Re: [OAUTH-WG] review comments on draft-ietf-oauth-dyn-reg-11.txt

[Justin Richer <[e-mail]>]

Tim, thanks for your review! Comments inline.

On 06/05/2013 04:59 PM, Tim Bray wrote:
> FWIW, I just read the spec through with fresh eyes, and I found the 
> explanation of the workflow in 1.4.2 very useful.
>
> - A developer manually registers and then is able to request “Initial 
> tokens” tokens for a dynamic-app-registration-scope,
> - you use that “Initial token” token to register, in exchange you get 
> the client-id & so on, and also a a per-registration “Registration 
> token” for updating that particular registration information
> - you fetch/update/delete your registration information with that 
> registration token.
>
> The first part, where the developer registers & gets a token for a 
> scope, is vanilla OAuth 2. (right?)

Yes, it can be vanilla Oauth2 or it can be the developer (or someone) 
getting a token through some other means, like browsing to a developer 
portal and getting a Bearer token. I've edited the example in 1.4.3 in 
the latest (unpublished) text so that the developer is literally doing 
OAuth2 to get the initial token. It's important to note that this could 
be any flavor of OAuth2 token, though Bearer tokens are of course the 
most common.

> The bit about getting an access token specific to that registration is 
> a new flow (right?), but it seems convenient.

Right, it's a new way to get a bearer token so that you can use it at 
the protected resource. We wanted to re-use the token endpoint for this, 
but couldn't come up with a reasonable way of doing so (as has been 
discussed on the list.

>   From an OAuth 2 point of view, there's nothing special about how you 
> get or use the Initial token, but giving it a special name makes 
> explaining a plausible workflow easier.

Right, and I've admitted that "Initial Access Token" a crappy name, but 
I haven't heard a better suggestion yet.

>
> Having said that, I have trouble imagining the scenario where you'd 
> use the 1.4.1 flow, but that may be because of my Google-centric 
> worldview.

Could be -- but if Google wants to be an open-registration identity 
provider (like it has been with OpenID 2.0), it will need to handle this 
flow as well. This is the client acting on its own behalf, showing up 
and saying "hi, I'm a client!" and that's that. I think this is a very 
important case for interoperability of dynamic registration.

>
> And I’m not sure 1.4.3 adds any value at all.  It just seems to be a 
> matter of different ways you could get and make use of the 
> registration access token; and I'm sure there are various interesting 
> combinations that haven't been thought of there.  I'd just lose 1.4.3.
>

1.4.3 in -11 is too close to 1.4.2, so what I've done in the current 
working text is make the initial process of getting the Initial Access 
Token different (the developer now uses OAuth2 to configure their build 
environment). The *real* important difference that's being shown here, 
though, is that the client doesn't call the registration endpoint, the 
developer (and their build environment) does. So yes, it's exactly all 
about how you get and use the registration access token. There are 
plenty of other ways to do it as well, so that's why this section was a 
non-normative set of examples. To facilitate that understanding, I've 
moved it to an appendix in the working copy of draft -12.

