IETF Logo Mail Archive

Re: [Ntp] Circular dependencies

Mark Andrews <marka@isc.org> Sun, 17 January 2021 12:30 UTC

Return-Path: <marka@isc.org>
X-Original-To: ntp@ietfa.amsl.com
Delivered-To: ntp@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 2B24A3A10AD for <ntp@ietfa.amsl.com>; Sun, 17 Jan 2021 04:30:30 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.118
X-Spam-Level:
X-Spam-Status: No, score=-2.118 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_BLOCKED=0.001, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (1024-bit key) header.d=isc.org
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id BUjBneuzoxCY for <ntp@ietfa.amsl.com>; Sun, 17 Jan 2021 04:30:28 -0800 (PST)
Received: from mx.pao1.isc.org (mx.pao1.isc.org [149.20.64.53]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 121283A10AA for <ntp@ietf.org>; Sun, 17 Jan 2021 04:30:28 -0800 (PST)
Received: from zmx1.isc.org (zmx1.isc.org [149.20.0.20]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx.pao1.isc.org (Postfix) with ESMTPS id D54033AB0CF; Sun, 17 Jan 2021 12:30:27 +0000 (UTC)
Received: from zmx1.isc.org (localhost [127.0.0.1]) by zmx1.isc.org (Postfix) with ESMTPS id CBC4C160046; Sun, 17 Jan 2021 12:30:27 +0000 (UTC)
Received: from localhost (localhost [127.0.0.1]) by zmx1.isc.org (Postfix) with ESMTP id B3B8D16005A; Sun, 17 Jan 2021 12:30:27 +0000 (UTC)
DKIM-Filter: OpenDKIM Filter v2.9.2 zmx1.isc.org B3B8D16005A
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=isc.org; s=05DFB016-56A2-11EB-AEC0-15368D323330; t=1610886627; bh=d/FIVFWmwlbeweukL/ajSokgiHFBhSFW5p3UUnDds6Y=; h=Content-Type:Content-Transfer-Encoding:From:Mime-Version:Subject: Date:Message-Id:To; b=ksH5HzFea5BjvQIgW+TrTbJ93cPVK0lXdnS4dZOdsXgl1vQ6c/cvQXA4ODPPVKmwm gFFSPB7jnArj0+j6ncs2v+F3fmBoaDysUe8ywWK9AKL9JWcdN2ov3xLTvE9dVvs6cc W8tdRAhtVhDwp2RRCHxcdEm8a0Vy//93iHdj7pDM=
Received: from zmx1.isc.org ([127.0.0.1]) by localhost (zmx1.isc.org [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id 6nT0XmjyKKC7; Sun, 17 Jan 2021 12:30:27 +0000 (UTC)
Received: from [172.30.42.84] (n114-75-69-161.bla3.nsw.optusnet.com.au [114.75.69.161]) by zmx1.isc.org (Postfix) with ESMTPSA id 475B0160046; Sun, 17 Jan 2021 12:30:25 +0000 (UTC)
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: quoted-printable
From: Mark Andrews <marka@isc.org>
Mime-Version: 1.0 (1.0)
Date: Sun, 17 Jan 2021 23:30:17 +1100
Message-Id: <6BDD9FA5-732C-4D25-9191-97C2ABD4892D@isc.org>
References: <24FF71B3-4A33-4C32-8A95-F77A0BE0D811@isc.org>
Cc: NTP WG <ntp@ietf.org>
In-Reply-To: <24FF71B3-4A33-4C32-8A95-F77A0BE0D811@isc.org>
To: Hal Murray <hmurray@megapathdsl.net>
X-Mailer: iPhone Mail (18C66)
Archived-At: <https://mailarchive.ietf.org/arch/msg/ntp/aCLtffxx9FnNjQmD5enCSK4oUHo>
Subject: Re: [Ntp] Circular dependencies
X-BeenThere: ntp@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: <ntp.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/ntp>, <mailto:ntp-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/ntp/>
List-Post: <mailto:ntp@ietf.org>
List-Help: <mailto:ntp-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/ntp>, <mailto:ntp-request@ietf.org?subject=subscribe>
X-List-Received-Date: Sun, 17 Jan 2021 12:30:30 -0000

One can also do DO=1 as well and ignore inception dates when validating in the app so that records signed after the last file system date are not rejected. 

-- 
Mark Andrews

> On 17 Jan 2021, at 23:22, Mark Andrews <marka@isc.org> wrote:
> 
> The initial address queries by ntpdate/ntpd/etc at boot time can be done with CD=1  (checking disabled).
> 
> For real long term shelf storage the trust anchors for the root will need to be updated. 
> 
> -- 
> Mark Andrews
> 
>> On 17 Jan 2021, at 22:24, Hal Murray <hmurray@megapathdsl.net> wrote:
>> 
>> 
>> marka@isc.org said:
>>> In practice DNS does not need precise time.  Implementations know that
>>> validators and signers are NOT using precise time. BIND for example signs
>>> records with a time stamp a hour in the past and records are supposed to be
>>> replaced days before they expire.
>> 
>> I'm thinking of a different scale on "precise", months or years rather than 
>> hours or days.
>> 
>> The usual example is a device that has been sitting on the shelf for 10 years. 
>> The only time it has is when the software was built or installed, just before 
>> it was packaged up.
>> 
>> The telcom guys do that.  (Or did.)  I wouldn't be surprised by military gear 
>> with similar time scales.
>> 
>> I could easily imagine a Raspberry Pi being powered off for a whole summer.  Or a smart fridge being off for half a year if it lives at a summer home.
>> 
>> Anything with a file system that is operating can update the last-known-time occasionally.  That's good enough for normal certificates if "operating" means turned on once a month, maybe even once a year.
>> 
>> -----------
>> 
>> We should collect a list of files/data that need to be updated occasionally.  The obvious ones for this group are root certificates and the time-zone database if you need local time and maybe the leap-second file.
>> 
>> There is the whole can of worms about the software/protocols still being in use after 10 years.
>> 
>> -- 
>> These are my opinions.  I hate spam.
>> 
>> 
>>

v2.23.0 | Report a Bug | By Email