From owner-freebsd-security@FreeBSD.ORG Fri Sep 14 16:29:39 2012 Return-Path: Delivered-To: freebsd-security@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 933DE1065677; Fri, 14 Sep 2012 16:29:39 +0000 (UTC) (envelope-from benlaurie@gmail.com) Received: from mail-vb0-f54.google.com (mail-vb0-f54.google.com [209.85.212.54]) by mx1.freebsd.org (Postfix) with ESMTP id D8B358FC14; Fri, 14 Sep 2012 16:29:38 +0000 (UTC) Received: by vbmv11 with SMTP id v11so6485337vbm.13 for ; Fri, 14 Sep 2012 09:29:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type; bh=B7JoMUi+o9yM3oPhmwrozmuEOWO69UQDYKmJSZyn8SQ=; b=SBlcGZAfisuQg+Q8QTBy4ABXsZ/hZp4eaCcY/b+ekuw/RYUoEhfnuwj0S/jTSlZscy 416y5Sgcjnt5xvhJObusrNMaxcQdajAPgUPr5TwitORwmF4KbybtaDojk/LLsDYiDI6c cU21pTQ9AqAHsB+lV7dlQLrm+zGWpsIqPXRz9aHbB6DotHkefYSQDyX4ucMxqFqHBfZh fPCoKsx+oT4GjiK9gMhkhErdpwYnbWnl0uclKePt9FWB+NVb6epdWxWHb62tBwG2sM8s sb9jFYnQUeftMs3ci43HBmkZo7ave7FklxQcGITdn7JUYfARl7CIV6PnU5miqagSxOVc HBAw== MIME-Version: 1.0 Received: by 10.220.157.65 with SMTP id a1mr2739023vcx.39.1347640177955; Fri, 14 Sep 2012 09:29:37 -0700 (PDT) Sender: benlaurie@gmail.com Received: by 10.58.79.243 with HTTP; Fri, 14 Sep 2012 09:29:37 -0700 (PDT) In-Reply-To: References: <50453686.9090100@FreeBSD.org> <20120911082309.GD72584@dragon.NUXI.org> <504F0687.7020309@FreeBSD.org> <201209121628.18088.jhb@freebsd.org> <5050F477.8060409@FreeBSD.org> <20120912213141.GI14077@x96.org> <20120913052431.GA15052@dragon.NUXI.org> Date: Fri, 14 Sep 2012 17:29:37 +0100 X-Google-Sender-Auth: xdHfNVSJB-0s1WZbEfdZxSBwCro Message-ID: From: Ben Laurie To: Mark Murray Content-Type: text/plain; charset=ISO-8859-1 Cc: Arthur Mesh , Ian Lepore , Doug Barton , freebsd-security@freebsd.org, RW , "Bjoern A. Zeeb" Subject: Re: svn commit: r239569 - head/etc/rc.d X-BeenThere: freebsd-security@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Security issues \[members-only posting\]" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 14 Sep 2012 16:29:39 -0000 On Fri, Sep 14, 2012 at 3:59 PM, Mark Murray wrote: >> 5) send all data to the kernel but XORing the data together on >> overflow in the kernel (can control when buffer full and only then >> take action when needed, indepedent on how seed data is chosen, >> withdrawn) > > I've already coded this up :-) (well, similar). This is the "improved > file handling" that I was thinking of. Note that I only do it for writes > to /d/r, and not for all entropy harvesting. It still largely kills the > entropy swamping, and while an attacker can subvert this, the attack > would be obvious. > > I'll send patches (untested) in a couple of hours for discussion. I used to like this idea, but it can break pretty badly if you repeat input, so in the end I decided hashes were the only safe way. > >> 6) send all data to the kernel but XORing the data + counter value >> together on overflow in the kernel (can control when buffer full and >> only then take action when needed, indepedent on how seed data is >> chosen, but why XOR?) > > Variation on above. > >> 7) send all data to the kernel and hash (arch dependent?) it + counter >> value into the buffer on overflow, as in b[n] = H(b[n] + c + i[n]) in >> the kernel (can control when buffer full and only then take action >> when needed, indepedent on how seed data is chosen, uses standard >> technology) > > Variation on above. > > M > -- > Mark R V Murray > Pi: 132511160 > > _______________________________________________ > freebsd-security@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-security > To unsubscribe, send any mail to "freebsd-security-unsubscribe@freebsd.org"