[keycloak-dev] Better support for "scope" in adapters
Marek Posolda
mposolda at redhat.com
Wed Feb 6 05:53:22 EST 2019
On 05/02/2019 09:39, Stian Thorgersen wrote:
> Tried to filter out implementation details here, so may have lost some
> details. It would be good if we can try to keep discussions at a
> higher level at least initially as it makes it much easier to follow
> the discussion.
Point taken :) Will try to improve next time.
>
> For scopes I can see the most common use-case will be the ability to
> do incremental scopes. By that I mean the application doesn't request
> all permissions it may need, but rather starts small and asks for more
> as the user extends use of the application. This is mostly relevant to
> applications that require consent.
>
> Now with regards to the application being able to have different
> tokens to invoke different services I'm not convinced this is needed
> so we should rather wait for demand here. There's two ways a single
> app can consume multiple services:
>
> 1) Application directly invokes multiple services - in this case the
> application should be able to use scopes or token exchange to obtain
> tokens to invoke different services. In fact I'd say token exchange is
> probably what is wanted here rather than scopes.
> 2) Application invokes a backend service that aggregates multiple
> services - in this case token exchange comes in as the backend service
> needs to be able to obtain tokens to invoke the different services
>
> I would think option 2 is the best approach as it allows implementing
> the complex code in server side code and also makes the application
> more transparent to API changes.
This seems to be inline with what Pedro mentioned as well. +1 for
waiting for a demand for this.
>
> With regards to incremental scope support we need to be able to do
> that without requiring logout. For JS adapter that should already
> work, but it has one issue and that is you can't set the scope to use
> with automated login. We should probably make the scope configurable
> in the init function as well as when invoking login function directly.
> For servlet we should probably also have a way to configure the
> initial scope and expose a method to obtain additional scopes without
> requiring logout.
+1
Regarding JS adapter, there are few other things, which you can't do at
"init" method. For example adding the "prompt" . Maybe all the current
options of "login" method can be just used as arguments to "init" method?
For the servlet adapter, it will be probably good to have something like
JS adapter "keycloak.login" method or "keycloak.createLoginUrl", which
allows to add things like custom scope, prompt etc. I proposed something
like KeycloakLoginUrlBuilder, which will allow to easy add things like
"scope" or "prompt" in the adapters code.
>
> I'm not convinced about client scope inheritance. It has an additional
> implementation complexity, but most importantly usability with regards
> to understand what is actually included in the token when you have
> inheritance. It may also have some strange side-effects like how do
> you make sure the order of what is applied is correct. Again, probably
> something best left until there is demand for it.
We already have "priority" on protocolMappers, so ordering likely won't
be an issue. You can add protocolMappers of all the "effective" client
scopes and sort the protocol mappers. But agree that will be good to
wait for more demand before adding this.
Marek
> On Thu, 31 Jan 2019 at 17:04, Pedro Igor Silva <psilva at redhat.com
> <mailto:psilva at redhat.com>> wrote:
>
> +1
>
> On Thu, Jan 31, 2019 at 11:14 AM Marek Posolda
> <mposolda at redhat.com <mailto:mposolda at redhat.com>> wrote:
>
> > On 31/01/2019 14:07, Pedro Igor Silva wrote:
> >
> > This what I like most about client scopes (in addition to all
> mapping you
> > do to claims in the tokens) :) Would also make sense to do the
> same thing
> > to client scopes ? So clients requesting "foo" would also get
> "bar" and
> > "xpto", for instance ?
> >
> > Maybe this could avoid the client to request 10 scopes but just
> a more
> > coarse-grained scope representing all of them.
> >
> > There is opened JIRA for client scopes inheritance
> > https://issues.jboss.org/browse/KEYCLOAK-6633 . I believe this
> will cover
> > what you have in mind? It's just not yet done...
> >
> > Marek
> >
> >
> >
> > On Thu, Jan 31, 2019 at 10:43 AM Marek Posolda
> <mposolda at redhat.com <mailto:mposolda at redhat.com>>
> > wrote:
> >
> >> On 30/01/2019 14:40, Pedro Igor Silva wrote:
> >>
> >>
> >>
> >> On Wed, Jan 30, 2019 at 5:25 AM Marek Posolda
> <mposolda at redhat.com <mailto:mposolda at redhat.com>>
> >> wrote:
> >>
> >>> On 29/01/2019 19:49, Pedro Igor Silva wrote:
> >>>
> >>> I'm not sure if we need to consider that in our adapters.
