SSL on internal-network & localhost with self-signed cert without letsencrypt?

[lx07]

I've spent almost 2 nights looking for a solution, since I noticed that https://docs.rocket.chat/installation/snaps/autossl , basically depends on caddy establishing an online connection to letsencrypt?

What if about internal networks that are not supposed to go online and don't have public domains? Is there a way to generate an offline certificate somehow on localhost?

My Caddyfile currently looks like this, where 3333 would be the ssl and 3000 the non-ssl.

/var/snap/rocketchat-server/current/Caddyfile

https://localhost:3333` { tls self_signed proxy / localhost:3000 { websocket transparent } }

Thanks!

[0bliss]

This would be very good to know..