Re: [TLS] no fallbacks please [was: Downgrade protection, fallbacks, and server time]
Eric Rescorla <ekr@rtfm.com> Fri, 03 June 2016 13:40 UTC
Return-Path: <ekr@rtfm.com>
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 924C112D1A4 for <tls@ietfa.amsl.com>; Fri, 3 Jun 2016 06:40:47 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.599
X-Spam-Level:
X-Spam-Status: No, score=-2.599 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_LOW=-0.7] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=rtfm-com.20150623.gappssmtp.com
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 qxtan3UOfAH6 for <tls@ietfa.amsl.com>; Fri, 3 Jun 2016 06:40:45 -0700 (PDT)
Received: from mail-yw0-x231.google.com (mail-yw0-x231.google.com [IPv6:2607:f8b0:4002:c05::231]) (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 D525F12D69A for <tls@ietf.org>; Fri, 3 Jun 2016 06:40:38 -0700 (PDT)
Received: by mail-yw0-x231.google.com with SMTP id x189so80279476ywe.3 for <tls@ietf.org>; Fri, 03 Jun 2016 06:40:38 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rtfm-com.20150623.gappssmtp.com; s=20150623; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=GAzFO+j0eydZ5AAxA1QFx7Qh+AGdqvM4CC7s0vRrRd4=; b=hSBVXIr/pI3Woo9lHuZa6HW6eiNPlx9FFBFFJCx2wF3+lFeSS12eZV0KQhkWi20MtF Vx6dvW/uNZutBHRvNud/4mr0QjnRgNI+3Eymb9vmz1AxLNAwzWiC/NNvVn1WgJ+Buoz2 WfZN6iBCt5V2aJkKneY0f+Log3gb09I8+tzGzKaG9Xls42ynM7uqbBB1D+XvkPJmeVTE iYdYwygiUzxyD2POEB/oNC3ZPpxUTXQ/L3TdSnYmJjU0K8WbUiF45HWsUM9p/lsS7pIL GGq8RXvI6qx2wlFgQjJOPsK+ore6wlyj7uplxmSNze2lCF9oAKwjFOAnbxJLo2hNObic 9JQg==
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:from:date :message-id:subject:to:cc; bh=GAzFO+j0eydZ5AAxA1QFx7Qh+AGdqvM4CC7s0vRrRd4=; b=DcFn2IMCLHCaiKp9RtV2Ikh/t4TzjJstJ38EOer6WT8LzZ3+fhVq9otzizZlhyuuKZ d5YQGabQbhO8uW21cGykkVhjgA9odyXmo1fd4Ixs9oE+Bc2nUdThGLqf9n/8eGFSBtG/ eLG9FsZ3g9Mp+jdQlCe6Cyh2jcWuISaoJ/QsNgTxyYGEeL/wG88E+xB2s3jNozwExHZ8 d6w1UjWyyAPvrxWEhWR7eZkvfIBQ4Euj1OjI70cuLw5yVr6/PXBPgMY53mu7MKY0qXdM WPfbhdILN2E38HqA/cEuGsdO2a/Kl0+Ng2EEWvCCBn8IgmPd6YP6r+SumWqxnwqobRPF VJIA==
X-Gm-Message-State: ALyK8tJ/iT76ISWKg6LyqppLmqEmSt3EW5RBjalRwedK0g8i4uY5brR459RxwijiSgsy1eAHDbpEh/iMXgoaqQ==
X-Received: by 10.129.4.8 with SMTP id 8mr2560138ywe.44.1464961238118; Fri, 03 Jun 2016 06:40:38 -0700 (PDT)
MIME-Version: 1.0
Received: by 10.13.230.76 with HTTP; Fri, 3 Jun 2016 06:39:58 -0700 (PDT)
In-Reply-To: <201606030017.20760.davemgarrett@gmail.com>
References: <CAF8qwaDuGyHOu_4kpWN+c+vJKXyERPJu-2xR+nu=sPzG5vZ+ag@mail.gmail.com> <CAF8qwaASpH3Fapo61TDBuF35++GyMbZa4c-9Uy-JZ8CKywpAFw@mail.gmail.com> <CABkgnnXs5UBPZRzPoyiVs1R7arBcPV7WuEY692SHkj=doW6bwQ@mail.gmail.com> <201606030017.20760.davemgarrett@gmail.com>
From: Eric Rescorla <ekr@rtfm.com>
Date: Fri, 03 Jun 2016 06:39:58 -0700
Message-ID: <CABcZeBN2UPNng_0zMEE=v1tWnYTep=q2QEmD91FZfWF69NCsMQ@mail.gmail.com>
