We have a need to customize the logic of our N2 authentication to add a couple of options.
I need to add a RadioButtonList that contains some options and set a session var based on the selection of that RadioButton on Login - otherwise the user cannot see the site in the preview pane of N2. I thought I could just add the RadioButtonList to the N2/Login.aspx and create a custom Login Class that extended N2.Edit.Login and override the Login1_Authenticate method to do my custom logic before calling base.Login1_Authenticate. It seems that it is not designed to be extensible and I cannot override that method. To make my change I would have to do a custom compile of N2 with these changes, which I want to avoid (should be closed to modification but open to extension) so we don't have to redo our changes every time we update N2.
Another route I tried was to create N2/CustomLogin.aspx and add all of my logic in that custom class and set the web.config to point to CustomLogin.aspx instead of Login.aspx - this sent me to the correct login page initially but a failed login redirected me to Login.aspx (assuming something hard coded) which did not have our radio button options.
We are using N2 CMS 2.0.0.0 on .Net 4.0 (MVC app)