safechat/html/login.php

<?php
try {
  require_once("usertable.php");
  $user = $db->real_escape_string($_REQUEST['user']);
  $pubkey = $db->real_escape_string($_REQUEST['pubkey']);
  $pgp = gnupg_init();
  if (!$pgp) {
    echo json_encode(array('success' => false, 'txt' => "pgp on server failed"));
  } else {
    $verify = gnupg_import($pgp, $_REQUEST['pubkey']);
    if (!$verify) {
      echo json_encode(array('success' => false, 'txt' => "wrong identity"));
    } else {
      $q = $db->query("select * from user where name='$user' and pubkey='$pubkey';");
      if ($q->num_rows==1) {
        echo json_encode(array('success' => true, 'txt' => "user verified"));
      } elseif ($q->num_rows==0) {
        $q = $db->query("insert into user (name, pubkey) values ('$user', '$pubkey');");
        echo json_encode(array('success' => true, 'txt' => "user created"));
      } else {
        echo json_encode(array('success' => false, 'txt' => "server database defect"));
      }
    }
  }
} catch (Exception $e) {
  echo json_encode(array('success' => false, 'txt' => "login failed"));
}
?>