> >>>
> >>> Usually, the front-end knows the set of scopes that it needs
> to interact
> >>> with the backend and stay functional.
> >>>
> >>> Maybe. I am personally not sure how people expect to use "scope"
> >>> parameters in their frontend applications. Maybe 90% of
> frontend clients
> >>> don't need to use "scope" parameter at all. And from the
> remaining, they
> >>> will be fine with the current support of the "scope" parameter.
> >>>
> >> I would say so, mainly because I think people are still using
> RBAC to
> >> enforce access to APIs. Enterprise scenarios don't really use
> scopes as
> >> they are more related with delegation.
> >>
> >> Yeah, maybe. Just a note that our client scopes support also
> allows to
> >> limit roles in the token. For example you can define role scope
> mappings of
> >> client scope "service1" to have role
> "service1.my-service1-role" . So by
> >> requesting "scope=service1", you will also receive this role in
> the token
> >> and hence can be used for RBAC based authorization.
> >>
> >> But anyway, I probably won't create any JIRAs for now. Will
> wait if there
> >> is some more feedback or some more requests for better support
> of "scope"
> >> parameter in the adapters.
> >>
> >> Thanks for the feedback Pedro!
> >>
> >> Marek
> >>
> >> One possibility, where I can see usage of this, is when
> frontend client
> >>> wants to invoke multiple different services and he wants to
> use different
> >>> access tokens with properly "isolated" audiences. So for
> example you want
> >>> to have:
> >>>
> >>> - access token with "scope=service1", which will have in
> itself audience
> >>> claim "aud: service1" and you will use it to invoke backend
> service1
> >>> - access token with "scope=service2", which will have in
> itself audience
> >>> claim "aud: service2" and you will use it to invoke backend
> service2
> >>>
> >>> In this case, having the possibility for adapters to "cache"
> multiple
> >>> tokens for various scopes can be beneficial IMO, so client can
> easily
> >>> retrieve proper access token based on the service he wants to
> invoke.
> >>>
> >>> And the backend by itself is free to exchange tokens to call other
> >>> services (service chaining).
> >>>
> >>> Don't think that brings a lot of complexity to the front-end and,
> >> probably, indicates a bad design?
> >>
> >>> IMO in many cases, you're right. For example when frontend
> client uses
> >>> access token to invoke backend "service1", this backend may
> want to
> >>> retrieve some other data from "service11". So service1 backend
> needs to
> >>> reuse the token or he wants to exchange this token.
> >>>
> >>> But in many cases, you want to avoid this. So in my example
> above, when
> >>> you have access token with "aud: service1", you want this
> access token to
> >>> be used solely to invoke service1. You don't want to have one
> huge access
> >>> token, which will have all the audiences like:
> >>>
> >>> aud: [ "service1", "service2" ]
> >>>
> >> The access token is also tied with the client, what means "this
> client is
> >> allowed to invoke service1 and service2". I usually don't see a
> problem on
> >> that if you consider that multiple audiences mean that a high
> degree of
> >> trust between the parties involved. What I think is true for most
> >> enterprise use cases where the front-end is basically accessing
> internal
> >> services.
> >>
> >> It is also worthy to consider, IMO, that the fact that you have
> distinct
> >> services, does not mean they are not part of the same API, thus
> the same
> >> audience.
> >>
> >>> You may want separate access tokens with isolated audiences
> exactly
> >>> because you don't want service1 and service2 to be able to
> invoke each
> >>> other. IMO this isolation is one of the main usages of the
> "aud" claim in
> >>> the tokens.
> >>>
> >>>
> >>> One thing that makes sense though is "incremental
> authorization" and
> >>> allow apps to request additional scopes during an
> authentication session,
> >>> so the app gets what was previously granted and the new scopes
> (depending
> >>> on user consent). But I think we support that already, right ?
