editsilly

#!/usr/bin/env python3

import os, sys, getopt, random, string

_data = None

FILENAME = "users.dat"

def init():
    global _data

    _data = []
    names = set()
    if not os.path.isfile(FILENAME): return

    with open(FILENAME, 'r') as handle:
        for line in handle:
            line = line.rstrip()
            if len(line) == 0 or line[0] == '#':
                _data.append(('text', line))
                continue
            i = line.find(':')
            if i < 0: continue
            j = line.find(':', i + 1)
            if j < 0: continue
            uname, pwd = line[:i].strip(), line[i+1:j]
            if uname in names: continue
            _data.append(('user', uname, pwd))
            names.add(uname)

def usage():
    print()
    print("Usage: editsilly [options] username...")
    print("with options:")
    print("    -h, --help  Output this online help.")
    print("    -d, --delete Delete users instead of adding them.")

def make_pwd():
    """
    Construct a non-pronounceable word.

    THIS IS NOT SECURE, DO NOT USE IN PRODUCTION.
    """
    text = string.ascii_letters + string.digits
    text = text + ''.join(p for p in string.punctuation if p not in ':#')
    pwd = []
    for i in range(20):
        pwd.append(text[random.randrange(len(text))])
    return ''.join(pwd)

def check_uname(name):
    has_lower = False

    # First must be a letter
    if name[0] in string.ascii_lowercase:
        has_lower = True
    elif name[0] in string.ascii_uppercase:
        return False

    for a in name[1:]:
        if a in string.ascii_lowercase:
            has_lower = True
        elif a in string.ascii_uppercase:
            pass
        elif a in string.digits:
            pass
        else:
            return False

    if len(name) < 3 or not has_lower: return False
    return True


def main():
    global _data

    init()

    try:
        opts, args = getopt.getopt(sys.argv[1:], "hd", ["help", "delete"])
    except getopt.GetoptError as err:
        # print help information and exit:
        print("ERROR: " + str(err))
        usage()
        sys.exit(2)
    delete = False
    for opt, arg in opts:
        if opt in ('-h', '--help'):
            usage()
            sys.exit(0)
        if opt in ('-d', '--delete'):
            delete = True
            continue

        raise ValueError("Unexpected option value {} encountered".format(repr(opt)))

    if len(args) == 0:
        print("ERROR: Missing username argument")
        usage()
        sys.exit(1)


    for arg in args:
        if delete:
            _data = [line for line in _data if line[0] != 'user' or line[1] != arg]
        else:
            if not check_uname(arg):
                msg = ("Username \"{}\" is not acceptable (only letters and digits, " +
                       "length at least 3, and at least one lower case letter).")
                msg = msg.format(arg)
                print(msg)
                sys.exit(1)

            _data = [line for line in _data if line[0] != 'user' or line[1] != arg]
            pwd = make_pwd()
            _data.append(('user', arg, pwd))
            print("Username: " + arg)
            print("Password: " + pwd)
            print()

    with open(FILENAME, 'w') as handle:
        for line in _data:
            if line[0] == 'text':
                line = line[1]
                if len(line) != 0 and line[0] != '#': line = '#' + line
                handle.write(line + '\n')
            elif line[0] == 'user':
                handle.write(line[1] + ':' +line[2] + ':\n')

    print(" ******************************************")
    print(" * THIS SYSTEM USES UNENCRYPTED PASSWORDS *")
    print(" * USE AT YOUR OWN RISK                   *")
    print(" ******************************************")

main()