[keycloak-dev] Authz services feedback

Thu Jan 31 04:59:48 EST 2019

My 2¢: I've been recently tasked with creating a Spring Boot + Keycloak authz PoC. Somehow I've overlooked the existing app-authz-rest-springboot and did everything from scratch, which allowed me to discover many surprising bugs/features/snags (hope you'll help me to tell one from another).

1. It may sound crazy, but seems that with enforcer enabled there is no way to have public endpoints, i.e. those that are not protected by the  adapter security constraints. I've tried every possible combination of global and per-path enforcement-mode, tried creating the corresponding resource in Keycloak, but the enforcer would always deny access. The only scenario that worked was setting global enforcement-mode to DISABLED, which is obviously not an option.

I'm not sure if it's Spring Boot specific or not; I'm planning to test the same setup with other adapters too and report the result.

2. When configuring path-based resource, I have automatically put double quotes around the path like this:

keycloak.policy-enforcer-config.paths[0].path="/path"

Then I've killed some hours debugging the adapter trying to figure out why this wouldn't work, only to discover that the quotes are passed to the variables verbatim, i.e. including quotes. I think this is not something Keycloak specific, but maybe it could be worth mentioning in the docs, in order to help folks avoid frustrating experiences like mine.

3. {request.body[...]} pushed claim is totally broken. It drains out the servlet input stream before the control is passed to the underlying service, so when the service tries to process the request (which is, ehm, what services normally do) you will get something like "org.springframework.http.converter.HttpMessageNotReadableException: Required request body is missing". It's a well-known issue that servlet input streams are not rewindable, so I don't see any other solution than caching the whole request body in the memory and passing down a request wrapper.

As a cherry on top, it fails to recognize JSON request body, since it tries matching against "application/json" constant (RequestPlaceHolderResolver.java:125), and the browser would normally send something like "application/json; charset=UTF-8".

4. In JavaScript policies, $evaluation.context.identity.attributes has different meaning depending on whether the policy is used in authz or fine-grained permissions. In the first case it maps to the token claims, in the second to the custom attributes. Is this by design? It would be nice to have a unified API for both claims and attributes.

5. Let's say we need to implement a fine-grained permission for groups, which can be expressed as "a group admin is a user who 1) is a direct member of this group, 2) has a specific role, like group-admin". The first part can be implemented as a JS policy, but in order to obtain a GroupModel we'll need to parse resource name (which will be like "group.resource.e14f96e4-e06e-411f-bbdf-507e264dc33d"), extract group ID and finally call $evaluation.authorizationProvider.realm.getGroupById().

For authz resources used in fine-grained permissions, can we have a kind of link to the model object, or something like unwrap() method that would return the same?

Sorry for lengthy message, and again thanks a lot Pedro! Authorization services is a real power feature, and your contribution has been invaluable.

Kind regards,
Dmitry Telegin
CTO, Acutus s.r.o.

