 2);
 253                         }
 254
 255                         $c = q("SELECT * FROM `contact` WHERE `id` = %d LIMIT 1",
 256                                 intval($r[0]['cid'])
 257                         );
 258                         if (!DBA::isResult($c)) {
 259                                 System::xmlExit(3, 'No profile');
 260                         }
 261
 262                         $contact = $c[0];
 263
 264                         $sent_dfrn_id = hex2bin($dfrn_id);
 265                         $challenge = hex2bin($challenge);
 266
 267                         $final_dfrn_id = '';
 268
 269                         if ($contact['duplex'] && strlen($contact['prvkey'])) {
 270                                 openssl_private_decrypt($sent_dfrn_id, $final_dfrn_id, $contact['prvkey']);
 271                                 openssl_private_decrypt($challenge, $decoded_challenge, $contact['prvkey']);
 272                         } else {
 273                                 openssl_public_decrypt($sent_dfrn_id, $final_dfrn_id, $contact['pubkey']);
 274                                 openssl_public_decrypt($challenge, $decoded_challenge, $contact['pubkey']);
 275                         }
 276
 277                         $final_dfrn_id = substr($final_dfrn_id, 0, strpos($final_dfrn_id, '.'));
 278
 279                         if (strpos($final_dfrn_id, ':') == 1) {
 280                                 $final_dfrn_id = substr($final_dfrn_id, 2);
 281                         }
 282
 283                         if ($final_dfrn_id != $orig_id) {
 284                                 Logger::log('profile_check: ' . $final_dfrn_id . ' != ' . $orig_id, Logger::DEBUG);
 285                                 // did not decode properly - cannot trust this site
 286                                 System::xmlExit(3, 'Bad decryption');
 287                         }
 288
 289                         header("Content-type: text/xml");
 290                         echo "<?xml version=\"1.0\" encoding=\"UTF-8\"?><dfrn_poll><status>0</status><challenge>$decoded_challenge</challenge><sec>$sec</sec></dfrn_poll>";
 291                         exit();
 292                         // NOTREACHED
 293                 }
 294         }
 295
 296         $direction = -1;
 297         if (strpos($dfrn_id, ':') == 1) {
 298                 $direction = intval(substr($dfrn_id, 0, 1));
 299                 $dfrn_id = substr($dfrn_id, 2);
 300         }
 301
 302         $r = q("SELECT * FROM `challenge` WHERE `dfrn-id` = '%s' AND `challenge` = '%s' LIMIT 1",
 303                 DBA::escape($dfrn_id),
 304                 DBA::escape($challenge)
 305         );
 306
 307         if (!DBA::isResult($r)) {
 308                 exit();
 309         }
 310
 311         $type = $r[0]['type'];
 312         $last_update = $r[0]['last_update'];
 313
 314         DBA::delete('challenge', ['dfrn-id' => $dfrn_id, 'challenge' => $challenge]);
 315
 316         $sql_extra = '';
 317         switch ($direction) {
 318                 case -1:
 319                         $sql_extra = sprintf(" AND `issued-id` = '%s' ", DBA::escape($dfrn_id));
 320                         break;
 321                 case 0:
 322                         $sql_extra = sprintf(" AND `issued-id` = '%s' AND `duplex` = 1 ", DBA::escape($dfrn_id));
 323                         break;
 324                 case 1:
 325                         $sql_extra = sprintf(" AND `dfrn-id` = '%s' AND `duplex` = 1 ", DBA::escape($dfrn_id));
 326                         break;
 327                 default:
 328                         DI::baseUrl()->redirect();
 329                         break; // NOTREACHED
 330         }
 331
 332         $r = q("SELECT * FROM `contact` WHERE `blocked` = 0 AND `pending` = 0 $sql_extra LIMIT 1");
 333         if (!DBA::isResult($r)) {
 334                 exit();
 335         }
 336
 337         $contact = $r[0];
 338         $owner_uid = $r[0]['uid'];
 339         $contact_id = $r[0]['id'];
 340
 341         if ($type === 'reputation' && strlen($url)) {
 342                 $r = q("SELECT * FROM `contact` WHERE `url` = '%s' AND `uid` = %d LIMIT 1",
 343                         DBA::escape($url),
 344                         intval($owner_uid)
 345                 );
 346                 $reputation = 0;
 347                 $text = '';
 348
 349                 if (DBA::isResult($r)) {
 350                         $reputation = $r[0]['rating'];
 351                         $text = $r[0]['reason'];
 352
 353                         if ($r[0]['id'] == $contact_id) { // inquiring about own reputation not allowed
 354                                 $reputation = 0;
 355                                 $text = '';
 356                         }
 357                 }
 358
 359                 echo "<?xml version=\"1.0\" encoding=\"UTF-8\"?>
 360                 <reputation>
 361                         <url>$url</url>
 362                         <rating>$reputation</rating>
 363                         <description>$text</description>
 364                 </reputation>
 365                 ";
 366                 exit();
 367                 // NOTREACHED
 368         } else {
 369                 // Update the writable flag if it changed
 370                 Logger::log('dfrn_poll: post request feed: ' . print_r($_POST, true), Logger::DATA);
 371                 if ($dfrn_version >= 2.21) {
 372                         if ($perm === 'rw') {
 373                                 $writable = 1;
