2020-01-20 UTC
# 
@aaronpk ↩️ The wiki actually uses https://indielogin.com when you log in, which supports GitHub as well as Twitter and some other options.
If your site says to use http://indieauth.com then yes, GitHub is the only external authentication provider supported by http://indieauth.com. (twitter.com/_/status/1219309600106663936)