tf4mono on windows and ntlm authentication

Recently, I've had occasion to run not just the tf4mono "tf client", but also the tf4mono TeamFoundation assemblies on a windows virtual machine.

This uncovered several platform related issues, like code that was deleting or updating files that were read-only and deleting files that we still held open.

More importantly though, I got a new perspective on the longstanding issues I've seen with NTLM authentication on Mono from my linux box. Tf4mono basically is a client for a bunch of Team Foundation web services that frequently are setup to use NTLM for authentication. So here is what I found:

• on mono/linux I see periodic, somewhat predictable NTML authentication failures


• on mono/windows, it fails every time


• on msclr/windows, it works every time

I'm of course somewhat encouraged by the msclr/windows findings, which lead me to believe its not a problem in my code. Whew!

When I dug into the issue previously on mono/nix, I saw something somewhat similar to bugzilla bug 80687. Jim Matysczak suggests the problem is "that the the type 1 message and the type 3 message are not being sent in the same socket connection which is required by the protocol."

By the way, all the windows related changes are all in the project subversion and git repositories, but not in any release yet.