Login/Register User Remotely?

[binjured]

Hey, I am trying to solve a problem that's currently got me stuck. I have a vB forum and a main website not coded in PHP. Now, I want a single-signon and registration system for both the site and the forums. How can I achieve this? Basically, I need to know the following:

1) How passwords are hashed for input to the database for vBulletin.
2) What cookies need to be set for a logged-in user.
3) Any pertinent information on the 'session' table -- do I have to do something with this too?

That way, to login a user all I have to do is check their credentials (I probably won't even access the vB table for this, I will just check against my main site information) and then set the necessary cookies (and possibly session table info) to have them viewed as logged in. To log a user out, I just have to destroy those cookies. And to register a user all I have to do is know how the password should be hashed and put into the database, all the rest I can easily figure out on my own, the above information just seems really cryptic and somewhat hidden. I really need this information ASAP though, so if you can help I'd be very grateful