NTLM proxy without password?

Question

I work on a corporate windows network (which I log in to) with a HTTP proxy. When I use Internet Explorer it magically uses the proxy without me needing to type in my passwo

Answer 1

Might be a bit late but wanted to mention this nonetheless. The original question is generically asking about NTLM proxy auth without passwords on Windows where user has already logged in. No doubt curl can do this but I wanted to give another option.

NTLMAps and Cntlm are proxies that do the NTLM auth as an intermediary proxy. However, they both require the user/pass since they are mostly targeted towards Linux users. I historically used these tools on Windows but was annoyed by the same requirement of having to provide the credentials to them.

As a result, I've authored Px for Windows which is an HTTP proxy like the above two, but uses SSPI to manage the required authentication with the corporate proxy. All you need to configure is the proxy server and port. It helps for existing applications that cannot talk through NTLM proxies such as pip and npm for example.

For developing your own apps, the code should also help figure out how to do this within Python and perhaps languages which have access to SSPI.