Step One—Create a Directory for the Certificate
The SSL certificate has 2 parts main parts: the certificate itself and the public key. To make all of the relevant files easy to access, we should create a directory to store them in:
sudo mkdir /etc/nginx/ssl
We will perform the next few steps within the directory:
cd /etc/nginx/ssl
Step Two—Create the Server Key and Certificate Signing Request
Start by creating the private server key. During this process, you will be asked to enter a specific passphrase. Be sure to note this phrase carefully, if you forget it or lose it, you will not be able to access the certificate.
sudo openssl genrsa -des3 -out server.key 1024
Follow up by creating a certificate signing request:
sudo openssl req -new -key server.key -out server.csr
This command will prompt terminal to display a lists of fields that need to be filled in.
The most important line is "Common Name". Enter your official domain name here or, if you don't have one yet, your site's IP address. Leave the challenge password and optional company name blank.
You are about to be asked to enter information that will be incorporated
into your certificate request.
What you are about to enter is what is called a Distinguished Name or a DN.
There are quite a few fields but you can leave some blank
For some fields there will be a default value,
If you enter '.', the field will be left blank.
-----
Country Name (2 letter code) [AU]:US
State or Province Name (full name) [Some-State]:New York
Locality Name (eg, city) []:NYC
Organization Name (eg, company) [Internet Widgits Pty Ltd]:Awesome Inc
Organizational Unit Name (eg, section) []:Dept of Merriment
Common Name (e.g. server FQDN or YOUR name) []:example.com
Email Address []:webmaster@awesomeinc.com
Step Three—Remove the Passphrase
We are almost finished creating the certificate. However, it would serve us to remove the passphrase. Although having the passphrase in place does provide heightened security, the issue starts when one tries to reload nginx. In the event that nginx crashes or needs to reboot, you will always have to re-enter your passphrase to get your entire web server back online.
Use this command to remove the password:
sudo cp server.key server.key.org
sudo openssl rsa -in server.key.org -out server.key
Step Four— Sign your SSL Certificate
Your certificate is all but done, and you just have to sign it.
Keep in mind that you can specify how long the certificate should remain valid by changing the 365 to the number of days you prefer. As it stands this certificate will expire after one year.
sudo openssl x509 -req -days 365 -in server.csr -signkey server.key -out server.crt
You are now done making your certificate.
Step Five—Set Up the Certificate
Now we have all of the required components of the finished certificate.The next thing to do is to set up the virtual hosts to display the new certificate.
Let's create new file with the same default text and layout as the standard virtual host file. You can replace "example" in the command with whatever name you prefer:
sudo nano /etc/nginx/sites-available/example
Scroll down to the bottom of the file and find the section that begins with this:
# HTTPS server
server {
listen 443;
server_name example.com;
root /usr/share/nginx/www;
index index.html index.htm;
ssl on;
ssl_certificate /etc/nginx/ssl/server.crt;
ssl_certificate_key /etc/nginx/ssl/server.key;
}
sudo service nginx restart
Refs
https://www.digitalocean.com/community/articles/how-to-create-a-ssl-certificate-on-nginx-for-ubuntu-12-04
