How to Install an SSL Certificate on Apache

Introduction

Securing your website with SSL is critical for encryption and trust. This guide explains how to install SSL certificates on Apache for Debian-based and RPM-based systems.

Prerequisites

• Installed Apache server.
• SSL certificate files: certificate.crt, private.key, and intermediate.crt.

Enable SSL Module

# Debian-Based Systems
sudo a2enmod ssl
sudo systemctl restart apache2

# RPM-Based Systems
sudo yum install mod_ssl
sudo systemctl restart httpd

Configure Apache for SSL

Edit the following configuration files for your setup:

• Debian-Based: /etc/apache2/sites-available/yourdomain.conf
• RPM-Based: /etc/httpd/conf.d/ssl.conf

Modify the configuration to enable SSL:

<VirtualHost *:443>
    ServerName www.example.com
    DocumentRoot /var/www/html

    SSLEngine on
    SSLCertificateFile /path/to/certificate.crt
    SSLCertificateKeyFile /path/to/private.key
    SSLCertificateChainFile /path/to/intermediate.crt

    <Directory /var/www/html>
        AllowOverride All
    </Directory>
</VirtualHost>

Enable Virtual Host

# Debian-Based
sudo a2ensite yourdomain.conf
sudo systemctl restart apache2

# RPM-Based
sudo systemctl restart httpd

Redirect HTTP to HTTPS

Add this block to redirect HTTP to HTTPS:

<VirtualHost *:80>
    ServerName www.example.com
    Redirect permanent / https://www.example.com/
</VirtualHost>

Restart Apache:

sudo systemctl restart apache2  # Debian-Based
sudo systemctl restart httpd    # RPM-Based

Verify the Installation

Test your configuration using:

openssl s_client -connect www.example.com:443

Or use online tools like SSL Labs.