5 ms·
Yes, OCSP is unencrypted (and uses HTTP). OCSP requests only include the certificate's serial number, however, and (AFAIK) Apple does not publish a directory of
by jlgaddis 6y ago
Yes, OCSP is unencrypted (and uses HTTP). OCSP requests only include the certificate's serial number, however, and (AFAIK) Apple does not publish a directory of all issued certificates.
WRT the web PKI, though, yes, the serial number can be looked up in CT logs. Although that same "basic packet capture" will give you the hostname of the server -- at least until encrypted SNI is used everywhere.
(As for why OCSP is unencrypted, chicken and egg... rsponses are signed, however.)
- sneak 6y agoApple doesn't need to publish it. All one needs to do is collect a bunch of OSX apps (app store, creative cloud, web downloads of .dmg, whatever) and pull out the certificate serial numbers. This mapping is effectively public data, if you bother to go about collecting it. Then, anyone monitoring your connection knows which apps you launch, when, and where you do it. Additionally, Akamai (and their ISPs) get your complete (IP geolocation) tracklog, and knows when you're at home, when you're traveling, and which apps you use in those places. I wrote about the consequences of this just an hour ago: https://news.ycombinator.com/item?id=25078034 https://news.ycombinator.com/item?id=25078034 Interesting thing is, Apple will deny apps from the App Store that make unencrypted connections (via App Transport Security), but their own, firewall-exempt, vpn-bypassing system processes can do it just fine. :D
- mleonhard 6y agoI want this to be big news. Apple lately pretends that they care about user privacy. They might fix it.
- jlgaddis 6y agoSorry, what, exactly, should be fixed? If you're referring to OCSP requests / responses being unencrypted, I would be interested in hearing what your solution to this problem is. Also, I would recommend that you do not perform any packet captures (as mentioned earlier) to observe your OCSP traffic. You're gonna have a heart attack when you realize that this isn't just an Apple thing and that nobody encrypts OCSP. Once you understand why, I'd be interested in hearing your new, revised solution. Finally, it's not quite as bad as sneak makes it out to be. OCSP responses are cached so, as mentioned in TFA (so certificate status is not being checked every time you launch every app), although I'm not sure what the validity interval of OCSP responses from ocsp.apple.com is (and don't have anything running macOS to check). Additionally, I don't see anyone but Apple announcing any part of the 17/8 network (regardless of ocsp.apple.com. being CNAME'd to Akamai).
- mleonhard 6y agoThey could switch to a CRL.
- blakewatters 6y agoOCSP exists because CRLs don’t scale as you build an ever growing list of revoked certificates
- mleonhard 6y agoWith certificate age limits, the list is not ever-growing.