Re: [dhcwg] [ntpwg] Fwd: New Version Notification for draft-ogud-dhc-udp-time-option-01.txt

Mark Andrews <marka@isc.org> Mon, 02 December 2013 22:03 UTC

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To: Harlan Stenn <stenn@ntp.org>
From: Mark Andrews <marka@isc.org>
References: <20131202044734.B78E0406060@ip-64-139-1-69.sjc.megapath.net> <529C1A31.2080900@ntp.org> <258D838F-F4BA-45D2-AA41-BB05E3AB147C@ogud.com> <529CA616.3010402@ntp.org> <19575403-444E-4CBA-8818-5F46328787AE@bsdimp.com> <E1VnZdi-0000fA-CY@stenn.ntp.org> <220ED02D-AE73-436F-A81F-BDF54611173B@bsdimp.com> <E1Vnb6D-0000lV-Gy@stenn.ntp.org>
In-reply-to: Your message of "Mon, 02 Dec 2013 21:32:13 -0000." <E1Vnb6D-0000lV-Gy@stenn.ntp.org>
Date: Tue, 03 Dec 2013 09:03:11 +1100
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Cc: Hal Murray <hmurray@megapathdsl.net>, Bernie Volz <volz@cisco.com>, NTP Working Group <ntpwg@lists.ntp.org>, Ted Lemon <ted.lemon@nominum.com>, "dhcwg@ietf.org WG" <dhcwg@ietf.org>, Warner Losh <imp@bsdimp.com>
Subject: Re: [dhcwg] [ntpwg] Fwd: New Version Notification for draft-ogud-dhc-udp-time-option-01.txt
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The inception and expiration times in RRSIGs is specified as seconds
since 00:00:00 Jan 1 1970 UTC excluding leap seconds modulo 2^32.

There are no recommended fudge factors to use when evaluating these
times though named sets the expire time to 3600 seconds in the past
by default when generating RRSIGs.  I believe the other signers do
similar.  I've considered making the inception timestamp a whole
day in the past to cope with badly set timezones.

The signature validity intervals are on the order of days.  Named
defaults to 30 days.  They are regenerated about a week before they
are due expire if not already regenerated due to zone content
changes.  The records should expire from caches before they become
invalid if re-signing is being done properly.

So if the validator and the signer are both within 30 minutes of
the true time validation should succeed.

Mark
-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: marka@isc.org