private void setAuthAttributes()
      throws AuthenticationRequiredException, AuthenticationFailedException, ClassNotFoundException,
      NoSuchMethodException, InvocationTargetException, IOException, IllegalAccessException {
    logger.debug("setAttributes()");
    Object principal = getHandshake().verifyCredentials();

    long uniqueId;
    if (principal instanceof Subject) {
      uniqueId = getClientUserAuths(getProxyID()).putSubject((Subject) principal, -1);
    } else {
      // this sets principal in map as well....
      uniqueId = getUniqueId((Principal) principal);
      setPrincipal((Principal) principal);
    }
    setUserAuthId(uniqueId);
  }
returns the member ID byte array to be used for creating EventID objects
geode-core/src/main/java/org/apache/geode/internal/cache/tier/sockets/ServerConnection.java