SubCA branding; Subscriber identity and users misinformed by UI

[Matthias van de Meent]

Hi,

Today I noticed that Firefox shows "verified by <subCA subjectCompanyName>" when you hover over the lock in the URL box; and that on this website [0] that was Cloudflare, Inc. This was a suprise to me; as I had not before heard about Cloudflare operating a CA. After some digging, I found that the subCA that signed the certificate was  branded with Cloudflare Inc. [1] and is actually operated by DigiCert, and (according to crt.sh) would be subject to the DigiCert CPS (which seems to be [2]).

However; I could not find any reference to Cloudflare in the DigiCert CPS. And; seeing that DigiCert's CPS disallows delegation of IP / domain validation; this would mean that at least some part of the validation is done by DigiCert; not Cloudflare -- I'd even argue that the most important part of the validation was done by DigiCert -- organization information is of limited value in TLS connections.

This puts up the following questions:

Should this information be displayed as such?
In my opinion, it the current UI (both the hover and the second screen of the 'site security info' popup) misinforms the user in believing that (in this case) Cloudflare has validated that this certificate was issued to the right web server. This is not completely incorrect; as Cloudflare could have provided the organization validation of the OV certificate, but it did provide me with an incorrect impression until I had fully worked out the CA chain involved.

Next, should a subCA be allowed to be branded under another company's name while (presumably) still under full control of the parent CA?

Specifically; should a CA be allowed to sign an unconstrained CA certificate for which they know that they will be the ones operating it; and that the subject:organizationName donor is involved effectively only in name; not in function?

If that intermediate CA is the Issuing CA, then that would indicate that this second party that donated the name did meaningfully validate and sign the leaf certificate; which is incorrect and misleading.

I know that a Certificate Authority may be the delegated party of a subscriber and may thus sign (CA) certificates with the subscriber as subject; but I think that it is very much misleading the relying party; at which I'd like to note that when "[t]he Issuing CA determines that any of the information appearing in the [Subordinate CA] Certificate is inaccurate or misleading" the Subordinate CA Certificate must be revoked within 7 days (BR s4.9.1.2 (6)).

Kind regards,

Matthias van de Meent

[0] https://discord.com
[1] Cloudflare Inc ECC CA-3: https://crt.sh/?caid=157939, Cloudflare Inc RSA CA-2:https://crt.sh/?caid=157939
[2] https://www.digicert.com/content/dam/digicert/pdfs/legal/digicert-cps-v5-9.pdf, repository: https://www.digicert.com/legal-repository