public void ReadFully(byte[] b, int off, int len)
    {
        if(len < 0)
        {
            throw new IndexOutOfRangeException();
        }

        int n = 0;
        while(n < len)
        {
            int count = ClientInput.Read(b, off + n, len - n);
            if(count < 0)
            {
                throw new EndOfStreamException();
            }
            n += count;
        }
    }