Re: Proxy connect errors

From: Andrew Bushnell <>
Date: Wed, 06 Jul 2005 10:36:12 -0400

Daniel Stenberg wrote:

> On Wed, 6 Jul 2005, Andrew Bushnell wrote:
>> Much better, the latest snapshot seems to fix the issue
> Cool. Thanks for verifying!
No problem, thanks for fixing it :-)
>> however, I found a related problem now. This code works fine as long
>> as I use --proxy-ntlm on the command line. If I use --proxy-any then
>> things do not work. I can spend time debugging if that would be
>> helpful, but as long as I pre-specify that I use NTLM, then it is
>> fine. Anyway, the latest snapshot seems to now work and I am not
>> getting any connection problems using the command line curl that I
>> built from the latest snapshot.
> Hah, well I don't know if you are the one who posted the bug tracker
> entry, but we just today got a bug report with the subject "HTTP proxy
> tunneling with NTLM proxy authenticate won't work":
> I suspect it is exactly the case you describe above, which boils down to
> the fact that the proxy closes the connection after the first CONNECT
> response and libcurl doesn't deal with that and bails out.
> This bug tracker entry problem is a much bigger internal architectural
> problem within libcurl, and while I've slowly started to address this,
> it will require a rather big shake-around and I don't know when I'll be
> able to provide a fix for this. Expect it to take at least a week,
> perhaps a month. Or so. (Of course someone else could beat me to it, but
> I consider that very unlikely.)
I cannot take credit for the bug entry.
What we do in our application is 2 things before calling into pycurl:

#1: We have gui that has the user enter there proxy information, part of
which is the "type" if they know it.

#2: I have my own logic to "ping" the proxy to get the authentication
type if the user is unable to determine it.

In either case, the user choice/determination gets translated into the
appropriate proxy authentication type setting for pycurl to use and
avoids the problem.

Andrew Bushnell
Lead Development Engineer
Fluent Inc.
10 Cavendish Court
Centerra Resource Park
Lebanon, NH  03766
Phone: 603-643-2600, ext. 757
Fax: 603-643-1721
Received on 2005-07-06