getting HTTP proxy username/password config

[kibitz at graphesthesia.com (kibitz@xxxxxxxxxxxxxxxxx)]

hi-

As of OS 10.3 (I think) if you go to the Proxies tab on the Network preference 
pane and turn on the HTTP proxy, besides the server address and port you can 
specify a username and password.  This affects Safari and any code that uses 
the NSURLConnection/NSURLDownload classes that were introduced with Safari and 
10.2.7.

Question:  if you're not using those classes, how can you get the 
username/password settings?  My code uses CFStream because I have to work in 
the absence of Safari/10.2.7.  I know how to specify the proxy server & auth 
information with CFStream, and I know how to get the proxy server/port with 
SystemConfiguration, but I can't find the username/password anywhere in the 
network-related defaults.

(Yes, I know that if I'm running in 10.2 the user has no way to specify these 
anyway, so I need my own preference pane in that case.  I just need my HTTP 
code to be portable even if the configuration part isn't.)

thanks-
Eli