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Reliability via Automated Renewal Information
- webprofusion 4y agoCan anyone point to a working client implementation? It seems the API GET works but the POST to update the renewal isn't working for anyone as far as I can see.
- cm2187 4y agoI am not sure I understand the need for a reminder. Aren't all the certificate 90 days fixed? I am not sure how the default acmee client works (I built my own) but if you use it, by definition you already automated the renewal process on a schedule too. In which scenario do you need a reminder? Or is it when you don't have access to a scheduler but the acmee client still runs somehow automatically?
- jaas 4y agoIf Let's Encrypt needs to revoke the certificate prior to expiration (for compliance or any other reason) ARI can let a client know in advance of the revocation. The client can then renew early and avoid a disruption in service. Clients that renew based on ARI can also help Let's Encrypt avoid disruptive load spikes since ARI signals can spread out renewals.
- cm2187 4y agoHa ok, so it's specifically for revocations. Still a revocation would be done manually. It feels odd someone would revoke their certificate and not think about re-issuing a new one.
- jaas 4y agoAny CA can revoke a certificate they issued without the subscriber being involved, so subscribers aren't necessarily revoking their own certs. When that happens ARI is a more efficient automated mechanism by which to let people know that a revocation is coming and they should renew.
- WirelessGigabit 4y agoWhen revoking a certificate it gives peace of mind that whatever system is using that certificate will pull a new one.
- mcpherrinm 4y agoIf a certificate was detected to be mis-issued after the fact, it may need to be revoked. And in fact many certificates may need to be revoked. This has happened to Let's Encrypt a few times already, and was the main motivation for this API. Some existing systems like the Caddy server use OCSP to detect if a cert is revoked and can renew immediately, but ARI allows allows a certificate to be reissued before the old one is revoked. There are other related things that aren't specifically revocation: For example, certificates contain embedded Certificate Transparency timestamps from CT logs. If one or more of those logs fail, we might want to reissue those certificates before browsers distrust the logs. (I work for Let's Encrypt)
- mholt 4y ago> Some existing systems like the Caddy server use OCSP to detect if a cert is revoked and can renew immediately, but ARI allows allows a certificate to be reissued before the old one is revoked. Hi Matthew :) Caddy still serves a perfectly valid "GOOD" response from the OCSP responder while it renews the certificate, so the certificate is good as not-revoked until that OCSP staple expires. (As we know, revocation is broken anyway. We should deprecate it for public PKI and go with short cert lifetimes instead.)
- advisedwang 4y agoAs well as revocation, I suppose it means if certificate lifetimes do change in future it can be done without having to upgrade/reconfigure all existing clients. Perhaps someone using ACME for internal infrastructure may want shorter lifetimes, and this will make it easier.
- lisper 4y ago> by definition you already automated the renewal process on a schedule too No, certbot does not run on a schedule by default. You have to set that up separately, and that can be non-trivial because you have to be able handle failures.
- schoen 4y agoIf you installed it with pip, it doesn't; if you installed it with an OS package or snap, it does (although it also didn't in that case for about the first year and a half of its existence, I think).
- tomxor 4y agoCan confirm, I have been using certbot+apache in production across multiple servers from Ubuntu apt repos since 18.04 in 2018 and scheduled auto-renewal is the default.
- cm2187 4y agoBut if certbot doesn't run on schedule, presumably it will never connect to ARI either.
- mholt 4y agoThis is why Certbot should only be used temporarily to transition from legacy infrastructure. Ideally cert management (ACME client) needs to be baked into the server, like what Caddy does.
- detourdog 4y agoI don't understand why short duration IP, DNS, SSL lifetimes. I would think that IPs, DNSs, SSL, lifetimes that go unchanged would imply more stability thus better reputation.
- piperswe 4y agoShort TLS certificate lifetimes mean that the CA checks to ensure the certificate owner actually controls the DNS once every 3 months, so it's less likely someone will have a certificate for a domain they only had control of for a temporary period.
- cm2187 4y agoAnd I think the rationale is also to force people to automate the process which is a good thing.
- detourdog 4y agoI don't understand this sentiment. Once the process is automatic it won't be managed or monitored.
- cm2187 4y agoWell, even large companies do a crap job at managing and monitoring the renewal of certificates manually. There has been many occurences of large companies (including Microsoft or Linkedin) leaving some certificate expire.
- detourdog 4y agoRight and I don't expect them to manage an automatic process any better. I'm saying that there should be a form of trust for long standing stable environments.
- adql 4y agoYou don't need to control the domain (only for wildcards), ability to serve under .well-known is enough.
- mholt 4y agoThis is... fine... but I wish we were pushing for shorter cert lifetimes rather than expanding infrastructure to support longer cert lifetimes and to band-aid revocation, which is broken anyway. goes to make Caddy and CertMagic ACME clients even more complicated
- Ajedi32 4y agoThe blog post mentions how this does help with the push for shorter cert lifetimes. > ARI can be used to set subscribers up for success in terms of ideal renewal times in the event that Let’s Encrypt offers even shorter-lived certificates in the future.
- mholt 4y agoThat's not the same. That's saying "We issued a 90-day cert but now want it to be less than that." What I'm saying is "Issue 7 day certs."
- mcpherrinm 4y agoI hope we can use ARI to trigger renewals as-if we had short lived certs, along that pathway. From a scale-up perspective of running the CA, that’s very useful. Much of Let’s Encrypts engineering time has been spent on revocation infrastructure, and I don’t like it. I’d much rather issue 2.5 day certs than 2.5 day OCSP responses we need to serve with high availability. I’m hoping in the near future we see a CA/B ballot and and associated root program changes allowing us to not run OCSP infrastructure for short-lived certs. That’s the kick needed to support short-lived certs. Of course Caddy is one of the best implementations of TLS and certificate handling and is already ready for that world, but many other systems are going to have a much worse time. That’s a big concern, and it’ll take everyone a while to switch to Caddy to fix their busted manual processes :) (I’m an employee of Let’s Encrypt but these opinions are my own)
- mholt 4y agoThanks for the feedback. Congrats on deploying a new feature to production! I'll see about adding ARI to Caddy in the hopes that it will accelerate the transition to shorter-lived certs.
- dochtman 4y agoWouldn’t it be more efficient to get a list of renewable certificates/domains per account, instead of having to fetch renewal info separately for each certificate?
- jacooper 4y agoLoooking forwards to Caddy supporting this
- proactivesvcs 4y agoLooks like Matt's already on it: https://news.ycombinator.com/item?id=35294522 https://news.ycombinator.com/item?id=35294522