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\Database\DBA;
  13 use Friendica\Module\Login;
  14 use Friendica\Protocol\DFRN;
  15 use Friendica\Protocol\OStatus;
  16 use Friendica\Util\Network;
  17 use Friendica\Util\Strings;
  18 use Friendica\Util\XML;
  19
  20 function dfrn_poll_init(App $a)
  21 {
  22         Login::sessionAuth();
  23
  24         $dfrn_id         = defaults($_GET, 'dfrn_id'        , '');
  25         $type            = defaults($_GET, 'type'           , 'data');
  26         $last_update     = defaults($_GET, 'last_update'    , '');
  27         $destination_url = defaults($_GET, 'destination_url', '');
  28         $challenge       = defaults($_GET, 'challenge'      , '');
  29         $sec             = defaults($_GET, 'sec'            , '');
  30         $dfrn_version    = (float) defaults($_GET, 'dfrn_version'   , 2.0);
  31         $quiet                   = !empty($_GET['quiet']);
  32
  33         // Possibly it is an OStatus compatible server that requests a user feed
  34         $user_agent = defaults($_SERVER, 'HTTP_USER_AGENT', '');
  35         if (($a->argc > 1) && ($dfrn_id == '') && !strstr($user_agent, 'Friendica')) {
  36                 $nickname = $a->argv[1];
  37                 header("Content-type: application/atom+xml");
  38                 echo OStatus::feed($nickname, $last_update, 10);
  39                 exit();
  40         }
  41
  42         $direction = -1;
  43
  44         if (strpos($dfrn_id, ':') == 1) {
  45                 $direction = intval(substr($dfrn_id, 0, 1));
  46                 $dfrn_id = substr($dfrn_id, 2);
  47         }
  48
  49         $hidewall = false;
  50
  51         if (($dfrn_id === '') && empty($_POST['dfrn_id'])) {
  52                 if (Config::get('system', 'block_public') && !local_user() && !remote_user()) {
  53                         System::httpExit(403);
  54                 }
  55
  56                 $user = '';
  57                 if ($a->argc > 1) {
  58                         $r = q("SELECT `hidewall`,`nickname` FROM `user` WHERE `user`.`nickname` = '%s' LIMIT 1",
  59                                 DBA::escape($a->argv[1])
  60                         );
  61                         if (!$r) {
  62                                 System::httpExit(404);
  63                         }
  64
  65                         $hidewall = ($r[0]['hidewall'] && !local_user());
  66
  67                         $user = $r[0]['nickname'];
  68                 }
  69
  70                 Logger::log('dfrn_poll: public feed request from ' . $_SERVER['REMOTE_ADDR'] . ' for ' . $user);
  71                 header("Content-type: application/atom+xml");
  72                 echo DFRN::feed('', $user, $last_update, 0, $hidewall);
  73                 exit();
  74         }
  75
  76         if (($type === 'profile') && (!strlen($sec))) {
  77                 $sql_extra = '';
  78                 switch ($direction) {
  79                         case -1:
  80                                 $sql_extra = sprintf(" AND ( `dfrn-id` = '%s' OR `issued-id` = '%s' ) ", DBA::escape($dfrn_id), DBA::escape($dfrn_id));
  81                                 $my_id = $dfrn_id;
  82                                 break;
  83                         case 0:
  84                                 $sql_extra = sprintf(" AND `issued-id` = '%s' AND `duplex` = 1 ", DBA::escape($dfrn_id));
  85                                 $my_id = '1:' . $dfrn_id;
  86                                 break;
  87                         case 1:
  88                                 $sql_extra = sprintf(" AND `dfrn-id` = '%s' AND `duplex` = 1 ", DBA::escape($dfrn_id));
  89                                 $my_id = '0:' . $dfrn_id;
  90                                 break;
  91                         default:
  92                                 $a->internalRedirect();
  93                                 break; // NOTREACHED
  94                 }
  95
  96                 $r = q("SELECT `contact`.*, `user`.`username`, `user`.`nickname`
  97                         FROM `contact` LEFT JOIN `user` ON `contact`.`uid` = `user`.`uid`
  98                         WHERE `contact`.`blocked` = 0 AND `contact`.`pending` = 0
  99                         AND `user`.`nickname` = '%s' $sql_extra LIMIT 1",
 100                         DBA::escape($a->argv[1])
 101                 );
 102
 103                 if (DBA::isResult($r)) {
 104                         $s = Network::fetchUrl($r[0]['poll'] . '?dfrn_id=' . $my_id . '&type=profile-check');
 105
 106                         Logger::log("dfrn_poll: old profile returns " . $s, Logger::DATA);
 107
 108                         if (strlen($s)) {
 109                                 $xml = XML::parseString($s);
 110
 111                                 if ((int)$xml->status === 1) {
 112                                         $_SESSION['authenticated'] = 1;
 113                                         if (empty($_SESSION['remote'])) {
 114                                                 $_SESSION['remote'] = [];
 115                                         }
 116
 117                                         $_SESSION['remote'][] = ['cid' => $r[0]['id'], 'uid' => $r[0]['uid'], 'url' => $r[0]['url']];
 118
 119                                         $_SESSION['visitor_id'] = $r[0]['id'];
 120                                         $_SESSION['visitor_home'] = $r[0]['url'];
 121                                         $_SESSION['visitor_handle'] = $r[0]['addr'];
 122                                         $_SESSION['visitor_visiting'] = $r[0]['uid'];
 123                                         $_SESSION['my_url'] = $r[0]['url'];
 124                                         if (!$quiet) {
 125                                                 info(L10n::t('%1$s welcomes %2$s', $r[0]['username'], $r[0]['name']) . EOL);
 126                                         }
 127
 128                                         // Visitors get 1 day session.
