Question
Certbot SSL error "Unrecognized challenges: tls-sni"
- Posted on October 6, 2023
- Security
Asked by e7a6d5efa06d4211b4526cc1a86c2c
When I am try8ing to create an SSL certificate on port 443, I get the following error:
certbot: error: argument --preferred-challenges: Unrecognized challenges: tls-sni
Port 80 is already in use, so I am following the instructions of using “–preferred-challenges tls-sni” but it does not seem to be working.
Not sure if I am missing anything. Following this tutorial: https://www.digitalocean.com/community/tutorials/how-to-use-certbot-standalone-mode-to-retrieve-let-s-encrypt-ssl-certificates-on-ubuntu-1804
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Heya,
The error you’re encountering is due to the deprecation of the
tls-snichallenge by Let’s Encrypt. This challenge method is no longer supported because of some identified vulnerabilities.As for PORT 80, what is listening on that port? You can check by running: