Re: [Ntp] BCP 195
kristof.teichel@ptb.de Wed, 29 August 2018 06:09 UTC
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To: Marcus Dansarie <marcus@dansarie.se>
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From: kristof.teichel@ptb.de
Date: Wed, 29 Aug 2018 08:08:14 +0200
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Subject: Re: [Ntp] BCP 195
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"ntp" <ntp-bounces@ietf.org> schrieb am 28.08.2018 22:14:31: > Von: "Marcus Dansarie" <marcus@dansarie.se> > An: ntp@ietf.org > Datum: 28.08.2018 22:15 > Betreff: Re: [Ntp] BCP 195 > Gesendet von: "ntp" <ntp-bounces@ietf.org> > > Good observation on BCP 195! I'm in favor of this. > > The second paragraph is particularly diplomatic in view of the slightly > differing views on whether we should require TLS 1.2 or 1.3. My only > objection is that "when possible" is redundant in view of the RFC 2119 > definition of SHOULD. I disagree with your objection. The language in RFC 2119 to me seems to explicitly leave room for a deliberate decision (weighing implications), not just (im)possibility due to cirmustance. > Kind regards, > Marcus Dansarie > > On 2018-08-28 20:06, Daniel Franke wrote: > > How's this? > > > > <section title="TLS profile for Network Time Security" > anchor="tls-profile"> > > <t> > > Network Time Security makes use of TLS for NTS key establishment. > > </t> > > <t> > > Since securing time protocols is (as of 2018) a novel > > application of TLS, no backward-compatibility concerns exist > > to justify using obsolete, insecure, or otherwise broken TLS > > features or versions. Implementations MUST conform with <xref > > target="RFC7525"/> or with a later revision of BCP > > 195. Furthermore: > > </t> > > <t> > > Implementations MUST NOT negotiate TLS versions earlier than > > 1.2, SHOULD negotiate TLS 1.3 <xref target="RFC8446"/> or > > later when possible, and MAY refuse to negotiate any TLS > > version which has been superseded by a later supported > > version. > > </t> > > <t> > > Use of the <xref target="RFC7301">Application-Layer Protocol > > Negotiation Extension</xref> is integral to NTS and support for > > it is REQUIRED for interoperability. > > </t> > > </section> I like it. > > On Tue, Aug 28, 2018 at 1:46 PM Daniel Franke <dfoxfranke@gmail.com> wrote: > >> > >> I just learned (by reading draft-moriarty-tls-oldversions-diediedie) > >> that BCP 195 exists, which gives best current practices for secure use > >> of TLS. I'm going to rewrite the "TLS Profile for Network Time > >> Security" as primarily a mandate to comply with that BCP. It'll go on > >> to turn a couple of its SHOULDs into MUSTs where the BCP makes more > >> allowances for legacy compatibility than we need to. > > > > _______________________________________________ > > ntp mailing list > > ntp@ietf.org > > https://www.ietf.org/mailman/listinfo/ntp > > > > [Anhang "signature.asc" gelöscht von Kristof Teichel/PTB] > _______________________________________________ > ntp mailing list > ntp@ietf.org > https://www.ietf.org/mailman/listinfo/ntp
- [Ntp] BCP 195 Daniel Franke
- Re: [Ntp] BCP 195 Daniel Franke
- Re: [Ntp] BCP 195 dieter.sibold
- Re: [Ntp] BCP 195 Marcus Dansarie
- Re: [Ntp] BCP 195 kristof.teichel
- [Ntp] Antw: Re: BCP 195 Ulrich Windl
- Re: [Ntp] Antw: Re: BCP 195 kristof.teichel
- [Ntp] Antw: Re: Antw: Re: BCP 195 Ulrich Windl