Useful Openssl Commands

Certificates

Create a self signed certificate with no password

openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout hostcert.key -out hostcert.crt

Examine an x509 Certificate

openssl x509 -in certificate.crt -text -noout

Test for Expired x509 Certificate

openssl x509 -in certificate.crt -noout -checkend 0

• 0 Valid
• 1 Expired

Python ex:

import subprocess
import os

cert = '/tmp/x509up_u%s' % os.getuid() 
code = subprocess.call("openssl x509 -in %s -noout -checkend 0" % cert)
if code:
    print "Expired"
else:
    print "Valid"

-- MattVliet - 2010-12-20