python aes加解密

#coding: utf8
import sys
from Crypto.Cipher import AES
from binascii import b2a_hex, a2b_hex
from const import *
 
class AESHelper():
    def __init__(self):
        self.key = encode_secret
        self.mode = AES.MODE_CBC
     
    def encrypt(self, text):
        cryptor = AES.new(self.key, self.mode, self.key)
        length = 16
        count = len(text)
	if(count % length != 0) :
        	add = length - (count % length)
	else:
		add = 0
        text = text + ('\0' * add)
        self.ciphertext = cryptor.encrypt(text)
        return b2a_hex(self.ciphertext)
     
    def decrypt(self, text):
        cryptor = AES.new(self.key, self.mode, self.key)
        plain_text = cryptor.decrypt(a2b_hex(text))
        string = plain_text.rstrip('\0')
        result = ''
        strings = string.split(encode_salt)
        if len(strings) > 0:
            result = strings[0]
        return result