Subject: [lamps] I-D Action: draft-ietf-lamps-samples-01.txt

From: [email-masked]
Date: Fri, 07 May 2021 21:16:27 -0700

A New Internet-Draft is available from the on-line Internet-Drafts directories.
This draft is a work item of the Limited Additional Mechanisms for PKIX and SMIME WG of the IETF.

        Title           : S/MIME Example Keys and Certificates
        Author          : Daniel Kahn Gillmor
	Filename        : draft-ietf-lamps-samples-01.txt
	Pages           : 32
	Date            : 2021-05-07

Abstract:
   The S/MIME development community benefits from sharing samples of
   signed or encrypted data.  This document facilitates such
   collaboration by defining a small set of X.509v3 certificates and
   keys for use when generating such samples.

The IETF datatracker status page for this draft is:
https://datatracker.ietf.org/doc/draft-ietf-lamps-samples/

There is also an HTML version available at:
https://www.ietf.org/archive/id/draft-ietf-lamps-samples-01.html

A diff from the previous version is available at:
https://www.ietf.org/rfcdiff?url2=draft-ietf-lamps-samples-01

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/

---

From: Daniel Kahn Gillmor <[email-masked]>
Date: Sat, 08 May 2021 00:34:14 -0400

Hi folks--

>    keys for use when generating such samples.

This revision retains the 2048-bit RSA certificates (a CA, Alice, and
Bob) and adds some Curve25519 certificatees (another CA, Carlos, and
Dana).

Some open questions for the group:

 - The X25519 certificates are pretty bare-bones, and i'm not convinced
   that they would be usable for encryption yet, as most of the tooling
   i've played with is immature for X25519.  Should the certificates
   themselves include an SMIMECapabilities extension with some ECDH
   parameter choices as found in §8 of RFC 8418?  If so, which ones
   should be present?

 - Should the draft include cross-signed certificates between the two
   CAs?  This would enable testing of more sophisticated (and realistic)
   certificate chains, but it also adds to the complexity of the draft
   and potential decision-points/confusion for users of the artifacts.

Generating the encryption-capable ECDH certificates for Carlos and Data
(using X25519) was … interesting.  The tooling i've been using to create
the other certificates in a reproducible fashion (certtool from GnuTLS)
didn't initially support X25519 secret keys, public keys, or
certificates, but I hacked it in and submitted the fixes for review:
https://gitlab.com/gnutls/gnutls/-/merge_requests/1428

I had been testing the RSA certificates/keys for encryption/decryption
purposes using "openssl cms" but "openssl cms" doesn't seem to support
encrypting to the X25519 certificates as i've generated them, anyway.  I
intend to test them against gpgsm and NSS soon but I haven't gotten to
that yet -- and i didn't want to block WG review on my playing with a
bunch of different implementations.

I welcome feedback, particularly on the two questions above, and
*especially* feedback from people who have tried to actually use any of
these keys, certs, and cert chains with specific implementations.

Regards,

       --dkg