Re: [OAUTH-WG] problem statement

Eran Hammer-Lahav <eran@hueniverse.com> Tue, 06 September 2011 18:12 UTC

Return-Path: <eran@hueniverse.com>
X-Original-To: oauth@ietfa.amsl.com
Delivered-To: oauth@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 8D44921F8CB3 for <oauth@ietfa.amsl.com>; Tue, 6 Sep 2011 11:12:51 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.558
X-Spam-Level:
X-Spam-Status: No, score=-2.558 tagged_above=-999 required=5 tests=[AWL=0.041, BAYES_00=-2.599]
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 DN+YSvkRHPAG for <oauth@ietfa.amsl.com>; Tue, 6 Sep 2011 11:12:50 -0700 (PDT)
Received: from p3plex1out01.prod.phx3.secureserver.net (p3plex1out01.prod.phx3.secureserver.net [72.167.180.17]) by ietfa.amsl.com (Postfix) with SMTP id B5B8C21F8B58 for <oauth@ietf.org>; Tue, 6 Sep 2011 11:12:50 -0700 (PDT)
Received: (qmail 22905 invoked from network); 6 Sep 2011 18:14:37 -0000
Received: from unknown (HELO smtp.ex1.secureserver.net) (72.167.180.21) by p3plex1out01.prod.phx3.secureserver.net with SMTP; 6 Sep 2011 18:14:36 -0000
Received: from P3PW5EX1MB01.EX1.SECURESERVER.NET ([10.6.135.19]) by P3PW5EX1HT003.EX1.SECURESERVER.NET ([72.167.180.21]) with mapi; Tue, 6 Sep 2011 11:14:32 -0700
From: Eran Hammer-Lahav <eran@hueniverse.com>
To: "igor.faynberg@alcatel-lucent.com" <igor.faynberg@alcatel-lucent.com>
Date: Tue, 06 Sep 2011 11:14:25 -0700
Thread-Topic: [OAUTH-WG] problem statement
Thread-Index: AcxswNLvFuAFja1QTXyASEJbYfEyoA==
Message-ID: <CD0B1909-8298-4CC3-B273-7B26E71EAB31@hueniverse.com>
References: <4E665B25.6090709@mtcc.com> <4E6661FA.7050804@alcatel-lucent.com>
In-Reply-To: <4E6661FA.7050804@alcatel-lucent.com>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
acceptlanguage: en-US
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
Cc: "oauth@ietf.org" <oauth@ietf.org>
Subject: Re: [OAUTH-WG] problem statement
X-BeenThere: oauth@ietf.org
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: OAUTH WG <oauth.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/oauth>, <mailto:oauth-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/oauth>
List-Post: <mailto:oauth@ietf.org>
List-Help: <mailto:oauth-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/oauth>, <mailto:oauth-request@ietf.org?subject=subscribe>
X-List-Received-Date: Tue, 06 Sep 2011 18:12:51 -0000

I agree. If you are going to install a native app, you better trust it not to do bad things. Grabbing your password is the least interesting thing such an app can abuse. I don't see any need to change the v2 draft. 

EHL

On Sep 6, 2011, at 11:10, "Igor Faynberg" <igor.faynberg@alcatel-lucent.com> wrote:

> Mike,
> 
> You've got the problem statement right: allowing the user to authorize  
> resource access to another party without divulging user's credentials is 
> the objective of OAuth. You are also right in that the attack you have 
> described defies the whole purpose of OAuth.  I do not think though that 
> it is related to OAuth per se.
> 
> To this end, the security work led by Torsten has thoroughly analyzed 
> the protocol and specified protection against multiple protocol 
> attacks.  From what you described, it appears to me that the attack you 
> mention is not related to the protocol but rather to the user's 
> environment.  There is no possible protection from key loggers that a 
> protocol can implement. I could be mistaken; in any case, it looks like 
> the problem rests with the implementation of WebView.
> 
> If I am wrong, I would appreciate a detailed description of what happened.
> 
> Igor
> 
> On 9/6/2011 1:40 PM, Michael Thomas wrote:
>> Hi all,
>> 
>> Barry suggested that I might subscribe and explain what I sent him.
>> 
>> My basic problem is that in neither the protocol nor the threats drafts,
>> I can't seem to find what problem is actually trying to be solved with
>> oauth, and what assumptions you're making about various elements.
>> 
>> Here's what I did. I've written an app, and I wanted re-integrate the
>> ability to send tweets after they deprecated Basic. So the app has a
>> webView (android, iphone...) which it obviously completely controls.
>> With oauth, the webview UA will ultimately redirect off to Twitter's
>> site to collect the user's credentials and grant my app's backend an
>> access token (sorry if I get terminology screwed up, i'm just coming
>> up to speed).
>> 
>> What occurs to me is that webview affords exactly zero protection from
>> my client (ie, the app) from getting the user's twitter credentials. All
>> I have to do is set up a keypress handler on that webview and in a few
>> minutes of hacking I have a key logger. etc.
>> 
>> So what I can't tell is whether this is a "problem" or not, because I
>> don't know what problem you're trying to solve. If the object of oauth
>> isn't to keep user/server credentials out of the hands of a third party,
>> then what is it trying to solve? Is there an expectation that the
>> UA is trusted by the user/server? What happens when that's not the case?
>> 
>> Regardless of whether I'm misunderstanding, it would sure be nice to have
>> both the problem and your assumptions laid out, hopefully with some 
>> prominence
>> so you don't get these sort of dumb questions.
>> 
>> Mike
>> _______________________________________________
>> OAuth mailing list
>> OAuth@ietf.org
>> https://www.ietf.org/mailman/listinfo/oauth
> _______________________________________________
> OAuth mailing list
> OAuth@ietf.org
> https://www.ietf.org/mailman/listinfo/oauth