Standardised user login

[eluser]morph london[/eluser]
Hi I am very new to CodeIgniter and I am very impressed with what I have seen so far. Now my first CodeIgniter project involves a simple cms. I have been searching for a standardized way of

a) Creating a login page (email, password) from a database.
b) A piece of code I can add to each page that is "protected" that will redirect to the login page.

I was quite surprised in the documentation that there seems to be no way built into CodeIgniter to do this out of the box. Is there a standard was of achieving this? or is there a method anyone could recommend as being secure?

Also in my attempts to create such a page I have come across an issue with the Validation library. When I validate the password field and md5 it in the process, if the user has not entered a valid email it bounces back to the login page but the password field contains the md5 hash. I would like it to contain the original string.

Thanks for your help.