ABAC with keycloak - Using Resource attributes in policy - keycloak

Question

What I am trying to achieve
Protect a resource in Keycloak with policy like:
if (resource.status == 'draft') $evaluation.grant();
else $evaluation.deny();
Going by their official documents and mailing list responses, it seems attribute based access control is possible, however, I could not find a way of getting it to work.
What I have tried
Using Authorization Services: I was unable to figure out where and how I can inject the attributes from the resource instance.
Using Authorization Context: I was hoping to get the policies associated with a resource and a scope so that I could evaluate them my self.
So far, I have managed to get no where with both approaches. To be honest, I have been overwhelmed by the terminology used in the Authorization services.
Question
How can I use attributes of a resource instance while defining a policy in keycloak?

Answer 1

I solved this problem in Keycloak 4.3 by creating a JavaScript policy because Attribute policies don't exist (yet). Here is an example of the code I got working (note that the attribute values are a list, so you have to compare against the first item in the list):
var permission = $evaluation.getPermission();
var resource = permission.getResource();
var attributes = resource.getAttributes();
if (attributes.status !== null && attributes.status[0] == "draft") {
$evaluation.grant();
} else {
$evaluation.deny();
}

Answer 2

Currently there is no way to do what you are looking to do. ResourceRepresentation class only has (id, name, uri, type, iconUri, owner) fields. So you can use owner to determine ownership per Keycloak example. I've seen a thread that talks about adding additional resource attributes, but haven't seen a Keycloak JIRA for it.
Perhaps you could use Contextual Attributes in some way by setting what you need at runtime and writing a Policy around it.
var context = $evaluation.getContext();
var attributes = context.getAttributes();
var fooValue = attributes.getValue("fooAttribute");
if (fooValue.equals("something"))
{
$evaluation.grant();
}