We are looking for a way using which users can login into Drupal site using their Google Apps account user name and password. We use 'Google Apps for Education' and we do not want maintain separate username and password for our Drupal site.
We would also like to limit access to certain users having Google Apps accounts. Something like filtering or pre-approved account list. And, users' account should be created automatically when they login for the first time, and they should not need to fill any additional account information in Drupal, it should be directly pulled from Google Apps account.
Is there any module for Drupal 7 that provides this functionality? I have already tried OAuth, Loginza.ru, OpenID etc. like approaches and these are not what we are looking for.
If there is no such module, how shall I proceed with writing a custom module for the same?