Hi,

I’m integrating a web application using angularjs 1.4.6 and keycloak 1.5.0.
The application and keycloak app-servers are on different ports.
The application works ok when the session is not expired.
After session expiration keycloak.updateToken() fails with
400 Bad Request. Chrome shows the following in the console:

XMLHttpRequest cannot load http://localhost:8080/auth/realms/demo/protocol/openid-connect/token. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost:9080' is therefore not allowed access. The response had HTTP status code 400.

The behavior is same with Safari and Firefox.

If I get it right, this 400 response from keycloak shouldn’t be
interpreted as CORS failure by browsers?

This is keycloak response when session is alive:

--> HTTP/1.1 200 OK
X-Powered-By: Undertow/1
Server: WildFly/9
Access-Control-Expose-Headers: Access-Control-Allow-Methods
Date: Tue, 29 Sep 2015 04:54:52 GMT
Connection: keep-alive
Access-Control-Allow-Origin: http://localhost:9080
Access-Control-Allow-Credentials: true
Transfer-Encoding: chunked
Content-Type: application/json

And this one with session expired:

--> HTTP/1.1 400 Bad Request
Connection: keep-alive
X-Powered-By: Undertow/1
Server: WildFly/9
Transfer-Encoding: chunked
Content-Type: application/json
Date: Tue, 29 Sep 2015 04:55:03 GMT

So my concerns are:

1. Why CORS headers depend on session validity? This caused much confusion for me,
because I thought there is a problem with CORS, until I understood this was session problem.

2. I think it would also be great to have some more context on error responses
(like returning some json with error description), because HTTP responses are too generic.