*/
    @Override
    public final boolean isError () {
        return this.error;
    }


    /**
     * @return whether the packet has been signed.
     */
    public boolean isSigned () {
        return ( getFlags() & SMB2_FLAGS_SIGNED ) != 0;
    }


    /**
     * {@inheritDoc}
     *
     * @see jcifs.util.transport.Response#getExpiration()
     */
    @Override

        int index = offset + SIGNATURE_OFFSET;
        for ( int i = 0; i < SIGNATURE_LENGTH; i++ )
            data[ index + i ] = 0;

        // set signed flag
        int oldFlags = SMBUtil.readInt4(data, offset + 16);
        int flags = oldFlags | ServerMessageBlock2.SMB2_FLAGS_SIGNED;
        SMBUtil.writeInt4(flags, data, offset + 16);

        this.digest.update(data, offset, length);