 129                                         $session_id = session_id();
 130                                         $expire = time() + 86400;
 131                                         q("UPDATE `session` SET `expire` = '%s' WHERE `sid` = '%s'",
 132                                                 DBA::escape($expire),
 133                                                 DBA::escape($session_id)
 134                                         );
 135                                 }
 136                         }
 137
 138                         $profile = (count($r) > 0 && isset($r[0]['nickname']) ? $r[0]['nickname'] : '');
 139                         if (!empty($destination_url)) {
 140                                 System::externalRedirect($destination_url);
 141                         } else {
 142                                 $a->internalRedirect('profile/' . $profile);
 143                         }
 144                 }
 145                 $a->internalRedirect();
 146         }
 147
 148         if ($type === 'profile-check' && $dfrn_version < 2.2) {
 149                 if ((strlen($challenge)) && (strlen($sec))) {
 150                         DBA::delete('profile_check', ["`expire` < ?", time()]);
 151                         $r = q("SELECT * FROM `profile_check` WHERE `sec` = '%s' ORDER BY `expire` DESC LIMIT 1",
 152                                 DBA::escape($sec)
 153                         );
 154                         if (!DBA::isResult($r)) {
 155                                 System::xmlExit(3, 'No ticket');
 156                                 // NOTREACHED
 157                         }
 158
 159                         $orig_id = $r[0]['dfrn_id'];
 160                         if (strpos($orig_id, ':')) {
 161                                 $orig_id = substr($orig_id, 2);
 162                         }
 163
 164                         $c = q("SELECT * FROM `contact` WHERE `id` = %d LIMIT 1",
 165                                 intval($r[0]['cid'])
 166                         );
 167                         if (!DBA::isResult($c)) {
 168                                 System::xmlExit(3, 'No profile');
 169                         }
 170
 171                         $contact = $c[0];
 172
 173                         $sent_dfrn_id = hex2bin($dfrn_id);
 174                         $challenge = hex2bin($challenge);
 175
 176                         $final_dfrn_id = '';
 177
 178                         if (($contact['duplex']) && strlen($contact['prvkey'])) {
 179                                 openssl_private_decrypt($sent_dfrn_id, $final_dfrn_id, $contact['prvkey']);
 180                                 openssl_private_decrypt($challenge, $decoded_challenge, $contact['prvkey']);
 181                         } else {
 182                                 openssl_public_decrypt($sent_dfrn_id, $final_dfrn_id, $contact['pubkey']);
 183                                 openssl_public_decrypt($challenge, $decoded_challenge, $contact['pubkey']);
 184                         }
 185
 186                         $final_dfrn_id = substr($final_dfrn_id, 0, strpos($final_dfrn_id, '.'));
 187
 188                         if (strpos($final_dfrn_id, ':') == 1) {
 189                                 $final_dfrn_id = substr($final_dfrn_id, 2);
 190                         }
 191
 192                         if ($final_dfrn_id != $orig_id) {
 193                                 Logger::log('profile_check: ' . $final_dfrn_id . ' != ' . $orig_id, Logger::DEBUG);
 194                                 // did not decode properly - cannot trust this site
 195                                 System::xmlExit(3, 'Bad decryption');
 196                         }
 197
 198                         header("Content-type: text/xml");
 199                         echo "<?xml version=\"1.0\" encoding=\"UTF-8\"?><dfrn_poll><status>0</status><challenge>$decoded_challenge</challenge><sec>$sec</sec></dfrn_poll>";
 200                         exit();
 201                         // NOTREACHED
 202                 } else {
 203                         // old protocol
 204                         switch ($direction) {
 205                                 case 1:
 206                                         $dfrn_id = '0:' . $dfrn_id;
 207                                         break;
 208                                 case 0:
 209                                         $dfrn_id = '1:' . $dfrn_id;
