Re: [TLS] Update on TLS 1.3 Middlebox Issues
Hanno Böck <hanno@hboeck.de> Sat, 07 October 2017 15:35 UTC
Return-Path: <hanno@hboeck.de>
X-Original-To: tls@ietfa.amsl.com
Delivered-To: tls@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id E43D613457D for <tls@ietfa.amsl.com>; Sat, 7 Oct 2017 08:35:52 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.601
X-Spam-Level:
X-Spam-Status: No, score=-2.601 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, RCVD_IN_DNSWL_LOW=-0.7, SPF_PASS=-0.001] autolearn=ham autolearn_force=no
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 ddjPqnLogcPZ for <tls@ietfa.amsl.com>; Sat, 7 Oct 2017 08:35:50 -0700 (PDT)
Received: from zucker2.schokokeks.org (zucker2.schokokeks.org [178.63.68.90]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id A09D213490F for <tls@ietf.org>; Sat, 7 Oct 2017 08:35:50 -0700 (PDT)
Received: from pc1 ([::ffff:82.214.239.4]) (AUTH: LOGIN hanno-default@schokokeks.org, TLS: TLSv1/SSLv3, 256bits, ECDHE-RSA-AES256-GCM-SHA384) by zucker.schokokeks.org with ESMTPSA; Sat, 07 Oct 2017 17:35:47 +0200 id 0000000000000033.0000000059D8F454.00006B01
Date: Sat, 07 Oct 2017 17:35:30 +0200
From: Hanno Böck <hanno@hboeck.de>
To: tls@ietf.org
Message-ID: <20171007173530.34cfc216@pc1>
In-Reply-To: <CABcZeBMoW8B78C5UmLqAim4X=jQ8jVRYTP-L7RVnU3AScdFvFw@mail.gmail.com>
References: <CABcZeBMoW8B78C5UmLqAim4X=jQ8jVRYTP-L7RVnU3AScdFvFw@mail.gmail.com>
X-Mailer: Claws Mail 3.15.1-dirty (GTK+ 2.24.31; x86_64-pc-linux-gnu)
MIME-Version: 1.0
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Archived-At: <https://mailarchive.ietf.org/arch/msg/tls/fcE4dmZ0FGCMU-31VNvgd96v-nA>
Subject: Re: [TLS] Update on TLS 1.3 Middlebox Issues
X-BeenThere: tls@ietf.org
X-Mailman-Version: 2.1.22
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: Sat, 07 Oct 2017 15:35:53 -0000
Hi, On Fri, 6 Oct 2017 13:16:37 -0700 Eric Rescorla <ekr@rtfm.com> wrote: > - Fall back to TLS 1.2 (as we have unfortunately done for previous > releases) Thinking about this I honestly hope nobody is considering this seriously. This would be an unfixable security design flaw. And it also quite significantly differs from previous fallbacks. There were workarounds in the past for version intolerance by using SCSV and early versions of 1.3 used some trick with the server random value. However that was for nonconformant servers that allowed conformant servers and clients to prevent downgrade attacks. Such workarounds won't work if we talk about middleboxes, because what's proposed here is to fallback to TLS 1.2 even if both the server and the client speak TLS 1.3. In other words: It's a proposal to make all security advantages of TLS 1.3 irrelevant, as we have a universal downgrade to 1.2. Given that this would also mean there's no visible incentive to fix things it would very likely mean keeping this broken workaround for many years to come. -- Hanno Böck https://hboeck.de/ mail/jabber: hanno@hboeck.de GPG: FE73757FA60E4E21B937579FA5880072BBB51E42
- [TLS] Update on TLS 1.3 Middlebox Issues Eric Rescorla
- Re: [TLS] Update on TLS 1.3 Middlebox Issues Salz, Rich
- Re: [TLS] Update on TLS 1.3 Middlebox Issues Carl Mehner
- Re: [TLS] Update on TLS 1.3 Middlebox Issues Hanno Böck
- Re: [TLS] Update on TLS 1.3 Middlebox Issues Ilari Liusvaara
- Re: [TLS] Update on TLS 1.3 Middlebox Issues Yoav Nir
- Re: [TLS] Update on TLS 1.3 Middlebox Issues Eric Rescorla
- Re: [TLS] Update on TLS 1.3 Middlebox Issues Nick Sullivan
- Re: [TLS] Update on TLS 1.3 Middlebox Issues Salz, Rich
- Re: [TLS] Update on TLS 1.3 Middlebox Issues Watson Ladd
- Re: [TLS] Update on TLS 1.3 Middlebox Issues Richard Barnes
- Re: [TLS] Update on TLS 1.3 Middlebox Issues Eric Rescorla
- Re: [TLS] Update on TLS 1.3 Middlebox Issues Eric Rescorla
- Re: [TLS] Update on TLS 1.3 Middlebox Issues Salz, Rich
- Re: [TLS] Update on TLS 1.3 Middlebox Issues Jeffrey Walton
- Re: [TLS] Update on TLS 1.3 Middlebox Issues Hanno Böck
- Re: [TLS] Update on TLS 1.3 Middlebox Issues Eric Rescorla
- Re: [TLS] Update on TLS 1.3 Middlebox Issues Ilari Liusvaara
- Re: [TLS] Update on TLS 1.3 Middlebox Issues Salz, Rich
- Re: [TLS] Update on TLS 1.3 Middlebox Issues Adam Langley
- Re: [TLS] Update on TLS 1.3 Middlebox Issues Yoav Nir
- Re: [TLS] Update on TLS 1.3 Middlebox Issues Ilari Liusvaara
- Re: [TLS] Update on TLS 1.3 Middlebox Issues Randy Bush
- Re: [TLS] Update on TLS 1.3 Middlebox Issues Eric Rescorla
- [TLS] draft-rhrd (Was: Re: Update on TLS 1.3 Midd… Stephen Farrell
- Re: [TLS] draft-rhrd (Was: Re: Update on TLS 1.3 … Blumenthal, Uri - 0553 - MITLL
- Re: [TLS] Update on TLS 1.3 Middlebox Issues Randy Bush
- Re: [TLS] Update on TLS 1.3 Middlebox Issues Salz, Rich
- Re: [TLS] Update on TLS 1.3 Middlebox Issues Martin Rex
- Re: [TLS] Update on TLS 1.3 Middlebox Issues Martin Rex
- Re: [TLS] draft-rhrd (Was: Re: Update on TLS 1.3 … Stephen Farrell
- Re: [TLS] Update on TLS 1.3 Middlebox Issues Ilari Liusvaara
- Re: [TLS] Update on TLS 1.3 Middlebox Issues Martin Rex
- Re: [TLS] Update on TLS 1.3 Middlebox Issues Hannes Tschofenig
- Re: [TLS] Update on TLS 1.3 Middlebox Issues Ilari Liusvaara
- Re: [TLS] Update on TLS 1.3 Middlebox Issues Ilari Liusvaara
- Re: [TLS] Update on TLS 1.3 Middlebox Issues Martin Rex
- Re: [TLS] Update on TLS 1.3 Middlebox Issues Hubert Kario
- Re: [TLS] Update on TLS 1.3 Middlebox Issues Loganaden Velvindron
- Re: [TLS] Update on TLS 1.3 Middlebox Issues Matt Caswell