On Wed, 2019-01-30 at 09:29 -0200, Pedro Igor Silva wrote:
> Thanks for the feedback, Marek. Kudos to you too for talking about this
> stuff.
> 
> Answers inline.
> 
> > On Wed, Jan 30, 2019 at 8:39 AM Marek Posolda <mposolda at redhat.com> wrote:
> 
> > I recently have a chance to play a bit more with authz services when
> > preparing for the devconf demo. Great stuff and cudos to Pedro and all
> > the others who contributed to authorization services!
> > 
> > I just have few questions and possible suggestions to improve in the
> > future :) Also based on some questions and discussion I had after the talk:
> > 
> > - My REST service was SpringBoot based and protected by policy enforced
> > configured in the applications.properties like this
> > 
> > https://github.com/mposolda/devconf2019-authz/blob/master/devconf2019-service/src/main/resources/application.properties#L23-L32
> > . However I was stuck when I wanted to enable UserManagedAccess for my
> > service. The PolicyEnforcerConfig.UserManagedAccessConfig is an empty
> > class and I couldn't figure how to properly add it in the
> > application.properties file. I've tried to add various things in
> > application.properties like this, but none of them helped:
> > 
> > keycloak.policy-enforcer-config.user-managed-access
> > keycloak.policy-enforcer-config.user-managed-access=
> > keycloak.policy-enforcer-config.user-managed-access= (Just left single
> > space here after equals character)
> 
> 
> > As a workaround, I ended with having separate bean to do it
> > programatically -
> > 
> > https://github.com/mposolda/devconf2019-authz/blob/master/devconf2019-service/src/main/java/org/keycloak/quickstarts/devconf2019/config/KeycloakUMAConfigResolver.java
> > . Is it a bug or is it just me doing something stupid?
> > 
> 
> He had some feedback in the past about that too, but the workaround you did
> is what people are doing. I've created
> https://issues.jboss.org/browse/KEYCLOAK-9458.
> 
> Similar issue we have when you just want to enable the policy-enforcer
> without any configuration. You need to specify at least one property of
> policy-enforcer (or create a bean).
> 
> 
> > 
> > 
> > - I wonder about possible improvements of keycloak-authz.js and if
> > usability can be a bit improved? More specifically I mean this:
> > -- Handling of the 401 response with UMA ticket from resource-server -
> > Can this be done "automatically"? I meant the flow described here:
> > 
> > https://www.keycloak.org/docs/latest/authorization_services/index.html#handling-authorization-responses-from-a-uma-protected-resource-server
> > . Maybe the keycloak-authz itself can just handle the response from
> > resource server, then send the AuthorizationRequest to KC with the UMA
> > ticket and then possibly re-send the request to resource-server with new
> > RPT and do this "automatically" without a need to manually handle it by
> > the application like this:
> > 
> > https://github.com/keycloak/keycloak-quickstarts/blob/latest/app-authz-uma-photoz/photoz-html5-client/src/main/webapp/js/app.js#L154-L208
> > . WDYT?
> > 
> 
> We had that before, but due to some changes in UMA specs, I decided to
> remove this capability from the adapter. We can discuss to get it back
> again.
> 
> 
> > 
> > -- Another thing is refreshing of RPT. It looks that RPT response
> > contains the refresh token, so refreshing of RPTs is possible. However
> > the keycloak-authz.js client doesn't have any support for automatically
> > refreshing RPT token. I mean something similar, which is provided by
> > keycloak.js itself (method "keycloak.updateToken" which automatically
> > refreshes the token if needed). Due this limitation, it seems there is a
> > bug in our quickstart. When you try the quickstart
> > "app-authz-uma-photoz" and you go through the flow like this:
> > > > - Open http://localhost:8080/photoz-html5-client and login as jdoe
> > - Create some album
> > - Wait 10 minutes (RPT expiration is same like AccessTokenLifespan, so 5
> > minutes by default)
> > - Try to create some album again - now fails with 403 due the RPT
> > expired and no support for refreshing it in the keycloak-authz.js or the
> > application itself.
> > Should I create JIRA for this?
> > 
> 
> Yes, please.
> 
> 
> > 
> > 
> > - It seems we don't have any Java based adapter for the frontend clients
> > written in Java? We have Java based authorization client, but that
> > provides just sending REST requests. It doesn't provide things like I
> > mentioned above though (Storing RPT, automatically refreshing RPT,
> > Automatically handling 401 response with the UMA ticket from
> > resource-server and sending the request to KC etc). Any plan to have this?
> > 
> 
> Could we leverage the authz client for that ? If you could create a JIRA
> with more details about the scenarios we are trying to support, we can
> start thinking about a solution.
> 
> Thanks !
> 
> 
> > 
> > Marek
> > 
> > _______________________________________________
> > keycloak-dev mailing list
> > keycloak-dev at lists.jboss.org
> > https://lists.jboss.org/mailman/listinfo/keycloak-dev
> > 
> 
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