Downloads Microsoft IPs for specific URLs to a file

fetch-ms-ips.py

from datetime import datetime
from requests import Session

def fetch_microsoft_ips(url: str) -> dict:
    '''
    Pulls down the Microsoft IP JSON list
    '''
    s = Session()
    result = s.get(url)
    if result.status_code == 200:
        return result.json()
    else:
        raise Exception('Unable to fetch IP information from Microsoft')

def get_ips_by_url(data: list, urls: list) -> list:
    '''
    Retreives all the IPS from a service area based on the URLs in the service
    area
    '''
    ips = []

    # Type checking
    if not isinstance(data, list):
        raise ValueError('{data} is not a Dict')
    if not isinstance(urls, list):
        raise ValueError("URLs {urls} is not a List")

    else:
        for url in urls:
            if not isinstance(url, str):
                raise ValueError("Service Area {sa} is not a String")

            for entry in data:
                if 'urls' in entry and url in entry['urls']:
                    if 'ips' in entry and isinstance(entry['ips'], list):
                        ips += entry['ips']
    return ips

outfile = "/opt/threat-lists/microsoft-exchange-ips.txt"
urls = ['smtp.office365.com','*.mail.protection.outlook.com']
data = fetch_microsoft_ips('https://endpoints.office.com/endpoints/worldwide?clientrequestid=b10c5ed1-bad1-445f-b386-b919946339a7')
ips = get_ips_by_url(data, urls)
with open(outfile, 'w') as f:
    f.write(f"# Last Updated: {datetime.utcnow()}\n#\n")
    for ip in ips:
        f.write(f"{ip}\n")