Thanks,
  -- Justin

>  -T
>
>
>
>
>
>
> On Fri, May 31, 2013 at 1:04 PM, Donald F Coffin 
> <[e-mail] 
> <mailto:[e-mail]>> wrote:
>
>     See my comments inline [DFC]
>
>     Best regards,
>
>     Don
>
>     Donald F. Coffin
>
>     Founder/CTO
>
>     REMI Networks
>
>     22751 El Prado Suite 6216
>
>     Rancho Santa Margarita, CA  92688-3836
>
>     Phone: [phone] <tel:%28949%29%20636-8571>
>
>     Email: [e-mail]
>     <mailto:[e-mail]>
>
>     *From:*Justin Richer [mailto:[e-mail]
>     <mailto:[e-mail]>]
>     *Sent:* Friday, May 31, 2013 12:40 PM
>     *To:* Phil Hunt
>     *Cc:* Donald F Coffin; [e-mail] <mailto:[e-mail]>
>
>
>     *Subject:* Re: [OAUTH-WG] review comments on
>     draft-ietf-oauth-dyn-reg-11.txt
>
>     I feel the need to clarify a couple erroneous things in Phil's
>     statement:
>
>
>
>       * To be clear, Draft 11 has the same Registration Access Token
>     system that has been in place since draft 01, it is not inventing
>     something new at the last minute as could be inferred from the
>     statement below.
>
>     [DFC]  I agree with Justin.  There is nothing new in draft 11
>     regarding Registration Access Tokens that wasn’t in the initial
>     draft.  It appears because Phil hasn’t been following the proposed
>     drafts until the last call he is now raising an issue no one in
>     the WG saw as an issue.  That’s not to say his point isn’t valid,
>     but the discussion continues to go all over the map between
>     “local” and “federated” tokens, usage of the RFC6749 “Token”
>     endpoint, etc.  It would be great if all of Phil’s points could be
>     addressed in priority
>     without the threads becoming so convoluted no one is able to make
>     sense or even comprehend the point being discussed.
>
>
>       * DynReg is using an absolutely standard OAuth 2 Bearer token as
>     the Registration Access Token, it's just not coming from a Token
>     Endpoint. However, since an OAuth Protected Resource doesn't care
>     where its tokens come from so long as it can validate them, I
>     don't see this as a problem -- this is a key point where Phil and
>     I disagree.
>
>     [DFC]  I understand the disagreement, but I have not seen a
>     proposal from Phil that would describe the differences between the
>     two perspectives other than to say that the Dynamic Registration
>     should use the Token endpoint defined in RFC6749, which does not
>     discuss dynamic registration.  Phil’s point as I understand it is
>     that there should be no difference between an access token used to
>     access resource owner protected data and the registration
>     structure, which I do not agree with.  As I said in the previous
>                 response, my users do NOT want to provide implied
>     access to resource owner protected data just because a client is
>     creating a registration with an AS.  This would be the situation
>     if the client credential flow is used to register an application. 
>     Since our
>                 implementation does NOT support the implicit flow,
>     that use case is one we have elected NOT to support.
>
>                 [DFC]  I repeat my initial comment, this conversation
>     has been a circular exchange now for the past few days without any
>     appearance of an alternative option to resolve the issues.
>
>
>      -- Justin
>
>     On 05/31/2013 03:33 PM, Phil Hunt wrote:
>
>         Don,
>
>         I am not proposing any change in meaning. If registration
>         acces token issues by normal token server with scope
>         registration everything is clear as it is for any other
>         protected API. Draft 11 invents a whole new system. I strongly
>         disagree with this.
>
>         Phil
>
>
>         On 2013-05-31, at 15:16, Donald F Coffin
>         <[e-mail]
>         <mailto:[e-mail]>> wrote:
>
>             For something that was agreed to be parked a few hours
>             ago, there sure seems to still be a lot of circular
>             discussion.  Should we ask a mediator to intervene?
>
>             FWIW I believe that is a significantly strong reason to
>             differentiate an access token that can access the
>             registration information without having the ability to
>             access protected data.  Especially given the implied
>             strength of the “client credential” obtained access
>             token.  I have found it extremely confusing to users when
>             explaining the difference between an access token obtained
>             thorough an authorization code flow and a client
>             credential flow, simply because they are both called an
>             “access token”.  Changing the meaning of an access token
>             obtained through the client credential flow to mean it has
>             the ability to update a registration, when a user may not
>             want it to have access to protected data will only
>             increase both the complexity of the access tokens as well
>             as make their usage harder to explain to non-technical
>             individuals who have to understand the differences between
>             the access tokens obtained through the various flows.
>
>             Just my two cents.
>
>             Best regards,
>
>             Don
>
>             Donald F. Coffin
>
>             Founder/CTO
>
>             REMI Networks
>
>             22751 El Prado Suite 6216
>
>             Rancho Santa Margarita, CA  92688-3836
>
>             Phone: [phone] <tel:%28949%29%20636-8571>
>
>             Email: [e-mail]
>             <mailto:[e-mail]>
>
>             *From:*Phil Hunt [mailto:[e-mail]]
>             *Sent:* Friday, May 31, 2013 11:11 AM
>             *To:* Justin Richer
>             *Cc:* [e-mail] <mailto:[e-mail]> WG
>             *Subject:* Re: [OAUTH-WG] review comments on
>             draft-ietf-oauth-dyn-reg-11.txt
>
>             To be clear.
>
>             It is two separate issues.
>
>             1. Anonymous clients can easily be handled through policy
>             config.
>
>             2. Support for implicit clients needs to be discussed. The
>             current proposal creates large negative value for the
>             service provider and most would never allow in current
>             form. Yes it gives each execution instance a new id, but
>             that isnt what sp's want. It is a huge attack and
>             management headache. Eliminate or propose a different
>             solution.
>
>             Phil
>
>
>             On 2013-05-31, at 13:58, Justin Richer <[e-mail]
>             <mailto:[e-mail]>> wrote:
>
>                 I'm not willing to write out an entire class of
>                 clients from this spec, especially when we have stated
>                 use cases for them doing dynamic registration.
>
>                 I'm sorry, but your proposed solution will simply not
>                 work.
>
>                  -- Justin
>
>                 On 05/31/2013 01:56 PM, Phil Hunt wrote:
>
>                     Well the only client that wouldn't have a
>                     credential is an implicit client. An implicit
>                     client is transient and so would never update.
>
>                     Besides, as i have stated, implicit clients should
>                     not use dyn reg.
>
>
>                     Phil
>
>
>                     On 2013-05-31, at 13:41, Justin Richer
>                     <[e-mail] <mailto:[e-mail]>> wrote:
>
>                         But the outstanding question is: how do you
>                         get the access token to access the created
>                         resource (IE: the Registration Access Token)?
>                         You can't use the client_credentials flow for
>                         a client with no credentials!
>
>                          -- Justin
>
>
>                         On 05/31/2013 12:58 PM, Phil Hunt wrote:
>
>                             Yes. I specified the trivial solution to
>                             anonymous clients earlier.
>
>                             Even simpler. You don't need an access
>                             token to create a new resource. You just
>                             need one to access one. That is just basic
>                             security config.
>
>
>                             Phil
>
>
>                             On 2013-05-31, at 12:34, Justin Richer
>                             <[e-mail]
>                             <mailto:[e-mail]>> wrote:
