Configuring SSL/TLS on a VPS server varies slightly depending on the operating system and the web server software you’re using. However, here is a general outline of how you can accomplish this. I’m describing the procedure for Apache server on an Ubuntu system:
Step 1: Purchase an SSL Certificate
You can purchase the certificate from SSL certificate providers like Digicert, Comodo, Symantec, etc. After you install the certificate, any data passing between the server and clients will be encrypted.
Step 2: Install the Certificate
You’ll be given a .crt file, and you may have two of them: one is the certificate and the other may be a CA bundle. Login to your server using ssh and create a directory where you can save them. Upload the certificate files to this directory.
Step 3: Install Apache
If you haven’t installed Apache web server yet, install it using the terminal command:
```
sudo apt-get install apache2
```
Step 4: Enable SSL Module
Next, enable the Apache SSL module using this command:
```
sudo a2enmod ssl
```
Step 5: Create a New Virtual Host File
You’ll also have to configure Apache to use SSL, and doing this requires creating a new virtual host file.
```
sudo cp /etc/apache2/sites-available/default /etc/apache2/sites-available/default-ssl
```
Step 6: Configure Virtual Host File
Open the new virtual host file in your text editor with root privileges:
```
sudo nano /etc/apache2/sites-available/default-ssl
```
Fill in your details and make sure you include the directory where your certificate and CA bundle are stored.
Step 7: Enable the Site
Once you’ve filled in your details for the virtual host file, you can enable it by using this command:
```
sudo a2ensite default-ssl
```
Step 8: Restart Apache
The final step is to restart Apache so these changes take effect.
```
sudo service apache2 restart
```
Now your web server has SSL/TLS configured and it will serve your site over a secure HTTPS connection.
For other server software like Nginx or OS like CentOS, the process will be similar but the commands and the configuration file format may differ. Always refer to the official documentation of the relevant software.
