mod/dfrn_poll.php

   1 <?php
   2 /**
   3  * @copyright Copyright (C) 2020, Friendica
   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 use Friendica\App;
  23 use Friendica\Core\Logger;
  24 use Friendica\Core\System;
  25 use Friendica\Core\Session;
  26 use Friendica\Database\DBA;
  27 use Friendica\DI;
  28 use Friendica\Protocol\DFRN;
  29 use Friendica\Protocol\OStatus;
  30 use Friendica\Util\Network;
  31 use Friendica\Util\Strings;
  32 use Friendica\Util\XML;
  33
  34 function dfrn_poll_init(App $a)
  35 {
  36         DI::auth()->withSession($a);
  37
  38         $dfrn_id         =  $_GET['dfrn_id']         ?? '';
  39         $type            = ($_GET['type']            ?? '') ?: 'data';
  40         $last_update     =  $_GET['last_update']     ?? '';
  41         $destination_url =  $_GET['destination_url'] ?? '';
  42         $challenge       =  $_GET['challenge']       ?? '';
  43         $sec             =  $_GET['sec']             ?? '';
  44         $dfrn_version    = floatval(($_GET['dfrn_version'] ?? 0.0) ?: 2.0);
  45         $quiet                   = !empty($_GET['quiet']);
  46
  47         // Possibly it is an OStatus compatible server that requests a user feed
  48         $user_agent = $_SERVER['HTTP_USER_AGENT'] ?? '';
  49         if (($a->argc > 1) && ($dfrn_id == '') && !strstr($user_agent, 'Friendica')) {
  50                 $nickname = $a->argv[1];
  51                 header("Content-type: application/atom+xml");
  52                 echo OStatus::feed($nickname, $last_update, 10);
  53                 exit();
  54         }
  55
  56         $direction = -1;
  57
  58         if (strpos($dfrn_id, ':') == 1) {
  59                 $direction = intval(substr($dfrn_id, 0, 1));
  60                 $dfrn_id = substr($dfrn_id, 2);
  61         }
  62
  63         $hidewall = false;
  64
  65         if (($dfrn_id === '') && empty($_POST['dfrn_id'])) {
  66                 if (DI::config()->get('system', 'block_public') && !Session::isAuthenticated()) {
  67                         throw new \Friendica\Network\HTTPException\ForbiddenException();
  68                 }
  69
  70                 $user = '';
  71                 if ($a->argc > 1) {
  72                         $r = q("SELECT `hidewall`,`nickname` FROM `user` WHERE `user`.`nickname` = '%s' LIMIT 1",
  73                                 DBA::escape($a->argv[1])
  74                         );
  75                         if (!$r) {
  76                                 throw new \Friendica\Network\HTTPException\NotFoundException();
  77                         }
  78
  79                         $hidewall = ($r[0]['hidewall'] && !local_user());
  80
  81                         $user = $r[0]['nickname'];
  82                 }
  83
  84                 Logger::log('dfrn_poll: public feed request from ' . $_SERVER['REMOTE_ADDR'] . ' for ' . $user);
  85                 header("Content-type: application/atom+xml");
  86                 echo DFRN::feed('', $user, $last_update, 0, $hidewall);
  87                 exit();
  88         }
  89
  90         if (($type === 'profile') && (!strlen($sec))) {
  91                 $sql_extra = '';
  92                 switch ($direction) {
  93                         case -1:
  94                                 $sql_extra = sprintf(" AND ( `dfrn-id` = '%s' OR `issued-id` = '%s' ) ", DBA::escape($dfrn_id), DBA::escape($dfrn_id));
  95                                 $my_id = $dfrn_id;
  96                                 break;
  97                         case 0:
  98                                 $sql_extra = sprintf(" AND `issued-id` = '%s' AND `duplex` = 1 ", DBA::escape($dfrn_id));
  99                                 $my_id = '1:' . $dfrn_id;
 100                                 break;
 101                         case 1:
 102                                 $sql_extra = sprintf(" AND `dfrn-id` = '%s' AND `duplex` = 1 ", DBA::escape($dfrn_id));
 103                                 $my_id = '0:' . $dfrn_id;
 104                                 break;
 105                         default:
 106                                 DI::baseUrl()->redirect();
 107                                 break; // NOTREACHED
 108                 }
 109
 110                 $r = q("SELECT `contact`.*, `user`.`username`, `user`.`nickname`
 111                         FROM `contact` LEFT JOIN `user` ON `contact`.`uid` = `user`.`uid`
 112                         WHERE `contact`.`blocked` = 0 AND `contact`.`pending` = 0
 113                         AND `user`.`nickname` = '%s' $sql_extra LIMIT 1",
 114                         DBA::escape($a->argv[1])
 115                 );
 116
 117                 if (DBA::isResult($r)) {
