}

    @Override
    public boolean isMICAvailable() {
        return !this.auth.isGuest() && this.signKey != null && this.verifyKey != null;
    }

    @Override
    public byte[] calculateMIC(final byte[] data) throws CIFSException {
        final byte[] sk = this.signKey;
        if (sk == null) {
            throw new CIFSException("Signing is not initialized");
        }