// Calculate hash
        Method calcMethod = findMethod(transport.getClass(), "calculatePreauthHash", byte[].class, int.class, int.class, byte[].class);
        calcMethod.setAccessible(true);

        byte[] input = "test data".getBytes();
        byte[] oldHash = new byte[64];

        byte[] newHash = (byte[]) calcMethod.invoke(transport, input, 0, input.length, oldHash);