Brain on Fire » Blog Tim McCormack, distilled

I like using HTTPS whenever possible. Usually this is as simple as adding a single letter to a URL, but some sites have separate domains for SSL. The Wikimedia sites are a great example of this; they share the domain secure.wikimedia.org and use the first elements of the path to specify the site.

Now, I could have set up a Greasemonkey script to redirect me once I hit an unsecure Wikipedia page, but then it's too late. (I'm usually going directly to the article via web search results.) I could also use Greasemonkey to rewrite URLs in web pages, but that's a mess. Instead, I wanted to intercept any requests to unsecure Wikipedia and redirect them on the fly, before they even left my machine. Here's how I set up my browser to always use SSL for Wikimedia sites:

1. Have Apache with virtual hosts and Mozilla Firefox with FoxyProxy
2. In my default virtual host:

   <Directory /var/www/>
   	RewriteEngine On
   	RewriteBase /
   	RewriteCond ${HTTP_HOST} !.*mycomputername.*
   	RewriteRule . rewriter.php [L]
   </Directory>

3. And this file at /var/www/rewriter.php:

   <?php
   
   $host = $_SERVER['HTTP_HOST'];
   $path = $_SERVER['REQUEST_URI'];
   
   // ensure path is not of form http://...
   if(strpos($path, '/') !== 0) {
   	$start = "http://$host/";
   	if(strpos($path, $start) === 0) {
   		$path = substr($path, strlen($start) - 1); // include slash
   	} else {
   		die();
   	}
   }
   
   if(preg_match('/([a-z0-9]+)\.wikipedia\.org/', $host, $m_domain)) {
   	header("Location: https://secure.wikimedia.org/wikipedia/{$m_domain[1]}{$path}");
   	die();
   }
   
   ?>

4. Then set up a proxy in FoxyProxy, early in the chain, called "rewriter". Set it to a SOCKS 5 proxy at localhost:80, using the whitelist regex http://[a-z]+\.wikipedia\.org/.*

Obviously, the setup as written here only gets Wikipedia, but it could easily be expanded to Wiktionary, Wikibooks, Wikimedia Commons, and other sister sites.

I'll delete any tech-support questions in the comments area, so don't ask them. This guide is for advanced users only. Discussions of potential improvements are welcome.