crypthelper.py

from hashlib import md5
from base64 import b64decode
from base64 import b64encode
from Crypto.Cipher import AES

# Padding for the input string --not
# related to encryption itself.
BLOCK_SIZE = 16  # Bytes
pad = lambda s: s + (BLOCK_SIZE - len(s) % BLOCK_SIZE) * \
                    chr(BLOCK_SIZE - len(s) % BLOCK_SIZE)
unpad = lambda s: s[:-ord(s[len(s) - 1:])]


class AESCipher:
    """
    Usage:
        c = AESCipher('password').encrypt('message')
        m = AESCipher('password').decrypt(c)
    Tested under Python 3 and PyCrypto 2.6.1.
    """

    def __init__(self , key):
        self.key = md5(key.encode('utf8')).hexdigest().encode('utf-8')

    def encrypt(self , raw):
        raw = pad(raw).encode('utf-8')
        cipher = AES.new(self.key, AES.MODE_ECB)
        return b64encode(cipher.encrypt(raw))

    def decrypt(self , enc):
        enc = b64decode(enc)
        cipher = AES.new(self.key , AES.MODE_ECB)
        return unpad(cipher.decrypt(enc)).decode('utf8')


"""FROM https://gist.github.com/forkd/7ed4a8392fe7b69307155ab379846019"""