An implementation of the Oplop password hashing algorithm in Python.

oplop.py

#!/usr/bin/env python

"""Generate a password using the Oplop password hashing algorithm.
For more information: http://code.google.com/p/oplop/wiki/HowItWorks"""

from sys import argv, stdout
from hashlib import md5
from base64 import urlsafe_b64encode as b64
import re

PASS_LEN = 8
DIGIT_RE = re.compile('\d+')

def oplop(nickname, master_password, pass_len=PASS_LEN):
    hashed = b64(md5(master_password + nickname).digest())
    digits = DIGIT_RE.findall(hashed[:pass_len])
    if not digits:
        digits = DIGIT_RE.findall(hashed)
        hashed = (digits and digits[0] or '1') + hashed
    return hashed[:pass_len]

if __name__ == '__main__':
    import argparse
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument('nickname', help='Account nickname')
    parser.add_argument('master_password', help='Master password')
    args = parser.parse_args()
    stdout.write(oplop(args.nickname, args.master_password))