Request: refresh 'id_token' w/ 'access_token'

[nwoolls]

Which version of Duende IdentityServer are you using?

I am using only Duende.AccessTokenManagement, version 2.0.3.

Which version of .NET are you using?

.NET 8 RC2.

Describe the bug

This is a feature request. I apologize if this is not the right forum. I tried to find the right path from the here.

I saw this mentioned and closed previously here:

https://github.com/IdentityModel/IdentityModel.AspNetCore/issues/291

We are using a 3rd-party IDP (Ping Identity) and, if we try to sign out using the normal SignOutAsync() after the id_token has expired, we receive an error that the id token is expired.

I can see that the new id_token is returned with the refresh call, but in the current implementation of this library, it is dropped rather than returned with the user token and stored in the cookie.

I've put together a very simple bit of code that unfortunately has to duplicate some of your internal logic to refresh the id_token with the rest of them, e.g. similar to what is seen here:

https://devforum.okta.com/t/get-token-from-asp-net-core-to-pass-to-backend-as-verification/5914/6

And confirmed that this does work.

Given there may be other IDPs with this challenge, is it possible you may revisit refreshing the id_token along with the access_token and refresh_token?

To Reproduce

Output an id_token, access_token, and refresh_token before calling e.g. HttpContext.GetUserAccessTokenAsync(). Note that afterward only the access_token and refresh_token were updated / persisted.

Expected behavior

I'd like to see, either OOTB or optionally, the id_token returned when using a refresh_token returned in the UserToken object and persisted in the store / cookie.

Additional context

You can see the report on this to the IDP (Ping) here: https://github.com/pingidentity/pingone-sample-dotnet/issues/8

[AndersAbel]

The logout is described in the OpenID Connect RP-Initiated Logout 1.0 spec. Section 2 states that:

The OP SHOULD accept ID Tokens when the RP identified by the ID Token's aud claim and/or sid claim has a current session or had a recent session at the OP, even when the exp time has passed.

The interpretation of SHOULD is defined in RFC2119 as

This word, or the adjective "RECOMMENDED", mean that there may exist valid reasons in particular circumstances to ignore a particular item, but the full implications must be understood and carefully weighed before choosing a different course.

To me, it looks like an OP should not validate the exp of the id_token_hint, unless there are specific reasons to do it. IdentityServer does accept expired id tokens as id_token_hint, so I don't think this will be anything that is a high priority for us to fix.

[nwoolls]

@AndersAbel thank you for your feedback and for chiming in on the linked post!

[AndersAbel]

The Duende.AccessTokenManagement library is, as the name implies, all about access token management. We never really considered the id_token.

The only use we see for the id_token after the initial session establishment is to be used at logout. As discussed previously an old id_token should be valid for that. Usually and id_token has a very short lifespan, shorter than the access token, so even if we would save it there's no guarantee that the id_token is valid when logout is tried. The real fix here is for Ping to fix their implementation.

Our conclusion is that we will not make any changes to the library to automatically save the id_token. However, we try to make our libraries flexible enough to allow users to customize behaviour. Apparently, there is no extension point in the existing library that would allow saving the updated id_token. We are looking into possibilities to add such an extension point.