I've already read an excellent explanation of what is HTTPS and SOCKS proxy. What I understand, is that by HTTPS proxy people mean:
- Secure channel between proxy and target server
- Secure channel between client and proxy
- Both from above: secure channel between client-proxy and proxy-target_server. But that requires two SSL (one nested inside other). This is pretty complex.
In other hand, SOCKS protocol is more low level and it's easy to configure with SSH and forget about pain of configuring nested SSL:
An alternative is to use a SOCKS proxy. This is easy to setup with SSH. With a SSH-powered SOCKS proxy, all the communications emanating from your browser will go through a SSH tunnel between your client machine and the proxy server.
So why SOCKS proxies haven't forced HTTPS proxies out yet? When HTTP proxy is better?