Let’s Encrypt is a revolutionary new certificate authority that provides free certificates in a completely automated process. These certificates are issued via the ACME protocol. Over the last 2 years or so, the Internet has widely adopted Let’s Encrypt — over 50% of the web’s SSL/TLS certificates are now issued by Let’s Encrypt.
But while there are many tools to automatically renew certificates for publicly available webservers (certbot, simp_le, I wrote about how to do that 3 years back), it’s hard to find any useful information about how to issue certificates for internal non Internet facing servers and/or devices with Let’s Encrypt.
This blog posts describes how to issue Let’s Encrypt certificates for internal servers. At Datto, we issued a certificate for each of our 65,000+ BCDR appliances using this exact mechanism.