1. for browser: should be able to edit them via the preferences section.
2. command line:
export http_proxy="http://username:password@proxy:port/" export https_proxy="ftp://username:password@proxy:port/" export ftp_proxy="https://username:password@proxy:port/"
we should be able to automate this by adding to ~/.bashrc
3. apt:
In /etc/apt/apt.conf.d/80oproxy, add
Acquire::http::proxy "http://username:password@proxy:port/"; Acquire::ftp::proxy "ftp://username:password@proxy:port/"; Acquire::https::proxy "https://username:password@proxy:port/";