How to Check if an SSL Certificate Matches its Private Key

Applies to Parallels Plesk Panel.

Warning Signs:

If you encounter this error message while trying to upload an SSL certificate in the Plesk control panel:

ERROR message:

“Unable to set the certificate: Incompatible private key/certificate pair.”

The same problem may occur when using the .txt format.

Reason: This issue arises when the private key and the SSL certificate don’t match.

Problem-Solving:

To address this problem, you must compare the modulus part of the private key and the SSL certificate.

Copy the private key content of your domain name into a file (e.g., abc.com) and check its modulus part:

For example:

openssl rsa -text -noout -in abc.com -modulus | grep Modulus=

Now, you need to check the modulus part of the certificate:

openssl x509 -text -noout -in abc.com.crt -modulus | grep Modulus=

If the modulus parts don’t match, then the issue lies with the certificate itself, indicating the need for re-issuance.

Solution:

Contact the Certificate Authority (CA) that issued the certificate with the same CSR (SSL Certificate Signing Request) for a new certificate. For further assistance and SSL offers visit host.co.in