I am working on building a platform in my company that will provide a single sign on to all of the internal products to the customer. To do that we need to build an Authorisation server to comply with the OIDC protocol. Earlier we had built the Auth server using the Spring Security OAuth project but since in Spring Security 5.x it is no longer supported we are planning to get over with it as well. Below are the 2 options that I was considering to replace the Spring Auth Server. 1. Keycloak 2. Okta 3. Auth0 Please advise which one to use.