>
>                                 I agree that we are going in circles,
>                                 since I just was going to bring up my
>                                 counter argument of "what about
>                                 clients with no credentials?" again,
>                                 which *still* isn't addressed by what
>                                 you suggest doing, below. I also
>                                 believe that getting rid of the
>                                 Registration Access Token but using
>                                 some other token method would actually
>                                 make the spec larger, though I'd be
>                                 glad to review a concrete
>                                 counter-proposal if you'd like to
>                                 write one. And the fact that OIDC is
>                                 doing it this way, and considered but
>                                 rejected the way that you're
>                                 describing, should say something to
>                                 the WG here about whether or not this
>                                 is the right choice. Rough consensus
>                                 and running code, after all.
>
>                                 Regardless, I agree to park this issue
>                                 and leave the text as is. We'll move
>                                 to the next draft in the last call
>                                 process shortly, as I have a handful
>                                 of non-normative editorial changes
>                                 that I need to make, thanks to
>                                 feedback from a few folks.
>
>                                 Again, thanks for your thorough
>                                 review, Phil, and I look forward to
>                                 future feedback.
>
>                                  -- Justin
>
>                                 On 05/31/2013 12:28 PM, Phil Hunt wrote:
>
>                                     I disagree.
>
>                                     There is absolutely no need for a
>                                     registration access token.
>
>                                     Get rid of it and just use access
>                                     tokens as per 6749. If you can't
>                                     follow 6749 and need new issuing
>                                     methods, what are others to say
>                                     regarding inventing new methods?
>
>                                     I have not heard a good reason for
>                                     the special process or one good
>                                     enough to warrant a new method for
>                                     issuing an access token. Does the
>                                     broader group realize this is what
>                                     the spec says?
>
>                                     Yes, i heard a lot saying OIDC
>                                     does it this way. But that is a
>                                     political reason, not a technical
>                                     reason. Still, compatibility is
>                                     always a strong objective.  Even
>                                     so, oidc could keep using their
>                                     method just fine. There is no
>                                     obligation here to do the same.
>
>                                     The only reason so far was expiry
>                                     of client creds. Well, why not
>                                     require the client to update prior
>                                     to expiry? It makes no sense to
>                                     have another token with longer
>                                     expiry. B'sides, even expired the
>                                     client can re-register from scratch.
>
>                                     Why force the client to persist
>                                     multiple tokens and creds? That is
>                                     far far too complex.
>
>                                     Finally if you get rid of
>                                     registration access token the spec
>                                     size will drop roughly in half
>                                     IMO. This suggests simplicity to me.
>
>                                     Apologies for my rant. Maybe we
>                                     should park this for now. We are
>                                     going in circles.
>
>                                     Phil
>
>
>                                     On 2013-05-31, at 11:25, Justin
>                                     Richer <[e-mail]
>                                     <mailto:[e-mail]>> wrote:
>
>                                         Phil,
>
>                                         We *can* keep it straight just
>                                         fine, but I just need you to
>                                         be clear about which part
>                                         you're objecting to because
>                                         the answers are different.
>                                         Please use the terms as
>                                         defined in the document so
>                                         that we all know which
>                                         component we're talking about.
>                                         I'm sure you'd agree than in
>                                         specification work such as
>                                         this, precision of language
>                                         and labels is key for
>                                         communication between parties.
>                                         This is precisely why there's
>                                         a Terminology section right up
>                                         front, so that when I say
>                                         "Registration Access Token"
>                                         you can know that I mean a
>                                         very specific thing, and when
>                                         I say "Initial Registration
>                                         Token" I mean a very different
>                                         specific thing. So I'm asking
>                                         you, please, use the defined
>                                         terms so that we can avoid
>                                         this unnecessary confusion.
>
>                                         But anyway, what you're
>                                         talking about below, "the
>                                         token the client uses to
>                                         update is profile" *IS* the
>                                         Registration Access Token.
>                                         That's all that that token is
>                                         used for. You're not asking
>                                         for it to go away, you're
>                                         asking for it to come from the
>                                         Token Endpoint instead of the
>                                         response from the Registration
>                                         Endpoint. I don't see how the
>                                         client *can* get it from the
>                                         normal token process without
>                                         jumping through specialized
>                                         hoops to make that happen.
>                                         I've implemented the draft the
>                                         way that it is right now, both
>                                         client and server side, and it
>                                         works. Others have implemented
>                                         it, too. We've done interop
>                                         testing, and it works. This is
>                                         a proven pattern and from
