https://github.com/simpleidserver/SimpleIdServer


https://github.com/Shoogn/OAuth20Server/tree/master


https://www.rfc-editor.org/rfc/rfc6749


https://openid.net/developers/how-connect-works/


https://docs.duendesoftware.com/general/licensing/


https://auth0.com/resources/ebooks/open-id-connect-pt