Re: [OAUTH-WG] JWT Secured Authorization Request (JAR) vs OIDC request object

[Filip Skokan <[e-mail]>]

I don't think we have the separation of OAuth and non-OAuth parameters and
let's please not. Even OIDC parameters are part of the OAuth parameters
registry
<https://www.iana.org/assignments/oauth-parameters/oauth-parameters.xhtml#parameters>
and
I cannot imagine the hardship if we were to explain that to developers.

With passing time I believe it should be up to the profile or application
of JAR to define how to treat *recognized* parameters outside of the
request object. In my personal OSS project the AS can be configured to be
*strict* (jar), *lax* (oidc merge all) or *whitelist* (merge only
whitelisted - code_challenge, nonce, state, ...) similar to what Vladimir
is describing.

S pozdravem,
*Filip Skokan*


On Mon, 6 Jan 2020 at 07:05, n-sakimura <[e-mail]> wrote:

> Up until -12 (Feb 13, 2017), it was using merge + JAR precedence if
> duplicated.
>
> As of -13 (Mar 30, 2017), it was changed that the server does not have to
> do the merge, at least for OAuth Authorization request parameters. It says
> nothing about other parameters.
>
> As of -14 (Jul 21, 2017), the wording was further strengthened by adding
>
>
>
> The Authorization Server MUST only use the parameters in the Request
> Object even if the same parameter is provided in the query parameter.
>
>
>
> So, the entire 6.3 now became
> 6.3 <https://tools.ietf.org/html/draft-ietf-oauth-jwsreq-20#section-6.3>.
> Request Parameter Assembly and Validation
>
>    The Authorization Server MUST extract the set of Authorization
>
>    Request parameters from the Request Object value.  The Authorization
>
>    Server MUST only use the parameters in the Request Object even if the
>
>    same parameter is provided in the query parameter.  The Authorization
>
>    Server then validates the request as specified in OAuth 2.0
>
>    [RFC6749 <https://tools.ietf.org/html/rfc6749>].
>
>
>
> It says nothing on the non-OAuth parameters that came with the
> authorization request.
>
> My take on the text is that all OAuth Authorization Request parameters
> MUST be in the request object.
>
> Behaviors towards other parameters that happens to have come together with
> the authorization request outside of request object will be treated as
> non-OAuth parameters.
>
>
>
> Nat Sakimura
>
> Research Fellow, Nomura Research Institute
>
> E: [e-mail]
>
> T: [phone]
>
> ---------------------------------------------------------
>
> PLEASE READ:This e-mail is confidential and intended for the named
> recipient only.
>
> If you are not an intended recipient, please notify the sender and delete
> this e-mail.
>
>
>
> *From:* OAuth <[e-mail]> *On Behalf Of *Justin Richer
> *Sent:* Friday, January 3, 2020 2:35 AM
> *To:* Takahiko Kawasaki <[e-mail]>
> *Cc:* Brian Campbell <bcampbell=[e-mail]>; oauth
> <[e-mail]>; Nat Sakimura <[e-mail]>
> *Subject:* Re: [OAUTH-WG] JWT Secured Authorization Request (JAR) vs OIDC
> request object
>
>
>
> For solution [2], this is the behavior that’s required for OIDC today, so
> I would say that’s the New Client behaving like an Old Client in order to
> talk to an Old Server. So in reality, (2) causes the request to be
> rejected, and that’s OK.
>
>
>
> I don’t think it’s viable to require parameters to exist inside the
> request object at all times. Nor should we try to enumerate which
> parameters go inside and outside at all times — at least from the JAR/OAuth
> level of things. I think there are too many things that are application and
> deployment specific for us to make this call. The very nature of the
> request object changes for people — some have a static object that’s
> deployed with clients and some have something that the client creates at
> runtime for each request.
>
>
>
> If the instead the New Server requires that any parameters duplicated
> between the two places have to match (the OIDC method) or that in a
> conflict the request object values take precedence (the merge method), then
> problems 3-1 and 3-2 go away.
