From owner-freebsd-rc@FreeBSD.ORG Mon Sep 10 20:32:16 2012 Return-Path: Delivered-To: freebsd-rc@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id B6508106564A; Mon, 10 Sep 2012 20:32:16 +0000 (UTC) (envelope-from arthurmesh@gmail.com) Received: from mail-pz0-f54.google.com (mail-pz0-f54.google.com [209.85.210.54]) by mx1.freebsd.org (Postfix) with ESMTP id 6C5438FC0C; Mon, 10 Sep 2012 20:32:16 +0000 (UTC) Received: by dadr6 with SMTP id r6so1677733dad.13 for ; Mon, 10 Sep 2012 13:32:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; bh=DCPms6rjcwehmPYSuS4k8VfNJZrUvsmIb0eBI9Thy8w=; b=Qase8B+9s8HHTv7sFd/w9HyR5S8gG/qaKuRMo46qBvb8tfXcbJPGRWVIOw/fpZ6Gqe RnMeqU37nACKnsQcQfn4CLJEJ/4b+6WysaxlN6lrWY3RIqSUEkY/sbOR+hi24yB2Ogo4 GG4oXzhQEqrdTf9OnKlFW+RnZg8ziUsDnJ7pi5UZJzwSfBCjR56n2VwbXVnBXVeUwSkl Th5T/m7irVE3NvF7qjHrXAXjaNXKLEbIRugOEvztsuUHCJ0+7JanwMAJoSrxgy/7zbMU vZZ9j192RIUxGXo8KbT0S01/ULYjU5t/RFx2O88wsoF+AotmNUDtTwjrh1A0DallFCn1 eSRA== Received: by 10.68.189.161 with SMTP id gj1mr7365660pbc.21.1347309135880; Mon, 10 Sep 2012 13:32:15 -0700 (PDT) Received: from x96.org (x96.org. [64.85.165.177]) by mx.google.com with ESMTPS id sr3sm8599352pbc.44.2012.09.10.13.32.13 (version=SSLv3 cipher=OTHER); Mon, 10 Sep 2012 13:32:14 -0700 (PDT) Date: Mon, 10 Sep 2012 13:32:10 -0700 From: Arthur Mesh To: Doug Barton Message-ID: <20120910203210.GB90314@x96.org> References: <20120906174247.GB13179@dragon.NUXI.org> <20120906230157.5307a21f@gumby.homeunix.com> <20120906224703.GD89120@x96.org> <20120907015157.GA29497@server.rulingia.com> <20120910135218.GA68128@dragon.NUXI.org> <504E343A.4020802@FreeBSD.org> <86pq5tu1zr.fsf@ds4.des.no> <504E3DAB.3090000@FreeBSD.org> <86fw6pu0l0.fsf@ds4.des.no> <504E4765.1020909@FreeBSD.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <504E4765.1020909@FreeBSD.org> User-Agent: Mutt/1.5.21 (2010-09-15) Cc: Arthur Mesh , freebsd-rc@freebsd.org, obrien@freebsd.org, freebsd-security@freebsd.org, RW , Dag-Erling Sm?rgrav , Xin Li Subject: Re: svn commit: r239569 - head/etc/rc.d X-BeenThere: freebsd-rc@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Discussion related to /etc/rc.d design and implementation." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 10 Sep 2012 20:32:16 -0000 On Mon, Sep 10, 2012 at 01:02:45PM -0700, Doug Barton wrote: > > I was exaggerating a bit - but my reasoning was that since it hasn't > > blown up in our faces yet, it's probably subtle enough to require a > > large number of samples. > > > If I were Arthur, here is how I would test the "replay attack" assertion: > > 1. Install a virgin system with everything as it was before David's > first commit, and let it run for 24 hours with all the defaults intact. > Ideally, have it do something over the network periodically to make sure > that some kind of entropy is harvested from the network drivers. Run > 'find / -name SASLKASDJKL' to make sure you get some from the disk > drivers too. > 2. Disable the cron job for the /var/db/entropy script, and comment out > the writing of /entropy at shutdown time in /etc/rc.d/random. > 3. Write a script to reboot, and once the system is fully booted do 'dd > if=/dev/random of=saved-random-out.$i count=4096' then reboot again > immediately. Values of i from 1 to 10,000 ought to do it. > 4. sha256 the saved-random-out files and see how many duplicates there are. This test doesn't prove anything useful for the reason des@ outlined. To summarize, I have provided my findings and reasoning multiple times. I've sent a separate report with pointers to problematic code of how entropy is consumed by yarrow to secteam@. You keep asking for empirical proof of my claims. There are two claims that I make: 1) entropy isn't fully consumed by yarrow all the time - for this I have empirical proof. 2) reusing entropy seeds is a bad thing - for this I don't have empirical proof. But I have Bruce Schneier's word. Take it or leave it.