We have implemented Spring Oauth authorization+resource server that can be used for external applications.
Now we would like to add custom checks before some oauth calls returns in the authorization server, most importantly for the authorization code but also before allowing returning a token sometimes.
An example use case might be that which users that are allowed to login for a specific client_id might vary and if not allowed this should generate a redirect back with an error. So for example a user might trigger a login from a third-party app, redirected to our authorization server and shown a login page, however after login it is discovered (through our business logic) that this specific user is not allowed to authorize access to that specific app/client id.
What is the best way to achive this result in a way that is consistent error handling in Spring oauth?
Also, a related question is also how to resolve the client details before the login screen shown so more specific client details can be shown when logging in? We could parse the client_id parameter manually but maybe there is a more elegant way to hook into Spring oauth to solve this? (sorry for dual question but its sort of related and the first question is the most important one)