>
>
>
> With the merge-and-precedence behavior, which is what I thought that JAR
> had during WGLC, [3-1] is well-defined. The request is processed the same
> way every time because this is a New Server. The client is going to do
> OIDC’s “duplicate” method, so “merge with precedence” is effectively a
> no-op.
>
>
>
> With the merge-and-precedence behavior, [3-2] doesn’t happen because the
> required parameters aren’t required to be in the request object itself. As
> long as the request object is valid, it protects all parameters within it.
> I don’t think it’s up to us to determine what makes sense to put in that
> object. Security guidance is probably a good idea here.
>
>
>
> Solution [3] is what Old Clients already do in OIDC today, so that’s what
> already happens and why problem space (3) isn’t a problem.
>
>
>
>  — Justin
>
>
>
> On Jan 2, 2020, at 12:24 PM, Takahiko Kawasaki <[e-mail]> wrote:
>
>
>
> Thank you, Justin. Actually, I wanted to see someone write a summary about
> what happens in each combination from a viewpoint of both RP and AS with
> regard to backward compatibility (as I told you in other channel just
> before you posted your email ^_^).
>
> So,
>
> *(1) New Client + New Server*
> No problem will happen.
>
> *(2) New Client + Old Server*
> *[Problem 2-1]* If an authorization request contains 'request' or
> 'request_uri' but doesn't have old mandatory request parameters
> ('client_id' and 'response_type') outside the request object, the request
> is rejected.
>
> *[Solution 2]* New Client should include the old mandatory request
> parameters duplicately outside the request object. This means that New
> Client should always send old mandatory request parameters duplicately
> outside the request object if it wants to get maximum compatibility.
>
> *(3) Old Client + New Server*
> *[Problem 3-1]* If an authorization request contains 'request' or
> 'request_uri' and some "optional" request parameters are not included in
> the request object, AS will interpret the request differently. Imagine what
> happens when optional parameters such as 'scope', 'state', 'nonce',
> 'redirect_uri', 'response_mode', 'max_age', 'acr_values', 'code_challenge',
> 'code_challenge_method' and 'prompt' are not included in the request object
> but present outside the request object.
>
> *[Problem 3-2]* If an authorization request contains 'request' or
> 'request_uri' and some "mandatory" request parameters ('client_id' and
> 'response_type') are not included in the request object, the request is
> rejected.
>
> *[Solution 3]* Old Client should include all request parameters
> duplicately in the request object. This means that Old Client should always
> include all request parameters duplicately in the request object if it
> wants to get maximum compatibility.
>
> *(4) Old Client + Old Server*
> No problem will happen.
>
> - - -
>
>
> From a Client's point of view, for maximum compatibility, both Old and New
> Clients should put mandatory request parameters outside the request object
> and put all request parameters duplicately inside the request object.
>
> [Problem 3-1] is difficult to detect because the authorization request is
> not rejected. But, if New Server requires that all request parameters
> outside the request object be put inside the request object duplicately,
> [Problem 3-1] is handled as an error and thus client developers can detect
> the problem.
>
> Consequently, introducing the following requirement in "FAPI Part 2, 5.2.2
> <https://openid.net/specs/openid-financial-api-part-2-ID2.html#authorization-server>,
> 10" to JAR seems a good compromise (as I told before)
>
> shall require that all parameters are present inside the signed request
> object passed in the request or request_uri parameter;
>
>
> instead of just saying "the authorization server supporting this
> specification MUST only use the parameters included in the request object."
> which will bring about [Problem 3-1]. That is, how about adding a rule like
> "if request parameters exist outside the request object, they must exist
> inside the request object, too."?
>
> Any thoughts?
>
>
>
> Best,
>
> Taka
>
>
>
>
>
> On Fri, Jan 3, 2020 at 12:48 AM Justin Richer <[e-mail]> wrote:
>
> I think the nature of the backwards incompatibility is important here. The
> way that things are now, using merge-with-precedence, you have the
> following matrix of compatibility:
>
>
>
>
>
>              New Server  |  Old Server  |
>
> -----------+-------------+--------------+
>
> New Client |      YES    |      NO      |
>
> Old Client |      YES    |     YES      |
>
>
>
>
>
> If you ask me, this is the right balance for a breaking change. Old
> clients, where the vast majority of the code is, don’t have to change. New
> clients can only talk to servers with the new features, which is the
> ability to drop parameters from the external request. This would apply to
> both OIDC and plain OAuth.
