Re: [TLS] Commentary on the client authentication presentation slides

mrex@sap.com (Martin Rex) Wed, 19 August 2015 15:56 UTC

Return-Path: <mrex@sap.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 645631B2AA0 for <tls@ietfa.amsl.com>; Wed, 19 Aug 2015 08:56:58 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -3.851
X-Spam-Level:
X-Spam-Status: No, score=-3.851 tagged_above=-999 required=5 tests=[BAYES_50=0.8, HELO_EQ_DE=0.35, RCVD_IN_DNSWL_HI=-5, 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 wvMLPVPC4Wl0 for <tls@ietfa.amsl.com>; Wed, 19 Aug 2015 08:56:56 -0700 (PDT)
Received: from smtpde01.smtp.sap-ag.de (smtpde01.smtp.sap-ag.de [155.56.68.170]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 67D021B2A8D for <tls@ietf.org>; Wed, 19 Aug 2015 08:56:56 -0700 (PDT)
Received: from mail05.wdf.sap.corp (mail05.sap.corp [194.39.131.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtpde01.smtp.sap-ag.de (Postfix) with ESMTPS id 272F32AA00; Wed, 19 Aug 2015 17:56:54 +0200 (CEST)
X-purgate-ID: 152705::1439999814-00000CCB-9C7BB5DA/0/0
X-purgate-size: 739
X-purgate: clean
X-purgate: This mail is considered clean (visit http://www.eleven.de for further information)
X-purgate-Ad: Categorized by eleven eXpurgate (R) http://www.eleven.de
X-purgate-type: clean
X-SAP-SPAM-Status: clean
Received: from ld9781.wdf.sap.corp (ld9781.wdf.sap.corp [10.21.82.193]) by mail05.wdf.sap.corp (Postfix) with ESMTP id 18B2240422; Wed, 19 Aug 2015 17:56:54 +0200 (CEST)
Received: by ld9781.wdf.sap.corp (Postfix, from userid 10159) id 0ECBA1A247; Wed, 19 Aug 2015 17:56:54 +0200 (CEST)
In-Reply-To: <BLUPR03MB1396C25B04D58DB47C9676AE8C700@BLUPR03MB1396.namprd03.prod.outlook.com>
To: Andrei Popov <Andrei.Popov@microsoft.com>
Date: Wed, 19 Aug 2015 17:56:54 +0200 (CEST)
X-Mailer: ELM [version 2.4ME+ PL125 (25)]
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Content-Type: text/plain; charset="US-ASCII"
Message-Id: <20150819155654.0ECBA1A247@ld9781.wdf.sap.corp>
From: mrex@sap.com (Martin Rex)
Archived-At: <http://mailarchive.ietf.org/arch/msg/tls/4dF9sFC2PsXmW9GWYFQMPuG_jmw>
Cc: "tls@ietf.org" <tls@ietf.org>
Subject: Re: [TLS] Commentary on the client authentication presentation slides
X-BeenThere: tls@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
Reply-To: mrex@sap.com
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, 19 Aug 2015 15:56:58 -0000

Andrei Popov wrote:
> Hi Ilari,
> 
>>
>> What sort of usecase you have in mind for this?
>
> This is to support a fairly common website design where the landing
> page does not require client auth, but subsequent request to a
> protected resource triggers client authentication within an existing
> TLS connection.
>
> In TLS<=1.2, this was accomplished via renegotiation. In TLS1.3,
> there is no renegotiation, so we need an alternative solution if we
> want to support these existing sites over TLS1.3.

While this might have been the structure of a few legacy sites,
this will meet the axe longe before TLSv1.3 is done, because
HTTP/2 prohibits renegotiation with TLSv1.2 as well.

R.I.P. renegotiation.

-Martin