Answer by Ted for How to retrieve the private keys from keycloack realms keys?

at recent versions of Keycloak, there is DefaultKeyManager which can be used to retrieve keys from realms.

KeyManager keyManager = new DefaultKeyManager(keycloakSession);Key key = keyManager.getActiveKey(keycloakSession.getContext().getRealm(), KeyUse.SIG, "RS256").getPrivateKey();