}

        if ( oldHash != null ) {
            dgst.update(oldHash);
        }
        dgst.update(input, off, len);
        return dgst.digest();
    }


    Cipher createEncryptionCipher ( byte[] key ) throws CIFSException {
        if ( !this.smb2 || this.negotiated == null ) {
            throw new SmbUnsupportedOperationException();
        }