ISPConfig SSL Certificate Installation and CSR Creation Guide

ISPConfig is an open source hosting control panel widely used on Debian and Ubuntu based servers. It is ideal for professional hosting environments with its multi-server support and flexible configuration options. In this guide, we explain in detail SSL installation, CSR creation and Let's Encrypt integration in the ISPConfig 3 panel.

1. Creating CSR

Via ISPConfig Panel

1. Login to ISPConfig administration panel
2. Switch to "Sites" tab
3. Select the relevant website
4. Click on the "SSL" tab
5. Select "Create Certificate" from the "SSL Action" dropdown
6. Fill in the required information:
   • SSL Country: TR
   • SSL State: Istanbul
   • SSL Locality: Istanbul
   • SSL Organization: Company Name
   • SSL Organization Unit: IT
   • SSL Domain: www.example.com
7. Click the "Save" button
8. The CSR will appear in the "SSL Request" field

Creating CSR from Command Line

openssl req -new -newkey rsa:2048 -nodes \
  -keyout /var/www/clients/client1/web1/ssl/example.com.key\
  -out /var/www/clients/client1/web1/ssl/example.com.csr

2. Installing an SSL Certificate

1. ISPConfig → "Sites" → Select website → "SSL" tab
2. Select "Save Certificate" from the "SSL Action" dropdown
3. Fill in the following fields:
   • SSL Key: Paste private key
   • SSL Certificate: CRT certificate content
   • SSL Bundle: CA Bundle / Intermediate certificate
4. Click the "Save" button
5. Select "On" from "SSL" dropdown
6. Save again

# Auto-generated file: /etc/apache2/sites-available/example.com.vhost
<VirtualHost *:443>
    ServerName example.com
    ServerAlias www.example.com
    SSLEngine on
    SSLCertificateFile /var/www/clients/client1/web1/ssl/example.com.crt
    SSLCertificateKeyFile /var/www/clients/client1/web1/ssl/example.com.key
    SSLCertificateChainFile /var/www/clients/client1/web1/ssl/example.com.bundle
</VirtualHost>

1. "Redirect" tab in ISPConfig site settings
2. "Redirect Type": R,L (301 permanent)
3. "Redirect Path": https://www.example.com
4. Or select "www to non-www + https" from the "SEO Redirect" section

6. Common Errors and Solutions

Frequently Asked Questions

Does ISPConfig multi-server support SSL?

Yes, in ISPConfig's multi-server architecture, each web server can perform independent SSL management. The panel server distributes the certificate information to the relevant web server.

How do I back up my SSL certificate in ISPConfig?

SSL files are stored in the /var/www/clients/clientX/webX/ssl/ directory. Include this directory in your backup plan.