Script in Python3 que chequea fecha de vencimiento de certificados SSL y envia correos

Intro:
  Abajo les dejo un script realizado en Python3 que chequea fecha de vencimiento de certificados SSL (https) y realiza el envio de correos.

Importante:
  Que corra en OS modernos (Ubuntu 16.04 o mayor por ejemplo).., la razón es el soporte de librerías actualizadas SSL

El Script:
$ more check_ssl_certificates.py 

#!/usr/bin/python3

#El objetivo de este script es revisar los hostnames en la lista hostnames

#revisar cuantos dias faltan para que expire el certificado SSL

#y se expira pronto (definido por la variable umbral) enviar un correo

#con dicha notificacion




import OpenSSL

import ssl, socket

import argparse

from OpenSSL import SSL

from datetime import datetime




# Please add every FQDN you wish to be checked

hostnames = ["www.sitio1.com","www.sitio2.com","www.sitio3.com"]

umbral = 10 #threshold - number of days left in order to send the notification

notify_to= "you@yourserver.com, youyou@yourserver.com" #list of email addresses to send email separated by ,




def cert_expiration_date(hostname):

# get SSL Cert info

try:

cert = ssl.get_server_certificate((hostname, 443))

x509 = OpenSSL.crypto.load_certificate(OpenSSL.crypto.FILETYPE_PEM, cert)

x509info = x509.get_notAfter()




exp_day = x509info[6:8].decode('utf-8')

exp_month = x509info[4:6].decode('utf-8')

exp_year = x509info[:4].decode('utf-8')




exp_date = str(exp_day) + ' ' + str(exp_month) + ' ' + str(exp_year)

expire_date = datetime.strptime(exp_date, "%d %m %Y")







except Exception:

MSG='el host ' + str(hostname) + ' no pudo ser chequeado '

sendnotification(hostname, 0, MSG)

return #will enter here if could not connect to the website port 443




#print('SSL Certificate for hostname', hostname, 'will be expired on (DD-MM-YYYY)', exp_date)

#print('SSL Certificate for hostname', hostname, 'will be expired on (DD-MM-YYYY)', expire_date)



expire_in = expire_date - datetime.now()

expire_in = str(expire_in).split(' ')[0]




if int(expire_in) < umbral :

MSG='el cert ssl de ' + str(hostname) + ' expira en ' + str(expire_in) + ' dias'

sendnotification(hostname, str(expire_in), MSG)




#print ('Expira en: ', expire_in)




def sendnotification(hostname, expire_in, MSG):

from smtplib import SMTP_SSL as SMTP

import logging

import logging.handlers

import sys

from email.mime.text import MIMEText




#MSG = 'el cert ssl de ' + str(hostname) + ' expira en ' + str(expire_in) + ' dias'

#text = MSG

msg = MIMEText(MSG, 'plain')

msg['Subject'] = MSG

me = 'your@email.com'




recipients = notify_to

msg['To'] = notify_to

try:

conn = SMTP('yourmailserver.com')

conn.set_debuglevel(True)

conn.login('authusr', 'yourpassword')

try:

conn.sendmail(me,recipients.split(',') , msg.as_string())

finally:

conn.close()

except Exception as exc:

logger.error("ERROR!!!")

logger.critical(exc)

sys.exit("Mail failed: {}".format(exc))






if __name__ == "__main__":

for hostname in hostnames:

cert_expiration_date(hostname)