 118                         $s = Network::fetchUrl($r[0]['poll'] . '?dfrn_id=' . $my_id . '&type=profile-check');
 119
 120                         Logger::log("dfrn_poll: old profile returns " . $s, Logger::DATA);
 121
 122                         if (strlen($s)) {
 123                                 $xml = XML::parseString($s);
 124
 125                                 if ((int)$xml->status === 1) {
 126                                         $_SESSION['authenticated'] = 1;
 127                                         $_SESSION['visitor_id'] = $r[0]['id'];
 128                                         $_SESSION['visitor_home'] = $r[0]['url'];
 129                                         $_SESSION['visitor_handle'] = $r[0]['addr'];
 130                                         $_SESSION['visitor_visiting'] = $r[0]['uid'];
 131                                         $_SESSION['my_url'] = $r[0]['url'];
 132
 133                                         Session::setVisitorsContacts();
 134
 135                                         if (!$quiet) {
 136                                                 info(DI::l10n()->t('%1$s welcomes %2$s', $r[0]['username'], $r[0]['name']) . EOL);
 137                                         }
 138
 139                                         // Visitors get 1 day session.
 140                                         $session_id = session_id();
 141                                         $expire = time() + 86400;
 142                                         q("UPDATE `session` SET `expire` = '%s' WHERE `sid` = '%s'",
 143                                                 DBA::escape($expire),
 144                                                 DBA::escape($session_id)
 145                                         );
 146                                 }
 147                         }
 148
 149                         $profile = (count($r) > 0 && isset($r[0]['nickname']) ? $r[0]['nickname'] : '');
 150                         if (!empty($destination_url)) {
 151                                 System::externalRedirect($destination_url);
 152                         } else {
 153                                 DI::baseUrl()->redirect('profile/' . $profile);
 154                         }
 155                 }
 156                 DI::baseUrl()->redirect();
 157         }
 158
 159         if ($type === 'profile-check' && $dfrn_version < 2.2) {
 160                 if ((strlen($challenge)) && (strlen($sec))) {
 161                         DBA::delete('profile_check', ["`expire` < ?", time()]);
 162                         $r = q("SELECT * FROM `profile_check` WHERE `sec` = '%s' ORDER BY `expire` DESC LIMIT 1",
 163                                 DBA::escape($sec)
 164                         );
 165                         if (!DBA::isResult($r)) {
 166                                 System::xmlExit(3, 'No ticket');
 167                                 // NOTREACHED
 168                         }
 169
 170                         $orig_id = $r[0]['dfrn_id'];
 171                         if (strpos($orig_id, ':')) {
 172                                 $orig_id = substr($orig_id, 2);
 173                         }
 174
 175                         $c = q("SELECT * FROM `contact` WHERE `id` = %d LIMIT 1",
 176                                 intval($r[0]['cid'])
 177                         );
 178                         if (!DBA::isResult($c)) {
 179                                 System::xmlExit(3, 'No profile');
 180                         }
 181
 182                         $contact = $c[0];
 183
 184                         $sent_dfrn_id = hex2bin($dfrn_id);
 185                         $challenge = hex2bin($challenge);
 186
 187                         $final_dfrn_id = '';
 188
 189                         if (($contact['duplex']) && strlen($contact['prvkey'])) {
 190                                 openssl_private_decrypt($sent_dfrn_id, $final_dfrn_id, $contact['prvkey']);
 191                                 openssl_private_decrypt($challenge, $decoded_challenge, $contact['prvkey']);
 192                         } else {
 193                                 openssl_public_decrypt($sent_dfrn_id, $final_dfrn_id, $contact['pubkey']);
 194                                 openssl_public_decrypt($challenge, $decoded_challenge, $contact['pubkey']);
 195                         }
 196
 197                         $final_dfrn_id = substr($final_dfrn_id, 0, strpos($final_dfrn_id, '.'));
 198
 199                         if (strpos($final_dfrn_id, ':') == 1) {
 200                                 $final_dfrn_id = substr($final_dfrn_id, 2);
 201                         }
 202
 203                         if ($final_dfrn_id != $orig_id) {
 204                                 Logger::log('profile_check: ' . $final_dfrn_id . ' != ' . $orig_id, Logger::DEBUG);
