On my branch now, everything "should" work:
https://github.com/gbaz/Cabal/tree/https
By "should" I mean the refactor is in place, and we have support for curl, wget, powershell, and insecure-http.
You can pass a global flag to set your preferred transport (and it will not try insecure-http unless you explictly request it). If you use any transport but insecure-http it will convert http to https urls automatically.
Things that remain outstanding
1) ETags are not enabled on the new transports -- this is just some tedious work to emit them from the programs and parse them out.
2) http-transport is a global option and can be passed, but it doesn't seem to wind up in the documentation correctly. Not sure how to configure the options properly.
3) Proxy support is not fully tested on curl/wget -- it _did_ work on my machine at one point, but it lives behind a particularly perverse proxy and ceased working in a way I can't diagnose and might just be due to a hopeless proxy.
4) I haven't properly tested upload support on wget, which is fiddly since it needs to do its own multipart encoding just like insecure-http.
5) Proxies are not enabled on powershell -- this is some tedious work to automate parsing out the proxy settings better, since the "correct powershell" way to handle proxies with user/passwords doesn't seem to actually work.
6) Powershell also needs real escaping, in case package names/urls perversely have quotation marks in them.
Anyway, this touched a bunch of stuff in small ways and could use some review and _especially_ some testers across various platforms and transports to see what's still missing,
If any brave souls want to try out the various transports, or pick up some of the remaining work, please do! This was a nice exercise, but I could really use another set or two of eyes/hands to take it to 100%.
(note that even though I branched before the digest fix, I ported it over to this branch, so that the insecure-http transport _should_ be using digest auth properly already).
--Gershom