Re: [apps-discuss] [saag] [websec] [kitten] HTTP authentication: the next generation

Marsh Ray <marsh@extendedsubset.com> Fri, 14 January 2011 17:24 UTC

Return-Path: <marsh@extendedsubset.com>
X-Original-To: apps-discuss@core3.amsl.com
Delivered-To: apps-discuss@core3.amsl.com
Received: from localhost (localhost [127.0.0.1]) by core3.amsl.com (Postfix) with ESMTP id 27C0C3A6BA3; Fri, 14 Jan 2011 09:24:36 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.572
X-Spam-Level:
X-Spam-Status: No, score=-2.572 tagged_above=-999 required=5 tests=[AWL=0.027, BAYES_00=-2.599]
Received: from mail.ietf.org ([64.170.98.32]) by localhost (core3.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id zqPHCjGSpFEG; Fri, 14 Jan 2011 09:24:35 -0800 (PST)
Received: from mho-01-ewr.mailhop.org (mho-01-ewr.mailhop.org [204.13.248.71]) by core3.amsl.com (Postfix) with ESMTP id A0FAF3A6BB4; Fri, 14 Jan 2011 09:24:31 -0800 (PST)
Received: from xs01.extendedsubset.com ([69.164.193.58]) by mho-01-ewr.mailhop.org with esmtpa (Exim 4.72) (envelope-from <marsh@extendedsubset.com>) id 1PdnQM-000EKn-PO; Fri, 14 Jan 2011 17:26:54 +0000
Received: from [192.168.1.15] (localhost [127.0.0.1]) by xs01.extendedsubset.com (Postfix) with ESMTP id 0015C603E; Fri, 14 Jan 2011 17:26:50 +0000 (UTC)
X-Mail-Handler: MailHop Outbound by DynDNS
X-Originating-IP: 69.164.193.58
X-Report-Abuse-To: abuse@dyndns.com (see http://www.dyndns.com/services/mailhop/outbound_abuse.html for abuse reporting information)
X-MHO-User: U2FsdGVkX19CXS3o05S/+ZXWLvW9ImCQ+6e1DVdiVUQ=
Message-ID: <4D30875B.5050109@extendedsubset.com>
Date: Fri, 14 Jan 2011 11:26:51 -0600
From: Marsh Ray <marsh@extendedsubset.com>
User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2.13) Gecko/20101208 Thunderbird/3.1.7
MIME-Version: 1.0
To: Peter Gutmann <pgut001@cs.auckland.ac.nz>
References: <E1PdgdW-0005qZ-Me@login01.fos.auckland.ac.nz>
In-Reply-To: <E1PdgdW-0005qZ-Me@login01.fos.auckland.ac.nz>
Content-Type: text/plain; charset="ISO-8859-1"; format="flowed"
Content-Transfer-Encoding: 7bit
X-Mailman-Approved-At: Fri, 14 Jan 2011 10:23:12 -0800
Cc: apps-discuss@ietf.org, benl@google.com, dwm@xpasc.com, websec@ietf.org, kitten@ietf.org, zedshaw@zedshaw.com, http-auth@ietf.org, ietf-http-wg@w3.org, hallam@gmail.com, saag@ietf.org
Subject: Re: [apps-discuss] [saag] [websec] [kitten] HTTP authentication: the next generation
X-BeenThere: apps-discuss@ietf.org
X-Mailman-Version: 2.1.9
Precedence: list
List-Id: General discussion of application-layer protocols <apps-discuss.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/listinfo/apps-discuss>, <mailto:apps-discuss-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/apps-discuss>
List-Post: <mailto:apps-discuss@ietf.org>
List-Help: <mailto:apps-discuss-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/apps-discuss>, <mailto:apps-discuss-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 14 Jan 2011 17:24:36 -0000

On 01/14/2011 04:12 AM, Peter Gutmann wrote:
>
> Who says there's a password involved?  It's equally appropriate for public-
> key/certificate-based auth, "sign this challenge" for example.  I think "when
> the user can be relied upon to not authenticate to the wrong site" covers most
> of the bases and is technology- and mechanism-neutral.

What is being authenticated? How much of the surrounding context is 
being assumed or implied, and how much is actually being authenticated?

Who is doing the authentication?

What capabilities will the result be used to authorize?

These are real questions that go to the heart of the problem. I don't 
believe that they have been reconsidered in the context of today's 
computing environment.

Give a description of the semantics of the "sign this challenge" act, 
without presupposing agreement on definitions we take for granted like 
"authentication", "login", "session", etc.

I suspect the result would sound absurd enough that we would want to 
throw out the whole thing and start over.

I suspect we avoid this exercise because we realize this subconsciously, 
or at least avoid saying it out loud.

I suspect that this is a big part of why we find the problem intractable.

- Marsh