Re: [TLS] Consensus for AEAD IV

Joseph Salowey <joe@salowey.net> Fri, 24 April 2015 20:44 UTC

Return-Path: <joe@salowey.net>
X-Original-To: tls@ietfa.amsl.com
Delivered-To: tls@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 7DE231A895D for <tls@ietfa.amsl.com>; Fri, 24 Apr 2015 13:44:56 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.978
X-Spam-Level:
X-Spam-Status: No, score=-1.978 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, FM_FORGED_GMAIL=0.622, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_LOW=-0.7, SPF_PASS=-0.001] autolearn=ham
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id puC8HNjiBBcr for <tls@ietfa.amsl.com>; Fri, 24 Apr 2015 13:44:55 -0700 (PDT)
Received: from mail-qc0-f181.google.com (mail-qc0-f181.google.com [209.85.216.181]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 19F821A876A for <tls@ietf.org>; Fri, 24 Apr 2015 13:44:55 -0700 (PDT)
Received: by qcrf4 with SMTP id f4so32254921qcr.0 for <tls@ietf.org>; Fri, 24 Apr 2015 13:44:54 -0700 (PDT)
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:date :message-id:subject:from:to:cc:content-type; bh=SrR48xNEbeGbr/R/rAOrml8laqiBpOe7gx32C2wVo+w=; b=cj+f/WY859/WNmyBHHNs5PTEusCle9E5p5xQlTl272Ag4UVfn1yb03OPETjygTJVxk mW3oNujItJii9qBuNVATzvbS2saR2NCuwUtyA0yTvTeIFqhoLKlXzFOL+rUUZttoveKz oNfp5beiV3fJAXOWWW70EEw21N6cim9W34s7oaCq+qJFmd8fXk+CEyXTYrRhUy5NgzVu z1WSEoYhU6M0Vincgr9czQnDUHpLLkKHkDUl6N4CGSsGsuBYfwYgHes8p+8V29l1oP0k HrXIkMrQfy/29/TTwogg4OHOFYzCCPtney+0wePJ5Y5gKKpdtQ7H/Umcb4P5DTkye35z Ov4g==
X-Gm-Message-State: ALoCoQmtCcjFxJTghWLgJclQcL7taHfTaE107bulKspjWG0Zrzz7krRMdHAAdz3Jnvr857EU0NRC
MIME-Version: 1.0
X-Received: by 10.140.151.131 with SMTP id 125mr294491qhx.41.1429908294391; Fri, 24 Apr 2015 13:44:54 -0700 (PDT)
Received: by 10.96.121.104 with HTTP; Fri, 24 Apr 2015 13:44:54 -0700 (PDT)
X-Originating-IP: [67.168.161.122]
In-Reply-To: <CABkgnnU50pvH+LFsN3BL9LfvYhZOxmJV1JYzODeC=-JpZSh8Lw@mail.gmail.com>
References: <CAOgPGoC14uhjrZAQvDHFQrJoyoVNELpNNd4+Hh==zwf9ipyY5g@mail.gmail.com> <CABkgnnU50pvH+LFsN3BL9LfvYhZOxmJV1JYzODeC=-JpZSh8Lw@mail.gmail.com>
Date: Fri, 24 Apr 2015 13:44:54 -0700
Message-ID: <CAOgPGoDNuhmnNpZ7ELCfBHS4rKuj+3j1+YiuxLkST+z1J+tOKQ@mail.gmail.com>
From: Joseph Salowey <joe@salowey.net>
To: Martin Thomson <martin.thomson@gmail.com>
Content-Type: multipart/alternative; boundary="001a113769a8f2ef7d05147e7732"
Archived-At: <http://mailarchive.ietf.org/arch/msg/tls/vhXIT5jem61_41W9Ec9UBZSxgOc>
Cc: "tls@ietf.org" <tls@ietf.org>
Subject: Re: [TLS] Consensus for AEAD IV
X-BeenThere: tls@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: "This is the mailing list for the Transport Layer Security working group of the IETF." <tls.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/tls>, <mailto:tls-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/tls/>
List-Post: <mailto:tls@ietf.org>
List-Help: <mailto:tls-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/tls>, <mailto:tls-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 24 Apr 2015 20:44:56 -0000

On Fri, Apr 24, 2015 at 1:00 PM, Martin Thomson <martin.thomson@gmail.com>
wrote:

> On 24 April 2015 at 10:10, Joseph Salowey <joe@salowey.net> wrote:
> > The general consensus on the list seems to prefer to derive "IV" and use
> it
> > to make the AEAD nonce less predictable. Most folks seemed to be OK with
> > this approach.    In Dallas, there was significant support for using the
> > derived "IV" as a per session XOR mask for the counter.  If you have
> > objections to this approach please respond on the list by May 1, 2015 .
>
>
> You aren't being particularly precise about the process here.
>
> I believe that these were the two options that were most debated:
>
> a)  nonce = zeroes(N_MIN) XOR counter
> b)  nonce = HKDF(...., N_MIN) XOR counter
>
> Did you mean the latter option?
>

[Joe] Yes, the later where the quantity XORed with the counter is derived
during the handshake.