Help: Rest Client authentication through Keycloak having Identity provider as SAML

Hi,

Currently, my application has its own login page where we authenticate the user through REST APIs ( a spring boot application). This Spring boot application connects with Keycloak for authentication and returns the access and refresh tokens. In Keycloak console, the client is configured over the open-id protocol.
In our application, we also support the multitenancy through keycloak.

Now, we have a requirement to get the user authenticated outside the keycloak by redirecting the user to the client provided IDP ( through SSO). The client provided IDP will return the SAML response.

We have tried multiple approaches but could not get any success. All the references available on internet, they talk about the keycloak and SAML SSO integration but as we are not using keycloak’s login page so it is getting very difficult to get the my application(Rest Client) authenticated in this scenerio.

Can someone help me here to solve this use case?

FYR:: The current application components:

Front End application: An Angular application
Back End Application: A Spring REST application
Authentication: Keycloak over the REST APIs

Thanks