Some have argued that this is why CRL and (especially) OCSP are useless pieces of security theater: they don't actually protect against a crafted attack because they fail-open in the very situations that a determined adversary can trigger, so they only "protect" in situations where no real threat exists. It's simply feel-good bookkeeping.

Adam Langley, working on Google Chrome [1][2][3], has been very vocal about OCSP's faults, and Chrome began using its own auto-update to ship an aggregate of revocations of high-value certs directly to browsers out-of-band. Despite this being another famous instance of Chrome going against the grain of other browser vendors, I believe this was the correct solution: offering better protection for a curated subset of sites vs. pretending to -- but not actually -- protecting all sites.

[1] https://www.imperialviolet.org/2012/02/05/crlsets.html [2] https://www.imperialviolet.org/2014/04/19/revchecking.html [3] http://www.zdnet.com/article/chrome-does-certificate-revocat...

> I believe this was the correct solution: offering better protection for a curated subset of sites vs. pretending to -- but not actually -- protecting all sites.

I concur, but note that it is possible to do better and offer better revocation protection for all sites, with low bandwidth/storage costs: http://www.ccs.neu.edu/home/cbw/static/pdf/larisch-oakland17...

This paper -- the CRLite proposal -- is wonderfully well thought-out, experimentally tested, and meets the design goals much better and more elegantly than any other attempt to solve the certificate revocation problem.

Looks like it was posted here and got very little traction [1]; a shame. But it will be presented in a few days at the IEEE Symposium on Security and Privacy [2]. I hope it will get the coverage and examination it deserves.

[1] https://news.ycombinator.com/item?id=13982861 [2] https://www.ieee-security.org/TC/SP2017/program-papers.html

The one app chain (complex code signing) I worked on with OSCP, we defaulted to failsafe, but it could be overridden in the 'main' (enterprise CMS) app. The installer required OSCP or wouldn't install.

Basically the first and last mile were hard fails but everything in between was advisory if the signature checked out.