}

        int ver = SMBUtil.readInt4(mic, 0);
        if ( ver != 1 ) {
            throw new SmbUnsupportedOperationException("Invalid signature version");
        }

        MessageDigest mac = Crypto.getHMACT64(sk);
        int seq = SMBUtil.readInt4(mic, 12);
        mac.update(mic, 12, 4); // sequence
        byte[] dgst = mac.digest(data); // data

    /**
     * @param data
     * @return MIC
     * @throws CIFSException
     */
    byte[] calculateMIC ( byte[] data ) throws CIFSException;


    /**
     * @param data
     * @param mic
     * @throws CIFSException
     */
    void verifyMIC ( byte[] data, byte[] mic ) throws CIFSException;


    /**
     * @return whether MIC can be used
     */
    boolean isMICAvailable ();

            log.debug("Out Mech list MIC " + Hexdump.toHexString(mechanismListMIC));
        }
        return mechanismListMIC;
    }


    private void verifyMechListMIC ( byte[] mechanismListMIC ) throws CIFSException {
        if ( this.disableMic ) {
            return;
        }

        // No MIC verification if not present and not required

    @Override
    public String toString () {
        String mic = null;
        if ( this.getMechanismListMIC() != null ) {
            mic = Hexdump.toHexString(this.getMechanismListMIC(), 0, this.getMechanismListMIC().length);
        }
        return String.format("NegTokenInit[flags=%d,mechs=%s,mic=%s]", this.getContextFlags(), Arrays.toString(this.getMechanisms()), mic);
    }


    @Override

     */
    public byte[] getMic () {
        return this.mic;
    }


    /**
     * @param mic
     *            NTLM mic to set (16 bytes)
     */
    public void setMic ( byte[] mic ) {
        this.mic = mic;
    }


    /**
     * @return whether a MIC should be calulated
     */
    public boolean isMICRequired () {
        return this.micRequired;

            throw new CIFSException("Failed to calculate MIC", e);
        }
    }


    /**
     * {@inheritDoc}
     *
     * @see jcifs.smb.SSPContext#verifyMIC(byte[], byte[])
     */
    @Override
    public void verifyMIC ( byte[] data, byte[] mic ) throws CIFSException {
        try {
            this.gssContext.verifyMIC(mic, 0, mic.length, data, 0, data.length, new MessageProp(false));
        }

                        // a relatively large range of samba versions has a bug causing
                        // an invalid parameter error when a SPNEGO MIC is in place and auth fails
                        throw new SmbAuthException("Login failed", e);
                    }