executor.py

import argparse
import hasher
import os
import sys
import stdiomask


description = "The executor.py file was built to let you manually add users"\
    "and check user-pswd combinations for validity"
parser = argparse.ArgmentParser(description=description)


SALT_FILE = 'shadow_salt.txt'
NO_SALT_FILE = 'shadow_no_salt.txt'
# makes sure file exists


def startfile():
    if not os.path.exists(SALT_FILE):
        with open(SALT_FILE, 'w'):
            pass


def add_usr():
    username = input('  Username: ')
    password1 = stdiomask.getpass(prompt='     Enter Password: ')
    password2 = stdiomask.getpass(prompt='  Re-enter Password: ')
    if password1 != password2:
        print('  Passwords did not match')
        return

    content = hasher.register_account(username, password1)
    with open(SALT_FILE, 'a') as fOut:
        fOut.write(f'{content}\n')


def clean_file():
    with open(SALT_FILE, 'w') as fOut:
        fOut.truncate(0)
    with open(NO_SALT_FILE, 'w') as fOut:
        fOut.truncate(0)
    print('  files cleaned')


def kill_file():
    if os.path.exists(SALT_FILE):
        os.remove(SALT_FILE)
    if os.path.exists(NO_SALT_FILE):
        os.remove(NO_SALT_FILE)
        print('  files removed')


def num_format(number):
    if 3 < number < 20:
        return f'{number}th'

    remainder = number % 10
    if remainder == 1:
        return f'{number}st'
    if remainder == 2:
        return f'{number}nd'
    if remainder == 3:
        return f'{number}ed'
    return f'{number}th'


def login():
    username = input('  Username: ')
    password = stdiomask.getpass(prompt='  Password: ')
    with open('shadow.txt', 'r') as fIn:
        lines = fIn.readlines()
    for i, line in enumerate(lines):
        name, salt, hash = linux_line_split(line)
        if name == -1 or name != username:
            continue
        if eval(hash) == hasher.calc_hash(eval(salt), password):
            safe_password = '*' * len(password)
            print(
                f'  user {username} with password {safe_password} is the {num_format(i + 1)} user')
            return True
    return False


def linux_line_split(line):
    if ':' not in line or '$' not in line:
        return -1, -1, -1
    return line[:line.index(':')],
    line[line.index(':') + 1:line.index('$')],
    line[line.index('$') + 1:]


def help():
    print("""Comands:
  'add user'  - adds a new user
  'login'     - lets you try to login
  'make clean'- removes the shadow.txt file
  'length'    - returns the number of users currently reccorded
  'help'      - prints this menu
  'quit''exit'- closes the program""")


def get_num_users():
    with open(SALT_FILE, 'r') as fIn:
        return fIn.read().count('\n')


def listen():
    print('Welcome to executor.listen(), we are emulating the linux shadow\n'\
          'write help for more options')
    startfile()
    leave_request = ['q', 'quit', 'exit', 'leave']
    log_request = ['log', 'login', 'log in', 'check usr', 'check user']

    while True:
        comand = input('$ ').lower()

        if comand in leave_request:
            break

        elif comand == 'make clean' or comand == 'clean file':
            kill_file()
            continue
        elif comand == 'clear file':
            clean_file()
            continue

        elif comand == 'add usr' or comand == 'add user':
            add_usr()
            continue

        elif comand in log_request:
            status = login()
            if not status:
                print('  login failed')

        elif comand == 'help':
            help()
            continue

        elif comand == 'length':
            print(f'  There are {get_num_users()} users recorded in the shadow.txt file at the moment')
            continue


if __name__ == '__main__':
    args = parser.parse_args()
    listen()