[Openid-specs-ab] Transient Client Secret Extension for OAuth

Brian Campbell bcampbell at pingidentity.com
Mon Jul 29 07:51:06 UTC 2013


I'm just trying to be realistic.

The client can send the values regardless of if the sever supports this or
not.

If a client really cares enough and will not use the AS if this isn't
supported, it can find out out of band. Or it's easy enough to test it out.

Most clients are written to a particular AS so they'll know already.
Libraries are more general and they need to support it first.

Connect (and eventually general OAuth) can put this in dico. But the basic
functionality doesn't need to address that.


On Mon, Jul 29, 2013 at 9:45 AM, Nat Sakimura <sakimura at gmail.com> wrote:

> Hmmm. Then, the client has lost its capability to find out whether the
> server is secure or not dynamically.
> Do you mean that the client should find it out out-of-band?
> That's possible, and is more OAuthy.
>
> So, instead of current 3.2, it can just state :
>
> The client MUST find out if the server supports this mode before issuing
> the authorizaiton request. The exact method of how it can be done is out of
> scope.
>
> Is that what you mean?
>
> Nat
>
>
> 2013/7/29 Brian Campbell <bcampbell at pingidentity.com>
>
>> Pretty much just removing 3.1 and 3.2 and 2.2 from your draft.
>>
>>
>> On Mon, Jul 29, 2013 at 9:36 AM, Nat Sakimura <sakimura at gmail.com> wrote:
>>
>>> Yup. It is too late. The client needs to know whether the server is
>>> secure or not to start with.
>>>
>>> > I still think that a base definition of this shouldn't try and
>>> address discovering or publishing support for the functionality.
>>>
>>> Could you kindly propose a concrete method? A concrete text would be
>>> even better.
>>>
>>>
>>> 2013/7/29 Brian Campbell <bcampbell at pingidentity.com>
>>>
>>>> As John pointed out, putting metainfo about support into the token
>>>> response is too late in the flow.
>>>>
>>>> I still think that a base definition of this shouldn't try and address
>>>> discovering or publishing support for the functionality.
>>>>
>>>>
>>>> On Mon, Jul 29, 2013 at 9:28 AM, Nat Sakimura <sakimura at gmail.com>wrote:
>>>>
>>>>> OK. Fair enough.
>>>>>
>>>>> I will change it to the invalid_grant.
>>>>>
>>>>> What do you think about the idea for "meta"?
>>>>>
>>>>>
>>>>> 2013/7/29 Brian Campbell <bcampbell at pingidentity.com>
>>>>>
>>>>>> It's really not client authentication. It's something that links the
>>>>>> initial authorization request with the corresponding access token request,
>>>>>> which enables detecting a particular problem/attack. Similar to a mismatch
>>>>>> on the redirect URI value between the authorization request and the
>>>>>> corresponding access token request, it's the grant (or transaction) that is
>>>>>> invalid.
>>>>>>
>>>>>> http://tools.ietf.org/html/rfc6749#section-5.2
>>>>>>
>>>>>>            invalid_grant
>>>>>>                The provided authorization grant (e.g., authorization
>>>>>>                code, resource owner credentials) or refresh token is
>>>>>>                invalid, expired, revoked, does not match the redirection
>>>>>>                URI used in the authorization request, or was issued to
>>>>>>                another client.
>>>>>>
>>>>>> Discovery is maybe useful but is definitely not necessary. What is
>>>>>> necessary is to define the parameter(s) and their treatment on the
>>>>>> authorization request and access token request so that clients and servers
>>>>>> can interop.
>>>>>>
>>>>>>
>>>>>> On Mon, Jul 29, 2013 at 9:07 AM, Nat Sakimura <sakimura at gmail.com>wrote:
>>>>>>
>>>>>>> Hi Brian,
>>>>>>>
>>>>>>> inline:
>>>>>>>
>>>>>>> 2013/7/29 Brian Campbell <bcampbell at pingidentity.com>
>>>>>>>
>>>>>>>> IMHO, invalid_grant is the proper error response code, not
>>>>>>>> invalid_client.
>>>>>>>>
>>>>>>>
>>>>>>> I have thought a bit about that when I was writing it down.
>>>>>>> invalid_grant is concerned about the token which has been previously
>>>>>>> issued.
>>>>>>> invalid_client is concerned about the client authentication.
>>>>>>> In the initial path, I had it as invalid_grant, then, I thought -
>>>>>>> well, it is the client
