The information can be found in various postings - including the ones you found, but the general steps to replace a custom SSL certificate on a 3CX server running on Linux are as follows - please do take backups of everything, if a VM the whole server before you begin editing anything on the filesystem directly -:
1. Prepare the Certificate Files:
- Ensure you have the necessary certificate files:
- The certificate itself (e.g., `mypbx.example.com.crt`).
- The private key file (e.g., `mypbx.example.com.key`).
- The Certificate Authority (CA) bundle (e.g., `mypbx.example.com.ca`).
- Make sure your certificate and intermediate certificates are trusted by the devices connecting to your 3CX system.
2. Upload Certificate to 3CX:
- Access your 3CX system via SSH.
- Navigate to the directory containing your 3CX configuration, often `/var/lib/3cxpbx/Bin/nginx/conf/Instance1` for SSL configurations.
- Use a tool like WinSCP to upload:
- Merge your `.crt` and `.ca` files to form a `.pem` file and rename it, e.g., `domain_cert_example.pem`.
- Rename your `.key` file to `domain_key_example.pem`.
- Upload these files to the `/opt/3cx/cert/` directory to replace the existing certificates.
3. Configure 3CX to Use New Certificate:
- Log in to the 3CX Management Console.
- Go to "Security" and then the "Secure SIP" tab.
- Place the contents of the `.pem` file into the "Certificate" field and the `.key` file into the "Key" field.
- Save the changes.
4. Restart Necessary Services:
- After uploading the new certificates and configuring 3CX, you'll need to restart the Nginx server to apply changes:
```bash
sudo service nginx restart
```
- Consider restarting the entire 3CX server to ensure all services recognize the new certificate.
By following these instructions, your 3CX server on Linux should be updated with the new custom SSL certificate. Ensure you backup any original configuration files before making changes.
