For my use cases, I am looking for a solution that works in such a way that an existing user account on server/service A can also be used for the login on server B. This would also solve the problem that an SSO can no longer be set up sensibly with an existing, large user base. (If the SSO requires all existing users to recreate an account in the new SSO-Server.)
So from the point of view of a user who wants to sign-up on to the B-server:
Create new local account with:
- new user name: …
or
- sign-up with your username from server A: …
Of course, it would be very cool if the reverse were also possible. So log in to A with the B credentials.
Could keycloak be used in this way?