func (l *Config) GetValidatedUserDN(conn *ldap.Conn, userDN string) (*xldap.DNSearchResult, bool, error) {
	return l.GetValidatedDNUnderBaseDN(conn, userDN,
		l.LDAP.GetUserDNSearchBaseDistNames(), l.LDAP.GetUserDNAttributesList())
}

// GetValidatedGroupDN validates the given group DN. If conn is nil, creates a
// connection. The returned boolean is true iff the group DN is found under one
// of the configured LDAP base DNs.