> >>>
> >>> We don't support it directly and maybe this is something to
> improve. ATM
> >>> you will need programatically do something like this:
> >>>
> >>> String existingScope = existingAccessToken.getScope();
> >>>
> >>> // I want to use existingScope and add "phone" scope to it
> >>> String newScope = existingScope + " phone";
> >>>
> >>> // Request the login for new scope now
> >>>
> >>>
> >>> The part of "requesting login for new scope" is possible with
> javascript
> >>> adapter, but not easily with the "java" adapter. With java
> adapter, there
> >>> is no easy way to manually "build" URL to sent to OIDC
> authentication
> >>> endpoint (equivalent of keycloak.js method "createLoginUrl").
> That's also
> >>> one of the things, which I proposed to improve in this email
> thread.
> >>>
> >> Marek
> >>>
> >>>
> >>> Regards.
> >>> Pedro Igor
> >>>
> >>> On Tue, Jan 29, 2019 at 9:36 AM Marek Posolda
> <mposolda at redhat.com <mailto:mposolda at redhat.com>>
> >>> wrote:
> >>>
> >>>> During my work on Client Scopes last year, I did not any work
> on the
> >>>> adapters side. I think there is a space for improvement here.
> I will
> >>>> try
> >>>> to summary current issues and some initial proposals for improve
> >>>> things.
> >>>> Suggestions welcomed! And sorry for longer email :)
> >>>>
> >>>>
> >>>> Both javascript adapter and servlet adapter has some way for
> requesting
> >>>> the additional "scope" and ensure that that initial OIDC
> authentication
> >>>> request sent to Keycloak will contain some custom "scope"
> parameter.
> >>>> The
> >>>> javascript adapter has support for "scope" as an option of
> the "login"
> >>>> method [1]. The servlet adapter has a possibility to inject
> custom
> >>>> "scope" with parameters forwarding [2]. I am not sure about
> node.js and
> >>>> other adapters TBH. But even for javascript and servlet
> adapter, the
> >>>> current support is quite limited for few reasons. For example:
> >>>>
> >>>> - The approach of parameters forwarding used in servlet adapters
> >>>> requires to logout before requesting the additional scope.
> Because
> >>>> when
> >>>> I am already authenticated in the application and I open
> secured URL
> >>>> like http://localhost/app/secured?scope=some-custom-scope,
> the adapter
> >>>> will just ignore it in case that user is already logged-in
> and it will
> >>>> automatically forward to the application.
> >>>>
> >>>> - Both servlet and javascript adapters support to have just
> single
> >>>> "triplet" of tokens per browser session. In this context
> "triplet"
> >>>> means
> >>>> the single set of 3 tokens (ID token , Access Token , Refresh
> token).
> >>>> So
> >>>> for example when I want to request the custom scope for being
> able to
> >>>> invoke "service1", I can use "scope=service1". However after
> Keycloak
> >>>> redirects me back to the application, the existing triplet of
> tokens is
> >>>> just replaced with the new one for "service1" . Then when I
> want to
> >>>> later invoke another service like "service2", I need to
> request the
> >>>> additional scope "scope=service2", which will replace my
> tokens on the
> >>>> adapter's side with the "service2" tokens . But then later
> when I want
> >>>> to switch again to "service1", I need to redirect to Keycloak
> again as
> >>>> the current triplet of tokens for "service1" etc.
> >>>>
> >>>>
> >>>> To improve this limitation, I think that it will be good if
> adapters
> >>>> easily support the following:
> >>>>
> >>>> - Instead of having single triplet of tokens, it will be good if
> >>>> adapters can contain Map of tokens. Key of the map can be "scope"
> >>>> parameter. So for example, the adapter will have "default" tokens
> >>>> (those, which were used for initial login), the tokens for
> "service1"
> >>>> and the tokens for "service2" .
> >>>>
> >>>> - It will be nice if there is easy way to ask adapter for
> "service1"
> >>>> scope. In case that I don't have yet this scope, adapter will
> redirect
> >>>> me to Keycloak with "scope=service1". If I already have it,
> adapter
> >>>> will
> >>>> return me an existing token. If existing access token is expired,
> >>>> adapter will refresh the access token for requested scope in the
> >>>> background and return me the "updated" token.
