Support SOCKS proxy for Gemini

[makew0rld]

From the mailing list:

Currently at a very nice hotel, with a great breakfast but a WiFi networks which allows only ports 80 and 443. As a result, I need to tunnel all the Gemini traffic :-(

(By the way, it seems there is currently no Gemini client with SOCKS support?)

Source

This should be very easy to support in client/ using golang.org/x/net/proxy.

[makew0rld]

Actually this will need changes to go-gemini to allow custom dialers.

[makew0rld]

A SOCKS5 dialer for go-gemini should most likely live in its own repo that Amfora and gemget import. See makew0rld/go-gemini#13 (comment) for details.

[makew0rld]

https://github.com/makeworld-the-better-one/go-gemini-socks5 exists now, and go-gemini supports using proxies. Next step is to add support for SOCKS5 in gemget, and run my own SOCKS5 server and test with it.

[makew0rld]

Added support to gemget in makew0rld/gemget@316a083, and tested using the default TOR socks5 proxy. Was able to download the content of a Gemini capsule hosted over TOR. So everything works great, next step is to add to Amfora as well.

[makew0rld]

Did the same TOR test with Amfora and it worked. Proxy host is set by AMFORA_SOCKS5 env var. Proxy username and password is not supported, it doesn't seem to be used often from what I've seen, since SOCKS5 isn't encrypted, and/or is often running locally.