Comment by jthoward64
12 hours ago
According to https://bugzilla.mozilla.org/show_bug.cgi?id=2083449 they actually did use an HSM? Though some of the jargon is a bit beyond me, maybe this will finally get me to learn more PKI stuff.
> The hardware used for each of the issuers is in the attached file. These HSMs are FIPS 140-2 Level 3 compliant.
My vague and inexperienced read on their description boils down to "we were doing something weird and non-standard as part of our key ceremony because we intended these keys to be exported, and because of that process weirdness we blundered and gave the HSM faulty instructions."
The most likely explanation is that they generated the weak key externally, imported it into the HSM, generated the CSR from it, and finally had Root CA sign it.
A FIPS HSM does not forbid one to import keys into it.
But shouldn't such a HSM support key attestation (and the parent require such attestation)? Attestation would also track whether a key was imported or generated on the HSM, and of sufficient length.
Attestation is not required by the compliance standard for browser CAs (WebTrust) and it is also quite vendor-specific and not very interoperable, so it is not commonly done.
The Root CA must sign requests after authentication, but a "manual" approval is also accepted if done with the appropriate oversight with witnesses (clearly not the case here).
2 replies →