Custom Authorization extension


I am a new user and was trying out Opendistro’s security plugin. I want to extend the security plugin with new Authorization extension. We have a requirement to integrate it with Apache Ranger. Current code in security plugin provides an interface ‘’ which only provides API ‘fillRoles()’ which can be implemented by custom class. However, what I am looking for is an extension API where it can pass (User, action, request) as arguments and API returns if request should is allowed or not (an extension or new implementation to what is currently being done in PrivilegesEvaluator evaluate() API).

Can someone please guide or tell me on how can I go about making changes for the same ?