openssl x509

OpenSSL command to manage X.509 certificates. More information: https://www.openssl.org/docs/manmaster/man1/openssl-x509.html.

• Display certificate information:

openssl x509 -in filename.crt -noout -text

• Display a certificate's expiration date:

openssl x509 -enddate -noout -in filename.pem

• Convert a certificate between binary DER encoding and textual PEM encoding:

openssl x509 -inform der -outform pem -in original_certificate_file -out converted_certificate_file

• Store a certificate's public key in a file:

openssl x509 -in certificate_file -noout -pubkey -out output_file