A better AzDG crypt for python.

AzDG_crypt.py

import hashlib
import random
import string
import base64


def randomword(length):
    return ''.join(random.choice(string.lowercase) for i in range(length))


def encode_key(key, input):
    md5_hash = hashlib.md5()
    md5_hash.update(key)
    encrypt_key = md5_hash.hexdigest()
    result, idx = ('', 0)
    for item in input:
        if idx == len(encrypt_key):
            idx = 0
        result += chr(ord(item) ^ ord(encrypt_key[idx]))
        idx += 1
    return result


def encrypt(key, input):
    rand_str = randomword(20)
    result, idx = ('', 0)
    for item in input:
        if idx == len(rand_str):
            idx = 0
        result += rand_str[idx]
        result += chr(ord(item) ^ ord(rand_str[idx]))
        idx += 1
    return base64.b64encode(encode_key(key, result)).replace('/', '_').replace('+', '-')


def decrypt(key, message):
    message = message.replace('_', '/').replace('-', '+')
    origin_str = base64.b64decode(message)
    encoded_key = encode_key(key, origin_str)
    result = ''
    for (idx, val) in enumerate(encoded_key):
        if idx % 2:
            continue
        result += chr(ord(val) ^ ord(encoded_key[idx + 1]))
    return result

if __name__ == '__main__':
    screct = 'heloworld'
    print decrypt(screct, encrypt(screct, 'this is a message'))