Encrypt & Decrypt using PyCrypto AES 256

Question

I want to create two methods using PyCrypto that accept two arguments: the message and the key, and then encrypt/decrypt the message. How can I do that?

Answer 1

You can refer to the below implementation with 32 bytes and iv to 16 bytes in Python:

import base64

import hashlib

from Crypto import Random

from Crypto.Cipher import AES

class AESCipher(object):

    def __init__(self, key): 

        self.bs = AES.block_size

        self.key = hashlib.sha256(key.encode()).digest()

    def encrypt(self, raw):

        raw = self._pad(raw)

        iv = Random.new().read(AES.block_size)

        cipher = AES.new(self.key, AES.MODE_CBC, iv)

        return base64.b64encode(iv + cipher.encrypt(raw.encode()))

    def decrypt(self, enc):

        enc = base64.b64decode(enc)

        iv = enc[:AES.block_size]

        cipher = AES.new(self.key, AES.MODE_CBC, iv)

        return self._unpad(cipher.decrypt(enc[AES.block_size:])).decode('utf-8')

    def _pad(self, s):

        return s + (self.bs - len(s) % self.bs) * chr(self.bs - len(s) % self.bs)

    @staticmethod

    def _unpad(s):

        return s[:-ord(s[len(s)-1:])]