Re: [TLS] Another [Well-deserved] attack on TLS CCA

Anders Rundgren <anders.rundgren@telia.com> Tue, 18 June 2013 18:47 UTC

Return-Path: <anders.rundgren@telia.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 1F04D11E80EE for <tls@ietfa.amsl.com>; Tue, 18 Jun 2013 11:47:18 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -3.599
X-Spam-Level:
X-Spam-Status: No, score=-3.599 tagged_above=-999 required=5 tests=[BAYES_00=-2.599, RCVD_IN_DNSWL_LOW=-1]
Received: from mail.ietf.org ([12.22.58.30]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id X5o054ZngpMQ for <tls@ietfa.amsl.com>; Tue, 18 Jun 2013 11:47:13 -0700 (PDT)
Received: from smtp-out21.han.skanova.net (smtp-out21.han.skanova.net [195.67.226.208]) by ietfa.amsl.com (Postfix) with ESMTP id 2F25111E80F7 for <tls@ietf.org>; Tue, 18 Jun 2013 11:47:13 -0700 (PDT)
Received: from [192.168.0.203] (213.64.1.89) by smtp-out21.han.skanova.net (8.5.133) (authenticated as u36408181) id 51AC7836005DACDD; Tue, 18 Jun 2013 20:46:19 +0200
Message-ID: <51C0AAFB.6010103@telia.com>
Date: Tue, 18 Jun 2013 20:46:19 +0200
From: Anders Rundgren <anders.rundgren@telia.com>
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/20130509 Thunderbird/17.0.6
MIME-Version: 1.0
To: Adam Langley <agl@google.com>
References: <51C0A762.9030909@telia.com> <CAL9PXLyDpHVErFjq80ryUdEgmD0LuwDVFmji_3ZFO4qSg5Pkbw@mail.gmail.com>
In-Reply-To: <CAL9PXLyDpHVErFjq80ryUdEgmD0LuwDVFmji_3ZFO4qSg5Pkbw@mail.gmail.com>
X-Enigmail-Version: 1.5.1
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: 7bit
Cc: "tls@ietf.org" <tls@ietf.org>
Subject: Re: [TLS] Another [Well-deserved] attack on TLS CCA
X-BeenThere: tls@ietf.org
X-Mailman-Version: 2.1.12
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: Tue, 18 Jun 2013 18:47:18 -0000

On 2013-06-18 20:39, Adam Langley wrote:
> On Tue, Jun 18, 2013 at 2:30 PM, Anders Rundgren
> <anders.rundgren@telia.com> wrote:
>> Luckily for all users Google didn't select TLS CCA (Client Certificate
>> Authentication) for their coming U2F system; only a moron would base a
>> future consumer authentication system on a scheme that is only suited
>> for VPN tunnels and invisible authentications like as ChannelID.
> 
> The U2F system originally did use client-side certificates. We changed
> it to ChannelID, but not for the reasons you suggested, but rather as
> explained in https://tools.ietf.org/html/draft-balfanz-tls-channelid-00#section-2

Not exactly; U2F builds on JSON objects and ChannelID is an optional
element in the login protocol.

Cheers
Anders

> 
> 
> Cheers
> 
> AGL
>