[Servercert-wg] SC-59 Weak Key Guidance v.2 - Discussion Period

Thu Jun 29 16:55:10 UTC 2023

Christophe, 

The consideration of removing the checks brings up many questions.  As a CA
representative, do you feel that the removal of a requirement to check for
and revoke Debian Weak Key certificates would pose a risk to relying
parties?  Granted, the method has been patched for 15 years and the
certificates are almost never seen in the wild, and to generate DWK
certificates someone would either have not patched their system in over a
decade or specifically gone out of their way to obtain the software versions
capable of creating those certs. Should we chalk it up to a "Darwin Award"
for the subscribers who accidentally, or ignorantly, fall into that
category?  Should CAs still be responsible for the relying parties who will
undoubtedly be hurt when the certificate is cracked, or would/could that
burden be placed upon the subscriber by an Agreement clause akin to "keep
your private key safe"?

Tom

From: Christophe Bonjean <christophe.bonjean at globalsign.com> 
Sent: Thursday, June 29, 2023 7:11 AM
To: Tom Zermeno <tom at ssl.com>; CA/B Forum Server Certificate WG Public
Discussion List <servercert-wg at cabforum.org>
Subject: RE: SC-59 Weak Key Guidance v.2 - Discussion Period

Hi Tom

Thank you for looking into the feedback. 

With the concerns about Debian weak key checks and revocation, where there
is already today doubt about keeping it in a future version of the
requirements, with some suggestions to remove it in a next ballot, it seems
we would be spending double efforts with first this ballot and a subsequent
discussion for a topic that we already know has not fully been clarified. I
would suggest we aim to reach a consensus on this before we proceed with
this ballot. 

Christophe

From: Servercert-wg <servercert-wg-bounces at cabforum.org
<mailto:servercert-wg-bounces at cabforum.org> > On Behalf Of Tom Zermeno via
Servercert-wg
Sent: Monday, June 26, 2023 11:53 PM
To: Tom Zermeno <tom at ssl.com <mailto:tom at ssl.com> >; CA/B Forum Server
Certificate WG Public Discussion List <servercert-wg at cabforum.org
<mailto:servercert-wg at cabforum.org> >
Subject: Re: [Servercert-wg] SC-59 Weak Key Guidance v.2 - Discussion Period

While the ballot does not specifically address the concerns about the value
of Debian checks, etc., I felt that the removal of the review should be
better considered in a future ballot initiative. SSL.com believes that an
overabundance of caution is beneficial to the community, even if it is a
drain on resources. We hope that the ballot, as presented, does not
represent an overwhelming burden on CAs. 

We do agree with the sentiment that most weak-key submissions have been by
security researchers, but the occasional customer who is spared the
potentially devastating effects of using a weak certificate makes the
efforts worthwhile.  We would consider, and possibly agree, to the removal
of Debian weak-key checks and the revocation requirements of 4.9.1.1 (4),
but we would also likely continue to perform the assessments for the
benefits of our customers and relying parties.  However, as stated, we feel
that this avenue of discussion is better traveled after the strengthening of
current BR requirements for the prevention of modern threats.   

Thanks,

Tom

From: Servercert-wg <servercert-wg-bounces at cabforum.org
<mailto:servercert-wg-bounces at cabforum.org> > On Behalf Of Tom Zermeno via
Servercert-wg
Sent: Monday, June 26, 2023 4:35 PM
To: Infrastructure Bot via Servercert-wg <servercert-wg at cabforum.org
<mailto:servercert-wg at cabforum.org> >
Subject: [Servercert-wg] SC-59 Weak Key Guidance v.2 - Discussion Period

My apologies to the community for not properly submitting the updated
version (v2) of the SC-59 Weak Key Guidance ballot for discussion.  Please
disregard the previous call to vote and allow a 7-day period to discuss the
changes made to the ballot. 

Notes:

*	Thank you to the participants who voiced opinions and concerns about
the previous version of the ballot.  While there were many concerns about
the inclusion of the Debian weak keys checks, we have decided to leave the
checks in the ballot.  Our reasoning is that we wanted to strengthen the
guidance statements, to help CAs ensure compliant certificate generation.
Future reviews of the BRs may cull the requirements, as is required by the
needs of the community. 
*	We believe that the requested date of November 15, 2023, will allow
enough time for Certificate Authorities to enact any changes to their
systems to ensure that they perform the weak key checks on all CSRs
submitted for TLS certificates. 
*	The changes introduced in SC-59 do not conflict with any of the
recent ballots. As observed with other ballots in the past, minor
administrative updates must be made to the proposed ballot text before
publication such that the appropriate Version # and Change History are
accurately represented (e.g., to indicate these changes will be represented
in Version 2.0.1).  

The following motion has been proposed by Thomas Zermeno of SSL.com and has
been endorsed by Martijn Katerbarg of Sectigo and Ben Wilson of Mozilla. 

- Motion Begins -  

This ballot modifies the "Baseline Requirements for the Issuance and
Management of Publicly-Trusted Certificates" ("Baseline Requirements"),
based on Version 2.0.0. 

MODIFY the Baseline Requirements as specified in the following Redline:
<https://github.com/cabforum/servercert/compare/a0360b61e73476959220dc328e3b
68d0224fa0b3...SSLcom:servercert:958e6ccac857b826fead6e4bd06d58f4fdd7fa7a>
https://github.com/cabforum/servercert/compare/a0360b61e73476959220dc328e3b6
8d0224fa0b3...SSLcom:servercert:958e6ccac857b826fead6e4bd06d58f4fdd7fa7a  

- Motion Ends - 

The procedure for approval of this ballot is as follows:

Discussion (7 days) 

. Start time: 2023-06-26 22:00:00 UTC 

. End time: 2023-07-03 21:59:59 UTC 

Vote for approval (7 days) 

  .  Start Time:  TBD

  .  End Time:   TBD 

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