Generate an email hash to check the Spamhaus Hash Blocklist (HBL)

hblhash.py

#!/usr/bin/env python3
#
# hblhash.py - generate hashes to check against the Spamhaus Hash Blocklist
#
# Spamhaus operates a blocklist of hashed email addresses (and other data types)
# it can't be used without an API key - but single hash queries can be made
# via check.spamhaus.org (eg useful for diagnosing specific delivery issues)
#
# This script will take an email address and generate a URL to check the HBL
#
#  $ hblhash.py -e -l [email protected]
#  https://check.spamhaus.org/listed/?searchterm=GHCVIPAXGTJFY4QG6X6VSFJF2AUVX3DP5BH7QL4UNI2P5FYKDZTA
#
# 2022 Lee Maguire

import sys
import getopt
from hashlib import sha256, sha1
from base64 import b32encode, b32decode
import re

source = "[email protected]"
opt_email = 0
opt_sha1 = 0
opt_lookup = 0
opt_verbose = 0

## https://docs.spamhaus.com/datasets/docs/source/10-data-type-documentation/datasets/030-datasets.html#hbl

def mungeEmail( email ):
    local_part, domain_part = email.lower().split("@")
    local_part = re.sub('\+.*$', '', local_part)
    if (domain_part == 'googlemail.com'):
        domain_part = 'gmail.com'
    if (domain_part == 'gmail.com'):
        local_part = local_part.replace('.','')
    return( local_part + '@' + domain_part )

opts, args = getopt.getopt(sys.argv[1:],"heclv",["email","cw","sha1","lookup"])
for opt, arg in opts:
  if opt == '-h':
    print('Usage: hblhash.py [--email][--lookup][--sha1][-v] [email protected]')
    sys.exit()
  elif opt in ("-e", "--email"):
    opt_email = 1
  elif opt in ("--sha1"):
    opt_sha1 = 1
    opt_email = 1
  elif opt in ("-c", "--cw"):
    opt_email = 0
  elif opt in ("-l", "--lookup"):
    opt_lookup = 1
  elif opt in ("-v"):
    opt_verbose = 1

if args:
    source = args[0]
else:
    opt_verbose = 1

if opt_verbose:
    sys.stdout.write('source: ' + source + '\n')

if opt_email:
    if opt_verbose:
        sys.stdout.write('source_munged: '+ mungeEmail(source)+'\n')
    byte_str = bytes(mungeEmail(source), 'ascii')
else:
    byte_str = bytes(source, 'ascii')

if opt_sha1:
    hash_str = sha1(byte_str).hexdigest()
else:
    hash_str = b32encode(sha256(byte_str).digest()).decode().replace('=','')

if opt_lookup:
    sys.stdout.write('https://check.spamhaus.org/listed/?searchterm=' + hash_str +'\n')
else:   
    if opt_verbose:
        sys.stdout.write('hash: ')
    sys.stdout.write(hash_str +'\n')

sys.exit(0)