1Key

cipher.py

import base64
import getpass
from cryptography.fernet import Fernet

BLOCK_SIZE = 32

# the character used for padding--with a block cipher such as AES, the value
# you encrypt must be a multiple of BLOCK_SIZE in length. This character is
# used to ensure that your value is always a multiple of BLOCK_SIZE
PADDING = b'{'

# one-liner to sufficiently pad the text to be encrypted
pad = lambda s: s + (BLOCK_SIZE - len(s) % BLOCK_SIZE) * PADDING


class Cipher(object):
    def __init__(self, key):
        self.bs = 32
        self.key = pad(key)
        self.cipher = Fernet(base64.urlsafe_b64encode(self.key))

    def encrypt(self, raw):
        return self.cipher.encrypt(raw)

    def decrypt(self, raw):
        return self.cipher.decrypt(raw)

    def test(self, raw):
        print("result: ", self.encrypt(raw))
        assert self.encrypt(raw), self.decrypt(raw)


if __name__ == '__main__':
    #key = getpass.getpass("Key:")
    key = "This is a key"
    cipher = Cipher(bytes(key, "utf-8"))
    cipher.test(b"This is a test")

requirements.txt

cryptography==2.3.1