Proposal: crypto/tls: Support RFC 6961 Multiple Certificate Status Request Extension

[nhooyr]

Go's TLS library supports RFC 6066's status_request TLS extension. The status_request extension allows servers to send status information to the client directly, rather than the client having to contact the certificate's OCSP responder separately.

A new extension, status_request_v2 has been defined in RFC 6961 that allows servers to send multiple OCSP responses so that the server can send status information for intermediate CAs as well.

I say we add support for RFC 6961's status_request_v2 extension.

[odeke-em]

/cc @agl @FiloSottile and this is a proposal/feature request.

[agl]

I don't think this gels with the direction that revocation is taking. Instead, I expect to see browsers shipping information about intermediate revocations and using OCSP stapling only for the leaf. See Mozilla's efforts in recent years to require disclosure of all intermediates.

[nhooyr]

I'll give more context about why I wanted this. It's not for browsers but for my company's internal PKI.

We have intermediate CAs that sign certificates for sets of similar servers. If one of our intermediate CAs gets somehow compromised, we can just revoke it in our DB, generate a new one and have every server in the intermediate CA's cluster get new certificates from the new intermediate CA.

A CRL would definitely work but it would be a lot less elegant because then we'll have a split of revoked certificates. Some in our DB and some in the CRL. Along with all the other downsides of using and maintaining a CRL.

Also, I forgot to mention that if we decide to implement it, I'm available to create the CL.

[ianlancetaylor]

Ping @agl @FiloSottile

[FiloSottile]

status_request_v2 is now deprecated, we are not going to implement it.