function checkPassword($realPass, $checkPass) {
    //check for old encryption (md5 or whirlpool)
    if (strlen($realPass) == 32 || strlen($realPass) == 128) {
        $hash = (strlen($realPass) == 32 ? md5($checkPass) : hash('whirlpool', $checkPass));
        if ($realPass == $hash) {
            // change password to new encryption?
            return true;
        } else
            return false;
    }

    // xAuth 2 encryption
    $saltPos = (strlen($checkPass) >= strlen($realPass) ? strlen($realPass) : strlen($checkPass));

    // extract salt
    $salt = substr($realPass, $saltPos, 12);

    $hash = hash('whirlpool', $salt . $checkPass);
    return substr($hash, 0, $saltPos) . $salt . substr($hash, $saltPos) == $realPass;
}