[cabfpub] Use of wildcard certificates by cloud operators

Gervase Markham gerv at mozilla.org
Tue May 6 10:01:25 UTC 2014

I agree with Ryan :-)

On 05/05/14 18:10, Kelvin Yiu wrote:
> 1.       Section 11.1.3 of the BR explicitly disallow wildcard
> certificates for registry controlled domains (e.g. *.com). The Mozilla
> maintained http://publicsuffix.org is cited as an example of a public
> suffix list where Azure, GAE, and AWS domains can be found. Does the
> current usage of wildcard certificates by cloud operators violate the
> BR? If so, is this intentional and what is the reason?

No. The PSL is in two sections for precisely this reason - there are
privately-owned sites where an e.g. appspot.com cookie should not be
allowed (allows one appspot site to perform cookie fixation attacks
against another) but a *.appspot.com cert should be allowed. So we split
the PSL logically into two to put sites like this in their own section.

> 2.       Section 13.1.5 of the BR explicitly require wildcard
> certificates that were “used to authenticate fraudulently misleading
> subordinate FQDN” to be revoked within 24 hours. If the fraudulent sites
> never had access to the private key of the wildcard certificate and the
> cloud operator has a process to take down fraudulent sites, should these
> wildcard certificates be required to be revoked?

Hmm. This is tricky. I suspect this situation was not considered when we
wrote that. I'd lean towards No, but I'm not sure that's what the BRs
say on their face, and I'd welcome more discussion.


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