Allowed returns Authenticator.Allowed result, it user is not allowed to use current resource, an non nil error is returned.

GetCurrentUsername returns Authenticator.GetCurrentUsername response, it must give the current logged user name.

Login will return the Authenticator.Login result - if the user login process failed, an error is returned.

SetAuthenticator will register given Authenticator to use.

Authenticator interface to implement user management (eg.