 205                                 // did not decode properly - cannot trust this site
 206                                 System::xmlExit(3, 'Bad decryption');
 207                         }
 208
 209                         header("Content-type: text/xml");
 210                         echo "<?xml version=\"1.0\" encoding=\"UTF-8\"?><dfrn_poll><status>0</status><challenge>$decoded_challenge</challenge><sec>$sec</sec></dfrn_poll>";
 211                         exit();
 212                         // NOTREACHED
 213                 } else {
 214                         // old protocol
 215                         switch ($direction) {
 216                                 case 1:
 217                                         $dfrn_id = '0:' . $dfrn_id;
 218                                         break;
 219                                 case 0:
 220                                         $dfrn_id = '1:' . $dfrn_id;
 221                                         break;
 222                                 default:
 223                                         break;
 224                         }
 225
 226                         DBA::delete('profile_check', ["`expire` < ?", time()]);
 227                         $r = q("SELECT * FROM `profile_check` WHERE `dfrn_id` = '%s' ORDER BY `expire` DESC",
 228                                 DBA::escape($dfrn_id));
 229                         if (DBA::isResult($r)) {
 230                                 System::xmlExit(1);
 231                                 return; // NOTREACHED
 232                         }
 233                         System::xmlExit(0);
 234                         return; // NOTREACHED
 235                 }
 236         }
 237 }
 238
 239 function dfrn_poll_post(App $a)
 240 {
 241         $dfrn_id      =  $_POST['dfrn_id']   ?? '';
 242         $challenge    =  $_POST['challenge'] ?? '';
 243         $url          =  $_POST['url']       ?? '';
 244         $sec          =  $_POST['sec']       ?? '';
 245         $ptype        =  $_POST['type']      ?? '';
 246         $perm         = ($_POST['perm']      ?? '') ?: 'r';
 247         $dfrn_version = floatval(($_GET['dfrn_version'] ?? 0.0) ?: 2.0);
 248
 249         if ($ptype === 'profile-check') {
 250                 if (strlen($challenge) && strlen($sec)) {
 251                         Logger::log('dfrn_poll: POST: profile-check');
 252
 253                         DBA::delete('profile_check', ["`expire` < ?", time()]);
 254                         $r = q("SELECT * FROM `profile_check` WHERE `sec` = '%s' ORDER BY `expire` DESC LIMIT 1",
 255                                 DBA::escape($sec)
 256                         );
 257                         if (!DBA::isResult($r)) {
 258                                 System::xmlExit(3, 'No ticket');
 259                                 // NOTREACHED
 260                         }
 261
 262                         $orig_id = $r[0]['dfrn_id'];
 263                         if (strpos($orig_id, ':')) {
 264                                 $orig_id = substr($orig_id, 2);
 265                         }
 266
 267                         $c = q("SELECT * FROM `contact` WHERE `id` = %d LIMIT 1",
 268                                 intval($r[0]['cid'])
 269                         );
 270                         if (!DBA::isResult($c)) {
 271                                 System::xmlExit(3, 'No profile');
 272                         }
 273
 274                         $contact = $c[0];
 275
 276                         $sent_dfrn_id = hex2bin($dfrn_id);
 277                         $challenge = hex2bin($challenge);
 278
 279                         $final_dfrn_id = '';
 280
 281                         if ($contact['duplex'] && strlen($contact['prvkey'])) {
 282                                 openssl_private_decrypt($sent_dfrn_id, $final_dfrn_id, $contact['prvkey']);
 283                                 openssl_private_decrypt($challenge, $decoded_challenge, $contact['prvkey']);
 284                         } else {
 285                                 openssl_public_decrypt($sent_dfrn_id, $final_dfrn_id, $contact['pubkey']);
 286                                 openssl_public_decrypt($challenge, $decoded_challenge, $contact['pubkey']);
 287                         }
 288
 289                         $final_dfrn_id = substr($final_dfrn_id, 0, strpos($final_dfrn_id, '.'));
 290
 291                         if (strpos($final_dfrn_id, ':') == 1) {
 292                                 $final_dfrn_id = substr($final_dfrn_id, 2);
 293                         }
 294
 295                         if ($final_dfrn_id != $orig_id) {
 296                                 Logger::log('profile_check: ' . $final_dfrn_id . ' != ' . $orig_id, Logger::DEBUG);