>                                         where I sit there is both
>                                         rough consensus and running code.
>
>                                         I believe that I've already
>                                         pointed out how the solutions
>                                         you've proposed so far won't
>                                         work in practice, for various
>                                         reasons, many of which have
>                                         already been brought up and
>                                         discussed previously. If you
>                                         have another way for the
>                                         client to get its Registration
>                                         Access Token, please propose
>                                         it; but I haven't seen
>                                         anything yet that will fly.
>
>                                          -- Justin
>
>                                         On 05/31/2013 11:10 AM, Phil
>                                         Hunt wrote:
>
>                                             Justin,
>
>                                             This is my primary
>                                             objection! We can't keep
>                                             it straight. Their should
>                                             be no such thing as a
>                                             registrstion access token!
>                                              Just the token the client
>                                             obtains to update its
>                                             profile through the normal
>                                             token request process.
>
>                                             Phil
>
>
>                                             On 2013-05-31, at 10:55,
>                                             Justin Richer
>                                             <[e-mail]
>                                             <mailto:[e-mail]>> wrote:
>
>                                                 Which token are you
>                                                 referring to here?
>
>                                                 If it's the Initial
>                                                 Registration Token,
>                                                 then you could get
>                                                 that through the
>                                                 normal token server no
>                                                 problem. (The
>                                                 lifecycle writeups
>                                                 don't call this out
>                                                 explicitly but I would
>                                                 be willing to do so.)
>                                                 Or you could get it
>                                                 elsewhere. Doesn't
>                                                 matter, just like it
>                                                 doesn't matter with
>                                                 any other OAuth2
>                                                 protected resource.
>
>                                                 If it's the
>                                                 Registration Access
>                                                 Token, then having the
>                                                 token come from the
>                                                 token endpoint would
>                                                 require a lot more
>                                                 work and complexity on
>                                                 behalf of both of the
>                                                 client and server.
>                                                 Either you end up with
>                                                 public clients getting
>                                                 secrets they shouldn't
>                                                 need or with granting
>                                                 clients access to the
>                                                 client_credentials
>                                                 flow when they
>                                                 shouldn't actually
>                                                 have it. Plus it adds
>                                                 extra round trips
>                                                 which don't buy you
>                                                 anything.
>
>                                                  -- Justin
>
>                                                 On 05/31/2013 10:15
>                                                 AM, Phil Hunt wrote:
>
>                                                     The preference is
>                                                     to have the access
>                                                     token for
>                                                     registration
>                                                     issued by the
>                                                     normal token
>                                                     server rather then
>                                                     by the
>                                                     registration
>                                                     endpoint.
>
>                                                     In the current
>                                                     draft it is
>                                                     obtained through a
>                                                     unique process and
>                                                     must outlive the
>                                                     client.
>
>
>                                                     Phil
>
>
>                                                     On 2013-05-30, at
>                                                     19:47, "Richer,
>                                                     Justin P."
>                                                     <[e-mail]
>                                                     <mailto:[e-mail]>>
>                                                     wrote:
>
>                                                         I don't
>                                                         understand any
>                                                         of the
>                                                         comments below
>                                                         -- it already
>                                                         *is* an OAuth2
>                                                         protected
>                                                         resource
>                                                         without any
>                                                         special
>                                                         handling. Your
>                                                         access tokens
>                                                         can be
>                                                         short-lived,
>                                                         long-lived,
>                                                         federated,
>                                                         structured,
>                                                         random blobs
>                                                         ... totally
>                                                         doesn't
>                                                         matter. They
>                                                         are access
>                                                         tokens being
>                                                         used to access
>                                                         a normal
>                                                         protected
>                                                         resource. Full
>                                                         stop.