>>>>>>> authentication that is failing when the client has provided invalid
>>>>>>> tcs.
>>>>>>> The code is correct. It is the client authentication which is going
>>>>>>> wrong, is it not?
>>>>>>>
>>>>>>>
>>>>>>>>
>>>>>>>> Along the same lines, I'd like to see it named something more like
>>>>>>>> "message correlation id" rather than anything involving client secret.
>>>>>>>>
>>>>>>>
>>>>>>> The name "message correlation identifier" does not convey the nature
>>>>>>> of the parameter, which is the high entropy credential for the client. Just
>>>>>>> for the sake of the correlation, it does not have to have a high entropy.
>>>>>>> Thus, I have chosen the name.
>>>>>>>
>>>>>>>
>>>>>>>>
>>>>>>>> This is a general OAuth problem and I believe the solution should
>>>>>>>> be general too. Thus, at least the base definition of the parameter(s)
>>>>>>>> should not require discovery or rely on any of the Connect documents.
>>>>>>>>
>>>>>>>
>>>>>>> OAuth generally does not need discovery. However, this spec really
>>>>>>> needs it, at least in one form or another.
>>>>>>> I have thought of making a new file but then that would amount to
>>>>>>> having the client hit those discovery endpoints twice.
>>>>>>> I did not want the duplicate situation that resulted in the dynamic
>>>>>>> client registration. That's why I am referring OpenID Connect.
>>>>>>> OpenID Connect originated the Discovery and Registration. On the
>>>>>>> hind site, even registration should have been referring OpenID Connect
>>>>>>> documents instead of duplicating. At least, that's how academic papers work
>>>>>>> :-)
>>>>>>>
>>>>>>> Another idea is to have the metadata come back in the token
>>>>>>> response.
>>>>>>> I actually prefer this. It increases the server traffic a bit,
>>>>>>> though.
>>>>>>>
>>>>>>> The way it works is this.
>>>>>>> Instead of doing the discovery and caching it at the client, the
>>>>>>> client finds the server capability from the token endpoint reference. For
>>>>>>> this, the server includes something like:
>>>>>>>
>>>>>>> "meta": {
>>>>>>>    "tcs_supported":true;
>>>>>>> }
>>>>>>>
>>>>>>> You guys know that I like this idea because then I would have a stub
>>>>>>> to put link relationship there as well.
>>>>>>> Do you like the idea? If so, I can update the draft in this manner.
>>>>>>> Well, perhaps I should anyways.
>>>>>>>
>>>>>>> Thanks for pointing out.
>>>>>>>
>>>>>>> Best,
>>>>>>>
>>>>>>> Nat
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> On Sun, Jul 28, 2013 at 9:39 PM, Nat Sakimura <sakimura at gmail.com>wrote:
>>>>>>>>
>>>>>>>>> As some of you knows, passing the code securely to a native app on
>>>>>>>>> iOS platform is next to impossible. Malicious application may register the
>>>>>>>>> same custom scheme as the victim application and hope to obtain the code,
>>>>>>>>> whose success rate is rather high.
>>>>>>>>>
>>>>>>>>> We have discussed about it during the OpenID Conenct Meeting at
>>>>>>>>> IETF 87 today, and I have captured the discussion in the form of I-D. It is
>>>>>>>>> pretty short and hopefully easy to read.
>>>>>>>>>
>>>>>>>>> You can find it at:
>>>>>>>>>
>>>>>>>>> https://bitbucket.org/Nat/drafts/src/
>>>>>>>>>
>>>>>>>>> Comments are welcome.
>>>>>>>>>
>>>>>>>>> --
>>>>>>>>> Nat Sakimura (=nat)
>>>>>>>>> Chairman, OpenID Foundation
>>>>>>>>> http://nat.sakimura.org/
>>>>>>>>> @_nat_en
>>>>>>>>>
>>>>>>>>> _______________________________________________
>>>>>>>>> Openid-specs-ab mailing list
>>>>>>>>> Openid-specs-ab at lists.openid.net
>>>>>>>>> http://lists.openid.net/mailman/listinfo/openid-specs-ab
>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> --
>>>>>>> Nat Sakimura (=nat)
>>>>>>> Chairman, OpenID Foundation
>>>>>>> http://nat.sakimura.org/
>>>>>>> @_nat_en
>>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> Nat Sakimura (=nat)
>>>>> Chairman, OpenID Foundation
>>>>> http://nat.sakimura.org/
>>>>> @_nat_en
>>>>>
>>>>
>>>>
>>>
>>>
>>> --
>>> Nat Sakimura (=nat)
>>> Chairman, OpenID Foundation
>>> http://nat.sakimura.org/
>>> @_nat_en
>>>
>>
>>
>
>
> --
> Nat Sakimura (=nat)
> Chairman, OpenID Foundation
> http://nat.sakimura.org/
> @_nat_en
>
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