> >>>>
> >>>> - When I want to invoke service1 and I need to use
> "scope=service1", I
> >>>> usually need just access token and refresh token. I don't
> need ID Token
> >>>> anymore. I also don't need the "profile" and "email" claims to be
> >>>> returned in the new access token. This is related to the JIRA
> of having
> >>>> the server-side support for client scopes like (always, default,
> >>>> optional) instead of current (default, optional) [3]. In
> other words,
> >>>> the client scopes "profile" and "email" will be default
> client scopes,
> >>>> which means that if I don't use "scope=openid" in the OIDC
> initial
> >>>> request, the "profile" and "email" will be ommited from the
> response as
> >>>> well as the ID Token will be ommited from the response.
> >>>>
> >>>>
> >>>> So how to support this on adapters? For Keycloak.js, I can
> think about
> >>>> some variation of existing "update" method like this:
> >>>>
> >>>>
> >>>> keycloak.updateTokenWithScope('service1',
> >>>> 5).success(function(accessToken, refreshed) {
> >>>> if (refreshed) {
> >>>> alert("I had existing accessToken for scope
> 'service1',
> >>>> but
> >>>> it needed to be refreshed as it was expired or about to
> expire in less
> >>>> than 5 seconds");
> >>>> } else {
> >>>> alert('I have accessToken for 'service1', which
> didn't
> >>>> need to be refreshed');
> >>>> }
> >>>> // I can invoke REST service now with the accessToken
> >>>> ...
> >>>> }).error(function() {
> >>>> alert("Failed to refresh the token OR I don't have
> yet scope
> >>>> for 'service1' .");
> >>>> // User usually need to call keycloak.login with the
> requested
> >>>> scope now...
> >>>> });
> >>>>
> >>>>
> >>>>
> >>>>
> >>>> For servlet adapter something like:
> >>>>
> >>>> KeycloakSecurityContext ctx = ... // Retrieved from
> HttpServletRequest
> >>>> or Principal as currently
> >>>>
> >>>> if (ctx.hasScope("service1")) {
> >>>> try {
> >>>> String accessToken = ctx.getScope("service1");
> >>>> // Invoke service1 with accessToken now
> >>>> } catch (TokenRefreshException ex) {
> >>>> log.error("I already had scope for service1, but
> failed to
> >>>> refresh the token. Need to re-login for the scope service1");
> >>>>
> >>>> // See method below
> >>>> redirectToKeycloakWithService1Scope();
> >>>> }
> >>>> } else {
> >>>> // See method below
> >>>> redirectToKeycloakWithService1Scope();
> >>>> }
> >>>>
> >>>>
> >>>> private void redirectToKeycloakWithService1Scope() {
> >>>> KeycloakRedirectUriBuilder builder = ctx.createLoginUrl();
> >>>> URL url = builder.scope("service1").build();
> >>>> httpServletResponse.sendRedirect(url);
> >>>> }
> >>>>
> >>>>
> >>>> Regarding the class KeycloakRedirectUriBuilder, I was
> thinking about
> >>>> this class so that servlet adapter are able to easily create
> login URL
> >>>> with custom values for things like scope, prompt, max_age
> etc. This
> >>>> capability is currently missing in servlet adapters and the
> current
> >>>> approach based on parameters forwarding is a bit clunky for few
> >>>> reasons.
> >>>> One reason is usability and the other is, that you need to
> logout first.
> >>>>
> >>>>
> >>>> [1]
> >>>>
> >>>>
> https://www.keycloak.org/docs/latest/securing_apps/index.html#javascript-adapter-reference
> >>>> [2]
> >>>>
> >>>>
> https://www.keycloak.org/docs/latest/securing_apps/index.html#_params_forwarding
> >>>> [3] https://issues.jboss.org/browse/KEYCLOAK-8323
> >>>>
> >>>> Marek
> >>>>
> >>>> _______________________________________________
> >>>> keycloak-dev mailing list
> >>>> keycloak-dev at lists.jboss.org
> <mailto:keycloak-dev at lists.jboss.org>
> >>>> https://lists.jboss.org/mailman/listinfo/keycloak-dev
> >>>
> >>>
> >>>
> >>
> >
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