Re: Continuing /dev/random problems with 2.4

Jeff Garzik
2002-02-01T20:36:44Z

On Fri, Feb 01, 2002 at 12:27:14PM -0800, H. Peter Anvin wrote:
> Peter Monta wrote:
>
> >>Anything that is meant to be a server really pretty much needs an
> >>enthropy generator these days.
> >>
> >
> > Many motherboards have on-board sound. Why not turn the mic
> > gain all the way up and use the noise---surely there will be
> > a few bits' worth?
> >
> > Perhaps there ought to be a way to give bits to the kernel's
> > /dev/random input hopper from user space.
> >
>
>
> There already is. If I'm not completely mistaken, just write the raw data
> to /dev/random, then there is an ioctl() saying "add N bits to the
> entrophy counter."

Yep. The i810 RNG userspace daemon, rngd, does this. It reads from
i810 RNG data from /dev/intel_rng, tests the data, and injects it back
into /dev/random with the specified entropy bits. (zero bits by default,
because we default to paranoia mode of not trusting, but that can and is
usually increased)

Jeff