crypt3gen.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

"""
Transorme user password to cryp(3) compliant line.
Could be usefull to use with useradd -p 'crypt(3) line'


"""

__author__ = "braoru@gmail.com"
__maintainer__ = ""
__version__ = "0.0.1"


import crypt
import random
import getpass
import optparse
import sys
import csv

from string import ascii_letters, digits


#command line parsing
parser = optparse.OptionParser(
    "%prog [options]", version="%prog " + __version__
)
parser.add_option(
    '-F',
    '--input-file',
    dest="source_file",
    help='file to load'
)
parser.add_option(
    '-I',
    '--interactive',
    dest="is_interactive",
    action="store_true",
    default=False,
    help='Enable interactive mode'
)


def salted_crypt_3(
    password,
    method_id=6
):
    """
        Generate a crpyt(3) compliant line
    Keyword arguments:
    password     -- password to process
    method_id    -- Method id to use (default is 6)
    """
    salt = ''.join(
        [
            random.choice(
                ascii_letters + digits
            ) for _ in range(16)
        ]
    )

    crypt_3_line = crypt.crypt(
        password,
        '${method}${salt}'.format(
            method=str(method_id),
            salt=salt
        )
    )

    return crypt_3_line

if __name__ == "__main__":

    opts, args = parser.parse_args()
    if args:
        parser.error("Does not accept any argument.")

    if opts.is_interactive:
        password = getpass.getpass("password please: ")
        print(
            salted_crypt_3(
                password=password
            )
        )
        sys.exit(2)

    if not opts.source_file:
        print("Error : If not interfactive you must specify an input file")
        sys.exit(2)

    #Read the file and generate for each line the hash line
    with open(opts.source_file, 'rb') as password_file:
        lines = csv.reader(
            password_file,
            delimiter=','
        )

        for line in lines:
            username = line[0]
            shadow = salted_crypt_3(
                password=line[1]
            )
            print(
                "{username}:{shadow}".format(
                    username=username,
                    shadow=shadow
                )
            )