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by bombcar6 hours ago |
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upvoteby nightpool5 hours ago|
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No, they're not useless at all. The point of shortening certificate periods is that companies complain when they have to put customers on revocation lists, because their customers need ~2 years to update a certificate. If CRLs were useless, nobody would complain about being put on them. If you follow the revocation tickets in ca-compliance bugzilla, this is the norm—not the exception. Nobody wants to revoke certificates because it will break all of their customers. Shortening the validity period means that CAs and users are more prepared for revocation events.
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upvoteby pas4 hours ago|
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... what are the revocation tickets about then? how is it even a question whether to put a cert on the CRL? either the customer wants to or the key has been compromised? (in which case the customer should also want to have it revoked ASAP, no?)

can you elaborate on this a bit? thank you!

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upvoteby crote44 minutes ago|
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> what are the revocation tickets about then

Usually, technical details. Think: a cert issued with a validity of exactly 1000 days to the second when the rules say the validity should be less than 1000 days. Or, a cert where the state name field contains its abbreviation rather than the full name. The WebPKI community is rather strict about this: if it doesn't follow the rules, it's an invalid cert, and it MUST be revoked. No "good enough" or "no real harm done, we'll revoke it in three weeks when convenient".

> either the customer wants to or the key has been compromised

The CA wants to revoke, because not doing so risks them being removed from the root trust stores. The customer doesn't want to revoke, because to them the renewal process is a massive inconvenience and there's no real risk of compromise.

This results in CAs being very hesitant to revoke because major enterprise / government customers are threatening to sue and/or leave if they revoke on the required timeline. This in turn shows the WebPKI community that CAs are fundamentally unable to deal with mass revocation events, which means they can't trust that CAs will be able to handle a genuinely harmful compromise properly.

By forcing an industry-wide short cert validity you are forcing large organizations to also automate their cert renewal, which means they no longer pose a threat during mass revocation events. No use threatening your current CA when all of its competitors will treat you exactly the same...

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upvoteby bombcar3 hours ago|
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From my experience the biggest complaints/howlings are when the signing key is compromised; e.g., your cert is valid and fine, but the authority screwed up and so they had to revoke all certs signed with their key because that leaked.

E.g., collateral damage.

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upvoteby nathanaldensr6 hours ago|
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Right. It's the same debate about how long authorization cookies or tokens should last. At one point in time--only one--authentication was performed in a provable enough manner that the certificate was issued. After that--it could be seconds, hours, days, years, or never--that assumption could become invalid.
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