 210                                         break;
 211                                 default:
 212                                         break;
 213                         }
 214
 215                         DBA::delete('profile_check', ["`expire` < ?", time()]);
 216                         $r = q("SELECT * FROM `profile_check` WHERE `dfrn_id` = '%s' ORDER BY `expire` DESC",
 217                                 DBA::escape($dfrn_id));
 218                         if (DBA::isResult($r)) {
 219                                 System::xmlExit(1);
 220                                 return; // NOTREACHED
 221                         }
 222                         System::xmlExit(0);
 223                         return; // NOTREACHED
 224                 }
 225         }
 226 }
 227
 228 function dfrn_poll_post(App $a)
 229 {
 230         $dfrn_id      = defaults($_POST, 'dfrn_id'  , '');
 231         $challenge    = defaults($_POST, 'challenge', '');
 232         $url          = defaults($_POST, 'url'      , '');
 233         $sec          = defaults($_POST, 'sec'      , '');
 234         $ptype        = defaults($_POST, 'type'     , '');
 235         $perm         = defaults($_POST, 'perm'     , 'r');
 236         $dfrn_version = !empty($_POST['dfrn_version']) ? (float) $_POST['dfrn_version'] : 2.0;
 237
 238         if ($ptype === 'profile-check') {
 239                 if (strlen($challenge) && strlen($sec)) {
 240                         Logger::log('dfrn_poll: POST: profile-check');
 241
 242                         DBA::delete('profile_check', ["`expire` < ?", time()]);
 243                         $r = q("SELECT * FROM `profile_check` WHERE `sec` = '%s' ORDER BY `expire` DESC LIMIT 1",
 244                                 DBA::escape($sec)
 245                         );
 246                         if (!DBA::isResult($r)) {
 247                                 System::xmlExit(3, 'No ticket');
 248                                 // NOTREACHED
 249                         }
 250
 251                         $orig_id = $r[0]['dfrn_id'];
 252                         if (strpos($orig_id, ':')) {
 253                                 $orig_id = substr($orig_id, 2);
 254                         }
 255
 256                         $c = q("SELECT * FROM `contact` WHERE `id` = %d LIMIT 1",
 257                                 intval($r[0]['cid'])
 258                         );
 259                         if (!DBA::isResult($c)) {
 260                                 System::xmlExit(3, 'No profile');
 261                         }
 262
 263                         $contact = $c[0];
 264
 265                         $sent_dfrn_id = hex2bin($dfrn_id);
 266                         $challenge = hex2bin($challenge);
 267
 268                         $final_dfrn_id = '';
 269
 270                         if ($contact['duplex'] && strlen($contact['prvkey'])) {
 271                                 openssl_private_decrypt($sent_dfrn_id, $final_dfrn_id, $contact['prvkey']);
 272                                 openssl_private_decrypt($challenge, $decoded_challenge, $contact['prvkey']);
 273                         } else {
 274                                 openssl_public_decrypt($sent_dfrn_id, $final_dfrn_id, $contact['pubkey']);
 275                                 openssl_public_decrypt($challenge, $decoded_challenge, $contact['pubkey']);
 276                         }
 277
 278                         $final_dfrn_id = substr($final_dfrn_id, 0, strpos($final_dfrn_id, '.'));
 279
 280                         if (strpos($final_dfrn_id, ':') == 1) {
 281                                 $final_dfrn_id = substr($final_dfrn_id, 2);
 282                         }
 283
 284                         if ($final_dfrn_id != $orig_id) {
 285                                 Logger::log('profile_check: ' . $final_dfrn_id . ' != ' . $orig_id, Logger::DEBUG);
 286                                 // did not decode properly - cannot trust this site
 287                                 System::xmlExit(3, 'Bad decryption');
 288                         }
 289
 290                         header("Content-type: text/xml");
 291                         echo "<?xml version=\"1.0\" encoding=\"UTF-8\"?><dfrn_poll><status>0</status><challenge>$decoded_challenge</challenge><sec>$sec</sec></dfrn_poll>";
 292                         exit();
 293                         // NOTREACHED
 294                 }
 295         }
 296
 297         $direction = -1;
