What is CPG currently integrated with in terms of Authentication?

[skullz]

Currently I have a site that has an open spot for users can input their name and password, I wish to have it connect to coppermines database on mysql 4 and return if the username exists and if password is correct ( not sure how secure that would be... heh ) would have to add captcha i guess to secure it from brute force...

Anyways, what Authentication scripts is CPG 1.4.x currently bridged or integrated with? ( Like allowing me to do the above )?

or is there a way to use the login.php from coppermine file directory and call it all from the sites root directory?

Because honestly, I dunno how to go about doing this and could really use some help.