How to add extra checks during login (Rails + Devise) - ruby-on-rails

Question

I have a Ruby On Rails 3.x application using device.
My goal is to add a Yubikey input field to the login screen.
I have generated the views, adjusted the screen (i.e. the extra field shows up) and updated the routes as follows:
devise_for :users, :controllers => { :sessions=>"sessions", :registrations => "registrations" }, :path => "users", :path_names => { :sign_in => "login", :sign_out => "logout", :sign_up => "register" }
Not to forget, I created a session controller:
class SessionsController < Devise::SessionsController
def create
begin
if do_some_other_checks
super
else
build_resource
clean_up_passwords(resource)
flash[:alert] = "Login error"
render :new
end
rescue => e
build_resource
clean_up_passwords(resource)
flash[:alert] = "Login error"
render :new
end
end
end
Unfortunately the code doesn't quite work, it gets called after Devise has the user logged on, i.e. even if the additional check fails, the user still gets logged in.

Answer 1

There is a simple way to do this in your user model by adding in the following, no need to create any devise controllers or change default routes ...
class User < ActiveRecord::Base
# check to see if a user is active or not and deny login if not
def active_for_authentication?
super && do_some_other_checks
end
end