Re: [TLS] Last Call: <draft-ietf-tls-dtls-connection-id-10.txt> (Connection Identifiers for DTLS 1.2) to Proposed Standard

[Hannes Tschofenig <[e-mail]>]

Hi Tom,

I added a few PRs to address your review (see https://github.com/tlswg/dtls-conn-id/pulls).

Regarding the zero-length CID I believe the current version in the repo at https://github.com/tlswg/dtls-conn-id might have already address your remark.

In general, the zero-length CID in the ClientHello / ServerHello allows us to use CIDs unidirectionally.

Ciao
Hannes

-----Original Message-----
From: TLS <[e-mail]> On Behalf Of Thomas Fossati
Sent: Friday, March 12, 2021 11:58 AM
To: tom petch <[e-mail]>; [e-mail]
Cc: [e-mail]; [e-mail]; [e-mail]
Subject: Re: [TLS] Last Call: <draft-ietf-tls-dtls-connection-id-10.txt> (Connection Identifiers for DTLS 1.2) to Proposed Standard

Hi Tom,

Thanks very much!

Your review is tracked in the issues below.

On 12/03/2021, 10:39, "tom petch" <[e-mail]> wrote:
>
> Some editorial quirks
>
> s.2
> lacks the boiler plate of RFC8174

https://github.com/tlswg/dtls-conn-id/issues/88

> s.3
> I found this unclear until I had understood it all (or perhaps I do
> not understand it)
>
> "...or again, alternately, to use a zero-length CID)."
> This suggests that a zero length CID is valid in Application Data
> which later text seems to contradict; otherwise I cannot see what this is saying.
>
> "  If DTLS peers have negotiated the use of a CIDs using the
> ClientHello and the ServerHello messages "
> arguably sending a zero CID and receiving a zero CID is a successful
> Hello negotiation perhaps " If DTLS peers have negotiated the use of a
> non-zero CID in at least one direction, using the ClientHello and the
> ServerHello messages"
>
> "The DTLS peers determine whether incoming and outgoing messages need.."
> seems not to cater for unidirectional CIDs; perhaps "The DTLS peers
> determine whether incoming or outgoing, or both, messages need.. "

https://github.com/tlswg/dtls-conn-id/issues/89

> s.4
> /always recieve CIDs/always receive CIDs/
>
>
> s.5.1
> "the with Encrypt-then-MAC processing described in [RFC7366]."
> I do not understand why 'with' is needed
>
> s.5.2
> ditto
>
> s.8
> /this aspects SHOULD refuse/these aspects SHOULD refuse/

https://github.com/tlswg/dtls-conn-id/issues/90

> s.10
> I would find this clearer as three sections for the three IANA actions
> 10.1 new column for ExtensionType
> 10.2 new value for ExtensionType
> 10.3 new value for ContentType
>
> "   IANA is requested to allocate an entry to the existing TLS
>     "ExtensionType Values" registry, defined in [RFC5246],.."
> well no; whatever you think of RFC8447 the name has changed
> "   IANA is requested to allocate an entry to the existing "TLS
>     ExtensionType Values" registry, defined in [RFC5246],.."
> or, if you are picky (which I am not),
>     IANA is requested to allocate an entry to the existing "TLS
>     "ExtensionType Values" registry, defined in [RFC5246], and
>     renamed by RFC8447
>
> An extra column is added but I cannot see what value should be placed
> in that column for existing entries.
>
> "The tls12_cid ContentType is only applicable to DTLS 1.2."
> Good information but I struggle to see what IANA will do with it; I
> see nowhere for it to go.

https://github.com/tlswg/dtls-conn-id/issues/91


cheers, t

> Tom Petch
>
>
> On 08/03/2021 11:19, The IESG wrote:
>
>
> >
> > The IESG has received a request from the Transport Layer Security WG
> > (tls) to consider the following document: - 'Connection Identifiers for DTLS 1.2'
> >    <draft-ietf-tls-dtls-connection-id-10.txt> as Proposed Standard
> >
> > The IESG plans to make a decision in the next few weeks, and
> > solicits final comments on this action. Please send substantive
> > comments to the [e-mail] mailing lists by 2021-03-28.
> > Exceptionally, comments may be sent to [e-mail] instead. In
> > either case, please retain the beginning of the Subject line to allow automated sorting.
> >
> > Abstract
> >
> >
> >     This document specifies the Connection ID (CID) construct for the
> >     Datagram Transport Layer Security (DTLS) protocol version 1.2.
> >
> >     A CID is an identifier carried in the record layer header that gives
> >     the recipient additional information for selecting the appropriate
> >     security association.  In "classical" DTLS, selecting a security
> >     association of an incoming DTLS record is accomplished with the help
> >     of the 5-tuple.  If the source IP address and/or source port changes
> >     during the lifetime of an ongoing DTLS session then the receiver will
> >     be unable to locate the correct security context.
> >
> >
> >
> >
> > The file can be obtained via
> > https://datatracker.ietf.org/doc/draft-ietf-tls-dtls-connection-id/
> >
> >
> >
> > No IPR declarations have been submitted directly on this I-D.
> >
> >
> >
> >
> >
> > _______________________________________________
> > IETF-Announce mailing list
> > [e-mail]
> > https://www.ietf.org/mailman/listinfo/ietf-announce
> > .
> >
>

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