Re: [Trans] draft-ietf-trans-rfc6962-bis-31

[Paul Wouters <[e-mail]>]

On Wed, 19 Jun 2019, Rashmi Jha wrote:

> Have you looked into the options of not requiring CT for CAs which are constrained to a brief list of domains ? I understand this was considered in the past but couldn’t find details why this was not
> accepted.

Whether or not to require CT is not part of the document. This seems
more like a question to browser vendors. The draft only states:


    In addition, if TLS clients will not accept unlogged certificates,
    then site owners will have a greater incentive to submit certificates
    to logs, possibly with the assistance of their CA, increasing the
    overall transparency of the system.

The "if" there is important. It is not a decision made in this document
or this Working Group.

The draft only lists the requirements and formats for when CT is used.

> Named constraint by default provide the assurance as to what domains they will issue. CT becomes an additional network call in in issuance of certificate which can be prevented.  

Not "assurance", but "expectation". CT is there to confirm this
expectation. Surely, you want CT logs to show captured certificates that
were signed by a CA outside of that CA's own Named constraint policy?

Additionally, if you skip accepting certificates within a named
constraint, what do you do when some CA claims ".com" as their
named constraint?

Paul