>
>                                                         Anything else
>                                                         is out of
>                                                         scope. The
>                                                         lifecycle
>                                                         discussions at
>                                                         the beginning
>                                                         are merely
>                                                         examples of
>                                                         some ways you
>                                                         *could* use it
>                                                         and are
>                                                         non-normative
>                                                         and
>                                                         non-exhaustive.
>
>                                                         You seem to be
>                                                         asking for
>                                                         something
>                                                         that's already
>                                                         in the draft.
>
>                                                          -- Justin
>
>                                                         ------------------------------------------------------------------------
>
>                                                         *From:*Phil
>                                                         Hunt
>                                                         [[e-mail]
>                                                         <mailto:[e-mail]>]
>                                                         *Sent:*
>                                                         Thursday, May
>                                                         30, 2013 7:31 PM
>                                                         *To:* Richer,
>                                                         Justin P.
>                                                         *Cc:* John
>                                                         Bradley;
>                                                         [e-mail]
>                                                         <mailto:[e-mail]>
>                                                         WG
>                                                         *Subject:* Re:
>                                                         [OAUTH-WG]
>                                                         review
>                                                         comments on
>                                                         draft-ietf-oauth-dyn-reg-11.txt
>
>
>
>                                                         Phil
>
>
>                                                         On 2013-05-30,
>                                                         at 16:11,
>                                                         "Richer,
>                                                         Justin P."
>                                                         <[e-mail]
>                                                         <mailto:[e-mail]>>
>                                                         wrote:
>
>                                                             Comments
>                                                             inline,
>                                                             marked by
>                                                             [JR].
>
>                                                             ------------------------------------------------------------------------
>
>                                                             *From:*Phil Hunt
>                                                             [[e-mail]
>                                                             <mailto:[e-mail]>]
>                                                             *Sent:*
>                                                             Thursday,
>                                                             May 30,
>                                                             2013 5:25 PM
>                                                             *To:*
>                                                             Richer,
>                                                             Justin P.
>                                                             *Cc:* John
>                                                             Bradley;
>                                                             [e-mail]
>                                                             <mailto:[e-mail]>
>                                                             WG
>                                                             *Subject:*
>                                                             Re:
>                                                             [OAUTH-WG]
>                                                             review
>                                                             comments
>                                                             on
>                                                             draft-ietf-oauth-dyn-reg-11.txt
>
>                                                             See below.
>
>                                                             Phil
>
>                                                             @independentid
>
>                                                             www.independentid.com
>                                                             <http://www.independentid.com>
>
>                                                             [e-mail]
>                                                             <mailto:[e-mail]>
>
>                                                             On
>                                                             2013-05-30, at
>                                                             2:09 PM,
>                                                             Justin
>                                                             Richer wrote:
>
>
>
>
>                                                             OK, I
>                                                             think see
>                                                             part of
>                                                             the hang
>                                                             up. I have
>                                                             not seen
>                                                             the
>                                                             scenario
>                                                             that you
>                                                             describe,
>                                                             where you
>                                                             trade a
>                                                             3rd party
>                                                             token for
>                                                             a "local"
>                                                             token. I
>                                                             have seen
>                                                             where
>                                                             access
>                                                             tokens are
>                                                             federated
>                                                             directly
>                                                             at the PR.
>                                                             (Introspection
>                                                             lets you
>                                                             do some
>                                                             good
>                                                             things
>                                                             with that
>                                                             pattern.)
>
>
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