>
>
>
> I think we should follow this kind of pattern in the discussions on OAuth
> 2.1, which I think JAR should be a part of/
>
>
>
>  — Justin
>
>
>
>
>
>
>
> On Jan 2, 2020, at 3:40 AM, Takahiko Kawasaki <[e-mail]> wrote:
>
>
>
> Breaking backward compatibility in this part would mean that OpenID
> Certification given to AS implementations with request_uri support will be
> invalidated once they support JAR. It also would mean that test cases in
> the official conformance suite need to be changed in a
> backward-incompatible manner, which would implicitly encourage that all
> certified implementations should re-try to get certification.
>
> Changing the spec now might need more three to six months, but it would be
> worth considering what we get and lose by saving the months and breaking
> backward compatibility.
>
> Best Regards,
> Taka
>
>
>
> On Wed, Dec 18, 2019 at 4:14 PM Nat Sakimura <[e-mail]> wrote:
>
> So, no change is OK?
>
>
>
> On Wed, Dec 11, 2019 at 10:01 PM John Bradley <[e-mail]> wrote:
>
> I also slightly prefer the merge approach.
>
>
>
> There are plusses and minuses to both.
>
>
>
> Changing again now that it is past ISEG review and backing out a Discuss
> will add another three to six months at this point, if we can get them to
> agree to the change.
>
>
>
> John B.
>
>
>
> On Tue, Dec 10, 2019, 11:29 PM Nat Sakimura <[e-mail]> wrote:
>
> Correct. The WG supported the precedence approach and even merge just like
> OIDC as it is very useful from the implementation point of view and helps
> with a bunch of deployment patter.
>
>
>
> The push back came in from the Ben Campbell’s DISCUSS.
>
> See
>
>
> https://bitbucket.org/Nat/oauth-jwsreq/issues/70/bc-the-current-text-actually-specifies-the
>
>
>
> I am willing to go either way as long as people agree. My slight
> preference is to the original approach.
>
>
>
> Best,
>
>
>
> Nat Sakimura
>
>
>
> 2019年8月29日(木) 6:56 Brian Campbell <bcampbell=
> [e-mail] <[e-mail]>>:
>
> FWIW, as best I can remember the change in question came as I result of
> directorate/IESG review rather than a WG decision/discussion. Which is
> likely why you can't find the "why" anywhere in the mailing list archive.
>
>
>
> On Wed, Aug 28, 2019 at 3:23 PM Filip Skokan <[e-mail]> wrote:
>
> Well it kind of blows, doesn't it? I wasn't able to find the "why"
> anywhere in the mailing list archive around the time this was changed.
>
>
>
> My take on satisfying both worlds looks like this
>
>
>
> - allow just JAR - no other params when possible.
>
>     (which btw isn't possible to do with request_uri when enforcing client
> based uri whitelist and the jwsreq 5.2.2 shows as much)
>
> - enforce the "dupe behaviours" defined in OIDC (if response_type or
> client_id is in request object it must either be missing or the same in
> regular request).
>
> - allows merging request object and regular parameters with request object
> taking precedence since it is a very useful feature when having pre-signed
> request object that's not one time use and clients using it wish to vary
> state/nonce per-request.
>
>
>
> I wish the group reconsidered making this breaking change from OIDC's take
> on request objects - allow combination of parameters from the request
> object with ones from regular parameters (if not present in request object).
>
>
> S pozdravem,
> *Filip Skokan*
>
>
>
>
>
> On Wed, 28 Aug 2019 at 23:02, Brian Campbell <[e-mail]>
> wrote:
>
> Filip, for better or worse, I believe your assessment of the situation is
> correct. I know of one AS that didn't choose which of the two to follow but
> rather implemented a bit of a hybrid where it basically ignores everything
> outside of the request object per JAR but also checks for and enforces the
> presence and value of the few regular parameters (client_id, response_type)
> that OIDC mandates.