 297                                 // did not decode properly - cannot trust this site
 298                                 System::xmlExit(3, 'Bad decryption');
 299                         }
 300
 301                         header("Content-type: text/xml");
 302                         echo "<?xml version=\"1.0\" encoding=\"UTF-8\"?><dfrn_poll><status>0</status><challenge>$decoded_challenge</challenge><sec>$sec</sec></dfrn_poll>";
 303                         exit();
 304                         // NOTREACHED
 305                 }
 306         }
 307
 308         $direction = -1;
 309         if (strpos($dfrn_id, ':') == 1) {
 310                 $direction = intval(substr($dfrn_id, 0, 1));
 311                 $dfrn_id = substr($dfrn_id, 2);
 312         }
 313
 314         $r = q("SELECT * FROM `challenge` WHERE `dfrn-id` = '%s' AND `challenge` = '%s' LIMIT 1",
 315                 DBA::escape($dfrn_id),
 316                 DBA::escape($challenge)
 317         );
 318
 319         if (!DBA::isResult($r)) {
 320                 exit();
 321         }
 322
 323         $type = $r[0]['type'];
 324         $last_update = $r[0]['last_update'];
 325
 326         DBA::delete('challenge', ['dfrn-id' => $dfrn_id, 'challenge' => $challenge]);
 327
 328         $sql_extra = '';
 329         switch ($direction) {
 330                 case -1:
 331                         $sql_extra = sprintf(" AND `issued-id` = '%s' ", DBA::escape($dfrn_id));
 332                         break;
 333                 case 0:
 334                         $sql_extra = sprintf(" AND `issued-id` = '%s' AND `duplex` = 1 ", DBA::escape($dfrn_id));
 335                         break;
 336                 case 1:
 337                         $sql_extra = sprintf(" AND `dfrn-id` = '%s' AND `duplex` = 1 ", DBA::escape($dfrn_id));
 338                         break;
 339                 default:
 340                         DI::baseUrl()->redirect();
 341                         break; // NOTREACHED
 342         }
 343
 344         $r = q("SELECT * FROM `contact` WHERE `blocked` = 0 AND `pending` = 0 $sql_extra LIMIT 1");
 345         if (!DBA::isResult($r)) {
 346                 exit();
 347         }
 348
 349         $contact = $r[0];
 350         $owner_uid = $r[0]['uid'];
 351         $contact_id = $r[0]['id'];
 352
 353         if ($type === 'reputation' && strlen($url)) {
 354                 $r = q("SELECT * FROM `contact` WHERE `url` = '%s' AND `uid` = %d LIMIT 1",
 355                         DBA::escape($url),
 356                         intval($owner_uid)
 357                 );
 358                 $reputation = 0;
 359                 $text = '';
 360
 361                 if (DBA::isResult($r)) {
 362                         $reputation = $r[0]['rating'];
 363                         $text = $r[0]['reason'];
 364
 365                         if ($r[0]['id'] == $contact_id) { // inquiring about own reputation not allowed
 366                                 $reputation = 0;
 367                                 $text = '';
 368                         }
 369                 }
 370
 371                 echo "<?xml version=\"1.0\" encoding=\"UTF-8\"?>
 372                 <reputation>
 373                         <url>$url</url>
 374                         <rating>$reputation</rating>
 375                         <description>$text</description>
 376                 </reputation>
 377                 ";
 378                 exit();
 379                 // NOTREACHED
 380         } else {
 381                 // Update the writable flag if it changed
 382                 Logger::log('dfrn_poll: post request feed: ' . print_r($_POST, true), Logger::DATA);
 383                 if ($dfrn_version >= 2.21) {
 384                         if ($perm === 'rw') {
 385                                 $writable = 1;
 386                         } else {
 387                                 $writable = 0;
 388                         }
 389
 390                         if ($writable != $contact['writable']) {
 391                                 q("UPDATE `contact` SET `writable` = %d WHERE `id` = %d",
 392                                         intval($writable),
 393                                         intval($contact_id)
 394                                 );
 395                         }
 396                 }
 397
 398                 header("Content-type: application/atom+xml");
 399                 $o = DFRN::feed($dfrn_id, $a->argv[1], $last_update, $direction);
 400                 echo $o;
 401                 exit();
 402         }
 403 }
 404
 405 function dfrn_poll_content(App $a)
 406 {
 407         $dfrn_id         =  $_GET['dfrn_id']         ?? '';
