Let's Encrypt with the Ubiquiti EdgeRouter

This guide uses https://letsencrypt.org/ and https://github.com/Neilpang/acme.sh to generate a valid SSL certificate for the EdgeRouter.

• Does not ever expose the admin GUI to the internet
• 100% /config driven, does not require modification to EdgeOS system files

Install acme.sh & scripts

mkdir -p /config/.acme.sh
curl -o /config/.acme.sh/acme.sh https://raw.githubusercontent.com/Neilpang/acme.sh/master/acme.sh
curl -o /config/scripts/renew.acme.sh https://raw.githubusercontent.com/j-c-m/ubnt-letsencrypt/master/scripts/renew.acme.sh
chmod 755 /config/.acme.sh/acme.sh /config/scripts/renew.acme.sh

Configuration

• In the steps below replace/verify the following:
  • subdomain.example.com - FQDN
  • 192.168.1.1 - LAN IP of Router
  • eth0 - WAN device
• Configure DNS record for subdomain.example.com to your public WAN IP.
• Connect via ssh to your EdgeRouter and enter configuration mode.

1. Setup static host mapping for FQDN to the LAN IP.

   set system static-host-mapping host-name subdomain.example.com inet 192.168.1.1
   

2. Configure cert-file location for gui.

   set service gui cert-file /config/ssl/server.pem
   set service-gui ca-file /config/ssl/ca.pem
   

3. Configure task scheduler to renew certificate automatically.

   set system task-scheduler task renew.acme executable path /config/scripts/renew.acme.sh
   set system task-scheduler task renew.acme interval 1d
   set system task-scheduler task renew.acme executable arguments '-d subdomain.example.com -i eth0'
   

   You can include additional common names for your certificate, so long as they resolve to the same WAN address:

   set system task-scheduler task renew.acme executable arguments '-d subdomain.example.com -d subdomain2.example.com -i eth0'
   

4. Initialize your certificate.

   sudo /config/scripts/renew.acme.sh -d subdomain.example.com -i eth0
   

   If you included multiple names in step 4, you'll need to include any additional names here as well.

5. Commit and save your configuration.

   commit
   save
   

6. Accesss your router by going to https://subdomain.example.com

Changelog

20171028 - Add ca.pem for complete certificate chain
20171013 - Remove reload.acme.sh
20170530 - Check wan ip
20170417 - Stop gui service during challenge
20170320 - Add multiple name support
20170317 - Change from standalone to webroot auth using lighttpd
20170224 - Bug fixes
20170110 - Born