Keycloak, java plugin, auth user custom connected to third party

Question

I have a need to make "hacky" oauth flow. I mean add ability for users, to login to my system using credentials from other, which does not have oidc unfortunately and wont have for many months.

I would like to have this option, to enter this other system login/password click login in button, and then inside keycloak flow try those credentials to connect this other system, get tokens and then login this user with keycloak user database as usual or if this user does not exists create him.

I am not sure how to achieve this goal, any one did smth similar ?

thanks!

EDIT: hmm probably I need to use AbstractUsernameFormAuthenticator, will send here response when done.

Answer 1

Ok I found very good article explaining how to do it step by step, I highly recommend it.

java-keycloak-custom-user-providers