* @throws CIFSException
     */
    public abstract byte[] getSessionKey () throws CIFSException;


    @Override
    public String toString () {
        return this.binding.toString();
    }


    protected abstract void doSendFragment ( byte[] buf, int off, int length ) throws IOException;

    public Principal getPrincipal() {
        if (this instanceof DcerpcPipeHandle)
            return ((DcerpcPipeHandle)this).pipe.getPrincipal();
        return null;
    }
    public String toString() {
        return binding.toString();
    }

    protected abstract void doSendFragment(byte[] buf,
                int off,
                int length,
                boolean isDirect) throws IOException;