NTLM / Windows Authentication with Firefox


Firefox, my browser of choice, doesn’t support NTLM “out of the box”

What that means is, if you visit a site on your domain (for example http://intranet) that you should have access to, you’re presented with a username and password box.
Visit the same site in IE, and it lets you straight through, based on your credentials.

What you need to do, is explicitly set the allowed URIs that Firefox is allowed to pass your credentials to.
Since I only use this on a couple of sites, it’s not really a problem.

Here’s how to do it:

Step One

Load about:config in Firefox (more information on about:config)
Click “I’ll be careful, I promise!” (and make sure you are careful, you did promise….)


Step Two

Locate network.automatic-ntlm-auth.trusted-uris
The easiest way to do this is to type “network.automatic” into the filter box. Then, only two entries show up.
Double click network.automatic-ntlm-auth.trusted-uris


Step Three

Enter your url into the box.
In my case, it’s http://intranet

That’s it! Firefox will now allow NTLM on that url!