On Wednesday 29 December 2010, Andrew Farmer wrote:
> On 29 Dec 2010 at 01:25, Igor Galić wrote:
> > Please share your particularly ugly, involved, unaesthetic or
> > otherwise /wrong/ solutions done with mod_rewrite because it
> > was the only hammer available for the screws at that time ;)
>
> I came up with the following abomination a while back to disable
> hotlinking to files when the referrer doesn't match the request
> host (in
>
> conjunction with a setup that amounts to wildcard DNS):
> > RewriteEngine on
> > RewriteCond %{HTTP_REFERER} ://([^/]+)/
> > RewriteRule . - [E=RHOST:%1]
> >
> > RewriteCond %{REQUEST_URI} ^/(albums|cache)/
> > RewriteCond %{ENV:RHOST} !^$
> > RewriteCond %{HTTP_HOST}:%{ENV:RHOST} !^([^:]*):(\1)$
> > RewriteRule . - [F]
>
> The observant will notice a novel abuse of regex backreferences
> used here to implement string comparison. A reimplementation of
> the same configuration in Lua should be able to avoid this. :)
Not what Igor wanted, but this could be simplified a lot by using the
shiny new ability of RewriteCond to use ap_expr:
RewriteCond %{REQUEST_URI} ^/(albums|cache)/
RewriteCond expr "%{HTTP_REFERER} -strmatch '*://%{HTTP_HOST}/*'"
RewriteRule . - [F]
BTW, is it possible to implement rewrite maps with mod_lua? I think it
would be an interesting application of mod_lua if it could be used to
add rewrite map functions, and ap_expr functions and operators.
