install-comodo-ssl-cert-for-nginx.rst

Setting up a SSL Cert from Comodo

Purchasing a Comodo PositiveSSL cert via gogetssl.com and installing it on an Nginx server.

Purchase the cert

Prior to purchasing a cert, you need to generate a private key, and a CSR file (Certificate Signing Request). You'll be asked for the content of the CSR file when ordering the certificate.

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

This gives you two files:

• example_com.key -- your Private key. You'll need this later to configure ngxin.
• example_com.csr -- Your CSR file.

Now, purchase the certificate. You'll get an email with your PositiveSSL Certificate. It contains a zip file with the following:

• Root CA Certificate - AddTrustExternalCARoot.crt
• Intermediate CA Certificate - PositiveSSLCA2.crt
• Your PositiveSSL Certificate - example_com.crt

Install the Commodo SSL cert

Combine everything for Nginx:

1. Combine the above crt files into a bundle (the order matters, here):

   cat example_com.crt PositiveSSLCA2.crt AddTrustExternalCARoot.crt >> ssl-bundle.crt
   

2. Store the bundle wherever Nginx expects to find it:

   mkdir -p /etc/nginx/ssl/example_com/
   mv ssl-bundle.crt /etc/nginx/ssl/example_com/
   

3. Make sure your nginx config points to the right cert file and to the private key you generated earlier:

   server {
       listen 443;
       server_name example_com
   
       ssl on;
       ssl_certificate /etc/nginx/ssl/example_com/ssl-bundle.crt;
       ssl_certificate_key /etc/nginx/ssl/example_com/example_com.key;
   
       # ...
   
   }
   
   server {
       listen         80;
       server_name    example_com;
       rewrite        ^ https://$server_name$request_uri? permanent;
   }
   

4. Restart nginx.