mi version del password del dia para Arris

password_of_the_day.py

#!/usr/bin/env python

#    Version limpia del generador de: password-of-the-day
# ------------------------------------------------------------
#   El generador se trata de cifrado desplazado del seed inicial
# considerando el seed total un string infinito circular
# que en realidad es el mismo seed repetido infinitas veces.
# para esto se utiliza el modulo del largo del seed. (index % largo)
#
#   Los desplazamientos que se utilizan para cada caracter
# son calculados con matrices que tienen datos predeterminados
# por el mismo algoritmo del router y aplicando operaciones
# matematicas sobre ellos (sumas entre los mismos numeros mayormente).
#
#   Finalmente se aplican los desplazamientos a cada numero ascii
# de cada caracter del seed y se aplica modulo 36 (% 36) para asegurar
# que cada desplazamiento este dentro del rango del alfabeto (alphanum).
#

import datetime

seed = 'vtr2014' #'MPSJKMDHAI'

week_shifts_matrix = [
  [15, 15, 24, 20, 24],
  [13, 14, 27, 32, 10],
  [29, 14, 32, 29, 24],
  [23, 32, 24, 29, 29],
  [14, 29, 10, 21, 29],
  [34, 27, 16, 23, 30],
  [14, 22, 24, 17, 13]
]

lookup_matrix = [
  [0, 1, 2, 9, 3, 4, 5, 6, 7, 8],
  [1, 4, 3, 9, 0, 7, 8, 2, 5, 6],
  [7, 2, 8, 9, 4, 1, 6, 0, 3, 5],
  [6, 3, 5, 9, 1, 8, 2, 7, 4, 0],
  [4, 7, 0, 9, 5, 2, 3, 1, 8, 6],
  [5, 6, 1, 9, 8, 0, 4, 3, 2, 7]
]

alphanum = (
  '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D',
  'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R',
  'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'
)


def calculate_shifts(day_of_week, day_of_month, year, month, seed):
  # get initial shifts from matrix
  date_shifts = list(week_shifts_matrix[day_of_week])

  # appends day of the actual month
  date_shifts.append(day_of_month)

  # appends date math calculation
  # if negative it counts in reverse ((auxsum + 36) % 36)
  auxsum = (year + month) - day_of_month
  date_shifts.append(auxsum % 36)

  # another calculation
  date_shifts.append((((3 + ((year + month) % 12)) * day_of_month) % 37) % 36)

  # add ascii codes to previously calculated shifts
  # and creates a new calculated_shifts list
  calculated_shifts = []
  for i in range(8):
    seed_shift = ord(seed[i % seedlen]) % 36
    date_shift = date_shifts[i]
    total_shift = seed_shift + date_shift
    calculated_shifts.append(total_shift)

  # appends a sum of calculated shifts
  shift = sum(calculated_shifts) % 36
  calculated_shifts.append(shift)

  # index for lookup matrix
  shift_num8 = shift % 6

  # appends the index for lookup by square
  calculated_shifts.append(int(shift_num8 ** 2))

  # filter shifts by lookup matrix indexes row
  lookup_list = lookup_matrix[shift_num8]
  filtered_shifts = []
  for index in lookup_list:
    shift = calculated_shifts[index]
    filtered_shifts.append(shift)

  return filtered_shifts


now = datetime.datetime.now()
year = now.year % 100
month = now.month
day_of_month = now.day
day_of_week = now.weekday()
seedlen = len(seed)

# gets shifts for cipher then adds to ascii resized (by 36)
password_of_the_day = []
shifts = calculate_shifts(day_of_week, day_of_month, year, month, seed)
for i in range(len(shifts)):
  char_index = ord(seed[i % seedlen])
  shift = shifts[i]
  char_index = (char_index + shift) % 36
  pass_character = alphanum[char_index]
  password_of_the_day.append(pass_character)

# transform to string
print ''.join(password_of_the_day);