Using curl to access basic auth protected website via proxy (polipo)

Not necessary to use http_proxy, try this:

curl -x PROXY-SERVER:PORT -U USER:PASS URL

curl -x 127.0.0.1:8123 -U XXXXX:Pass "http://example.com/blub/bla.bin"

Found the anwser myself after some more digging:

http://curl.haxx.se/docs/manual.html states

NOTE! According to the URL specification, HTTP URLs can not contain a user and password, so that style will not work when using curl via a proxy, even though curl allows it at other times. When using a proxy, you must use the -u style for user and password.

So I was doing it the wrong way :)