Install certificates on a 3CX PBX

If you wish to assign a valid certificate to 3CX this guide can show you how you can achieve this in a few easy steps.

Prerequisites

• Debian with SSH enabled and sudo permissions
• 3CX PBX
• Valid certificates in pem, crt & key file format
• Winscp or another SSH copy tool
• Putty

How to

Update 2025-06-15 : Discovered that the latest 3CX version requires a specific name for your certificate and private key in the nginx.conf file!

e.g. domain_cert_YourFQDN.pem and domain_key_YourFQDN.pem

Updated the document below to reflect this change.

1. Open WinSCP and connect to your 3CX PBX
   
   
2. Upload your certs (domain_cert_YourFQDN.pem and domain_key_YourFQDN.pem) in PEM format to your home folder (or convert them openssl from PFX to PEMs)
   
   
3. Logon to your 3CX PBX server via SSH
   
   
4. Copy your certs to the 3CX instance:
   sudo cp /certLocation/domain_cert_YourFQDN.pem /var/lib/3cxpbx/Bin/nginx/conf/Instance1/domain_cert_YourFQDN.pem
sudo cp /certLocation/domain_key_YourFQDN.pem /var/lib/3cxpbx/Bin/nginx/conf/Instance1/domain_key_YourFQDN.pem
   
   
5. Edit the following lines with your certificate file and key
   ssl_certificate /var/lib/3cxpbx/Bin/nginx/conf/Instance1/domain_cert_YourFQDN.pem;
ssl_certificate_key /var/lib/3cxpbx/Bin/nginx/conf/Instance1/domain_key_YourFQDN.pem;
   
   
6. Restart the nginx service (or reboot your server)
   sudo systemctl restart nginx