Subscribing to a members-only SMF forum via RSS

This is one of those bug or feature? cases. I'm member of an online forum which uses Simple Machine Forum (or SMF for short. This is a members only forum, meaning that if you are not a member (or not logged in) you see a very little subset of the forum.

Now I would like to subscribe via RSS to the posts (since this is my preferred way of consumption), but faced the following problem: unless I accessed the feed from Firefox, I only got the posts which were in the public area (not very interesting). This was true both for desktop based and web based readers, and I suspected the cause was that these clients were not logged in when they were fetching the feed.

So I did a little hack: I got the value for my PHP session ID (also, my session is set never to expire, which is not very secure, but convenient). You can do this by viewing the cookies associated with the given site and getting the value from the PHPSESSID cookie (it should look like something like: "d41d8cd98f00b204e9800998ecf8427e" - without the quotes).

Now take the RSS feed URL and append the session id to it like this:

http://example.com/index.php?type=rss;action=.xml;PHPSESSID=d41d8cd98f00b204e9800998ecf8427e

This will fetch the feed with your credentials. Some caveats: if you are using an online reader (like Bloglines), this means effectively trusting them with your session. Also, this may or may not work depending on PHP settings and the given SMF version (I didn't look at the source code for the forum to confirm that it would always work). If your session expires, this method will stop working.