I guess now would be a great time for browsers/OSes to ship a "trust this CA, but only for this TLD/list of domains" feature.
I guess now would be a great time for browsers/OSes to ship a "trust this CA, but only for this TLD/list of domains" feature.
One possible alternative might be to add the ability for user configuration to substitute one certificate for another one (both will need the same public key and subject name, but the substitute will not be self-signed (since you do not have the private key)), and to use the data in the substitute certificate instead of the original. If the name constraints extension is implemented, then it would make this and other things possible. Since the substitute certificate will be considered trusted, it is not necessary for the substitute certificate to have a signature (if it does (e.g. because you got it from somewhere else instead of making it yourself), then the signature can be ignored), nor is it necessary for the substitute certificate to be issued by anyone (this applies even if it is the end certificate being substituted).
I think some servers do not send a copy of the root certificate to the client. In this case, what I described above might already be possible even if that feature has not already been added to existing implementations, as long as it does not require the installed certificate to be self-signed.
This exists in Firefox at least, but I don’t think it’s easily exposed in the UI
It would be simple today to abolish the use of CAs but it just a big cargo biz that makes money on nothing as usual based on peoples incompetence. For 99% of all sites today security would be handled better without CAs. People simply don't understand how it works.
All that was true until fairly recently. Today, you can get certificates for free and there’s more transparency than ever thanks to CT.
What would you suggest as an alternative? TOFU?
I could see that for local applications (e.g. making mDNS/.local and private IP certs TOFU capable by default would be amazing, and maybe even for some explicit hobbyist public TLDs?), but I don’t think I’d love it for my bank or email provider.
> It would be simple today to abolish the use of CAs […]
The main technical way I know of doing this would be by putting TLS public keys in DNS (DANE, RFC 6698), but then you have to make sure that DNS packets are not fiddled with, so you need to bring in DNSSEC.
Exactly, and in some ways, DNS is even more centralized. At least there’s a choice of CAs independent of TLDs.
That's a false concern, because the names the CAs are certifying are still DNS names. If your TLD reasssigns your DNS name out from under you, or even if your TLD starts returning false data on only selected queries, the CAs will be happy to issue a cert to the new holder.
It would be great to have a widely-recognizable pseudodomain out there where the names were key hashes. It would actually graft really easily into DNSSEC. The zone format doesn't have to change at all; you just declare that if the KSK hash matches the domain label under this specific TLD, you don't need to check upstream of that. Then you add a P2P protocol for getting the actual data, and start slowly pushing that protocol down the resolver tree to incrementally decentralize everything.
20 years ago would have been a great time for that one.