4 ms·
Isn't a sub-CA just another "intermediate", basically in the same way the actually CA certificate Let's Encrypt uses to sign is an intermediate? In that case,
by gregmac 5y ago
Isn't a sub-CA just another "intermediate", basically in the same way the actually CA certificate Let's Encrypt uses to sign is an intermediate?
In that case, I'd have expected the failure mode of something not supporting the name constraints extension to be that it doesn't recognize the constraints: it would accept any certificate issued by the sub-CA.
Is that not true? Or is the problem that Apple devices are a big enough target that allowing these bad certificates to be issued in the wild would be too much of a problem?
- wiml 5y agoMostly right, yes: You can mark the field containing the constraint as "critical" or "non critical", which indicates to the end software what it should do if it doesn't understand this constraint. Apple software doesn't understand it, so it looks at the critical bit (at least Apple got that right): you can choose whether to fail by having it accept invalid certificates for any other website on the planet, or to fail by having it reject the intermediate completely. I just assume that any general CA who's issuing a sub-CA instead of a wildcard would be unwilling to leave it marked non-critical.
- infogulch 5y agoI would be satisfied with that solution. Sure it would exclude Apple devices until Apple gets its act together but at least we'd have something. Mark it as Beta and note that it doesn't support Apple prominently and maybe we can start making progress. CA management and issuance software is not very well developed and needs broad scale active use to get it into a usable state.
- infogulch 5y agoApparently this issue has been resolved in newer Apple OS versions: https://news.ycombinator.com/item?id=29812443 https://news.ycombinator.com/item?id=29812443