Maybe this is more of a home lab question, but I’m utterly clueless regarding PKI and HTTPS certs, despite taking more than one class that goes into some detail about how the system works. I’ve tried finding guides on how to set up your own CA, but my eyes glaze over after the third or fourth certificate you have to generate.
Anyway, I know you need a public DNS record for HTTPS to work, and it struck me recently that I do in fact own a domain name that I currently use as my DNS suffix on my LAN. Is there a way I can get Let’s Encrypt to dole out a wildcard certificate I can use on the hosts in my LAN so I don’t have to fiddle with every machine that uses every service I’m hosting? If so, is there a guide for the brain dead one could point me to? Maybe doing this will help me grock the whole PKI thing.
Yep. Just specify the domains
yourdomain.comand*.yourdomain.comin the certbot request. Wildcard domains require the DNS-based challenge, but you’ve said you’re already good there. You don’t technically need the apex domain (yourdomain.com) but I always add it since I do have services running there.Any subdomains under the wildcard can use internal DNS or internal IPs on the public DNS (I do the former, but the latter works too).
I used to run an internal CA, and it wasn’t too hard to setup a CA and distribute my root cert. Except on mobile devices. On Android it was easy, but there was a persistent warning that my network traffic could be intercepted (which is true when there’s a custom root cert installed), but it since it was my cert, it got annoying seeing that all the time. Not sure if Apple devices can even do that, but regardless, it wasn’t practical for friends who wanted to use my self-hosted services to install a custom cert when they were over.
Cool. Follow up question: Do I generate the cert once and distribute the same private key to all the servers I’m running? I’m guessing not, but does that mean I run the certbot command on every server?