AES encoding sample

aes_encryption.py

import base64

from Crypto.Cipher import AES


class AESCipher(object):
    BS = 16

    def __init__(self, key):
        self.key = key
        self.pad = lambda s: s + (self.BS - len(s) % self.BS) * chr(self.BS - len(s) % self.BS).encode()
        self.unpad = lambda s: s[:-ord(s[len(s)-1:])]

    @staticmethod
    def iv():
        """
        The initialization vector to use for encryption or decryption.
        It is ignored for MODE_ECB and MODE_CTR.
        """
        return chr(0) * 16

    def encrypt(self, message):
        """
        It is assumed that you use Python 3.0+, so plaintext's type must be str type(== unicode).
        """
        message = message.encode()
        raw = self.pad(message)
        cipher = AES.new(self.key, AES.MODE_CBC, self.iv())
        enc = cipher.encrypt(raw)
        return base64.b64encode(enc).decode('utf-8')

    def decrypt(self, enc):
        enc = base64.b64decode(enc)
        cipher = AES.new(self.key, AES.MODE_CBC, self.iv())
        dec = cipher.decrypt(enc)
        return self.unpad(dec).decode('utf-8')
      
  
def main():
    data = "Hello world!"
    key = '1234567890ABCDEF'  # 16 chars long
    code = AESCipher(key).encrypt(data)
    print(code)
      
  
if __name__ == '__main__':
    main()