Python Multi-byte aes crypto

aes_crypto.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import base64

from Crypto import Random
from Crypto.Cipher import AES

# Block size
BS = 32


class AESCrypto(object):
    def __init__(self, key):

        if len(key) >= len(str(BS)):
            self.key = key[:BS]
        else:
            self.key = AESCrypto._pad(key)

    def encrypt(self, raw, iv=0):
        raw = AESCrypto._pad(raw)

        if iv is 0:
            iv = Random.new().read(AES.block_size)

        cipher = AES.new(self.key, AES.MODE_CBC, iv)
        return base64.b64encode(iv + cipher.encrypt(raw))

    def mb_encrypt(self, raw, iv=0):
        raw = base64.b64encode(raw.encode('utf-8')).decode('utf-8')

        raw = AESCrypto._pad(raw)

        if iv is 0:
            iv = Random.new().read(AES.block_size)

        cipher = AES.new(self.key, AES.MODE_CBC, iv)
        return base64.b64encode(iv + cipher.encrypt(raw))

    def decrypt(self, enc, iv=0):
        enc = base64.b64decode(enc)

        if iv is 0:
            iv = enc[:AES.block_size]

        cipher = AES.new(self.key, AES.MODE_CBC, iv)
        return AESCrypto._unpad(cipher.decrypt(enc[AES.block_size:])).decode('utf-8')

    def mb_decrypt(self, enc, iv=0):
        enc = base64.b64decode(enc)

        if iv is 0:
            iv = enc[:AES.block_size]

        cipher = AES.new(self.key, AES.MODE_CBC, iv)
        decrypt_enc = AESCrypto._unpad(cipher.decrypt(enc[AES.block_size:]))

        return base64.b64decode(decrypt_enc).decode('utf-8')

    @staticmethod
    def _pad(s):
        return s + (BS - len(s) % BS) * chr(BS - len(s) % BS)

    @staticmethod
    def _unpad(s):
        return s[:-ord(s[len(s)-1:])]

test_aes_crypto.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import unittest

from aes_crypto import AESCrypto


class TestAESCrypto(unittest.TestCase):
    def setUp(self):
        pass

    def test_encrypt_decrypt(self):
        plan_string = 'demo.test-0123456789@gmail.com'

        cipher = AESCrypto('oxrBXlJ5k35ytZVZSwJv0O8BiQJYZnVFgnCCofC3nI3SONCxA0')

		# Encrypt
        encrypt_string = cipher.encrypt(plan_string)
        self.assertIsNotNone(encrypt_string)
        self.assertNotEqual(encrypt_string, plan_string)

		# Decrypt
        decrypt_string = cipher.decrypt(encrypt_string)
        self.assertIsNotNone(decrypt_string)
        self.assertEqual(decrypt_string, plan_string)

    def test_mb_encrypt_decrypt(self):
        plan_string = 'भारत中国中國日本語にほんごニホンゴ한국어جزيره العرب'

        cipher = AESCrypto('oxrBXlJ5k35ytZVZSwJv0O8BiQJYZnVFgnCCofC3nI3SONCxA0')

		# Encrypt
        encrypt_string = cipher.mb_encrypt(plan_string)
        self.assertIsNotNone(encrypt_string)
        self.assertNotEqual(encrypt_string, plan_string)

		# Decrypt
        decrypt_string = cipher.mb_decrypt(encrypt_string)
        self.assertIsNotNone(decrypt_string)
        self.assertEqual(decrypt_string, plan_string)


if __name__ == '__main__':
    unittest.main()