RewriteCond: any workaround to match the HTTP_REFERER with HTTP_HOST?

Question

1) I need to verify whether the connections are referred by my same site or by someone else. 2) I can NOT simply type the HTTP_HOST manually because the .htaccess file is meant to be handled by subversion and shared across different development environments with different HTTP_HOST values

So the goal is to find a workaround to make this condition work transparently no matter what the environment is, and keep htaccess easily handled by svn without need of manual fixes.

Thanks!

Answer 1

With Apache 2 you can do this:

RewriteCond %{HTTP_REFERER} ^$ [OR]
RewriteCond %{HTTP_REFERER} ^[^:/?#]+://([^/?#]+)  # get authority
RewriteCond %1 ^(?:(?:[A-Za-z0-9-._~!$&'()*+,;=:]|%[0-9A-Fa-f]{2})*@)?((?:[A-Za-z0-9-._~!$&'()*+,;=]|%[0-9A-Fa-f]{2})*)(?::\d+)?$  # get host name
RewriteCond %1/%{HTTP_HOST} !^([^/]+)/\1$  # compare to HTTP_HOST
RewriteRule ^ …

Note that HTTP_HOST can also be empty in case of an pre-HTTP/1.1 request.