this.digest = Crypto.getMD5();
        this.macSigningKey = macSigningKey;
    }


    /**
     * Construct a digest with a non-zero starting sequence number
     * 
     * @param macSigningKey
     * @param initialSequence
     */
    public SMB1SigningDigest ( byte[] macSigningKey, int initialSequence ) {
        this.digest = Crypto.getMD5();
        this.macSigningKey = macSigningKey;

            log.debug("Server seal key is " + Hexdump.toHexString(this.sealServerKey));
        }
    }


    private static byte[] deriveKey ( byte[] masterKey, String cnst ) {
        MessageDigest md5 = Crypto.getMD5();
        md5.update(masterKey);
        md5.update(cnst.getBytes(StandardCharsets.US_ASCII));
        md5.update((byte) 0);
        return md5.digest();
    }


    @Override