* Check a Certificate Signing Request (CSR)
openssl req -text -noout -verify -in CSR.csr
* Check a private key
openssl rsa -in privateKey.key -check
* Check a certificate
openssl x509 -in certificate.crt -text -noout
* Check a PKCS#12 file (.pfx or .p12)
openssl pkcs12 -info -in keyStore.p12