Registration - Brian Campbell's review comments

[Michael Jones]

From: [e-mail] [mailto:[e-mail]] On Behalf Of Brian Campbell Sent: Thursday, January 24, 2013 3:48 PM To: [e-mail] Subject: [Openid-specs-ab] Comments on Registration (-14) Release Candidate D

Some comments/questions on http://openid.net/specs/openid-connect-registration-1_0-14.html follow:

http://openid.net/specs/openid-connect-registration-1_0-14.html#ClientRegistration 2.1. Client Registration and Client Update Request

The definition of access_token and the text near the bottom about registration_access_token seem to suggest that the (registration) access token need only be sent on client_update requests. But surly it's also needed for rotate_secret?

Changing from requiring client id and secret on client_update (and I assume rotate_secret) to needed the registration access token suggests that (short of some additional work) clients provisioned by some other means than this registration endpoint cannot update themselves or rotate their secret via the registration endpoint. I guess that could be a feature or a bug (or just meh) depending on how you look at it. But it just occurred to me and the change is relatively recent so I thought I'd mention it.

Honestly, it feels pretty awkward that the nature of the access token and if it's required or not differs based on the value of the operation parameter. It can work but means that the code that's doing the authn/z will need to examine the operation parameter in the request body in order to know what to do and the content of the token and how it's processed might be very different based on the operation. Anyway, I'm not necessarily objecting to it but still feel compelled to mention that it leaves kind of a bad taste.

jwk_url and x509_url say they are used for "signing Token Endpoint Requests" but there's nothing specified anywhere about signing Token Endpoint Requests, is there? Is it intended to mean signing the jwt when authenticating to the token endpoint using the private_key_jwt method?

All the jwk and x509 basically say that if both jwk and x509 are registered then. "the keys contained in both formats SHOULD be the same" but Messages 4.2 http://openid.net/specs/openid-connect-messages-1_0-15.html#sigenc.key has a MUST. Shouldn't these be consistent?

Issues 703 and 704 likely will impact the key parameters too.

A number of places say "The valid values are listed in Section 3.1 of JWA [JWA]" with respect to signing. But is "none" an acceptable/reasonalbe value for any or all of these?

http://openid.net/specs/openid-connect-registration-1_0-14.html#ClientRegisterResponse 2.2.1. Client Register Operation Response

says that "[client_secret] is not required for clients selecting a token_endpoint_auth_method of private_key_jwt" but what if they've selected HS256 (or other HSxxx) for request_object_signing_alg or any of the signed or singing parameters?

This section and 2.2.3 have "Additionally, the server MUST include all registered metadata about a client as described in Section 2.1, including any fields that the server has provisioned on the client's behalf." What is the expected behavior for default values from 2.1 (that very well might not be stored anywhere).

http://openid.net/specs/openid-connect-registration-1_0-14.html#ErrorResponse 2.3. Client Registration Error Response

I don't think invalid_client_id or invalid_client_secret are valid anymore?

http://openid.net/specs/openid-connect-registration-1_0-14.html#Security 5. Security Considerations "Requests to the Registration Endpoint for client_update MUST have some rate limiting on failures to prevent the Client secret from being disclosed though repeated access attempts." Which is true, I suppose, but no longer applies to the client secret but rather to the registration access token. Also doesn't it apply to rotate_secret as well?

http://openid.net/specs/openid-connect-registration-1_0-14.html#Acknowledgements Appendix A. Acknowledgements

Is empty. What does it take to get on there? ;) I'm sure I'm not the only one either...

Thanks, Brian

[Vladimir Dzhuvinov]

I also noticed that the invalid_client_id and invalid_client_secret error codes appear to be redundant now.

[Brian Campbell]

2.2.2 http://openid.net/specs/openid-connect-registration-1_0-14.html#RotateSecretResponse also has text that suggests the registration_access_token is only to be sent back for registration.

[Michael Jones]

You wrote:

2.2.1. Client Register Operation Response

says that "[client_secret] is not required for clients selecting a token_endpoint_auth_method of private_key_jwt" but what if they've selected HS256 (or other HSxxx) for request_object_signing_alg or any of the signed or singing parameters?

Do you have a suggested text change in response to this issue?

About your other comment on this section, see my note "Fields that the server has provisioned on the client's behalf".

[Michael Jones]

Fixed #727 - Deleted invalid_client_secret error

→ <<cset ff8e66e776f5>>