Hi Zoltan,
There are plans to support TLS for LDAP, but the current LDAP driver of Unfiace does not support it (yet). At the moment I cannot really tell you when this could become available. Sorry.
However, there is a workaround: I know that stunnel is used a lot in this scenario. It is a proxy that adds TLS encryption between clients and/or servers that do not support TLS. I've also found a setup example for using Secure LDAP here.
Hope this helps.
Kind regards,
Daniel Iseli
Uniface Support