I've been using the preauth mechanism for a little while from one client in testing.
I went to setup another client and wanted to re-step through the certificate process. I ran 'bin/zmprov gcf zimbraPreAuthKey' as the zimbra user, believing that I could get the already set key. But the value appears to be blank. We did upgrade twice (3.0 -> 3.01 and 3.01 -> 3.1), but as far as I know of the LDAP server has the same information as when the key was initially created.
I need to check if the original client is still working to make sure the preatuh mechanism is still working (honestly I've not tested that yet), but I believe it has not had problems.
Am I trying to get this value incorrectly?