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Re: NTLM and Squid Proxy Server

From: Isaac Boukris via curl-library <>
Date: Mon, 14 Aug 2017 21:33:20 +0300

On Fri, Aug 11, 2017 at 12:21 PM, Hölzl, Dominik
<> wrote:
> Hello!
> When I use cURL (Library from a C++-Program on Windows 10, cURL version
> 7.49.1) and connecting to an IIS Web Server using NTLM Authentication (with
> Username+Password, HTTP) over a Squid Proxy Server (3.5.20) and re-using the
> CURL-handle for a second request, the second request fails with

When using NTLM via proxy, the proxy should be aware of NTLM logic and
keep the up/down connections bound to each other. So I'd suggest to
debug the proxy.
Assuming the proxy supports NTLM, IIS may also need to be made aware
of that (by some header) otherwise it may require authentication again
for each request (if it sees 'via' header iirc), and maybe the proxy
interprets that as a failure.
See related:

Received on 2017-08-14