zokor

https://github.com/ab/zokor

Zokor is an HTTP proxy tunnelling tool that collapses multiple HTTP proxies into one. It's useful when you want to send traffic through a chain of two HTTP proxies where the first supports the CONNECT verb. Zokor presents a local server that transparently tunnels packets through the first proxy as though clients were directly connected to the second proxy. It optionally uses TLS to connect to the second proxy.