private void doNextBytes(
byte[] bytes,
int start,
int len)
{
lock (this)
{
int done = 0;
while (done < len)
{
if (windowCount < 1)
{
generator.NextBytes(window, 0, window.Length);
windowCount = window.Length;
}
bytes[start + done++] = window[--windowCount];
}
}
}