The advantages of OCSP were that you got a real-time understanding of the status of a certificate and you had no need to download large CRLs which become stale very quickly. If you set security.ocsp.require in the browser appropriately then you didn't have any risk of the browser failing open, either. I did that in the browser I was daily-driving for years and can count on one hand the number of times I ran into OCSP responder outages.
The privacy concerns could have been solved through adoption of Must-Staple, and you could then operate the OCSP responders purely for web-servers and folks doing research.
And let's not pretend users aren't already sending all the hostnames they are visiting to their selected DNS server. Why is that somehow okay, but OCSP not?
The underlying dynamics of any change to the Web ecosystem is that it has to be incrementally deployable, in the sense that when element A changes it doesn't experience breakage with the existing ecosystem. At present, approximately no Web servers do OCSP stapling, so any browser which requires it will just not work. In the past, when browsers want to make changes like this, they have had to give years of warning and then they can only actually make the change once nearly the entire ecosystem has switched and so you have minimal breakage. This is a huge effort an only worth doing when you have a real problem.
As a reference point, it took something like 7 years to disable SHA-1 in browsers [0], and that was an easier problem because (1) CAs were already transitioning (2) it didn't require any change to the servers, unlike OCSP stapling which requires them to regularly fetch OCSP responses [1] and (3) there was a clear security reason to make the change. By contrast, with Firefox's introduction of CRLite, all the major browsers now have some central revocation system, which works today as opposed to years from now and doesn't require any change to the servers.
[0] https://security.googleblog.com/2014/09/gradually-sunsetting... [1] As an aside it's not clear that OCSP stapling is better than short-lived certs.
> As an aside it's not clear that OCSP stapling is better than short-lived certs.
I agree this should be the end goal, really.
I think the argument isn’t that it’s okay, but that one bad thing doesn’t mean we should do two bad things. Just because my DNS provider can see my domain requests doesn’t mean I also want arbitrary CAs on the Internet to also see them.
Most people don't realize this.
It's quite insane given that Chrome will by default not check CRLs *at all* for internal, enterprise CAs.
GauntletWizard•2h ago
The alternative to the privacy nightmare is ocsp stapling, which has the first problem once again - it adds complexity to the protocol just to add an override of the not after attribute, when the not after attribute could be updated just as easily with the original protocol, reissuing the certificate. It was a Band-Aid on the highly manual process of certain issuance that once dominated the space.
Good riddance to ocsp, I for one will not miss it.
jeroenhd•1h ago
Certificates in air-gapped networks are problematic, but that problem can be solved with dedicated CRL-only certificate roots that suffer all of the downsides of CRLs for cases where OCSP stapling isn't available.
Nobody will miss OCSP now that it's dead, but assuming you used stapling I think it was a decent solution to a difficult problem that plagued the web for more than a decade and a half.
tremon•57m ago
arccy•54m ago
avianlyric•53m ago
How would a bad actor do that without a certificate authority being involved?
sugarpimpdorsey•36m ago
The browser-CA cartels stay relatively in sync.
You can verify this for yourself by creating and trusting a local CA and try issuing a 5 year certificate. It won't work. You'll have a valid cert, but it won't be trusted by the browser unless the lifetime is below their arbitrary limit. Yet that certificate would continue to be valid for non-browser purposes.
layer8•1h ago
That's not a viable solution if the server you want to verify is compromised. The point of CRL and OCSP is exactly to ask the authority one higher up, without the entity you want to verify being able to interfere.
In non-TLS uses of X.509 certificates, OCSP is still very much a thing, by the way, as there is no real alternative for longer-lived certificates.
arccy•55m ago
tgsovlerkhgsel•35m ago
Certificate volume in Certificate Transparency would increase a lot, adding load to the logs and making it even harder to follow CT.
Issues with domain validation would turn into an outage after 24h rather than when the cert expires, which could be a benefit in some cases (invalidating old certs quickly if a domain changes owner or is recovered after a compromise/hijack).
OCSP is simpler and has fewer dependencies than issuance (no need to do multi-perspective domain validation and the interaction with CT), so keeping it highly available should be easier than keeping issuance highly available.
With stapling (which would have been required for privacy) often poorly implemented and rarely deployed and browsers not requiring OCSP, this was a sensible decision.
tptacek•26m ago
charcircuit•8m ago
You can delete old logs or come up with a way to download the same thing with less disk space. Even if the current architecture does not scale we can always change it.
>even harder to follow CT.
It should be no harder to follow than before.