}
        engineReset();
    }

    private HMACT64(final HMACT64 hmac) throws CloneNotSupportedException {
        super("HMACT64");
        this.ipad = hmac.ipad;
        this.opad = hmac.opad;
        this.md5 = (MessageDigest) hmac.md5.clone();
    }

    @Override
    public Object clone() {
        try {
            return new HMACT64(this);
        } catch (final CloneNotSupportedException ex) {

        engineReset();
    }

    private HMACT64(final HMACT64 hmac) throws CloneNotSupportedException {
        super("HMACT64");
        this.ipad = hmac.ipad;
        this.opad = hmac.opad;
        this.md5 = (MessageDigest) hmac.md5.clone();
    }

    @Override
    public Object clone() {
        try {
            return new HMACT64(this);
        } catch (final CloneNotSupportedException ex) {

            throw new CIFSUnsupportedCryptoException(e);
        }
    }

    /**
     * Get an HMACT64 message authentication code instance.
     * @param key the key for the HMACT64 MAC
     * @return HMACT64 MAC instance
     */
    public static MessageDigest getHMACT64(final byte[] key) {
        return new HMACT64(key);
    }

    /**
     * Get an RC4 cipher instance initialized with the specified key.