 298         if (strpos($dfrn_id, ':') == 1) {
 299                 $direction = intval(substr($dfrn_id, 0, 1));
 300                 $dfrn_id = substr($dfrn_id, 2);
 301         }
 302
 303         $r = q("SELECT * FROM `challenge` WHERE `dfrn-id` = '%s' AND `challenge` = '%s' LIMIT 1",
 304                 DBA::escape($dfrn_id),
 305                 DBA::escape($challenge)
 306         );
 307
 308         if (!DBA::isResult($r)) {
 309                 exit();
 310         }
 311
 312         $type = $r[0]['type'];
 313         $last_update = $r[0]['last_update'];
 314
 315         DBA::delete('challenge', ['dfrn-id' => $dfrn_id, 'challenge' => $challenge]);
 316
 317         $sql_extra = '';
 318         switch ($direction) {
 319                 case -1:
 320                         $sql_extra = sprintf(" AND `issued-id` = '%s' ", DBA::escape($dfrn_id));
 321                         break;
 322                 case 0:
 323                         $sql_extra = sprintf(" AND `issued-id` = '%s' AND `duplex` = 1 ", DBA::escape($dfrn_id));
 324                         break;
 325                 case 1:
 326                         $sql_extra = sprintf(" AND `dfrn-id` = '%s' AND `duplex` = 1 ", DBA::escape($dfrn_id));
 327                         break;
 328                 default:
 329                         $a->internalRedirect();
 330                         break; // NOTREACHED
 331         }
 332
 333         $r = q("SELECT * FROM `contact` WHERE `blocked` = 0 AND `pending` = 0 $sql_extra LIMIT 1");
 334         if (!DBA::isResult($r)) {
 335                 exit();
 336         }
 337
 338         $contact = $r[0];
 339         $owner_uid = $r[0]['uid'];
 340         $contact_id = $r[0]['id'];
 341
 342         if ($type === 'reputation' && strlen($url)) {
 343                 $r = q("SELECT * FROM `contact` WHERE `url` = '%s' AND `uid` = %d LIMIT 1",
 344                         DBA::escape($url),
 345                         intval($owner_uid)
 346                 );
 347                 $reputation = 0;
 348                 $text = '';
 349
 350                 if (DBA::isResult($r)) {
 351                         $reputation = $r[0]['rating'];
 352                         $text = $r[0]['reason'];
 353
 354                         if ($r[0]['id'] == $contact_id) { // inquiring about own reputation not allowed
 355                                 $reputation = 0;
 356                                 $text = '';
 357                         }
 358                 }
 359
 360                 echo "<?xml version=\"1.0\" encoding=\"UTF-8\"?>
 361                 <reputation>
 362                         <url>$url</url>
 363                         <rating>$reputation</rating>
 364                         <description>$text</description>
 365                 </reputation>
 366                 ";
 367                 exit();
 368                 // NOTREACHED
 369         } else {
 370                 // Update the writable flag if it changed
 371                 Logger::log('dfrn_poll: post request feed: ' . print_r($_POST, true), Logger::DATA);
 372                 if ($dfrn_version >= 2.21) {
 373                         if ($perm === 'rw') {
 374                                 $writable = 1;
 375                         } else {
 376                                 $writable = 0;
 377                         }
 378
 379                         if ($writable != $contact['writable']) {
 380                                 q("UPDATE `contact` SET `writable` = %d WHERE `id` = %d",
 381                                         intval($writable),
 382                                         intval($contact_id)
 383                                 );
 384                         }
 385                 }
 386
 387                 header("Content-type: application/atom+xml");
 388                 $o = DFRN::feed($dfrn_id, $a->argv[1], $last_update, $direction);
 389                 echo $o;
 390                 exit();
 391         }
 392 }
 393
 394 function dfrn_poll_content(App $a)
 395 {
 396         $dfrn_id         = defaults($_GET, 'dfrn_id'        , '');
 397         $type            = defaults($_GET, 'type'           , 'data');
 398         $last_update     = defaults($_GET, 'last_update'    , '');
 399         $destination_url = defaults($_GET, 'destination_url', '');
 400         $sec             = defaults($_GET, 'sec'            , '');
 401         $dfrn_version    = !empty($_GET['dfrn_version'])    ? (float) $_GET['dfrn_version'] : 2.0;
