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Extract the IP addresses from SPF records.
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| #!/usr/bin/env python | |
| # | |
| # Author: Fred C. | |
| # Email: | |
| # | |
| from __future__ import print_function | |
| from collections import defaultdict | |
| import sys | |
| import DNS | |
| import re | |
| RE_PARSE = re.compile(r'(ip4|ip6|include|redirect)[:=](.*)', re.IGNORECASE) | |
| MAX_RECURSION = 5 | |
| def dns_txt(domain): | |
| try: | |
| resp = DNS.dnslookup(domain, 'TXT') | |
| except DNS.ServerError as err: | |
| print(err, file=sys.stderr) | |
| return None | |
| response = [] | |
| for r in resp: | |
| response.append(''.join(r)) | |
| return response | |
| def dns_parse(txt_field): | |
| 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)) | |
| 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 | |
| if __name__ == '__main__': | |
| whitelist = set() | |
| with open(sys.argv[1]) as fd: | |
| for line in fd: | |
| line = line.strip() | |
| for ip in process(line): | |
| whitelist.add(ip) | |
| for ip in sorted(whitelist): | |
| print(ip) |
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