openssl x509 -in

openssl x509 -in certificate.pem -text

openssl x509 -in tls.cert -noout -issuer -subject -dates -ext subjectAltName

openssl x509 -req
openssl x509 -inform

See also

• openssl x509[ -inform | -text | -dates | -req | -subject | -issuer | --help]
• Certificate: .pem, .ppk, .pfx, .p12, .cer, .crt, openssl pkcs12, .csr, .pub, PFX, PKCS, PKCS, RFC 5280