question about httpProxy prop.

[Dave Cragg]

On 10 Aug 2004, at 00:59, Andre Garzia wrote:

> Chipp,
>
> thank you very much for the reply! I am investigating what type of 
> damn-proxy I am dealing with, but I think it uses no auth, for the 
> students have no login and the explorer shows no auth...
>
> I am receiving weird errors, in some machines it work fine, others it 
> receives old data... I must go on site and see with my eyes, now, all 
> I have is their tech on the phone line screaming, I will be there in 
> couple days, then I'll see what I am dealing with.
>
> Thanks
> andre
>
It would be useful to go on site and try and and get a log extract 
(libUrlSetLogField) of the proxy server's response.

If the response has a 407 status code, then proxy authentication is 
needed (see below).

If it's a caching problem, then I think Dar's suggestions are good. I 
use the same headers to overcome such problems. However, I recently ran 
across a proxy server that served cached responses, whatever the 
headers. I was going to try an approach of changing the url for each 
request. Something like this:

   post tData to url 
"http://my.server.com/cgi-bin/somescript.cgi?userid=xxx0001&requestid=1

where the requestid value is incremented on each request. (The field 
has no significance for the remote cgi script, it's just to fool the 
proxy) I haven't tried it yet, but as a last resort, you might want to 
try.

Chipp Walters wrote:
> If you find out you're using Basic Authentication, then Dave Cragg has 
> a new version of libURL which supports both Basic and NTLM 
> authentication. If you need the NTLM authentication, then contact me 
> offlist and I'll send you a NTLM.dll external.

I've been a bit slow in putting out documentation of the features that 
Chipp is referring to. Perhaps just as well as I recently discovered a 
bug in the implementation which should be fixed for the next release. 
(However, it's possible to handle Basic authentication on a proxy 
server without the new features.)

(The new features allow setting a callback to handle the 
authentication. Although a bit complex, you can set it up once in your 
project and then forget about it. It's main benefit is in integrating 
more difficult authentication schemes such as NTLM (Windows only) which 
require an external to handle the messy stuff.)

Cheers
Dave