Re: [kitten] draft-hansen-scram-sha256 and incorporating session hashing for channel binding
Nico Williams <nico@cryptonector.com> Thu, 28 May 2015 16:40 UTC
Return-Path: <nico@cryptonector.com>
X-Original-To: kitten@ietfa.amsl.com
Delivered-To: kitten@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id AD1291B2C5E for <kitten@ietfa.amsl.com>; Thu, 28 May 2015 09:40:25 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.666
X-Spam-Level:
X-Spam-Status: No, score=-1.666 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, IP_NOT_FRIENDLY=0.334, RCVD_IN_DNSWL_NONE=-0.0001] autolearn=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 4MHuP9deEKg6 for <kitten@ietfa.amsl.com>; Thu, 28 May 2015 09:40:24 -0700 (PDT)
Received: from homiemail-a33.g.dreamhost.com (sub4.mail.dreamhost.com [69.163.253.135]) by ietfa.amsl.com (Postfix) with ESMTP id B9C7E1B2C62 for <kitten@ietf.org>; Thu, 28 May 2015 09:40:05 -0700 (PDT)
Received: from homiemail-a33.g.dreamhost.com (localhost [127.0.0.1]) by homiemail-a33.g.dreamhost.com (Postfix) with ESMTP id 5B73B594084; Thu, 28 May 2015 09:40:05 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=cryptonector.com; h=date :from:to:cc:subject:message-id:references:mime-version :content-type:in-reply-to; s=cryptonector.com; bh=n8IjU7eejr6/aB EPBcIT9Zk784g=; b=cqlTrkp+X9P/li2JSgPp40yLk275/7UvC0ZtrgFDZCeu/A s2znHGD1l5pvvfKYtpGyECjyeYKV5QxRrjvn5tw6ESTur7N/NN9b3OwDp9VXCBPm f+jGSL0OKipr0GKkxRqO1/0gHf+py2PVxayhimKwaGb8gJD+tC2Vjhq7YiUJs=
Received: from localhost (108-207-244-174.lightspeed.austtx.sbcglobal.net [108.207.244.174]) (Authenticated sender: nico@cryptonector.com) by homiemail-a33.g.dreamhost.com (Postfix) with ESMTPA id E202D59407D; Thu, 28 May 2015 09:40:03 -0700 (PDT)
Date: Thu, 28 May 2015 11:40:02 -0500
From: Nico Williams <nico@cryptonector.com>
To: Simon Josefsson <simon@josefsson.org>
Message-ID: <20150528164000.GF1733@localhost>
References: <54DC00D0.2050900@cs.tcd.ie> <54EC66FF.50603@cs.tcd.ie> <54ECABD8.3090902@att.com> <87zj82f1yj.fsf@latte.josefsson.org> <54F4B8B8.8090406@isode.com> <555FC6CF.5020306@att.com> <20150523162728.5b6b63cd@latte.josefsson.org> <5564F27D.70109@att.com> <20150526223206.GE27628@localhost> <20150528171122.2bceebb6@latte.josefsson.org>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Disposition: inline
In-Reply-To: <20150528171122.2bceebb6@latte.josefsson.org>
User-Agent: Mutt/1.5.21 (2010-09-15)
Archived-At: <http://mailarchive.ietf.org/arch/msg/kitten/xBUY0L672eog0ZxAq-GOREGPqHo>
Cc: "kitten@ietf.org" <kitten@ietf.org>
Subject: Re: [kitten] draft-hansen-scram-sha256 and incorporating session hashing for channel binding
X-BeenThere: kitten@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: Common Authentication Technologies - Next Generation <kitten.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/kitten>, <mailto:kitten-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/kitten/>
List-Post: <mailto:kitten@ietf.org>
List-Help: <mailto:kitten-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/kitten>, <mailto:kitten-request@ietf.org?subject=subscribe>
X-List-Received-Date: Thu, 28 May 2015 16:40:25 -0000
On Thu, May 28, 2015 at 05:11:22PM +0200, Simon Josefsson wrote: > > > You then go on to say: "Personally, I would prefer to change to > > > another mandatory channel binding that is secure for all TLS > > > versions." > > > > This is not really appropriate here because it's the applications that > > need to do this, and we can't say anything here about this that will > > force them to. > > > A reference to TLS-SESSION-HASH of the same level (i.e., normative > > or informative) as RFCs 5246 and 5929 would be nice. > > I believe that what is required is > > 1) scram-sha256 has a normative reference to tls-session-hash; or > > 2) tls-session-hash uses an Update: that makes it applicapable to all > TLS versions, and that it is clarified (if not already the case) that > tls-session-hash must