 408         $type            = ($_GET['type']            ?? '') ?: 'data';
 409         $last_update     =  $_GET['last_update']     ?? '';
 410         $destination_url =  $_GET['destination_url'] ?? '';
 411         $sec             =  $_GET['sec']             ?? '';
 412         $dfrn_version    = floatval(($_GET['dfrn_version'] ?? 0.0) ?: 2.0);
 413         $quiet           = !empty($_GET['quiet']);
 414
 415         $direction = -1;
 416         if (strpos($dfrn_id, ':') == 1) {
 417                 $direction = intval(substr($dfrn_id, 0, 1));
 418                 $dfrn_id = substr($dfrn_id, 2);
 419         }
 420
 421         if ($dfrn_id != '') {
 422                 // initial communication from external contact
 423                 $hash = Strings::getRandomHex();
 424
 425                 $status = 0;
 426
 427                 DBA::delete('challenge', ["`expire` < ?", time()]);
 428
 429                 if ($type !== 'profile') {
 430                         q("INSERT INTO `challenge` ( `challenge`, `dfrn-id`, `expire` , `type`, `last_update` )
 431                                 VALUES( '%s', '%s', '%s', '%s', '%s' ) ",
 432                                 DBA::escape($hash),
 433                                 DBA::escape($dfrn_id),
 434                                 intval(time() + 60 ),
 435                                 DBA::escape($type),
 436                                 DBA::escape($last_update)
 437                         );
 438                 }
 439
 440                 $sql_extra = '';
 441                 switch ($direction) {
 442                         case -1:
 443                                 if ($type === 'profile') {
 444                                         $sql_extra = sprintf(" AND (`dfrn-id` = '%s' OR `issued-id` = '%s') ", DBA::escape($dfrn_id), DBA::escape($dfrn_id));
 445                                 } else {
 446                                         $sql_extra = sprintf(" AND `issued-id` = '%s' ", DBA::escape($dfrn_id));
 447                                 }
 448
 449                                 $my_id = $dfrn_id;
 450                                 break;
 451                         case 0:
 452                                 $sql_extra = sprintf(" AND `issued-id` = '%s' AND `duplex` = 1 ", DBA::escape($dfrn_id));
 453                                 $my_id = '1:' . $dfrn_id;
 454                                 break;
 455                         case 1:
 456                                 $sql_extra = sprintf(" AND `dfrn-id` = '%s' AND `duplex` = 1 ", DBA::escape($dfrn_id));
 457                                 $my_id = '0:' . $dfrn_id;
 458                                 break;
 459                         default:
 460                                 DI::baseUrl()->redirect();
 461                                 break; // NOTREACHED
 462                 }
 463
 464                 $nickname = $a->argv[1];
 465
 466                 $r = q("SELECT `contact`.*, `user`.`username`, `user`.`nickname`
 467                         FROM `contact` LEFT JOIN `user` ON `contact`.`uid` = `user`.`uid`
 468                         WHERE `contact`.`blocked` = 0 AND `contact`.`pending` = 0
 469                         AND `user`.`nickname` = '%s' $sql_extra LIMIT 1",
 470                         DBA::escape($nickname)
 471                 );
 472                 if (DBA::isResult($r)) {
 473                         $challenge = '';
 474                         $encrypted_id = '';
 475                         $id_str = $my_id . '.' . mt_rand(1000, 9999);
 476
 477                         if (($r[0]['duplex'] && strlen($r[0]['pubkey'])) || !strlen($r[0]['prvkey'])) {
 478                                 openssl_public_encrypt($hash, $challenge, $r[0]['pubkey']);
 479                                 openssl_public_encrypt($id_str, $encrypted_id, $r[0]['pubkey']);
 480                         } else {
 481                                 openssl_private_encrypt($hash, $challenge, $r[0]['prvkey']);
 482                                 openssl_private_encrypt($id_str, $encrypted_id, $r[0]['prvkey']);
 483                         }
 484
 485                         $challenge = bin2hex($challenge);
 486                         $encrypted_id = bin2hex($encrypted_id);
 487                 } else {
 488                         $status = 1;
 489                         $challenge = '';
 490                         $encrypted_id = '';
 491                 }
 492
 493                 if (($type === 'profile') && (strlen($sec))) {
 494                         // heluecht: I don't know why we don't fail immediately when the user or contact hadn't been found.
 495                         // Since it doesn't make sense to continue from this point on, we now fail here. This should be safe.