To: Dave Garrett <davemgarrett@gmail.com>
Content-Type: multipart/alternative; boundary="001a113f575c35693405345fdeb0"
Archived-At: <http://mailarchive.ietf.org/arch/msg/tls/WZeEvKSkcUI6kzuy6WaU_hyE9QM>
Cc: "tls@ietf.org" <tls@ietf.org>
Subject: Re: [TLS] no fallbacks please [was: Downgrade protection, fallbacks, and server time]
X-BeenThere: tls@ietf.org
X-Mailman-Version: 2.1.17
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: Fri, 03 Jun 2016 13:40:47 -0000
My opinion on this hasn't really changed since the last time. This seems like it's more complicated and it's not clear to me why it won't lead to exactly the same version intolerance problem in future. -Ekr On Thu, Jun 2, 2016 at 9:17 PM, Dave Garrett <davemgarrett@gmail.com> wrote: > Allrighty then; time to dust off and rebase an old changeset I was > fiddling with last year on this topic: > > https://github.com/davegarrett/tls13-spec/commit/058ff1518508b094b8c9f1bd4096be9393f20076 > (I cleaned up a bit when rebasing, but it probably needs some work; was > just a WIP branch, never a PR) > > This was the result of prior discussions on-list about TLS version > intolerance. The gist of the proposal: > 1) Freeze all the various version number fields. > 2) Send a list of all supported versions in an extension. (version IDs > converted to 16-bit ints instead of 8-bit pairs) > 3) Use short (1 or 2 value, based on hello version) predefined lists for > hellos from old clients not sending the extension. > 4) Compare lists to find highest overlap, avoiding guesswork or problems > with noncontinuous lists. > 5) Forget the old mess of version intolerance existed. > > Do we want to consider scrapping the old version negotiation method again? > > > Dave >
- Re: [TLS] Downgrade protection, fallbacks, and se… David Benjamin
- Re: [TLS] Downgrade protection, fallbacks, and se… Martin Rex
- [TLS] Downgrade protection, fallbacks, and server… David Benjamin
- Re: [TLS] Downgrade protection, fallbacks, and se… Eric Rescorla
- Re: [TLS] Downgrade protection, fallbacks, and se… David Benjamin
- Re: [TLS] Downgrade protection, fallbacks, and se… Eric Rescorla
- Re: [TLS] Downgrade protection, fallbacks, and se… Martin Thomson
- [TLS] no fallbacks please [was: Downgrade protect… Nikos Mavrogiannopoulos
- Re: [TLS] no fallbacks please [was: Downgrade pro… Yoav Nir
- Re: [TLS] Downgrade protection, fallbacks, and se… Hubert Kario
- Re: [TLS] no fallbacks please [was: Downgrade pro… Hubert Kario
- Re: [TLS] Downgrade protection, fallbacks, and se… David Benjamin
- Re: [TLS] Downgrade protection, fallbacks, and se… Viktor Dukhovni
- Re: [TLS] no fallbacks please [was: Downgrade pro… David Benjamin
- Re: [TLS] Downgrade protection, fallbacks, and se… David Benjamin
- Re: [TLS] Downgrade protection, fallbacks, and se… Hubert Kario
