pypotd 1.0.3

ARRIS password of the day generator

PyPOTD

Python library to generate an ARRIS-compatible password of the day. Inspired by arrispwgen.

The original author essentially reverse-engineered the algorithm after poking modems. Thank you so much @borfast for this incredible work. I ran into a few niche issues based on my needs/specific seed that I hope this project will rectify.

First, the upstream project seems to lock you to a seed between 8-10 characters. The original ARRIS tooling to generate these passwords actually only allows seeds between 4-8 characters. (I find this strange, considering that the default ARRIS seed is 10 characters in length)

Second, if you supply a seed of less than 10 characters, the upstream project will present a password of the same number of characters. So an 8 character seed will yield the correct first 8 characters of the password, but will not provide the full password.

Third, if you supply a seed of less than 8 characters, the upstream project does not appear to output anything at all. The way ARRIS handles the seeds is to iterate through the seed, appending each character to the end of the supplied seed. For example, a seed of "ABCD" is a valid seed, however in effect it will become "ABCDABCDAB".

Fourth, as much as I would love to contribute upstream fixes rather than a fork/port, the upstream project was written in TypeScript and packaged via NPM. I do not have experience with either of these technologies, and as such a port became much more viable.

Installing

pip install pypotd

Usage

Single date

The generate() function accepts two keyword arguments.

• potd_date: Accepts a single date in ISO format (i.e., 2021-07-23)
• seed: Accepts a seed between 4 and 8 characters

Using defaults (current date, ARRIS default seed)

from pypotd import generate

generate()

Output (Assuming date is 2021-07-23): O9W2Q1O16V

Using custom date, custom seed

from pypotd import generate

generate(potd_date="2021-07-23", seed="ABCDABCD")

Output: F32CAZCJLU

Range of dates

The generate_multiple() function takes a start and end date, as well as an optional seed.

Using default seed

from pypotd import generate_multiple

generate_multiple(start_date="2021-07-23", end_date="2022-07-28")

Output (truncated):

{
    '07/23/21': 'O9W2Q1O16V',
    '07/24/21': '2SEIWWLZL1',
    '07/25/21': 'ZOU3MWRZN0',
    ...
}

Using custom seed

from pypotd import generate_multiple

generate_multiple(
    start_date="2021-07-23",
    end_date="2022-07-28",
    seed="ABCDABCD")

Output (truncated):

{
    '07/23/21': 'F32CAZCJLU',
    '07/24/21': '95L0GFUNCC',
    '07/25/21': 'CSBLM119CH',
    ...
}

Generating a DES Key for modem configs

Despite the fact that ARRIS/CommScope tools limit seed length to between 4 and 8 characters, the default seed they provide is 10 characters. This does not fit neatly into the 8 byte block size of our DES cipher. I was not able to determine what mutations they make to the default seed to return 8 byte values, so the DES value for their default seed is provided as a hardcoded fallback.

from pypotd import seed_to_des

seed_to_des("ABCDABCD")

Output:

'19.A2.3B.2A.F0.A0.F6.15'