I just got this email. However, I host many wabsites (not all of them on the same server). I guess that one of the server is using an old version on the
certbot client, but I'm not sure which. I however have a list of all the domains I host. Is there a command available to know which of them is using the old validation method ?
For reference, here is the email I got from Let's Encrypt on my contact email:
Action is required to prevent your Let's Encrypt certificate renewals from breaking.
Your Let’s Encrypt client used ACME TLS-SNI-01 domain validation to issue a certificate in the past 60 days.
TLS-SNI-01 validation is reaching end-of-life and will stop working on February 13th, 2019.
You need to update your ACME client to use an alternative validation method (HTTP-01, DNS-01 or TLS-ALPN-01) before this date or your certificate renewals will break and existing certificates will start to expire.
If you need help updating your ACME client, please open a new topic in the Help category of the Let's Encrypt community forum:
Please answer all of the questions in the topic template so we can help you.
For more information about the TLS-SNI-01 end-of-life please see our API announcement:
Thank you, Let's Encrypt Staff