3.10.1 HTTP parent proxies

The variable parentProxy specifies the hostname and port number of an HTTP parent proxy; it should have the form ‘host:port’.

If the parent proxy requires authorisation, the username and password should be specified in the variable parentAuthCredentials in the form ‘username:password’. Only Basic authentication is supported, which is vulnerable to replay attacks.

The main application of the parent proxy support is to cross firewalls. Given a machine, say trurl, with unrestricted access to the web, the following evades a firewall by using an encrypted compressed ssh link:

$ ssh -f -C -L 8124:localhost:8123 trurl polipo
$ polipo parentProxy=localhost:8124