 402         $quiet           = !empty($_GET['quiet']);
 403
 404         $direction = -1;
 405         if (strpos($dfrn_id, ':') == 1) {
 406                 $direction = intval(substr($dfrn_id, 0, 1));
 407                 $dfrn_id = substr($dfrn_id, 2);
 408         }
 409
 410         if ($dfrn_id != '') {
 411                 // initial communication from external contact
 412                 $hash = Strings::getRandomHex();
 413
 414                 $status = 0;
 415
 416                 DBA::delete('challenge', ["`expire` < ?", time()]);
 417
 418                 if ($type !== 'profile') {
 419                         q("INSERT INTO `challenge` ( `challenge`, `dfrn-id`, `expire` , `type`, `last_update` )
 420                                 VALUES( '%s', '%s', '%s', '%s', '%s' ) ",
 421                                 DBA::escape($hash),
 422                                 DBA::escape($dfrn_id),
 423                                 intval(time() + 60 ),
 424                                 DBA::escape($type),
 425                                 DBA::escape($last_update)
 426                         );
 427                 }
 428
 429                 $sql_extra = '';
 430                 switch ($direction) {
 431                         case -1:
 432                                 if ($type === 'profile') {
 433                                         $sql_extra = sprintf(" AND (`dfrn-id` = '%s' OR `issued-id` = '%s') ", DBA::escape($dfrn_id), DBA::escape($dfrn_id));
 434                                 } else {
 435                                         $sql_extra = sprintf(" AND `issued-id` = '%s' ", DBA::escape($dfrn_id));
 436                                 }
 437
 438                                 $my_id = $dfrn_id;
 439                                 break;
 440                         case 0:
 441                                 $sql_extra = sprintf(" AND `issued-id` = '%s' AND `duplex` = 1 ", DBA::escape($dfrn_id));
 442                                 $my_id = '1:' . $dfrn_id;
 443                                 break;
 444                         case 1:
 445                                 $sql_extra = sprintf(" AND `dfrn-id` = '%s' AND `duplex` = 1 ", DBA::escape($dfrn_id));
 446                                 $my_id = '0:' . $dfrn_id;
 447                                 break;
 448                         default:
 449                                 $a->internalRedirect();
 450                                 break; // NOTREACHED
 451                 }
 452
 453                 $nickname = $a->argv[1];
 454
 455                 $r = q("SELECT `contact`.*, `user`.`username`, `user`.`nickname`
 456                         FROM `contact` LEFT JOIN `user` ON `contact`.`uid` = `user`.`uid`
 457                         WHERE `contact`.`blocked` = 0 AND `contact`.`pending` = 0
 458                         AND `user`.`nickname` = '%s' $sql_extra LIMIT 1",
 459                         DBA::escape($nickname)
 460                 );
 461                 if (DBA::isResult($r)) {
 462                         $challenge = '';
 463                         $encrypted_id = '';
 464                         $id_str = $my_id . '.' . mt_rand(1000, 9999);
 465
 466                         if (($r[0]['duplex'] && strlen($r[0]['pubkey'])) || !strlen($r[0]['prvkey'])) {
 467                                 openssl_public_encrypt($hash, $challenge, $r[0]['pubkey']);
 468                                 openssl_public_encrypt($id_str, $encrypted_id, $r[0]['pubkey']);
 469                         } else {
 470                                 openssl_private_encrypt($hash, $challenge, $r[0]['prvkey']);
 471                                 openssl_private_encrypt($id_str, $encrypted_id, $r[0]['prvkey']);
 472                         }
 473
 474                         $challenge = bin2hex($challenge);
 475                         $encrypted_id = bin2hex($encrypted_id);
 476                 } else {
 477                         $status = 1;
 478                         $challenge = '';
 479                         $encrypted_id = '';
 480                 }
 481
 482                 if (($type === 'profile') && (strlen($sec))) {
 483                         // heluecht: I don't know why we don't fail immediately when the user or contact hadn't been found.
 484                         // Since it doesn't make sense to continue from this point on, we now fail here. This should be safe.
