Any SSL experts out there?

I'm using Letsencrypt.

I have 4 files:

privkey.pem
chain.pem
fullchain.pem
cert.pem

I need to know:
Which is the cert file?
Which is the key file?
Which is the ca cert file?
What the hell is the last one?

Show more
Mastodon

1929.com is one server in the network