- Re: [TLS] no fallbacks please [was: Downgrade pro… David Benjamin
- Re: [TLS] Downgrade protection, fallbacks, and se… David Benjamin
- Re: [TLS] no fallbacks please [was: Downgrade pro… Hubert Kario
- Re: [TLS] no fallbacks please [was: Downgrade pro… Hubert Kario
- Re: [TLS] Downgrade protection, fallbacks, and se… Viktor Dukhovni
- Re: [TLS] no fallbacks please [was: Downgrade pro… Martin Thomson
- Re: [TLS] no fallbacks please [was: Downgrade pro… Dave Garrett
- Re: [TLS] no fallbacks please [was: Downgrade pro… Nikos Mavrogiannopoulos
- Re: [TLS] no fallbacks please [was: Downgrade pro… Ilari Liusvaara
- Re: [TLS] no fallbacks please [was: Downgrade pro… Hubert Kario
- Re: [TLS] no fallbacks please [was: Downgrade pro… Xiaoyin Liu
- Re: [TLS] no fallbacks please [was: Downgrade pro… Hubert Kario
- Re: [TLS] no fallbacks please [was: Downgrade pro… Eric Rescorla
- Re: [TLS] no fallbacks please [was: Downgrade pro… Andrei Popov
- Re: [TLS] no fallbacks please [was: Downgrade pro… Eric Rescorla
- Re: [TLS] no fallbacks please [was: Downgrade pro… Viktor Dukhovni
- Re: [TLS] no fallbacks please [was: Downgrade pro… David Benjamin
- Re: [TLS] no fallbacks please [was: Downgrade pro… Dave Garrett
- Re: [TLS] no fallbacks please [was: Downgrade pro… Bill Frantz
- Re: [TLS] Downgrade protection, fallbacks, and se… Yaron Sheffer
- Re: [TLS] Downgrade protection, fallbacks, and se… Stefan Winter
- Re: [TLS] no fallbacks please [was: Downgrade pro… Hubert Kario
- Re: [TLS] [FORGED] Re: no fallbacks please [was: … Peter Gutmann
- Re: [TLS] [FORGED] Re: no fallbacks please [was: … Peter Gutmann
- Re: [TLS] no fallbacks please [was: Downgrade pro… Dave Garrett
- Re: [TLS] no fallbacks please [was: Downgrade pro… Jeffrey Walton
- Re: [TLS] [FORGED] Re: no fallbacks please [was: … Peter Gutmann
- Re: [TLS] [FORGED] Re: no fallbacks please [was: … Kyle Rose
- Re: [TLS] [FORGED] Re: no fallbacks please [was: … Hubert Kario
- Re: [TLS] [FORGED] Re: no fallbacks please [was: … Yoav Nir
- Re: [TLS] [FORGED] Re: no fallbacks please [was: … Salz, Rich
- Re: [TLS] [FORGED] Re: no fallbacks please [was: … Yoav Nir
- Re: [TLS] [FORGED] Re: no fallbacks please [was: … Hubert Kario
- Re: [TLS] [FORGED] Re: no fallbacks please [was: … Yoav Nir
- Re: [TLS] [FORGED] Re: no fallbacks please [was: … David Benjamin
- Re: [TLS] [FORGED] Re: no fallbacks please [was: … Andrei Popov
- Re: [TLS] [FORGED] Re: no fallbacks please [was: … Yuhong Bao
- Re: [TLS] [FORGED] Re: no fallbacks please [was: … Dave Garrett
- Re: [TLS] [FORGED] Re: no fallbacks please [was: … Hubert Kario
- Re: [TLS] [FORGED] Re: no fallbacks please [was: … Hubert Kario
- Re: [TLS] [FORGED] Re: no fallbacks please [was: … Nikos Mavrogiannopoulos
- Re: [TLS] no fallbacks please [was: Downgrade pro… Tony Arcieri