feat: add oidc authentication to allow sso

[fritterhoff]

Hey! :)

I just stumbled over this cool project and we plan to utilize it for the charging infrastructure at our campus. Since we don't want to share the admin password to several users and we would prefer to reuse existing credentials and MFA I implemented a POC version of an OIDC authentication in steve. For sure it is not perfect but we would like to contribute our adaptions to the official project 😉

[juherr]

Related to #991

[fritterhoff]

Some (long) time ago I created this PR. This is getting relevant again for us. I would consider to update the conflict. Are there any plans to integrate such a feature in the near future?

[goekay]

sure, lets reactivate this (there are many PRs that need to be revitalized :D)

i assume the code changes work without issues (functionally), but i am not sure whether the if ... else ... approach is the best solution in terms of modularity. can you take a look and maybe rethink that aspect of the solution?

[goekay]

another point: would you like to wait a bit for the project to migrate to spring boot? this migration is in the TODO list with a moderate urgency/priority. after the migration, i think you could use config params from spring security directly instead of reinventing the wheel in steve's own application properties.

[fritterhoff]

Would be fine for us!