what proxy server has this been tested against?

[eli-darkly]

I'm curious to know what the testing approach was, because I don't have any previous experience with NTLM. I couldn't find any suitable server tools on Linux, so I ended up running Wingate 9.4 on Windows 10 and testing some requests against that. And I can tell that Wingate receives a Negotiate message in the Proxy-Authorization header, and parses it successfully... but then it doesn't like something about the flags, and unfortunately it doesn't tell me anything more specific than that. This may have nothing to do with any of the Go code, it may just be something about Wingate that I don't understand (though it does accept NTLM credentials from, for instance, curl), but now I'm in a state where I can't really tell if what I'm doing is valid.

(I realize that the actual encoding of the NTLM messages is not done by this package but by the Azure/go-ntlmssp package. But I'm asking this question here instead of there because 1. that repo seems to be pretty inactive, and 2. proxy authentication is a rarer use case than authentication of direct requests, so you might have had more experience with testing that.)

[Codehardt]

I tested this package in a customer environment that I no longer have access to. If I remember it right, this was a Blue Coat proxy, requiring NTLM username and password.