Checking the Modulus

The modulus is an element found in the CSR, the private key and the certificate.
It is always the same value. So it is really useful when you need to prove that a certificate has not been generated from a CSR.

openssl x509 -noout -modulus -in certificate.crt | openssl md5
openssl rsa -noout -modulus -in privateKey.key | openssl md5
openssl req -noout -modulus -in CSR.csr | openssl md5