[keycloak-dev] Silent Re-authentication using ID Token

[Stian Thorgersen]

The sane approach to me is to extend the token introspection endpoint to be
able to introspect ID tokens.

Extending authorization endpoint with custom responses is just weird ;)

On Tue, 29 Oct 2019 at 21:23, Pedro Igor Silva <psilva at redhat.com> wrote:

> Yes, I was more thinking about re-using the authorization endpoint  +
> prompt=none + id_token_hint with a custom response to indicate whether or
> not the session is active. Similar to what some implementations do by
> extending the introspection endpoint or something else.
>
> On Tue, Oct 29, 2019 at 12:06 PM Stian Thorgersen <sthorger at redhat.com>
> wrote:
>
>> [Adding what we discussed]
>>
>> Authorization code flow should not be used as a backchannel API, but
>> rather only as a redirect-based API through the user-agent. That is pretty
>> obvious from the fact that all responses return a Location header. That
>> means that the cookie should always be there as the user is authenticated.
>>
>> id_token_hint should never be used to re-authenticate, but rather only as
>> a hint on the identity of the user as well as the session. If the id_token
>> could be used to actually authenticate the user it would effectively become
>> a user credential and giving a client full access to the user account, with
>> the ability to obtain tokens for any client.
>>
>> prompt=none with id_token_hint can be used as a way to identify if the
>> expected user is still authenticated, but only through a redirect (either
>> directly or with a hidden iframe), not as a backchannel mechanism.
>>
>> On Fri, 25 Oct 2019 at 18:25, Pedro Igor Silva <psilva at redhat.com> wrote:
>>
>>> Hi,
>>>
>>> I would like to confirm that we don't support the `id_token_hint`
>>> authorization request parameter.
>>>
>>> When in conjunction with `prompt=none` it is useful to re-authenticate as
>>> well as check whether or not the session associated with the token is
>>> active through a non-authenticated request (e.g.: no cookies set by the
>>> OP).
>>>
>>> The use case I'm trying to solve is based on the assumption that you only
>>> have/keep the ID Token, you don't want a front/back channel for logout
>>> (e.g.: app is stateless), you need to check whether or not session is
>>> active, and the check is done through a backchannel communication between
>>> the application and the OP.
>>>
>>> Spec-wise, using either user-info or introspection endpoint is not
>>> possible
>>> if you only have the ID Token (although some implementations like Google
>>> provide an addition `id_token_hint` to the introspection endpoint) given
>>> that you should use the access token as a bearer.
>>>
>>> Wdyt ?
>>>
>>> Regards.
>>> Pedro Igor
>>> _______________________________________________
>>> keycloak-dev mailing list
>>> keycloak-dev at lists.jboss.org
>>> https://lists.jboss.org/mailman/listinfo/keycloak-dev
>>>
>>