 374                         } else {
 375                                 $writable = 0;
 376                         }
 377
 378                         if ($writable != $contact['writable']) {
 379                                 q("UPDATE `contact` SET `writable` = %d WHERE `id` = %d",
 380                                         intval($writable),
 381                                         intval($contact_id)
 382                                 );
 383                         }
 384                 }
 385
 386                 header("Content-type: application/atom+xml");
 387                 $o = DFRN::feed($dfrn_id, $a->argv[1], $last_update, $direction);
 388                 echo $o;
 389                 exit();
 390         }
 391 }
 392
 393 function dfrn_poll_content(App $a)
 394 {
 395         $dfrn_id         =  $_GET['dfrn_id']         ?? '';
 396         $type            = ($_GET['type']            ?? '') ?: 'data';
 397         $last_update     =  $_GET['last_update']     ?? '';
 398         $destination_url =  $_GET['destination_url'] ?? '';
 399         $sec             =  $_GET['sec']             ?? '';
 400         $dfrn_version    = floatval(($_GET['dfrn_version'] ?? 0.0) ?: 2.0);
 401         $quiet           = !empty($_GET['quiet']);
 402
 403         $direction = -1;
 404         if (strpos($dfrn_id, ':') == 1) {
 405                 $direction = intval(substr($dfrn_id, 0, 1));
 406                 $dfrn_id = substr($dfrn_id, 2);
 407         }
 408
 409         if ($dfrn_id != '') {
 410                 // initial communication from external contact
 411                 $hash = Strings::getRandomHex();
 412
 413                 $status = 0;
 414
 415                 DBA::delete('challenge', ["`expire` < ?", time()]);
 416
 417                 if ($type !== 'profile') {
 418                         q("INSERT INTO `challenge` ( `challenge`, `dfrn-id`, `expire` , `type`, `last_update` )
 419                                 VALUES( '%s', '%s', '%s', '%s', '%s' ) ",
 420                                 DBA::escape($hash),
 421                                 DBA::escape($dfrn_id),
 422                                 intval(time() + 60 ),
 423                                 DBA::escape($type),
 424                                 DBA::escape($last_update)
 425                         );
 426                 }
 427
 428                 $sql_extra = '';
 429                 switch ($direction) {
 430                         case -1:
 431                                 if ($type === 'profile') {
 432                                         $sql_extra = sprintf(" AND (`dfrn-id` = '%s' OR `issued-id` = '%s') ", DBA::escape($dfrn_id), DBA::escape($dfrn_id));
 433                                 } else {
 434                                         $sql_extra = sprintf(" AND `issued-id` = '%s' ", DBA::escape($dfrn_id));
 435                                 }
 436
 437                                 $my_id = $dfrn_id;
 438                                 break;
 439                         case 0:
 440                                 $sql_extra = sprintf(" AND `issued-id` = '%s' AND `duplex` = 1 ", DBA::escape($dfrn_id));
 441                                 $my_id = '1:' . $dfrn_id;
 442                                 break;
 443                         case 1:
 444                                 $sql_extra = sprintf(" AND `dfrn-id` = '%s' AND `duplex` = 1 ", DBA::escape($dfrn_id));
 445                                 $my_id = '0:' . $dfrn_id;
 446                                 break;
 447                         default:
 448                                 DI::baseUrl()->redirect();
 449                                 break; // NOTREACHED
 450                 }
 451
 452                 $nickname = $a->argv[1];
 453
 454                 $r = q("SELECT `contact`.*, `user`.`username`, `user`.`nickname`
 455                         FROM `contact` LEFT JOIN `user` ON `contact`.`uid` = `user`.`uid`
 456                         WHERE `contact`.`blocked` = 0 AND `contact`.`pending` = 0
 457                         AND `user`.`nickname` = '%s' $sql_extra LIMIT 1",
 458                         DBA::escape($nickname)
 459                 );
 460                 if (DBA::isResult($r)) {
 461                         $challenge = '';
 462                         $encrypted_id = '';
 463                         $id_str = $my_id . '.' . mt_rand(1000, 9999);
 464
 465                         if (($r[0]['duplex'] && strlen($r[0]['pubkey'])) || !strlen($r[0]['prvkey'])) {
 466                                 openssl_public_encrypt($hash, $challenge, $r[0]['pubkey']);
 467                                 openssl_public_encrypt($id_str, $encrypted_id, $r[0]['pubkey']);
 468                         } else {
 469                                 openssl_private_encrypt($hash, $challenge, $r[0]['prvkey']);
 470                                 openssl_private_encrypt($id_str, $encrypted_id, $r[0]['prvkey']);
 471                         }
 472
 473                         $challenge = bin2hex($challenge);
 474                         $encrypted_id = bin2hex($encrypted_id);
 475                 } else {
 476                         $status = 1;
 477                         $challenge = '';
 478                         $encrypted_id = '';
 479                 }
 480
 481                 if (($type === 'profile') && (strlen($sec))) {
 482                         // heluecht: I don't know why we don't fail immediately when the user or contact hadn't been found.
