### — check properties of ssl files — ###

openssl req -noout -text -in https1.csr
openssl rsa -noout -text -in https1.key
openssl x509 -noout -text -in https1.crt

### — check modulus — ###

openssl req -noout -modulus -in https1.csr
openssl rsa -noout -modulus -in https1.key
openssl x509 -noout -modulus -in https1.crt

# CSR and KEY (RSA private key) and CERT (x509, works with base64 certs) all have to have the same modulus (think of the modulus like the private key checksum)