From owner-freebsd-questions@FreeBSD.ORG  Tue Sep 23 21:41:01 2008
Return-Path: <owner-freebsd-questions@FreeBSD.ORG>
Delivered-To: freebsd-questions@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id 53D221065673
	for <freebsd-questions@freebsd.org>;
	Tue, 23 Sep 2008 21:41:01 +0000 (UTC)
	(envelope-from fbsd06+2B=235abae4@mlists.homeunix.com)
Received: from mxout-03.mxes.net (mxout-03.mxes.net [216.86.168.178])
	by mx1.freebsd.org (Postfix) with ESMTP id 2C8018FC12
	for <freebsd-questions@freebsd.org>;
	Tue, 23 Sep 2008 21:41:01 +0000 (UTC)
	(envelope-from fbsd06+2B=235abae4@mlists.homeunix.com)
Received: from gumby.homeunix.com. (unknown [87.81.140.128])
	(using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits))
	(No client certificate requested)
	by smtp.mxes.net (Postfix) with ESMTP id 1868623E405
	for <freebsd-questions@freebsd.org>;
	Tue, 23 Sep 2008 17:40:59 -0400 (EDT)
Date: Tue, 23 Sep 2008 22:40:57 +0100
From: RW <fbsd06@mlists.homeunix.com>
To: freebsd-questions@freebsd.org
Message-ID: <20080923224057.46955938@gumby.homeunix.com.>
References: <18648.30321.369520.631459@jerusalem.litteratus.org>
X-Mailer: Claws Mail 3.5.0 (GTK+ 2.12.11; i386-portbld-freebsd7.0)
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Subject: Re: using /dev/random
X-BeenThere: freebsd-questions@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: User questions <freebsd-questions.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-questions>, 
	<mailto:freebsd-questions-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-questions>
List-Post: <mailto:freebsd-questions@freebsd.org>
List-Help: <mailto:freebsd-questions-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-questions>, 
	<mailto:freebsd-questions-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Tue, 23 Sep 2008 21:41:01 -0000

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

> Robert Huff <roberthuff@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.