SSL Certs

Certs for Devices not Actually Accessible on the Internet

• Build a minimal Linux VM
• sudo apt install certbot

For each machine:

Using HTTP challenge

• sudo certbot certonly -d MACHINE.DOMAIN.TLD
  • when it asks... choose option 1: Apache Web Server plugin
  • Copy your shiny new cert into place

Using DNS challenge

• sudo certbot -d MACHINE.DOMAIN.TLD --manual --preferred-challenges dns certonly
  • Follow the directions about setting up the DNS record & then hit enter
  • Copy your shiny new cert into place

Stuff still being worked out...

• Problem:  Renewal is potentially problematic
  • Tho... Apparently, renewal of a manual cert involves just running the original command again.
    • (every time you run certbot as above, the TXT Record value changes...)
    • one solution might be to use your DNS providers API calls...
    • ooohhh --reuse-key
• cron job to manage it all

Certs on an Apache based server

From /usr/share/doc/apache2/README.Debian.gz

Enabling SSL

To enable SSL, type:

• sudo a2ensite default-ssl
• sudo a2enmod ssl

If you want to use self-signed certificates, you should install the ssl-cert
package (see below). Otherwise, just adjust the SSLCertificateKeyFile and SSLCertificateFile directives in '/etc/apache2/sites-available/default-ssl.conf' to point to your SSL certificate. Then restart apache:

• sudo systemctl restart apache2

The SSL key file should only be readable by root; the certificate file may be globally readable. These files are read by the Apache parent process which runs as root, and it is therefore not necessary to make the files readable by the www-data user.

Getting proper certificates onto the machine

Sadly...

Between the time I wrote this up on the TinkerNet Wiki and now, Let's Encrypt has drastically changed things and certbot is now only supported if you want to deal with snapd...

Give me time & I'll work out new instructions.

For now...  The old version is still on the TinkerNet Wiki.

Now Do A Backup!