证书
openssl x509 -in cert.pem -text -noout
openssl x509 -in certificate.der -inform der -text -noout
openssl x509 -subject -dates -fingerprint -in postgresql.pem
public key
openssl x509 -in server.crt -noout -pubkey
key
openssl rsa -in key.pem -check
openssl pkey -in server.key -pubout
csr
openssl req -text -noout -verify -in avagent.csr