 485                         if (!DBA::isResult($r)) {
 486                                 System::httpExit(404, ["title" => L10n::t('Page not found.')]);
 487                         }
 488
 489                         // URL reply
 490                         if ($dfrn_version < 2.2) {
 491                                 $s = Network::fetchUrl($r[0]['poll']
 492                                         . '?dfrn_id=' . $encrypted_id
 493                                         . '&type=profile-check'
 494                                         . '&dfrn_version=' . DFRN_PROTOCOL_VERSION
 495                                         . '&challenge=' . $challenge
 496                                         . '&sec=' . $sec
 497                                 );
 498                         } else {
 499                                 $s = Network::post($r[0]['poll'], [
 500                                         'dfrn_id' => $encrypted_id,
 501                                         'type' => 'profile-check',
 502                                         'dfrn_version' => DFRN_PROTOCOL_VERSION,
 503                                         'challenge' => $challenge,
 504                                         'sec' => $sec
 505                                 ])->getBody();
 506                         }
 507
 508                         Logger::log("dfrn_poll: sec profile: " . $s, Logger::DATA);
 509
 510                         if (strlen($s) && strstr($s, '<?xml')) {
 511                                 $xml = XML::parseString($s);
 512
 513                                 Logger::log('dfrn_poll: profile: parsed xml: ' . print_r($xml, true), Logger::DATA);
 514
 515                                 Logger::log('dfrn_poll: secure profile: challenge: ' . $xml->challenge . ' expecting ' . $hash);
 516                                 Logger::log('dfrn_poll: secure profile: sec: ' . $xml->sec . ' expecting ' . $sec);
 517
 518                                 if (((int) $xml->status == 0) && ($xml->challenge == $hash) && ($xml->sec == $sec)) {
 519                                         $_SESSION['authenticated'] = 1;
 520                                         if (empty($_SESSION['remote'])) {
 521                                                 $_SESSION['remote'] = [];
 522                                         }
 523
 524                                         $_SESSION['remote'][] = ['cid' => $r[0]['id'], 'uid' => $r[0]['uid'], 'url' => $r[0]['url']];
 525                                         $_SESSION['visitor_id'] = $r[0]['id'];
 526                                         $_SESSION['visitor_home'] = $r[0]['url'];
 527                                         $_SESSION['visitor_visiting'] = $r[0]['uid'];
 528                                         $_SESSION['my_url'] = $r[0]['url'];
 529                                         if (!$quiet) {
 530                                                 info(L10n::t('%1$s welcomes %2$s', $r[0]['username'], $r[0]['name']) . EOL);
 531                                         }
 532
 533                                         // Visitors get 1 day session.
 534                                         $session_id = session_id();
 535                                         $expire = time() + 86400;
 536                                         q("UPDATE `session` SET `expire` = '%s' WHERE `sid` = '%s'",
 537                                                 DBA::escape($expire),
 538                                                 DBA::escape($session_id)
 539                                         );
 540                                 }
 541                         }
 542
 543                         $profile = ((DBA::isResult($r) && $r[0]['nickname']) ? $r[0]['nickname'] : $nickname);
 544
 545                         switch ($destination_url) {
 546                                 case 'profile':
 547                                         $a->internalRedirect('profile/' . $profile . '?f=&tab=profile');
 548                                         break;
 549                                 case 'photos':
 550                                         $a->internalRedirect('photos/' . $profile);
 551                                         break;
 552                                 case 'status':
 553                                 case '':
 554                                         $a->internalRedirect('profile/' . $profile);
 555                                         break;
 556                                 default:
 557                                         $appendix = (strstr($destination_url, '?') ? '&f=&redir=1' : '?f=&redir=1');
 558                                         $a->redirect($destination_url . $appendix);
 559                                         break;
 560                         }
 561                         // NOTREACHED
 562                 } else {
 563                         // XML reply
 564                         header("Content-type: text/xml");
 565                         echo '<?xml version="1.0" encoding="UTF-8"?>' . "\r\n"
 566                                 . '<dfrn_poll>' . "\r\n"
 567                                 . "\t" . '<status>' . $status . '</status>' . "\r\n"
 568                                 . "\t" . '<dfrn_version>' . DFRN_PROTOCOL_VERSION . '</dfrn_version>' . "\r\n"
 569                                 . "\t" . '<dfrn_id>' . $encrypted_id . '</dfrn_id>' . "\r\n"
 570                                 . "\t" . '<challenge>' . $challenge . '</challenge>' . "\r\n"
 571                                 . '</dfrn_poll>' . "\r\n";
 572                         exit();
 573                         // NOTREACHED
 574                 }
 575         }
 576 }