title: Keycloak SPI: Access pasword in getUserByUsername
body: <p>In Keycloak I implemented a custom UserLookupProvider and a CredentialInputValidator. The legacy system which I want to get connected to keycloak is only able to check if a user exist if I supply the system with the user ID and the password.</p>
  <p>Unfortunately I dont have access to the password in the getUserByUsername function. Therefore I cant check if the user exists in the legacy system.</p>
  <p>I found this similar question without an answer: <a href="https://lists.jboss.org/pipermail/keycloak-user/2019-May/018271.html" rel="nofollow noreferrer">https://lists.jboss.org/pipermail/keycloak-user/2019-May/018271.html</a></p>