Introduction

Secure Sockets Layer (SSL), or more accurately TLS (Transport Layer Security), encrypts communication between a user’s browser and your web server. Installing an SSL certificate ensures that data such as login credentials, payment information, and personal details are transmitted securely while also improving user trust and search engine rankings.

This guide explains how to manually configure an SSL-enabled website on CentOS or Ubuntu systems running Apache HTTP Server, without using a hosting control panel such as cPanel or Plesk.

---

Prerequisites

Before beginning the SSL installation, ensure you have the following:

• A server running CentOS or Ubuntu
• Apache HTTP Server installed
• Root or sudo access to the server
• A registered domain name pointing to the server’s public IP address
• An SSL certificate issued by a Certificate Authority (CA)
• The following SSL files:
  • SSL Certificate (.crt)
  • Private Key (.key)
  • Intermediate/CA Bundle (.ca or .crt)
• OpenSSL and Apache SSL module (mod_ssl) installed

---

Steps to Configure SSL

Step 1: Install Required Packages

CentOS

Install Apache SSL module and OpenSSL.

yum install mod_ssl openssl

Ubuntu

Install Apache packages.

apt-get install apache2 apache2-common

Enable the SSL module.

a2enmod ssl

---

Step 2: Generate a CSR and Obtain an SSL Certificate

Generate a Certificate Signing Request (CSR) and submit it to your Certificate Authority (CA).

After the certificate is issued, you should receive:

• SSL Certificate
• Private Key (generated during CSR creation)
• Intermediate/CA Certificate

---

Step 3: Configure the Apache Virtual Host

CentOS

Create a virtual host configuration file.

/etc/httpd/conf.d/example.com.conf

Ubuntu

Create the site configuration.

/etc/apache2/sites-available/example.com.conf

Enable the site.

a2ensite example.com

Add the SSL VirtualHost configuration.

<VirtualHost 192.168.1.56:443>

    ServerAdmin admin@example.com

    DocumentRoot /var/www/html/example_com_www/

    ServerName server1.example.com
    ServerAlias www.example.com

    ErrorLog logs/example.com-error_log
    CustomLog logs/example.com-access_log common

    SSLEngine on

    SSLCertificateFile /etc/ssl/example.com.crt
    SSLCertificateKeyFile /etc/ssl/example.com.key
    SSLCACertificateFile /etc/ssl/example.com.ca

    <Directory "/var/www/html/example_com_www/">
        AllowOverride All
    </Directory>

</VirtualHost>

Note: Modern Apache versions recommend using <VirtualHost *:443> instead of NameVirtualHost, as NameVirtualHost has been deprecated.

---

Step 4: Store SSL Certificate Files

Create the SSL directory if it does not already exist.

mkdir -p /etc/ssl

Copy the certificate files into the directory.

File	Example Location
SSL Certificate	/etc/ssl/example.com.crt
Private Key	/etc/ssl/example.com.key
Intermediate CA	/etc/ssl/example.com.ca

Ensure that the private key is readable only by the root user.

chmod 600 /etc/ssl/example.com.key

---

Step 5: Restart Apache

CentOS

systemctl restart httpd

or

service httpd restart

Ubuntu

systemctl restart apache2

or

service apache2 restart

---

Step 6: Verify the SSL Website

Access the website using HTTPS.

https://your-domain.com

or

https://192.168.1.56:443

Check the following:

• The website loads successfully over HTTPS.
• The browser displays a secure padlock.
• The certificate is valid and trusted.
• No mixed-content warnings are present.

You can also verify the certificate using:

openssl s_client -connect your-domain.com:443

---

Important Notes

• Replace 192.168.1.56 with your server’s actual IP address.
• Replace example.com with your domain name.
• Update the DocumentRoot to match your website location.
• Ensure DNS records point your domain to the correct server IP before testing.
• Keep the private key secure and never share it publicly.

---

Conclusion

Configuring SSL manually on an Apache web server without a control panel involves installing the necessary SSL modules, obtaining an SSL certificate, configuring an HTTPS virtual host, placing the certificate files in the appropriate locations, and restarting the web server. Once completed, your website will be accessible over HTTPS, providing encrypted communication, improved security, and greater trust for users. Regularly monitor certificate expiration dates and renew certificates before they expire to maintain uninterrupted secure access.