Is there any way to get a session variable without using Symfony?

[Nate]

Hello,

I want to use Ratchet to push notifications to specific users on my website. On each page load I have users subscribe to a topic with their id, but I need to be able to reject the connection if the user id in $_SESSION does not match the user id in the connection request.

The Ratchet documentation shows a SessionProvider class that allows session data to be retrieved, but it says a Symfony2 Session must be used. I have a custom session handler on my website and really don't want to mess around with installing the Symfony framework. Is there any other way to get this one session variable?

Thanks!