crypto.py

# -*- coding: utf-8 -*-

import base64
from Crypto.Cipher import AES
from Crypto import Random


class AESCipher:
    block_size = 32

    def __init__(self, key):
        key_length = 43
        token = "RainClassroom"

        if len(key) >= key_length:
            self.key = key[:key_length]
        else:
            padNum = key_length - len(key)
            self.key = key + token[padNum % len(token)] * padNum

        self.key = base64.b64decode(self.key + "=")
        self.mode = AES.MODE_CBC

    def encode(self, text):
        text_length = len(text)

        amount_to_pad = self.block_size = (text_length % self.block_size)
        if amount_to_pad == 0:
            amount_to_pad = self.block_size
        # 获得补位所用的字符

        pad = chr(amount_to_pad)
        return text + pad * amount_to_pad

    def decode(self, decrypted):
        pad = ord(decrypted[-1])
        if pad<1 or pad >32:
            pad = 0
        return decrypted[:-pad]

    def encrypt(self, raw):
        text = self.encode(raw)
        cryptor = AES.new(self.key,self.mode,self.key[:16])
        ciphertext = cryptor.encrypt(text)
        try:
            ciphertext = cryptor.encrypt(text)
            return True, base64.b64encode(ciphertext)
        except Exception, e:
            return False, None

    def decrypt(self, enc):
        try:
            cryptor = AES.new(self.key,self.mode,self.key[:16])
            plain_text  = cryptor.decrypt(base64.b64decode(enc))

            return True, self.decode(plain_text)
        except Exception, e:
            return False, None

if __name__ == "__main__":
    key = "RainID39"
    message = "0c2441ca-885d-488f-bf8b-cc6a423d67771468233499"
    aes = AESCipher(key)
    encrypt_message = aes.encrypt(message)
    print key
    print message
    print encrypt_message
    print aes.decrypt(encrypt_message)