HTTP::Server::Simple::Authen is an HTTP::Server::Simple plugin to allow HTTP
authentication. Authentication scheme is pluggable and you can use whatever
Authentication protocol that Authen::Simple supports.

You can use authenticate method whatever you want to authenticate the request.
The method returns $username taken from the request if the authentication is
successful, and undef otherwise. The code in "SYNOPSIS" requires authentication
for all the requests and behaves just the same as Apache's Require valid-user.