be used; or And RFC5929. My vote is for (2). I don't mind (1) in addition, but I want (2). > 3) scram-sha256 uses a new channel binding that is secure with or > without tls-session-hash. We disagree as to (3). This is advice we can give to apps in the security considerations section, not something we can force a SASL or GSS mechanism to do because API-wise the mechanism doesn't get a choice. > I believe 1) and 2) would be worse than 3) for the next ~5 years or > so, and things being equal after that. SASL libraries/applications > rarely have any influence over TLS internals, but they directly > influence the channel binding used. Using another channel binding for > [...] No, they don't. Certainly not GSS ones, and the SASL implementations I'm familiar with don't either. E.g., GSS_Init_sec_context() doesn't get a handle to a channel to bind to, it only gets the channel binding as already extracted by the app. Worse, GSS_Init_sec_context() doesn't even get the channel binding type. (3) is unworkable. Nico --
- [kitten] AD sponsoring draft-hansen-scram-sha256 Stephen Farrell
- Re: [kitten] AD sponsoring draft-hansen-scram-sha… Peter Saint-Andre - &yet
- Re: [kitten] AD sponsoring draft-hansen-scram-sha… Tony Hansen
- Re: [kitten] AD sponsoring draft-hansen-scram-sha… Peter Saint-Andre - &yet
- Re: [kitten] AD sponsoring draft-hansen-scram-sha… Simon Josefsson
- Re: [kitten] [saag] AD sponsoring draft-hansen-sc… Simon Josefsson
- Re: [kitten] [saag] AD sponsoring draft-hansen-sc… Alexey Melnikov
- Re: [kitten] [saag] AD sponsoring draft-hansen-sc… Dave Cridland
- Re: [kitten] AD sponsoring draft-hansen-scram-sha… Simon Josefsson
- Re: [kitten] [saag] AD sponsoring draft-hansen-sc… Martin Thomson
- Re: [kitten] [saag] AD sponsoring draft-hansen-sc… Sam Whited
- Re: [kitten] [saag] AD sponsoring draft-hansen-sc… Stephen Farrell
- Re: [kitten] [saag] AD sponsoring draft-hansen-sc… Tony Hansen
- Re: [kitten] [saag] AD sponsoring draft-hansen-sc… Tony Hansen
- [kitten] draft-hansen-scram-sha256 and the hash i… Tony Hansen
- [kitten] draft-hansen-scram-sha256 and incorporat… Tony Hansen
- Re: [kitten] draft-hansen-scram-sha256 and the ha… Dave Cridland
- Re: [kitten] draft-hansen-scram-sha256 and the ha… Alexey Melnikov
- Re: [kitten] draft-hansen-scram-sha256 and the ha… Tony Hansen
- Re: [kitten] draft-hansen-scram-sha256 and the ha… Simon Josefsson
- Re: [kitten] draft-hansen-scram-sha256 and incorp… Simon Josefsson
- Re: [kitten] draft-hansen-scram-sha256 and incorp… Alexey Melnikov
- Re: [kitten] draft-hansen-scram-sha256 and incorp… Simon Josefsson
- Re: [kitten] draft-hansen-scram-sha256 and incorp… Alexey Melnikov
- Re: [kitten] draft-hansen-scram-sha256 and incorp… Tony Hansen
- Re: [kitten] [saag] AD sponsoring draft-hansen-sc… Karthikeyan Bhargavan
- Re: [kitten] draft-hansen-scram-sha256 and incorp… Simon Josefsson
- Re: [kitten] [saag] AD sponsoring draft-hansen-sc… Simon Josefsson
- Re: [kitten] draft-hansen-scram-sha256 and incorp… Nico Williams
- Re: [kitten] draft-hansen-scram-sha256 and incorp… Nico Williams
- Re: [kitten] draft-hansen-scram-sha256 and incorp… Simon Josefsson
- Re: [kitten] draft-hansen-scram-sha256 and incorp… Simon Josefsson
- Re: [kitten] draft-hansen-scram-sha256 and incorp… Stephen Farrell
- Re: [kitten] draft-hansen-scram-sha256 and incorp… Nico Williams
- Re: [kitten] draft-hansen-scram-sha256 and incorp… Tony Hansen
- Re: [kitten] draft-hansen-scram-sha256 and incorp… Nico Williams
- Re: [kitten] draft-hansen-scram-sha256 and incorp… Simon Josefsson
- Re: [kitten] draft-hansen-scram-sha256 and incorp… Tony Hansen
- Re: [kitten] draft-hansen-scram-sha256 and incorp… Nico Williams
- Re: [kitten] draft-hansen-scram-sha256 and incorp… Simon Josefsson
- Re: [kitten] draft-hansen-scram-sha256 and incorp… Simon Josefsson
- Re: [kitten] draft-hansen-scram-sha256 and incorp… Nico Williams
- Re: [kitten] draft-hansen-scram-sha256 and incorp… Tony Hansen