timedatex replacing systemd-timedated for NTP packages

[Florian Weimer]

On 11/26/2014 10:09 AM, Miroslav Lichvar wrote:
> We still do. Unless the number of bad servers added from DHCP is large
> enough to disrupt the NTP source selection algorithm or the pool
> servers are not reachable (NTP traffic blocked), it shouldn't be a big
> problem. Of course, without authentication this can't reliably protect
> against MITM attacks.

Do we even use the DHCP NTP server assignment?

I was more worried about 123/UDP interception (which makes kind of sense 
to improve NTP accuracy, but can of course turn out to be quite wrong).

> I think Florian meant getting time over HTTPS from a Fedora server.

Yes, there are various places where the server time is included under 
cryptographic protection.  We'd have to hard-code the certificate, 
though, because we cannot do PKIX validation without system time 
information.

-- 
Florian Weimer / Red Hat Product Security