hi,

same here. I have the same recollection of the meeting in Darmstadt as Brian. I 
do appreciate the draft of Mike (kudos to him) and his will to steer toward the 
consensus.
regards

antonio

On Jan 13, 2016, at 5:31 AM, Phil Hunt (IDM) 
<phil.h...@oracle.com<mailto:phil.h...@oracle.com>> wrote:

I am in agreement with Brian.

I understand what Mike is trying to do is safer, but I too am concerned that 
the escalation in knowledge/skills for oauth clients is significant.

This may not be the same concern as for OIDC where we can expect more 
sophistication.

Phil

On Jan 12, 2016, at 20:03, Justin Richer 
<jric...@mit.edu<mailto:jric...@mit.edu>> wrote:

+1 to Brian’s point, and points to Mike for promising to address this. I wasn’t 
able to attend the meeting in Darmstadt, but I’ve been following the discussion 
and original papers. Let’s take this one piece at a time and not overreach with 
a solution.

In particular, the whole “late binding discovery” bit would cause huge problems 
on its own. There’s good reason that OpenID Connect mandates that the “iss” 
value returned from the discovery endpoint MUST be the same as the “iss” value 
coming back from the ID Token, so let’s not ignore that.

 — Justin

On Jan 12, 2016, at 5:53 PM, Mike Jones 
<michael.jo...@microsoft.com<mailto:michael.jo...@microsoft.com>> wrote:

John Bradley and I went over this today and I'm already planning on simplifying 
the draft along the lines described. I would have written this earlier but I've 
been busy at a NIST meeting today.

John has also stated writing a note about how cut-and-paste does and doesn't 
apply here but hasn't finished it yet because he's been similarly occupied.  
He's also started writing up the state_hash token request parameter, as he 
agreed to do.

Watch this space for the new draft...

Best wishes,
-- Mike
________________________________
From: Brian Campbell<mailto:bcampb...@pingidentity.com>
Sent: ‎1/‎12/‎2016 5:24 PM
To: oauth<mailto:oauth@ietf.org>
Subject: [OAUTH-WG] Mix-Up About The Mix-Up Mitigation

The "IdP Mix-Up" and "Malicious Endpoint" attacks (as well as variations on 
them) take advantage of the fact that there's nothing in the OAuth 
authorization response to the client's redirect_uri that identifies the 
authorization server. As a result, a variety of techniques can be used to trick 
the client into sending the code (or token in some cases) to the wrong endpoint.

To the best of my recollection the general consensus coming out of the meetings 
in Darmstadt (which Hannes mentioned in OAuth Security Advisory: Authorization 
Server 
Mix-Up<https://mailarchive.ietf.org/arch/msg/oauth/JIVxFBGsJBVtm7ljwJhPUm3Fr-w>)
 was to put forth an I-D as a simple extension to OAuth, which described how to 
return an issuer identifier for the authorization server and client identifier 
as authorization response parameters from the authorization endpoint. Doing so 
enables the client to know which AS the response came from and thus avoid 
sending the code to a different AS. Also, it doesn't introduce 
application/message level cryptography requirements on client implementations.

The mitigation draft that was posted 
yesterday<http://tools.ietf.org/html/draft-jones-oauth-mix-up-mitigation-00> 
diverges considerably from that with a significantly expanded scope that 
introduces OpenID Connect ID Tokens (sort of anyway) to regular OAuth and the 
retrieval of a metadata/discovery document in-between the authorization request 
and the access token request.

It is possible that my recollection from Darmstadt is wrong. But I expect 
others who were there could corroborate my account of what transpired. Of 
course, the agreements out of the Darmstadt meeting were never intended to be 
the final word - the whole WG would have the opportunity to weigh, as is now 
the case. However, a goal of meeting face-to-face was to come away with a good 
consensus towards a proposed solution that could (hopefully) be implementable 
in the very near term and move thought the IETF process in an expedited manner. 
I believe we'd reached consensus but the content of -00 draft does not reflect 
it.

I've made the plea off-list several times to simplify the draft to reflect the 
simple solution and now I'm doing the same on-list. Simplify the response 
validation to just say not to send the code/token back to an AS entity other 
that the one identified by the 'iss' in the response. And remove the id_token 
and JWT parts that .

If this WG and/or the larger community believes that OAuth needs signed 
responses, let's develop a proper singed response mechanism. I don't know if 
it's needed or not but I do know that it's a decent chunk of work that should 
be conscientiously undertaken independent of what can and should be a simple to 
understand and implement fix for the idp mix-up problem.



_______________________________________________
OAuth mailing list
OAuth@ietf.org<mailto:OAuth@ietf.org>
https://www.ietf.org/mailman/listinfo/oauth

_______________________________________________
OAuth mailing list
OAuth@ietf.org<mailto:OAuth@ietf.org>
https://www.ietf.org/mailman/listinfo/oauth
_______________________________________________
OAuth mailing list
OAuth@ietf.org<mailto:OAuth@ietf.org>
https://www.ietf.org/mailman/listinfo/oauth

_______________________________________________
OAuth mailing list
OAuth@ietf.org
https://www.ietf.org/mailman/listinfo/oauth

Reply via email to