I'm behind a web-proxy that needs me to authenticate on a web page in order to browse the web. It seems to me that because of this authentication page sytem, I can't set up my linux package manager to use this proxy (already tried to use my login/password the proxy configuration). Of course, this issue doesn't come up only for my package manager, but it is the most anoying case.
How can I get through this ? Am I screwed ?
Ps : I'm using Ubuntu 12.10 but this is probably a useless piece of information