Re: [Trans] Write-up of the "Strict CT" variant

[Ryan Sleevi <[e-mail]>]

On Wed, Jun 7, 2017 at 9:29 AM, Magnus Ahltorp <[e-mail]> wrote:

> CAs cannot be held responsible for domain-validated certificates for the
> simple reason that they don't have documentation, and therefore cannot be
> required to produce documentation, which means that they can claim anything.
>

At the risk of going offtopic, by broadening into policy discussions, at
least with respect to the Web PKI - which is certainly the only (publicly)
deployed instance of CT,
https://cabforum.org/baseline-requirements-documents/ govern and
https://cabforum.org/wp-content/uploads/CA-Browser-Forum-BR-1.4.5.pdf
applies (Sections 3.2.2.4 & .5 and Section 5.4)

TL;DR: Yes they do produce documentation, no, they cannot claim anything.


> It is definitely possible to generate new timestamps and not log them, but
> I was rebutting "they don't have to produce the list of SCTs they've
> signed", which is not true, unless "don't have to" is different from "not
> required to". Logs are required to produce the list of all timestamps they
> have signed when MMD has passed. That is what it means to be a log.


I'm not sure your usage of "required" to. If you mean in the abstract,
philosophical sense - yes, a well-behaving log is expected to do so.

However, an evil log can lie - and not produce such timestamps, by not
integrating them into the log, despite having signed them. Which was the
point - only an Honest Log can audit the production of all of its SCTs and
make sure they're integrated, but the concern here is about a Dishonest
Log, which would only integrate some of the SCTs into the STH.