openssl x509 -noout -modulus -in certificate.crt | openssl md5

openssl rsa -noout -modulus -in private.key | openssl md5

Verify that the md5 values match exactly.

openssl req -new -newkey rsa:2048 -nodes -keyout private.key -out mycsr.csr

openssl req -in mycsr.csr -noout -text