openssl-x509
OpenSSL command to manage X.509 certificates.
TLDR
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]
