[asjo]

A looong time ago, when OpenID was sort-of new, I implemented my own OpenID provider, because I wanted to log into StackOverflow and other places, but I didn't want to use a third party service.

That worked swimmingly in the few places that supported OpenID, but eventually even StackOverflow dropped support.

I must admit I haven't kept up with what has happened since in this area, so stupid question:

Could I install this server and have my own OAuth2/OIDC provider that would allow me to login to websites using my own provider (instead of "Login with Microsoft Github", "Login with Facebook", "Login with Google", "Login with Twitter"), or is this something else/the reverse?

[manigandham]

No, OIDC providers can only be accessed by registered clients so those sites cant use your provider unless they specifically add it. Otherwise you would be able to login with any of those accounts on any site already.

[asjo]

Ok, so there really isn't anything like OpenID any more?

[manigandham]

OpenID still required sites to implement that standard as a relying party so it couldn't be used arbitrarily. It gave you the ability to choose a specific OpenID identity provider to store your account info (including your own), but it didnt get adoption so now it's obsolete.

OpenID Connect is the latest version of OpenID, and it uses OAuth to federate access to other identity providers but sites now have to implement a separate registration for each provider (google, facebook, etc) so what they choose to implement is what you get, and there's no realistic option to use your own.

[asjo]

Thanks, the TL;DR is "Yes" then. Too bad.