>
>
>
> On Tue, Aug 27, 2019 at 5:47 AM Filip Skokan <[e-mail]> wrote:
>
> Hello everyone,
>
>
>
> in an earlier thread I've posed the following question that might have
> gotten missed, this might have consequences for the existing
> implementations of Request Objects in OIDC implementations - its making
> pure JAR requests incompatible with OIDC Core implementations.
>
>
>
> draft 14 of jwsreq (JAR) introduced this language
>
>
>
> The client MAY send the parameters included in the request object
> duplicated in the query parameters as well for the backward
> compatibility etc.
>
> *However, the authorization server supporting this specification MUST only
> use the parameters included in the request object. *
>
>
>
> Server MUST only use the parameters in the Request Object even if the
> same parameter is provided in the query parameter.  The Authorization
>
>
>
> The client MAY send the parameters included in the request object
> duplicated in the query parameters as well for the backward
> compatibility etc.
>
> *However, the authorization server supporting this specification MUST only
> use the parameters included in the request object.. *
>
>
>
> Nat, John, everyone - *does this mean a JAR compliant AS ignores
> everything outside of the request object while OIDC Request Object one
> merges the two with the ones in the request object being used over ones
> that are sent in clear?* The OIDC language also includes sections which
> make sure that some required arguments are still passed outside of the
> request object with the same value to make sure the request is "valid"
> OAuth 2.0 request (client_id, response_type), something which an example in
> the JAR spec does not do. Not having this language means that existing
> authorization request pipelines can't simply be extended with e.g. a
> middleware, they need to branch their codepaths.
>
>
>
> Is an AS required to choose which of the two it follows?
>
>
>
> Thank you for clarifying this in advance. I think if either the behaviour
> is the same as in OIDC or different this should be called out in the
> language to avoid confusion, especially since this already exists in OIDC
> and likely isn't going to be read in isolation, especially because the
> Request Object is even called out to be already in place in OIDC in the JAR
> draft.
>
>
>
> Best,
>
> *Filip*
>
> _______________________________________________
> OAuth mailing list
> [e-mail]
> https://www.ietf.org/mailman/listinfo/oauth
>
>
>
> *CONFIDENTIALITY NOTICE: This email may contain confidential and
> privileged material for the sole use of the intended recipient(s)... Any
> review, use, distribution or disclosure by others is strictly prohibited.
> If you have received this communication in error, please notify the sender
> immediately by e-mail and delete the message and any file attachments from
> your computer. Thank you.*
>
>
> *CONFIDENTIALITY NOTICE: This email may contain confidential and
> privileged material for the sole use of the intended recipient(s). Any
> review, use, distribution or disclosure by others is strictly prohibited..
> If you have received this communication in error, please notify the sender
> immediately by e-mail and delete the message and any file attachments from
> your computer. Thank you.*_______________________________________________
> OAuth mailing list
> [e-mail]
> https://www.ietf.org/mailman/listinfo/oauth
>
> --
>
> Nat Sakimura (=nat)
>
> Chairman, OpenID Foundation
> http://nat.sakimura.org/
> @_nat_en
>
> _______________________________________________
> OAuth mailing list
> [e-mail]
> https://www.ietf.org/mailman/listinfo/oauth
>
>
>
>
> --
>
> Nat Sakimura (=nat)
>
> Chairman, OpenID Foundation
> http://nat.sakimura.org/
> @_nat_en
>
> _______________________________________________
> OAuth mailing list
> [e-mail]
> https://www.ietf.org/mailman/listinfo/oauth
>
> _______________________________________________
> OAuth mailing list
> [e-mail]
> https://www.ietf.org/mailman/listinfo/oauth
>
>
>
>
> _______________________________________________
> OAuth mailing list
> [e-mail]
> https://www.ietf.org/mailman/listinfo/oauth
>