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Re: [TLS] Server time

Florian Weimer <fweimer@redhat.com> Wed, 08 April 2015 10:10 UTC

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Date: Wed, 08 Apr 2015 12:10:27 +0200
From: Florian Weimer <fweimer@redhat.com>
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To: Kurt Roeckx <kurt@roeckx.be>
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Subject: Re: [TLS] Server time
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On 04/08/2015 12:06 PM, Kurt Roeckx wrote:
> On Tue, Apr 07, 2015 at 11:01:56PM +0200, Florian Weimer wrote:
>> I don't know yet if they can be persuaded to adopt
>> DTLS (maybe lack of server-side state is absolutely critical to them).
> 
> The lack of server-side state really is important to them.  There
> are too many clients to keep track of.

DTLS would only be used to negotiate a shared key for subsequent message
authentication.  The DTLS sessions would not be persistent during an
entire NTP association.  If that's not clear from my comments, I should
send a clarification to the NTPWG list.

(UDP with large messages still needs state in the IP stack for fragment
reassembly, so even the current CMS-based proposal is not exactly
stateless.)

-- 
Florian Weimer / Red Hat Product Security

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