Postman NTLM Authentication

I’ve been looking at the NTLM beta functionality on and off for a while now. Today I went into it again and I noticed something I wanted to ask about.

When the Postman client generates temporary headers, one of them is the “Connection” header. I can see that Postman is generating a “Connection: Keep-alive” header; according to Microsoft’s documentation, NTLM requires a persistent connection so this is good.

However, when I watched the attempted negotiation through Fiddler, I noticed that Postman is sending “Connection: close”. This seems to be regardless of the header value.

I’m going through the code now trying to see if this value is being set somewhere downstream, but the code base is fairly large and complicated. I wanted to present this to the team hoping that someone may be able to point me toward some suspect modules to inspect.

Hey @rlnasuti, welcome!

I see your confusion, but I could not find the behaviour you mentioned. :confused:
I sent requests to a local NTLM server we have setup and captured responses using Wireshark. There was no instance where I could find Connection: close sent unless I explicitly sent it, maybe it’s a misconfigured server which is sending the Connection: close header, or maybe fiddler is fiddling with the request? :thinking:

Also, could you elaborate what you mean by “the code base is fairly large?” Which codebase?

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