Extract the IP addresses from SPF records.

whitelist.py

#!/usr/bin/env python
# Purpose: Print the list of ip addresses from SPF records
# Author: beppe9000

import dns
from dns import resolver
from collections import defaultdict
import re
import sys

RE_PARSE = re.compile(r'(ip4|ip6|include|redirect)[:=](.*)', re.IGNORECASE)
MAX_RECURSION = 5

def dns_txt(domain):
    response = []
    try:
        answers = dns.resolver.resolve(domain, 'TXT')
    except dns.exception.DNSException as err:
        print(err, file=sys.stderr)
        return None
        
    #print (' query qname:', answers.qname, ' num ans.', len(answers))
    
    for rdata in answers:
        for txt_string in rdata.strings:
            #print (' TXT: ', txt_string)            
            if (txt_string.decode().startswith('v=spf1')):
                #print (' SPF: ', str(txt_string))
                response.append(txt_string.decode())
            

    #print(dir(answers))
    #return "FUCKU"
    return response
            

def dns_parse(txt_field):
  # print("Parsing...")
  resp = defaultdict(set)
  for rec in txt_field:
    fields = rec.split()
    for field in fields:      
      match = RE_PARSE.match(field)
      if match:
        resp[match.group(1)].add(match.group(2) if not match.group(1).startswith("ipv6") else '"'+match.group(2)+'"')
        #print("MATCH [",match.group(1),"] => ",match.group(2))

  return resp

def process(domain):
  domains = [domain]
  ip_addresses = set()
  for cnt in range(MAX_RECURSION):
    includes = set()
    
    for dom in domains:
      txt = dns_txt(dom)
      if not txt:
        continue
      spf = dns_parse(txt)
      ip_addresses |= spf.get('ip4', set())
      ip_addresses |= spf.get('ip6', set())
      includes |= spf.get('include', set())
      includes |= spf.get('redirect', set())
    if not includes:
      break
    domains = includes
    
  return ip_addresses

def test():
    
    #for v in dns_txt("_spf.google.com"):
     #   print('VAL: ', v.to_text())

    r1 = dns_txt("_spf.google.com")

    for txt_string in r1:
        print (' SPF: ', txt_string)

    spf = dns_parse(r1)

    #for item in spf.items():
    #    print(item)


    includes = set()
    ip_addresses = set()
    ip_addresses |= spf.get('ip4', set())
    includes |= spf.get('include', set())

    print("INCLUDES: ",str(includes))
    print("IP ADDRS: ",str(ip_addresses))

    #print (' PARSED: ', str(txt_string))

    process("_spf.google.com")

if __name__ == '__main__':
    
  whitelist=set()

  if(len(sys.argv)>1):
      with open(sys.argv[1]) as fd:
          for line in fd:
              line = line.strip()
              for ip in process(line):
                  whitelist.add(ip)
  else:
      for ip in process("_spf.google.com"):
          whitelist.add(ip)

  for ip in sorted(whitelist):
    print(ip)