byte[] p24 = new byte[24];
        System.arraycopy(passwordHash, 0, p21, 0, 16);
        NtlmUtil.E(p21, challenge, p24);
        return p24;
    }


    /**
     * Generate the ANSI DES hash for the password associated with these credentials.
     * 
     * @param tc
     * @param password
     * @param challenge
     * @return the calculated response
     * @throws GeneralSecurityException