Openssl
Create a Certificate Signing Request (CSR)
openssl req -sha256 -newkey rsa:4096 -nodes -keyout my_server.key -out my_server.csr
Read a certificate
openssl x509 -noout -text -in yourcert.cert
The Issuer should be the Certificate Authority. The Subject should represent the organization behind the server.
Check a certificate
These commands should match for a certificate/private key pair:
openssl x509 -noout -modulus -in certificate.crt | openssl md5 openssl rsa -noout -modulus -in privateKey.key | openssl md5
InCommon SSL
Download this one: "as Certificate (w/ issuer after), PEM encoded"