Dealing with Openssl Certificates and Keys

# Get the details of a PEM cert:
openssl x509 -in <certname>.pem -text

# Get the details of a crt file:
openssl x509 -in your_certificate.crt -text -noout

# Check whether a key and cert match using openssl:
openssl rsa -noout -modulus -in server.key | openssl md5
openssl x509 -noout -modulus -in server.crt | openssl md5