XMCA3Hms

1"""
2I ran into this issue when trying to bot a site with emails. I tried to mass send with an address like 'hello@gmail.com' but after some sends they banned hello from sending mail. My first instinct was to use a +str alias onto the email which usually works but this site prevented special characters from being inputted.
3
4The idea after this point was to encode dots into the gmail username. Personal gmail accounts ignore dots in email usernames so the emails 'alias@gmail.com' and 'a.lias@gmail.com' point to the same person. By exploiting this trick we can encode in binary, any integer. So, the number '5' is '101' in binary, and encoded into 'alias@gmail.com' becomes 'a.li.as@gmail.com' where 1's are dots.
5
6This allows me to bot the contact form with the same email with the maximum integer allowed inside being equal to 2^len(username). Any integer larger than that will just wrap to the beginning. Please note that this DOES NOT work with non-gmail accounts; even gSuite accounts will be invalid. Only mail going to `gmail.com` will allow for this method.
7"""
8import itertools
9
10def dot_encode_email_username(username: str, member_id: int):
11    stripped_username = username.replace('.', '').rstrip('+')
12
13    max_id = pow(2, len(stripped_username)) - 1
14    bounded_id = member_id % max_id
15    bin_id = bin(bounded_id)[2:]
16
17    i_username = [c for c in stripped_username]
18    i_bin_id = ['.' if bool(int(n)) else '' for n in bin_id] #remove b0 from binary string
19
20    i_encoded_username = [x for x in itertools.chain.from_iterable(itertools.zip_longest(i_username,i_bin_id)) if x]
21    return ''.join(i_encoded_username).rstrip('.')
22    
23for member in members:
24    username = dot_encode_email_username(member['name'], member['id'])
25    encoded_email = f'{username}@gmail.com'
26    # do something with encoded_email