In the past, cPanel & WHM services used a self-signed certificate. Now all cPanel & WHM services use a cPanel-signed hostname certificate with a Comodo® trust chain. This document explains how the system installs a cPanel-signed hostname certificate and how to disable SSL if you do not wish to use it.
The system runs the
/usr/local/cpanel/bin/checkallsslcerts script during the nightly cPanel & WHM update (
upcp) process. This script performs the following actions:
- Installs a cPanel-signed hostname certificate on the server, if one does not exist.
- Updates the SSL certificate for all cPanel & WHM services.
Issues a Comodo signed SSL certificate on any server with a self-signed, expired, or soon-to-expire certificate.
A soon-to-expire certificate means that the SSL certificate expires in three days or fewer.
To execute these actions, the script performs the following steps:
The system creates a Domain Control Validation (DCV) file in the
/usr/local/apache/htdocs/DCV.txtfile, which resembles the following example:
The system performs a DNS lookup for the hostname's IP address on the
rootnameservers. To do this, it runs the following command:
- If the
digcommand returns multiple IP addresses, the system uses the first IP address that the command returns.
- In this example,
hostname.example.comrepresents the server's hostname.
- If the
The system uses the hostname's IP address to confirm that it can access the Domain Control Validation (DCV) file. To do this, it runs the following command:
In this example,
192.0.2.102represents the primary IP address, and
AFAA5C66A1EEF5812703A46C21C013B4.txtrepresents the DCV file.
When the local DCV check passes, the system sends a request to the cPanel Store API for the new SSL certificate.
If a valid SSL certificate exists and matches the DCV file, the system does not perform any action.
- If the system must issue a new SSL certificate, the systems sends a request to Comodo.
Comodo validates the DCV file from the following IP addresses:
Comodo uses these IP addresses to attempt to access the cPanel server. You must whitelist these IPs in the server firewall. For more information, read our How to Configure Your Firewall for cPanel Services documentation.
The system logs the Comodo requests in the
/usr/local/cpanel/logs/access_logsfile. It also contains user agent strings that show who accesses the DCV file. These user agent strings resemble the following examples:
Optional command line flags
/usr/local/cpanel/bin/checkallsslcerts script includes the following optional flags:
|Optional CLI Switches||Description|
Adjusts output to include messages that resemble the following:
If the cPanel Store continues the hostname certificate request, then the system checks the cPanel Store again in an hour. To do this, it runs the following command:
Click to view...
If the system must retry, an entry will apper in the
Disable a cPanel-signed hostname certificate.
To disable a cPanel-signed hostname certificate's installation, run the following command: