using /dev/random

[RW]

On Tue, 23 Sep 2008 11:52:07 -0400
Lowell Gilbert <freebsd-questions-local at be-well.ilk.org> wrote:

> Robert Huff <roberthuff at rcn.com> writes:
> 
> > 	What is the canonical way to get data from /dev/random?
> > Specifically: having opened the file, how do I read the stream?
> > I'm currently using
> >
> >
> >   union {
> >     float f;
> >     char c[4];
> >   } foo;
> >
> >   foo.f = 0.0;
> >
> >   fscanf(rand_fp,"%4c",foo.c);
> >
> >
> > 	which doesn't seem to produce anywhere near "random bytes"
> > as promised by the man page.
> 
> Have you turned off the "seeded" variable?  You'll fall back to a
> software pseudorandom sequence if you don't.

kern.random.sys.seeded is just a flag that gets set to 1 on each
reseed. IIRC it's also initialized to 1 so it doesn't actually do
anything very useful.