how to get ssl certificate details using python

Question

I am using the following code to validate the ssl certificate status, Can we get more details about certificate like common name (CN),expiry date and issuer using request module or urllib

import requests

def check_ssl(url):
    try:
        req = requests.get(url, verify=True)
        print url + ' has a valid SSL certificate!'
    except requests.exceptions.SSLError:
        print url + ' has INVALID SSL certificate!'

check_ssl('https://google.com')
check_ssl('https://example.com')

Answer 1

import socket
import ssl
import datetime

domains_url = [
"devnote.in",
"devnote_wrong.in",
"stackoverflow.com",
"stackoverflow.com/status/404"
]

def ssl_expiry_datetime(hostname):
    ssl_dateformat = r'%b %d %H:%M:%S %Y %Z'

    context = ssl.create_default_context()
    context.check_hostname = False

    conn = context.wrap_socket(
        socket.socket(socket.AF_INET),
        server_hostname=hostname,
    )
    # 5 second timeout
    conn.settimeout(5.0)

    conn.connect((hostname, 443))
    ssl_info = conn.getpeercert()
    # Python datetime object
    return datetime.datetime.strptime(ssl_info['notAfter'], ssl_dateformat)

if __name__ == "__main__":
    for value in domains_url:
        now = datetime.datetime.now()
        try:
            expire = ssl_expiry_datetime(value)
            diff = expire - now
            print ("Domain name: {} Expiry Date: {} Expiry Day: {}".format(value,expire.strftime("%Y-%m-%d"),diff.days))
        except Exception as e:
            print (e)

#Output :

Domain name: devnote.in Expiry Date: 2020-11-11 Expiry Day: 46
[Errno -2] Name or service not known
Domain name: stackoverflow.com Expiry Date: 2020-11-05 Expiry Day: 41
[Errno -2] Name or service not known