by richard4339 on WordPress.org
A plugin for Wordpress that redirects users to the login page whenever they try to visit any page/post/etc on the blog.

The Require Login Settings page.
A simple plugin for WordPress that redirects users to the login page whenever they try to visit any page/post/etc on the blog, with an option menu to turn this functionality on or off. When enabled, the entire blog essentially becomes a private blog.
In addition to the subversion access that WordPress is providing, this plugin is available through git at GitHub.