2006 Nov 16 - Thu

Linux Through Microsoft Proxy

Some organizations use Microsoft Proxy to protect their network edge. To pass through the proxy, Microsoft's NTLM authentication/authorization sequence is typicially required. For regular domain users, this is typically not a problem, as Microsoft's Internet Explorer will automatically supply credentials to the Microsoft ISA Proxy Server.

When one is on a linux box, say a Debian machine, and one wants to obtain 'apt-get' updates, or to obtain Perl updates from CPAN, the Linux application will need to authenticate with and pass through the ISA server. The usual 'http_proxy=...' statement just doesn't work in this context.

When 'http_proxy=...' is used along with another application, it does work. Enter the NTLM Authorization Proxy Server. This is a wonderful little Python script that will act as a proxy to Microsoft's Proxy server.

There is a straightforward configuration file, server.cfg, where you enter the ip address or host name of the proxy server, supply a username and password for authenticating, supply a listening port, and then start with './main.py'. You'll of course need a recent version of Python running for this script to work.

Then from any machine on the network, connect to this proxy. It will authenticate to the Microsoft Proxy server. They note on the web site it will even perform this function for Internet Explorer.

For Linux machine, from the command line, use the two statements:

http_proxy=http://ipaddress:port/
export http_proxy

Commands like wget and apt-get will now function as expected. For CPAN updates, you'll need to use 'o conf ftp_proxy' once you've 'perl -MCPAN -eshell' to update the proxy it uses.