https://raphting.dev/posts/monitor-rss/

raphting.dev

Free Monitor Certificate expiry via RSS

Friday, 23. February 2024

The expiration of TLS certificates is usually monitored with
established monitoring solutions. Sometimes monitoring happens via
services that send e-mails when the expiration date comes closer.
Often times, these services require a sign-up.

I created an entirely free service that monitors the expiry of TLS
certificates via RSS without any sign-up.

How it works

With your RSS Feed Reader of choice, you subscribe to

https://scrutineer.tech/monitor/cert/{domain}.rss

Example for scrutineer.tech: https://scrutineer.tech/monitor/cert/scrutineer.tech.rss

Some background info

  * This is a free service without sign-up
  * Notifications are generated 30 days, 7 days and 1 day in advance
  * No guarantees are given, for nothing 
  * There are no checks for the trustworthiness of certificates. Only
    the "Not After" field is checked
  * Which means self-signed certificates work

How it looks

github.com

Coming up

I have more plans for monitoring TLS certificates based on
certificate transparency logs. You can subscribe to this blog via RSS
as well to be notified when it is ready.

Some time ago, I created a transparency log monitoring for the Go
module ecosystem https://gosumdb.scrutineer.tech

By Raphael Sprenger licensed under CC BY-NC 4.0