Thank you for a great module! I have started to explore the many possibilities that this module opens up.
A note myself that might help someone else too: I have a shared hosting that uses FastCGI. I couldn't get the Basic authentication to work using the Authorization header. Adding the following line to .htaccess does the job (available in Apache HTTP Server 2.4.13 and later).
CGIPassAuth On
Earlier version of Apache may use
<IfModule mod_rewrite.c>
RewriteEngine on
RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization},L]
</IfModule>
Source: https://stackoverflow.com/questions/3663520/php-auth-user-not-set