[keycloak-user] X509 Registration Flow

Hello, I currently have Keycloak (5.0.0) configured to use X.509 client certificate authentication. However I have not been able to figure out a good way to handle the registration flow. What I would like to happen is have the `username` field on the registration form automatically populated with the certificate CN. Is there a way to handle this out of the box, or do I need to write a custom authentication SPI? Thanks, Justin W.