I'm bad at Nashorn. Did that working example ever get made? http://shibboleth.1660669.n2.nabble.com/Other-ways-to-transform-binary-LDAP-balues-td7630170.html byte[] decoded = org.ldaptive.LdapUtils.base64Decode(attributeValue); String guid = org.ldaptive.ad.GlobalIdentifier.toString(decoded);