Require Login on All Sites and Pages


I've searched and searched and I can't seem to find a current and reliable script or plugin that requires a login at any point of entry to the domain. I have Multisite Privacy running but it doesn't force a login at the root level of the domain, so the main site's default page is still displaying. Ultimately, I'd just like to add a function that makes wp-login.php the first page any non-authenticated registered user will see when they visit the site from any referrer.

Any ideas? The solutions I used in the past are not current with 3.5.1.

Thanks in advance!