- https://docs.spring.io/spring-security-oauth2-boot/docs/current/reference/html/boot-features-security-oauth2-authorization-server.html
- https://projects.spring.io/spring-security-oauth/docs/oauth2.html
- https://docs.spring.io/spring-security-oauth2-boot/docs/current/reference/htmlsingle/
- https://spring.io/guides/tutorials/spring-boot-oauth2/
- http://lunar.lyris.com/help/lm_help/12.0/Content/generating_public_and_private_keys.html
- https://www.youtube.com/watch?v=l9chhjL7Kuk
- https://tools.ietf.org/html/rfc6749
- https://tools.ietf.org/html/rfc6749#section-1.3.1
- https://www.youtube.com/watch?v=6DxRTJN1Ffo
- https://www.youtube.com/watch?v=996OiexHze0
- https://developers.google.com/identity/protocols/oauth2/openid-connect => for authentication(google api)
- https://github.com/spring-projects/spring-security/tree/5.3.2.RELEASE/samples/boot/oauth2login
- https://www.baeldung.com/spring-security-openid-connect
- https://www.baeldung.com/spring-security-5-oauth2-login