Codeigniter 3.x Authentication Library?
don't let the down votes get ya down.
check out Ion Auth https://github.com/benedmunds/CodeIgniter-Ion-Auth
take a look at the read me, you will have to rename two files for codeigniter 3. otherwise you can see that there are recent changes to the lib. the author Ben Edmunds is one of the four developers on the new codeigniter council. http://www.codeigniter.com/help/about
Please check Dnato System Login
Its Simple, Fast and Lightweight auth codeigniter.
Feature:
-Add user
-Delete user
-Ban, Unban user
-Register new user sent to email token
-Forget password
-Role user level
-Edit user profile
-Gravatar user profile
-Recaptcha by Google
-And much more
Frontend
With Bootstrap Framework.
For a simple library, I use https://github.com/trafficinc/CodeIgniter-Authit (Authit). It is very simple so I can do a lot of customizations to it or just leave it be.