IETF Logo Mail Archive

Re: [TLS] Fully encrypted and authenticated headers (was Re: Encrypting record headers: practical for TLS 1.3 after all?)

Martin Thomson <martin.thomson@gmail.com> Wed, 02 December 2015 05:02 UTC

Return-Path: <martin.thomson@gmail.com>
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 8E67F1A1B25 for <tls@ietfa.amsl.com>; Tue, 1 Dec 2015 21:02:36 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2
X-Spam-Level:
X-Spam-Status: No, score=-2 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, FREEMAIL_FROM=0.001, 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 9Ae0fjWGR7Ek for <tls@ietfa.amsl.com>; Tue, 1 Dec 2015 21:02:35 -0800 (PST)
Received: from mail-ig0-x234.google.com (mail-ig0-x234.google.com [IPv6:2607:f8b0:4001:c05::234]) (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 1A20F1A1B23 for <tls@ietf.org>; Tue, 1 Dec 2015 21:02:35 -0800 (PST)
Received: by igcto18 with SMTP id to18so23630058igc.0 for <tls@ietf.org>; Tue, 01 Dec 2015 21:02:34 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=0VRc1Q421jM8j/zlRvO/h7jPHgUFZtFOiAzAGi815a0=; b=OyLwhyIA8WNxKnr2Qh8VyPmqnGvTHtwTg2py+oobV+5UY922z+0RPrvoCrkozGsBmr 5PNmy5rJSq8e58rl3B8Uuhk6mIMG1WIgmPsEdMvkJVXoe0lJTP75dDQdmxfavXAoP6DA ZBorhrFKu07Ec8dFUFLRDPT+7oFBLSO2NtFHw7Lsj0jQlMdr676tF4qt2sNVSD9ZJAwR mraIicV08fTnmW1Gj5cBojdnq7qdTUFNnZU7Fc6BpVGUK1UE3fo4xPcPZT3g3stZc8Kd 32RNmqx5WRn117Ao4Ze28Sg0hFlkoi7iNV62f34WzW9HdqnW4uOD+OMYX+GIjwSL9/Ea aOSw==
MIME-Version: 1.0
X-Received: by 10.50.6.104 with SMTP id z8mr31321698igz.58.1449032554549; Tue, 01 Dec 2015 21:02:34 -0800 (PST)
Received: by 10.36.155.139 with HTTP; Tue, 1 Dec 2015 21:02:34 -0800 (PST)
In-Reply-To: <565DC935.2040607@gmail.com>
References: <56586A2F.1070703@gmail.com> <FB2973EF-F16C-404A-980D-CA0042EC4AEB@gmail.com> <565DBC63.5090908@gmail.com> <565DC935.2040607@gmail.com>
Date: Tue, 01 Dec 2015 21:02:34 -0800
Message-ID: <CABkgnnUoyVPC5QVc=ErzAm6DR8usjBw5scc==o4=-XaBoK5AWQ@mail.gmail.com>
From: Martin Thomson <martin.thomson@gmail.com>
To: Bryan A Ford <brynosaurus@gmail.com>
Content-Type: text/plain; charset="UTF-8"
Archived-At: <http://mailarchive.ietf.org/arch/msg/tls/VKlgDrn2Jtb7lxRiayrmproy-jA>
Cc: "tls@ietf.org" <tls@ietf.org>
Subject: Re: [TLS] Fully encrypted and authenticated headers (was Re: Encrypting record headers: practical for TLS 1.3 after all?)
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: <https://mailarchive.ietf.org/arch/browse/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: Wed, 02 Dec 2015 05:02:36 -0000

On 1 December 2015 at 08:22, Bryan A Ford <brynosaurus@gmail.com> wrote:
> The 2-byte length field in each record's header no longer indicates
> the length of the *current* record but instead indicates the length of
> the *next* record.

Ensuring that you know the length of the *next* record is difficult
and could dramatically degrade latency, or adding extra bogus padding
or extra bogus records.  For instance, I can always send in bursts of
two packets, a one octet packet that promises the remainder of the
burst and one that promises a single octet packet.  At that point, I
get to do what I've always done and you have gained little other than
an increase in packet size of around 19 octets (best case).

v2.14.0 | Report a Bug | By Email