 483                         // Since it doesn't make sense to continue from this point on, we now fail here. This should be safe.
 484                         if (!DBA::isResult($r)) {
 485                                 throw new \Friendica\Network\HTTPException\NotFoundException();
 486                         }
 487
 488                         // URL reply
 489                         if ($dfrn_version < 2.2) {
 490                                 $s = Network::fetchUrl($r[0]['poll']
 491                                         . '?dfrn_id=' . $encrypted_id
 492                                         . '&type=profile-check'
 493                                         . '&dfrn_version=' . DFRN_PROTOCOL_VERSION
 494                                         . '&challenge=' . $challenge
 495                                         . '&sec=' . $sec
 496                                 );
 497                         } else {
 498                                 $s = Network::post($r[0]['poll'], [
 499                                         'dfrn_id' => $encrypted_id,
 500                                         'type' => 'profile-check',
 501                                         'dfrn_version' => DFRN_PROTOCOL_VERSION,
 502                                         'challenge' => $challenge,
 503                                         'sec' => $sec
 504                                 ])->getBody();
 505                         }
 506
 507                         Logger::log("dfrn_poll: sec profile: " . $s, Logger::DATA);
 508
 509                         if (strlen($s) && strstr($s, '<?xml')) {
 510                                 $xml = XML::parseString($s);
 511
 512                                 Logger::log('dfrn_poll: profile: parsed xml: ' . print_r($xml, true), Logger::DATA);
 513
 514                                 Logger::log('dfrn_poll: secure profile: challenge: ' . $xml->challenge . ' expecting ' . $hash);
 515                                 Logger::log('dfrn_poll: secure profile: sec: ' . $xml->sec . ' expecting ' . $sec);
 516
 517                                 if (((int) $xml->status == 0) && ($xml->challenge == $hash) && ($xml->sec == $sec)) {
 518                                         $_SESSION['authenticated'] = 1;
 519                                         $_SESSION['visitor_id'] = $r[0]['id'];
 520                                         $_SESSION['visitor_home'] = $r[0]['url'];
 521                                         $_SESSION['visitor_visiting'] = $r[0]['uid'];
 522                                         $_SESSION['my_url'] = $r[0]['url'];
 523
 524                                         Session::setVisitorsContacts();
 525
 526                                         if (!$quiet) {
 527                                                 info(L10n::t('%1$s welcomes %2$s', $r[0]['username'], $r[0]['name']) . EOL);
 528                                         }
 529
 530                                         // Visitors get 1 day session.
 531                                         $session_id = session_id();
 532                                         $expire = time() + 86400;
 533                                         q("UPDATE `session` SET `expire` = '%s' WHERE `sid` = '%s'",
 534                                                 DBA::escape($expire),
 535                                                 DBA::escape($session_id)
 536                                         );
 537                                 }
 538                         }
 539
 540                         $profile = ((DBA::isResult($r) && $r[0]['nickname']) ? $r[0]['nickname'] : $nickname);
 541
 542                         switch ($destination_url) {
 543                                 case 'profile':
 544                                         DI::baseUrl()->redirect('profile/' . $profile . '?tab=profile');
 545                                         break;
 546                                 case 'photos':
 547                                         DI::baseUrl()->redirect('photos/' . $profile);
 548                                         break;
 549                                 case 'status':
 550                                 case '':
 551                                         DI::baseUrl()->redirect('profile/' . $profile);
 552                                         break;
 553                                 default:
 554                                         $appendix = (strstr($destination_url, '?') ? '&redir=1' : '?redir=1');
 555                                         DI::baseUrl()->redirect($destination_url . $appendix);
 556                                         break;
 557                         }
 558                         // NOTREACHED
 559                 } else {
 560                         // XML reply
 561                         header("Content-type: text/xml");
 562                         echo '<?xml version="1.0" encoding="UTF-8"?>' . "\r\n"
 563                                 . '<dfrn_poll>' . "\r\n"
 564                                 . "\t" . '<status>' . $status . '</status>' . "\r\n"
 565                                 . "\t" . '<dfrn_version>' . DFRN_PROTOCOL_VERSION . '</dfrn_version>' . "\r\n"
 566                                 . "\t" . '<dfrn_id>' . $encrypted_id . '</dfrn_id>' . "\r\n"
 567                                 . "\t" . '<challenge>' . $challenge . '</challenge>' . "\r\n"
 568                                 . '</dfrn_poll>' . "\r\n";
 569                         exit();
 570                         // NOTREACHED
 571                 }
 572         }
 573 }