certificate_varify.py

import ssl
import socket
import datetime
import boto3

client = boto3.client("ses", region_name="us-east-1")

print(f"Program to check SSL certificate validity and expiration date\n")

##opening file
with open("server_ip.txt") as ip_file:

    ##check  certificate expiration
    for ip in ip_file:

        try:
            host, port = ip.strip().split(":")
            print(f"\nChecking certifcate for server {host}")
            context = ssl.create_default_context()
            with socket.create_connection((host, port)) as sock:
                with context.wrap_socket(sock, server_hostname=host) as ssock:
                    certificate = ssock.getpeercert()
                certExpires = datetime.datetime.strptime(
                    certificate["notAfter"], "%b %d %H:%M:%S %Y %Z"
                )
                daysToExpiration = (certExpires - datetime.datetime.now()).days
                print(f"Expires on: {certExpires} in {daysToExpiration} days")
                ##preparing mailbody
                mailbody = (
                    "Server name: "
                    + host
                    + ", expires in "
                    + str(daysToExpiration)
                    + " days."
                )

        except:
            print(f"error on connection to Server, {host}")

        ##sending ses email
        if daysToExpiration < 45:
            response = client.send_email(
                Destination={
                    "ToAddresses": ["user@gmail.com"],
                },
                Message={
                    "Body": {
                        "Text": {
                            "Charset": "UTF-8",
                            "Data": "The following requires attention; "
                            + mailbody
                            + "\nThank you.",
                        },
                    },
                    "Subject": {
                        "Charset": "UTF-8",
                        "Data": "Certificate Expiring Soon",
                    },
                },
                Source="user@gmail.com",
            )

print(f"\nCert check complete!")