Re: [Ntp] I-D Action: draft-ietf-ntp-using-nts-for-ntp-26.txt

[Ragnar Sundblad <[e-mail]>]

All,

We would again like to thank all of you who have sent comments and
discuss issues, and for the overwhelming response from the reviewers
and others.

We also got some comments on the comments. With this version, we hope
to have addressed those too.

- No TLS 1.2
During this work, it became apparent that keeping support for TLS 1.2
and correctly covering for the differences between TLS 1.2 and TLS 1.3
would be a lot of work, with the risk of getting something wrong or
missing on important issues, in the specification or in the
implementations.

The last time the issue of 1.2 support was up for debate, there were
some operating systems that would not support TLS 1.3, and there was a
concern that this would impair the protocol adoption rate. Today most
(all?) major operating systems do have TLS 1.3 capable libraries in
their later versions.

Several of the reviewers questioned why TLS 1.2 was supported, and the
same have others done before.

We therefore decided to drop support for TLS 1.2.

For older operating systems, an NTS enabled NTP implementation can
still be linked with a separate TLS library that supports 1.3, a bit
inconvenient, but doable.

- New TLS export disambiguating label string
As we had a techincal change in there already, we also changed the TLS
export disambiguating label string to be more aligned with what is the
standard form today, to "EXPORTER-network-time-security”.

Best regards,
Ragnar Sundblad


> On 22 Mar 2020, at 16:48, [e-mail] wrote:
> 
> 
> A New Internet-Draft is available from the on-line Internet-Drafts directories.
> This draft is a work item of the Network Time Protocol WG of the IETF.
> 
>        Title           : Network Time Security for the Network Time Protocol
>        Authors         : Daniel Fox Franke
>                          Dieter Sibold
>                          Kristof Teichel
>                          Marcus Dansarie
>                          Ragnar Sundblad
> 	Filename        : draft-ietf-ntp-using-nts-for-ntp-26.txt
> 	Pages           : 44
> 	Date            : 2020-03-22
> 
> Abstract:
>   This memo specifies Network Time Security (NTS), a mechanism for
>   using Transport Layer Security (TLS) and Authenticated Encryption
>   with Associated Data (AEAD) to provide cryptographic security for the
>   client-server mode of the Network Time Protocol (NTP).
> 
>   NTS is structured as a suite of two loosely coupled sub-protocols.
>   The first (NTS-KE) handles initial authentication and key
>   establishment over TLS.  The second handles encryption and
>   authentication during NTP time synchronization via extension fields
>   in the NTP packets, and holds all required state only on the client
>   via opaque cookies.
> 
> 
> The IETF datatracker status page for this draft is:
> https://datatracker.ietf.org/doc/draft-ietf-ntp-using-nts-for-ntp/
> 
> There are also htmlized versions available at:
> https://tools.ietf.org/html/draft-ietf-ntp-using-nts-for-ntp-26
> https://datatracker.ietf.org/doc/html/draft-ietf-ntp-using-nts-for-ntp-26
> 
> A diff from the previous version is available at:
> https://www.ietf.org/rfcdiff?url2=draft-ietf-ntp-using-nts-for-ntp-26
> 
> 
> Please note that it may take a couple of minutes from the time of submission
> until the htmlized version and diff are available at tools.ietf.org.
> 
> Internet-Drafts are also available by anonymous FTP at:
> ftp://ftp.ietf.org/internet-drafts/
> 
> 
> _______________________________________________
> ntp mailing list
> [e-mail]
> https://www.ietf.org/mailman/listinfo/ntp