message_die(GENERAL_ERROR, "YubiCloud authentication not configured. Add \$Config['YubiCloud']['ClientID'] and \$Config['YubiCloud']['SecretKey'] to your config.");
}
if (!$key = $_GET['OTP']) {
message_die(GENERAL_ERROR, "Please add in URL ?OTP=, then put your cursor at right of the = and press your YubiKey button");
}
$yubi = new Auth_Yubico($Config['YubiCloud']['ClientID'], $Config['YubiCloud']['SecretKey']);
if (!$data = $yubi->parsePasswordOTP($key)) {
message_die(GENERAL_ERROR, "This is not an YubiKey OTP.");