Installing SSL certificate on Barracuda VPN server
From the appliance web interface, navigate to Basic and SSL Certificate.
In the SSL Certificate Configuration section choose Trusted (signed by a trusted CA).
In the Certificate Generation section download the private key (click Download next to Private Key).
Copy the entire key and paste it to text editor. Save it as private.key on your server.
Go to the Trusted Certificate section:
Click the Synchronize button to finish (the bottom of the page).
Synchronize this certificate with the SSL VPN interface on port 443.