 496                         if (!DBA::isResult($r)) {
 497                                 throw new \Friendica\Network\HTTPException\NotFoundException();
 498                         }
 499
 500                         // URL reply
 501                         if ($dfrn_version < 2.2) {
 502                                 $s = Network::fetchUrl($r[0]['poll']
 503                                         . '?dfrn_id=' . $encrypted_id
 504                                         . '&type=profile-check'
 505                                         . '&dfrn_version=' . DFRN_PROTOCOL_VERSION
 506                                         . '&challenge=' . $challenge
 507                                         . '&sec=' . $sec
 508                                 );
 509                         } else {
 510                                 $s = Network::post($r[0]['poll'], [
 511                                         'dfrn_id' => $encrypted_id,
 512                                         'type' => 'profile-check',
 513                                         'dfrn_version' => DFRN_PROTOCOL_VERSION,
 514                                         'challenge' => $challenge,
 515                                         'sec' => $sec
 516                                 ])->getBody();
 517                         }
 518
 519                         Logger::log("dfrn_poll: sec profile: " . $s, Logger::DATA);
 520
 521                         if (strlen($s) && strstr($s, '<?xml')) {
 522                                 $xml = XML::parseString($s);
 523
 524                                 Logger::log('dfrn_poll: profile: parsed xml: ' . print_r($xml, true), Logger::DATA);
 525
 526                                 Logger::log('dfrn_poll: secure profile: challenge: ' . $xml->challenge . ' expecting ' . $hash);
 527                                 Logger::log('dfrn_poll: secure profile: sec: ' . $xml->sec . ' expecting ' . $sec);
 528
 529                                 if (((int) $xml->status == 0) && ($xml->challenge == $hash) && ($xml->sec == $sec)) {
 530                                         $_SESSION['authenticated'] = 1;
 531                                         $_SESSION['visitor_id'] = $r[0]['id'];
 532                                         $_SESSION['visitor_home'] = $r[0]['url'];
 533                                         $_SESSION['visitor_visiting'] = $r[0]['uid'];
 534                                         $_SESSION['my_url'] = $r[0]['url'];
 535
 536                                         Session::setVisitorsContacts();
 537
 538                                         if (!$quiet) {
 539                                                 info(DI::l10n()->t('%1$s welcomes %2$s', $r[0]['username'], $r[0]['name']) . EOL);
 540                                         }
 541
 542                                         // Visitors get 1 day session.
 543                                         $session_id = session_id();
 544                                         $expire = time() + 86400;
 545                                         q("UPDATE `session` SET `expire` = '%s' WHERE `sid` = '%s'",
 546                                                 DBA::escape($expire),
 547                                                 DBA::escape($session_id)
 548                                         );
 549                                 }
 550                         }
 551
 552                         $profile = ((DBA::isResult($r) && $r[0]['nickname']) ? $r[0]['nickname'] : $nickname);
 553
 554                         switch ($destination_url) {
 555                                 case 'profile':
 556                                         DI::baseUrl()->redirect('profile/' . $profile . '/profile');
 557                                         break;
 558                                 case 'photos':
 559                                         DI::baseUrl()->redirect('photos/' . $profile);
 560                                         break;
 561                                 case 'status':
 562                                 case '':
 563                                         DI::baseUrl()->redirect('profile/' . $profile);
 564                                         break;
 565                                 default:
 566                                         $appendix = (strstr($destination_url, '?') ? '&redir=1' : '?redir=1');
 567                                         DI::baseUrl()->redirect($destination_url . $appendix);
 568                                         break;
 569                         }
 570                         // NOTREACHED
 571                 } else {
 572                         // XML reply
 573                         header("Content-type: text/xml");
 574                         echo '<?xml version="1.0" encoding="UTF-8"?>' . "\r\n"
 575                                 . '<dfrn_poll>' . "\r\n"
 576                                 . "\t" . '<status>' . $status . '</status>' . "\r\n"
 577                                 . "\t" . '<dfrn_version>' . DFRN_PROTOCOL_VERSION . '</dfrn_version>' . "\r\n"
 578                                 . "\t" . '<dfrn_id>' . $encrypted_id . '</dfrn_id>' . "\r\n"
 579                                 . "\t" . '<challenge>' . $challenge . '</challenge>' . "\r\n"
 580                                 . '</dfrn_poll>' . "\r\n";
 581                         exit();
 582                         // NOTREACHED
 583                 }
 584         }
 585 }