Re: [TLS] CRL Stapling? (was Re: I-D Action: draft-ietf-tls-multiple-cert-status-extension-00.txt)

[[e-mail] (Martin Rex)]

Rob Stradling wrote:
> 
> IIRC, when Opera does an online revocation check, it currently checks 
> CRLs for intermediate CA certificates and OCSP for end-entity 
> certificates.  This makes sense because:
>    - CRLs covering intermediate CA certificates tend to be roughly the 
> same size (sometimes smaller!) as the equivalent OCSP Responses (since 
> it's quite rare for intermediate CA certificates to be revoked).
>    - Possessing a current CRL means you won't have to do an online 
> revocation check if you encounter another certificate issued by the same 
> issuer.
>
>   [...]
> 
> How about changing the scope of the multi-stapling I-D so that it *only* 
> covers the intermediate CA certificate(s) in the chain?

This would significantly increase the complexity without adding value.
OCSP responses can be cached just as long as the CRLs on which they're
based.

> 
> With this approach, an end-entity OCSP Response could be stapled using 
> the RFC6066 TLS extension, and the intermediate CRL(s) could be stapled 
> using the new multi-stapling TLS extension.

This would require the complexity of two TLS extensions where a single
TLS extension is perfectly sufficient (i.e. a lot more code and a lot
more bugs).


While I might eventually look into implementing the multi-stapling
TLS extension, I will never consider doing the rfc6066 single OCSP
extension.


-Martin