#coding=utf-8

import hashlib
from Crypto.Cipher import AES
import base64

class AesCrypter(object):

    def __init__(self, key):
        # self.key = hashlib.sha256(key).digest()
        # self.iv = self.key[:16]
        # key是16個位元組，也就是128位 16*8
        # key可以是16*8=128, 24*8=192, 32*8=256位
        self.key = self.iv = key

    def encrypt(self, data):
        data = self.pkcs7padding(data)
        cipher = AES.new(self.key, AES.MODE_CBC, self.iv)
        encrypted = cipher.encrypt(data)
        return base64.b64encode(encrypted)

    def decrypt(self, data):
        data = base64.b64decode(data)
        cipher = AES.new(self.key, AES.MODE_CBC, self.iv)
        decrypted = cipher.decrypt(data)
        decrypted = self.pkcs7unpadding(decrypted)
        return decrypted

    def pkcs7padding(self, data):
        #AES.block_size 16位
        bs = AES.block_size
        padding = bs - len(data) % bs
        padding_text = chr(padding) * padding
        return data + padding_text

    def pkcs7unpadding(self, data):
        lengt = len(data)
        unpadding = ord(data[lengt - 1])
        return data[0:lengt-unpadding]

if __name__ == '__main__':
    aes = AesCrypter('UITN25LMUQC436IM')
 

    #原文必須是blocksize的整數倍
    encrypted = aes.encrypt('2633930920939309999333333')
    print encrypted
    plain = aes.decrypt(encrypted)
    print plain