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From: Sean Turner <sean@sn3rd.com>
In-Reply-To: <AM0PR08MB3716CD4DA4854230B57AB6AEFAC00@AM0PR08MB3716.eurprd08.prod.outlook.com>
Date: Fri, 10 Apr 2020 22:44:30 -0400
Cc: TLS List <tls@ietf.org>, "uta@ietf.org" <uta@ietf.org>,
 Hannes Tschofenig <Hannes.Tschofenig@arm.com>
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References: <CD58C8B5-BBB4-4D59-B2BF-4DE53A2725F1@ericsson.com>
 <AM0PR08MB3716CD4DA4854230B57AB6AEFAC00@AM0PR08MB3716.eurprd08.prod.outlook.com>
To: John Mattsson <john.mattsson@ericsson.com>
Archived-At: <https://mailarchive.ietf.org/arch/msg/tls/QlElrvYC7m6ijM06Kw-_KAKHgdw>
Subject: Re: [TLS] [Uta] CBOR Certificate Compression of RFC 7925
 certificates suitable for cTLS
Precedence: list

-hat

John,

There is already a certificate compression mechanism defined in =
draft-ietf-tls-certificate-compression, which is currently in the RFC =
editor=E2=80=99s queue. How do these documents relate to that one?

spt

> On Apr 8, 2020, at 09:29, Hannes Tschofenig =
<Hannes.Tschofenig@arm.com> wrote:
>=20
> Thanks for the info, John. I will have a look at this publication.
>=20
> -----Original Message-----
> From: John Mattsson <john.mattsson@ericsson.com>
> Sent: Wednesday, April 8, 2020 3:14 PM
> To: Hannes Tschofenig <Hannes.Tschofenig@arm.com>; tls@ietf.org; =
uta@ietf.org
> Subject: Re: [TLS] CBOR Certificate Compression of RFC 7925 =
certificates suitable for cTLS
>=20
> Hi Hannes,
>=20
> I have requested and been assigned time for =
draft-mattsson-tls-cbor-cert-compress-00 and =
draft-raza-ace-cbor-certificates-04 at the UTA virtual interim on March =
23.
>=20
> We have an implementation of =
https://link.springer.com/chapter/10.1007%2F978-3-319-93797-7_14 / =
draft-raza-ace-cbor-certificates-03, but the code is not written in a =
way so that the compression mechanism DER-> CBOR can be extracted. The =
example in draft-raza-ace-cbor-certificates-04 was created by hand with =
cbor.me. We are planning to implement a updated standalone version of =
the DER->CBOR compression and hopefully have interop testing in the COSE =
WG.
>=20
> Cheers,
> John
>=20
> =EF=BB=BF-----Original Message-----
> From: TLS <tls-bounces@ietf.org> on behalf of Hannes Tschofenig =
<Hannes.Tschofenig@arm.com>
> Date: Friday, 3 April 2020 at 14:20
> To: John Mattsson <john.mattsson=3D40ericsson.com@dmarc.ietf.org>, =
"TLS@ietf.org" <tls@ietf.org>, "uta@ietf.org" <uta@ietf.org>
> Subject: Re: [TLS] CBOR Certificate Compression of RFC 7925 =
certificates suitable for cTLS
>=20
>    Hi John,
>=20
>    Thanks for the heads-up.
>=20
>    Discussing this aspect in draft-tschofenig-uta-tls13-profile-01 =
makes sense.
>=20
>    I was wondering whether you have been working on an implementation =
of draft-mattsson-cose-cbor-cert-compress-00 / =
draft-raza-ace-cbor-certificates-04.
>=20
>    Ciao
>    Hannes
>=20
>    -----Original Message-----
>    From: TLS <tls-bounces@ietf.org> On Behalf Of John Mattsson
>    Sent: Friday, April 3, 2020 9:03 AM
>    To: TLS@ietf.org; uta@ietf.org
>    Subject: [TLS] CBOR Certificate Compression of RFC 7925 =
certificates suitable for cTLS
>=20
>    Hi,
>=20
>    During the COSE virtual interim meeting yesterday, there was =
agreement that the COSE working group should work on CBOR compression of =
RFC 7925 profiled X.509 certificates. The work will be based on =
draft-raza-ace-cbor-certificates and =
draft-mattsson-cose-cbor-cert-compress and the two drafts will be =
merged. Doing this work in a security group focused on CBOR makes a lot =
of sense.
>=20
>    =
https://tools.ietf.org/html/draft-mattsson-cose-cbor-cert-compress-00
>    https://tools.ietf.org/html/draft-raza-ace-cbor-certificates-04
>=20
>    The COSE draft charter has already been updated to reflect this.
>=20
>    https://github.com/cose-wg/Charter/blob/master/Charter.md
>=20
>    As the algorithm is focused on compressing RFC 7925 profiled =
certificates, It seems like a very good match for cTLS. To keep the =
number of internet-drafts down, I plan to also include the TLS IANA =
registrations in the merged draft submitted to the COSE WG and let =
draft-mattsson-tls-cbor-cert-compress-00 expire.
>=20
>    Any comments from the TLS WG are very welcome, but otherwise these =
is not so much to discuss, this is just another certificate compression =
algorithm. Any TLS related discussions would likely be regarding the =
certificate profile in RFC 7925 and if any clarifications or updates are =
