3 ms·

Revocation Confusion

11 points by nullpxl 1y ago

mholt 1y ago
Yeah, revocation is a hot mess, it's always been broken, and OCSP Stapling was our only hope -- but then most web servers (but not all! guess which one) dropped the ball. (Clients at least honored Must-Staple.) Short certificate lifetimes is the ultimate way forward, and thankfully it's already available through Let's Encrypt, via the "shortlived" profile. With a certificate that lives < ~7 days, there's virtually no need to revoke. Some clients/browsers will still move to revoke certificates within minutes or hours of their own choosing (see, that's the other frustrating thing, revocation is really just whatever you want), but I hope we'll only see that on internal PKIs, since doing that for public sites is essentially censorship.
- politelemon 1y ago
  I'm not seeing how there's no need to revoke. It means a compromised certificate is still considered valid for several days, in which a lot of damage can be done.
  - mholt 1y ago
    Propagating the revocation information often takes about as long.
- gucci-on-fleek 1y ago
  > thankfully it's already available through Let's Encrypt, via the "shortlived" profile Maybe if you're the developer of a major web server :), but the rest of us still have to wait for general availability [0] [1]. [0]: https://letsencrypt.org/docs/profiles/#shortlived https://letsencrypt.org/docs/profiles/#shortlived [1]: https://community.letsencrypt.org/t/shortlived-is-currently-locked-behind-an-allowlist/241956/2 https://community.letsencrypt.org/t/shortlived-is-currently-...
alanfranz 1y ago
One thing the article doesn’t mention is that a lot of certs are revoked for purely admin reasons. CeasedOperations seems to be the case for Flair - nothing bad happened to the key, but the cert was revoked nevertheless. This seems to be a common practice for some CAs or companies, but it’s not required AFAICT; and it contributes to the gigantic CRLsets that we have - most of those revocations wouldn’t actually be needed from a security pov.

11 points by nullpxl 1y ago

Yeah, revocation is a hot mess, it's always been broken, and OCSP Stapling was our only hope -- but then most web servers (but not all! guess which one) dropped the ball. (Clients at least honored Must-Staple.) Short certificate lifetimes is the ultimate way forward, and thankfully it's already available through Let's Encrypt, via the "shortlived" profile. With a certificate that lives < ~7 days, there's virtually no need to revoke. Some clients/browsers will still move to revoke certificates within minutes or hours of their own choosing (see, that's the other frustrating thing, revocation is really just whatever you want), but I hope we'll only see that on internal PKIs, since doing that for public sites is essentially censorship.

politelemon 1y ago
I'm not seeing how there's no need to revoke. It means a compromised certificate is still considered valid for several days, in which a lot of damage can be done.
- mholt 1y ago
  Propagating the revocation information often takes about as long.
gucci-on-fleek 1y ago
> thankfully it's already available through Let's Encrypt, via the "shortlived" profile Maybe if you're the developer of a major web server :), but the rest of us still have to wait for general availability [0] [1]. [0]: https://letsencrypt.org/docs/profiles/#shortlived https://letsencrypt.org/docs/profiles/#shortlived [1]: https://community.letsencrypt.org/t/shortlived-is-currently-locked-behind-an-allowlist/241956/2 https://community.letsencrypt.org/t/shortlived-is-currently-...

alanfranz 1y ago

One thing the article doesn’t mention is that a lot of certs are revoked for purely admin reasons. CeasedOperations seems to be the case for Flair - nothing bad happened to the key, but the cert was revoked nevertheless. This seems to be a common practice for some CAs or companies, but it’s not required AFAICT; and it contributes to the gigantic CRLsets that we have - most of those revocations wouldn’t actually be needed from a security pov.