Proxy Settings for an application under Local System Account Context

[Alexanderb4]

Stephen
I am struggling to understand the best approach to achieve the
following:-

How does one most effectively impose a rooting of http traffic through
an external proxy server:

1) do this for all IE users on Windows?
2) do this for all browsers used on a PC?

In another thread you suggested using Wininet APIs was the way to go:-

http://groups-beta.google.com/group/microsoft.public.inetsdk.programming.wininet/browse_thread/thread/3737f54e5f97c60f/a9eb069928cf47a3?q=proxy+server+settings&_done=%2Fgroup%2Fmicrosoft.public.inetsdk.programming.wininet%2Fsearch%3Fq%3Dproxy+server+settings%26start%3D10%26&_doneTitle=Back+to+Search&&d

And recommended this article at MS:
http://support.microsoft.com/default.aspx?scid=kb;EN-US;q226473
Look forward to your reply.

[Stephen Sulzer]

Do you want to configure the browser proxy settings on just a single
machine?

For Internet Explorer, you can either manually configure IE via the
Tools/Internet Options/Connections dialog, or programmatically configure IE
using WinInet via the INTERNET_OPTION_PER_CONNECTION_OPTIONS and
INTERNET_OPTION_SETTINGS_CHANGED WinInet options as I explain in that
newsgroup thread that you linked to.

But I do not believe there is a single way to set the proxy configuration
for all web browsers on a single machine. The problem is that there is no
central, shared location in Windows that stores the proxy configuration.
(There is no "global" proxy configuration in Windows.) Each web browser
manages its own proxy configuration. I do not know how to programmatically
configure other types of web browsers, although it probably involves writing
the information into the registry. You will probably have to write
special-case configuration code for each type of browser you need to
support.


If you are a network administrator, and want to manage Internet Explorer
across a group of machines, then you should take a look at the IE
Administrator Kit (IEAK).
http://www.microsoft.com/windows/ieak/default.mspx

With the IEAK it is possible to configure the proxy settings for IE across a
groups of Windows machines.

Internet Explorer, and I believe Netscape/Mozilla browsers too, support the
Web Proxy Auto Discovery (WPAD) protocol. This is a protocol in which the
browser queries the local network for a proxy auto-configuration (PAC) file.
The PAC file is a JavaScript script that the browser runs to find out what
proxy server to use for a given target URL. You, as the network
administrator, have to write this PAC JavaScript file, deploy it on a
server, and possibly configure DHCP in the local network environment so that
the web browser can locate the PAC file. You may also need to manually
configure your web browser installations to "automatically detect proxy
settings" or give them the URL of the PAC file.

The WPAD protocol specification is available at:
http://www.wrec.org/Drafts/draft-cooper-webi-wpad-00.txt

The format of a PAC file is specified at:
http://wp.netscape.com/eng/mozilla/2.0/relnotes/demo/proxy-live.html


Stephen