needed. This is likely best discussed in UTA which may take up work on a =
TLS/DTLS 1.3 update of RFC 7925.
>=20
>    https://tools.ietf.org/html/draft-tschofenig-uta-tls13-profile-01
>=20
>    Cheers,
>    John
>=20
>    -----Original Message-----
>    From: John Mattsson <john.mattsson@ericsson.com>
>    Date: Thursday, 12 March 2020 at 08:58
>    To: "TLS@ietf.org" <TLS@ietf.org>
>    Cc: "uta@ietf.org" <uta@ietf.org>
>    Subject: FW: New Version Notification for =
draft-mattsson-tls-cbor-cert-compress-00.txt
>=20
>        Hi,
>=20
>        We have submitted a new draft to TLS =
https://tools.ietf.org/html/draft-mattsson-tls-cbor-cert-compress-00 The =
draft register a new compression algorithms for use with TLS Certificate =
Compression in TLS 1.3 and DTLS 1.3 =
(draft-ietf-tls-certificate-compression).
>=20
>        The draft uses =
https://tools.ietf.org/html/draft-raza-ace-cbor-certificates-04 to =
compress RFC 7925 profiles certificates by encoding them from DER to =
CBOR. The aim is to be compatible with all RFC 7925 profiled =
certificates. With the included example DER encoded RFC 7925 certificate =
to certificate is compressed from 314 to 136 bytes, a compression rate =
of 57%.
>=20
>        The general purpose compression algorithms defined in =
draft-ietf-tls-certificate-compression do not seem able to compress =
profiled RFC 7925 X.509 certificates much at all. zlib compressed the =
example cert 9%, but for other certificates we tested, zlib did in many =
cases not provide any compression at all.
>=20
>        We have submitted a similar draft to the COSE WG registering a =
new algorithms for the TLS 1.3 certificate compression extension.
>=20
>        =
https://tools.ietf.org/html/draft-mattsson-tls-cbor-cert-compress-00
>=20
>        Cheers,
>        John
>=20
>        -----Original Message-----
>        From: "internet-drafts@ietf.org" <internet-drafts@ietf.org>
>        Date: Monday, 9 March 2020 at 21:19
>        To: John Mattsson <john.mattsson@ericsson.com>, John Mattsson =
<john.mattsson@ericsson.com>, Joel H=C3=B6glund <joel.hoglund@ri.se>, =
Joel Hoglund <joel.hoglund@ri.se>, G=C3=B6ran Selander =
<goran.selander@ericsson.com>, Martin Furuhed =
<martin.furuhed@nexusgroup.com>, G=C3=B6ran Selander =
<goran.selander@ericsson.com>, Shahid Raza <shahid.raza@ri.se>
>        Subject: New Version Notification for =
draft-mattsson-tls-cbor-cert-compress-00.txt
>=20
>=20
>            A new version of I-D, =
draft-mattsson-tls-cbor-cert-compress-00.txt
>            has been successfully submitted by John Preuss Mattsson and =
posted to the
>            IETF repository.
>=20
>            Name:draft-mattsson-tls-cbor-cert-compress
>            Revision:00
>            Title:CBOR Certificate Algorithm for TLS Certificate =
Compression
>            Document date:2020-03-09
>            Group:Individual Submission
>            Pages:6
>            URL:            =
https://www.ietf.org/internet-drafts/draft-mattsson-tls-cbor-cert-compress=
-00.txt
>            Status:         =
https://datatracker.ietf.org/doc/draft-mattsson-tls-cbor-cert-compress/
>            Htmlized:       =
https://tools.ietf.org/html/draft-mattsson-tls-cbor-cert-compress-00
>            Htmlized:       =
https://datatracker.ietf.org/doc/html/draft-mattsson-tls-cbor-cert-compres=
s
>=20
>=20
>            Abstract:
>               Certificate chains often take up the majority of the =
bytes
>               transmitted in TLS handshakes.  Large handshakes can =
cause problems,
>               particularly in constrained IoT environments.  RFC 7925 =
defines a TLS
>               certificate profile for constrained IoT.  General =
purpose compression
>               algorithms can in many cases not compress RFC 7925 =
profiled
>               certificates at all.  By using the fact that the =
certificates are
>               profiled, the CBOR certificate compression algorithms =
can in many
>               cases compress RFC 7925 profiled certificates with over =
50%. This
>               document specifies the CBOR certificate compression =
algorithm for use
>               with TLS Certificate Compression in TLS 1.3 and DTLS =
1.3.
>=20
>=20
>=20
>=20
>            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.
>=20
>            The IETF Secretariat
>=20
>=20
>=20
>=20
>=20
>=20
>    _______________________________________________
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>=20
>=20
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