First of all create a self-signed certificate by following the instructions at http://www.eclectica.ca/howto/ssl-cert-howto.php. I copied the private key and the certificates to /etc/ldap. Please make sure that the
private key is only readable by root.
Next add the following lines to /etc/ldap/slapd.conf:
Finally make sure that the LDAP server is listening at the ldaps port (636) by editing /etc/default/slapd
and restarting the LDAP server.