2mo ago

PSA: LetsEncrypt ending expiration notification emails

letsencrypt.org

Ending Support for Expiration Notification Emails

I think it's a good idea, everyone should be automating this anyway.

Technology @lemmy.world

Jeena @piefed.jeena.net

2mo ago

Let's Encrypt Ending Support for Expiration Notification Emails

letsencrypt.org /2025/01/22/ending-expiration-emails/

Pulse of Truth @infosec.pub

Resident Pulser @infosec.pub

BOT

2mo ago

Ending Support for Expiration Notification Emails

letsencrypt.org /2025/01/22/ending-expiration-emails/

Web Development @programming.dev

Nemeski @lemm.ee

3mo ago

Ending Support for Expiration Notification Emails

letsencrypt.org /2025/01/22/ending-expiration-emails/

63 comments

Those emails have warned me something was pooched in advance many times. I do find them useful.
Sad to see them go, but nice they mention an alternative.
- Pretty much all monitoring solutions on the market track cert expiration nowadays. I get an alert when any of my certs have <5 days left
  
  What monitoring solution do you use? I need to set something up for my own projects but haven't gotten around to it. Any experience with Nagios?
- I’ve mainly gotten false positives, myself. When I’ve added another subdomain or something and the certificate gets set up differently, so then you get 2-3 emails saying domain X will expire, but if you connect to the url you see it has 80+ days left. Setting up your own monitoring solution is probably long overdue for myself, and it’s nice I’m getting forced to do it, in a way
- Setup uptimekuma

Providing expiration notifications costs Let’s Encrypt tens of thousands of dollars per year
Not doubting them, but I don't understand how that's possible.
Storing the email addresses and expiration dates takes an irrelevant amount of storage space, even if they had billions of cutomers.
Sending the emails should also not cost thousands, even if a significant amount of customers regularly let their certificates expire (which hopefull isn't the case).
So where are the tens of thousands of yearly costs coming from?
- As with all things email, they probably really wanted to make sure that the mails were delivered and thus were using a commercial MTA to ensure that.
  I'd wager, even at 20 or 30 or 40k a year, that's way less than it'd cost to host infra and have at least two if not three engineers available 24/7 to maintain critical infra.
  Looking at my mail, over the years I've gotten a couple hundred email from them around certificates and expirations (and other things), and if you assume there's a couple million sites using these certs, I could easily see how you'd end up in a situation where this could scale in cost very very slowly, until it's suddenly a major drain.
- If they send 2 emails per subdomain per year, that could easily be 10s of millions which would make the cost per email measured in thousandths of a cent. And I could see the number of subdomains being larger by a factor of 10, maybe more.
  Another angle: someone with IT experience needs to manage the system that seems emails, and other engineers need to integrate other systems with the email reminder system. The time spent on engineering could easily add up to thousands per year, if not tens of thousands.
  I'm guessing their figure is based on both running costs and engineering costs.
  
  According to their stats page, Let's Encrypt's certificates are used by around 500M domains.
- Transactional email services are about $15 per 10,000 emails. I'll round down to $10 to consider b2b deals and let's just say it's $10,000 per year. That would be like idk 84k emails a month.
  Keep in mind this doesn't consider the DB hosting and the processing of expiring emails and salaries, so yeah, I could see it.
  Edit: before anyone yells at me. I can't math.
  
  Not yelling, but pointing out, to people who also dont math, that if we assume $10 per 10k emails (or $1 per 1k, for simpler math), that’d be $84 for 84000 emails in a month, so you need to add another 0 to the figure (ie 840k emails in a month)
- I just realized I have no idea who pays for Let's Encrypt. I just run the server commands, automate it, and move on.
  
  Let's Encrypt is run by a non-profit (Internet Security Research Group), they list their major sponsors and funders on their website.

I did setup UptimeKuma for notifications on this. let's see if it works out when the expiry arrives in a month
- I think I'll need to add notifications for my uptime kuma as well now. So far I've used it mostly for historical data but without the mails, I would like to get a notice
- UptimeKuma looks nice. Simple, but it does what it is supposed to.
  
  Just needs an API and an export/import feature.

I manage all my certs using Cert Warden which has a dashboard that displays the expiry date. It does lack alerting, so I use Uptime-kuma to monitor the expiry dates of the certs. So not a big loss for me.
- TIL Cert Warden is a thing. Looks awesome!

I think it's a good idea, everyone should be automating this anyway.
This is still not possible in all scenarios. For example, wildcard certificates for DNS providers with no API support.
- Then swap you nameservers to a DNS provider that allows that?
  
  There are a lot of embedded systems that do not offer API support to swap out certificates. Things like switches, dvr, nas devices, etc.

I just wish I wouldn't have to renew certs so often.
- If Apple gets their way, you'll be renewing every month:
  https://certera.com/blog/apples-proposal-to-shorten-ssl-tls-certificate-lifespans-to-45-days-by-2027/
  
  Fuck Apple and Microshit
- You're not supposed to do it manually.
  
  Tell that to all the embedded device manufacturers… switches, appliances, nas, etc.
  There’s a whole load of things that will have a massive administrative burden if the frequency is dropped.
  
  My server does it automatically, but I have few services I can't make to read the certs from server storage, so I have to manually copy cert content. Especially Adguard Home for some reason refuses to read my certs.
- Its done for better security
- Have you tried to automate it?
  
  Fullchain.pem works. Privkey doesn't. I've tried chmod 777 (yes, I know, just testing) and still can't access the file.

If you're using Prometheus, Blackbox exporter checks cert expiration as well

I have my home assistant check and also my nagios, better safe then sorry

Mine just auto renews anyway
- I think thats the case for most of us. But for some like myself, it does mean I have to do the monitoring myself now. I can't complain it was a free service. But it did warn me about a renewal problem before the cert expired, so it was a useful service for me.

PSA: If you use Cloudflare to proxy, you can get a free decade long certificate and not worry about it for awhile.
- Oh, look: the NSA dangling a carrot on a line.
  
  Hey, if you wanna put your home server out there so the first person who gets pissy at you can DDoS you off the net until your ISP decides to cancel your service, that's a perfectly acceptable decision to make for yourself.