I was looking for a simple letsencrypt tutorial for my home server running Fedora but it looks like the official (and quite capable) certbot is not availble in Fedora repos. So I have decided to go a more simple route of using acme-tiny shell script which is present and does the same, at least if you are running Apache httpd.

First off, install Apache httpd, SSL support and acme script itself:

# dnf install httpd mod_ssl acme-tiny

Let’s assume that the Apache server is already serving some files and is available on the desired domain via HTTP (not HTTPS yet):

# systemctl enable --now httpd
# curl -s http://home.zapletalovi.com | grep -o "Test Page"
Test Page

We are almost there, trust me. Generate a new certificate request. OpenSSL tool will ask several questions like name, organization and this stuff. Make sure that the Common Name (CN) is correct.

# cd /etc/pki/tls
# ln -s /var/lib/acme/csr .
# openssl req -new -nodes -keyout private/home.zapletalovi.com.key -out csr/home.zapletalovi.com.csr
# chmod 0400 private/home.zapletalovi.com.key

The next step is the actual communication with the authority, putting the challenge hash into /var/www/challenges directory which is exported by Apache httpd and downloading the signed request:

# systemctl start acme-tiny

See system journal for any errors. If you encounter one, just start the script manually but make sure to use acme user account not root:

# su acme -s /bin/bash
# /usr/libexec/acme-tiny/sign

And that’s really all! You should have your certificate signed by letsencrypt now. Configure the desired software to use the new certificate and the key from the following paths:

# find /var/lib/acme /etc/pki/tls/private

For example I want to actually configure the Apache httpd itself:

# grep zapletalovi /etc/httpd/conf.d/ssl.conf
SSLCertificateFile /var/lib/acme/certs/home.zapletalovi.com.crt
SSLCertificateKeyFile /etc/pki/tls/private/home.zapletalovi.com.key

If you are like me and running under SELinux enforcing, make sure that the newly generated certificates have the proper label:

# semanage fcontext -a -f a -t cert_t '/var/lib/acme/certs(/.*)?'
# restorecon -rv /var/lib/acme/certs

The final and the most important step - enable systemd timer which will automatically extend the certificate for you:

# systemctl enable --now acme-tiny.timer

That was easy.