From owner-freebsd-current@FreeBSD.ORG  Tue Nov 15 05:49:31 2011
Return-Path: <owner-freebsd-current@FreeBSD.ORG>
Delivered-To: current@FreeBSD.ORG
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id 35CE81065774;
	Tue, 15 Nov 2011 05:49:30 +0000 (UTC) (envelope-from das@FreeBSD.ORG)
Received: from zim.MIT.EDU (ZIM.MIT.EDU [18.95.3.101])
	by mx1.freebsd.org (Postfix) with ESMTP id ADDED8FC13;
	Tue, 15 Nov 2011 05:49:30 +0000 (UTC)
Received: from zim.MIT.EDU (localhost [127.0.0.1])
	by zim.MIT.EDU (8.14.5/8.14.2) with ESMTP id pAF5nU8P096037;
	Tue, 15 Nov 2011 00:49:30 -0500 (EST) (envelope-from das@FreeBSD.ORG)
Received: (from das@localhost)
	by zim.MIT.EDU (8.14.5/8.14.2/Submit) id pAF5nT6C096036;
	Tue, 15 Nov 2011 00:49:29 -0500 (EST) (envelope-from das@FreeBSD.ORG)
Date: Tue, 15 Nov 2011 00:49:29 -0500
From: David Schultz <das@FreeBSD.ORG>
To: Andrey Chernov <ache@FreeBSD.ORG>, Oliver Pinter <oliver.pntr@gmail.com>, 
	current@FreeBSD.ORG, secteam@FreeBSD.ORG
Message-ID: <20111115054929.GA27803@zim.MIT.EDU>
Mail-Followup-To: Andrey Chernov <ache@freebsd.org>,
	Oliver Pinter <oliver.pntr@gmail.com>, current@FreeBSD.ORG,
	secteam@FreeBSD.ORG
References: <20111112154135.GA21512@zim.MIT.EDU>
	<20111112171531.GA83419@vniz.net>
	<20111114013004.GA53392@zim.MIT.EDU>
	<20111114192721.GA16834@vniz.net>
	<20111114205855.GB58790@zim.MIT.EDU>
	<20111114212926.GA28783@vniz.net>
	<20111114230855.GA59545@zim.MIT.EDU>
	<20111115004443.GA50429@vniz.net>
	<CAPjTQNFSbkiaDUzMh_WYffM9vF1-H3j-FA2FZJfHR-0uJyJ3eQ@mail.gmail.com>
	<20111115023912.GA68523@vniz.net>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20111115023912.GA68523@vniz.net>
Cc: 
Subject: Re: Is fork() hook ever possible?
X-BeenThere: freebsd-current@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Discussions about the use of FreeBSD-current
	<freebsd-current.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>, 
	<mailto:freebsd-current-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-current>
List-Post: <mailto:freebsd-current@freebsd.org>
List-Help: <mailto:freebsd-current-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>,
	<mailto:freebsd-current-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Tue, 15 Nov 2011 05:49:31 -0000

On Tue, Nov 15, 2011, Andrey Chernov wrote:
> In case you mean passing later whole structure like:
> 
> arc4_addrandom((u_char *)&rdat, sizeof(rdat));
> 
> it will be incorrect because it change known algorithm parameters, which 
> defines exact 128 bytes and not anything else.

No, RC4 keys are anything up to 256 bytes.

I think what you really want is a union in any case, but relax.
arc4_stir() works right now, so I think it can stay as is until
we're ready to make further functional changes, e.g., getting
entropy from the KERN_ARND sysctl.  But that's complicated by
the fact that KERN_ARND won't tell you if it has failed to produce
any useful entropy, and I won't have the cycles to look into it for
a little while.