public static function challenge()
{
if (isset($_GET['bouncer-identity']) && isset($_GET['bouncer-feature'])) {
$id = $_GET['bouncer-identity'];
$identity = self::backend()->getIdentity($id);
if (isset($identity)) {
if ($_GET['bouncer-feature'] == 'image') {
$identity['features']['image'] = $identity['features']['image'] + 2;
self::setIdentity($identity['id'], $identity);
header('Content-Type:image/gif');
echo base64_decode("R0lGODlhAQABAIAAAAAAAAAAACH5BAEAAAAALAAAAAABAAEAAAICRAEAOw==");
} elseif ($_GET['bouncer-feature'] == 'javascript') {
$identity['features']['javascript'] = $identity['features']['javascript'] + 2;
self::setIdentity($identity['id'], $identity);
header('Content-Type:image/gif');
echo base64_decode("R0lGODlhAQABAIAAAAAAAAAAACH5BAEAAAAALAAAAAABAAEAAAICRAEAOw==");
} elseif ($_GET['bouncer-feature'] == 'iframe') {
$identity['features']['iframe'] = $identity['features']['iframe'] + 2;
self::setIdentity($identity['id'], $identity);
header("Content-Type:text/html");
echo '<html><head><meta name="robots" content="noindex,nofollow"></head><body> </body></html>';
}
}
exit;
}
if (self::$_challenged == true) {
return;
}
$method = strtoupper($_SERVER['REQUEST_METHOD']);
if ($method == 'HEAD' || $method == 'OPTIONS') {
return;
}
if (isset($_SERVER['HTTP_X_MOZ'])) {
return;
}
$identity = self::identity();
if (empty($identity) || empty($identity['id'])) {
return;
}
if ($identity['type'] == self::BROWSER) {
$store = false;
if (empty($identity['features'])) {
$identity['features'] = array('iframe' => 0, 'javascript' => 0, 'image' => 0);
}
if ($identity['features']['image'] < 1 && $identity['features']['image'] > -5) {
$url = '?bouncer-challenge=1&bouncer-identity=' . $identity['id'] . '&bouncer-feature=image&t=' . time();
$style = 'position:absolute;border:0;width:1px;height:1px;left:0;top:0;background:red;';
echo '<img style="' . $style . '" src="' . $url . '"/>';
$identity['features']['image'] = $identity['features']['image'] - 1;
$store = true;
}
if ($identity['features']['iframe'] < 1 && $identity['features']['iframe'] > -5) {
$url = '?bouncer-challenge=1&bouncer-identity=' . $identity['id'] . '&bouncer-feature=iframe&t=' . time();
$style = 'position:absolute;border:0;width:1px;height:1px;left:2px;top:0;background:transparent;';
echo '<iframe style="' . $style . '" src="' . $url . '"></iframe>';
$identity['features']['iframe'] = $identity['features']['iframe'] - 1;
$store = true;
}
if ($identity['features']['javascript'] < 1 && $identity['features']['javascript'] > -5) {
$url = '?bouncer-challenge=1&bouncer-identity=' . $identity['id'] . '&bouncer-feature=javascript&t=' . time();
$style = 'position:absolute;border:0;width:1px;height:1px;left:1px;top:0;background:lime;';
echo '<script type="text/javascript">';
echo 'document.write(\'<img style="' . $style . '" src="' . $url . '"/>\');';
echo '</script>';
$identity['features']['javascript'] = $identity['features']['javascript'] - 1;
$store = true;
}
if ($store) {
self::setIdentity($identity['id'], $identity);
}
self::$_challenged = true;
}
}
