Installing SSL certificates for Nginx on Ubuntu

Purchasing an SSL certificate requires creating a Certificate Signing Request (CSR) which you can do on your host using:

openssl req -new -newkey rsa:2048 -nodes -keyout yourdomain.key -out yourdomain.csr

When you purchase your certificate from your vendor, you’ll provide the text content from your CSR file. Once you have the certificate files (normally a .crt and a .key file), transfer them to your server, and place them somewhere like /etc/ssl-certs/.

In your /etc/nginx/nginx.conf (or /etc/nginx/sites-enabled/default), add to the server {  } block:

server {
  listen 443 ssl;
  ssl on;
  ssl_certificate     /etc/ssl-certs/yourdomain_com.crt;
  ssl_certificate_key /etc/ssl-certs/yourdomain.com.key;
  ssl_protocols       TLSv1 TLSv1.1 TLSv1.2;
  ssl_ciphers         HIGH:!aNULL:!MD5;
        
  # rest of server config
}

Restart nginx with:

sudo service nginx restart

This is documented in the nginx docs here.