一 代碼
# -*- coding: UTF-8 -*-
import string
import random
from Crypto.Cipher import AES
def keyGenerater(length):
'''生成指定長度的秘鑰'''
if length not in (16, 24, 32):
return None
x = string.ascii_letters+string.digits
return ''.join([random.choice(x) for i in range(length)])
def encryptor_decryptor(key, mode):
return AES.new(key, mode, b'0000000000000000')
#使用指定密鑰和模式對給定資訊進行加密
def AESencrypt(key, mode, text):
encryptor = encryptor_decryptor(key, mode)
return encryptor.encrypt(text)
#使用指定密鑰和模式對給定資訊進行解密
def AESdecrypt(key, mode, text):
decryptor = encryptor_decryptor(key, mode)
return decryptor.decrypt(text)
if __name__ == '__main__':
text = 'Python3.5 is excellent.'
key = keyGenerater(16)
#随機選擇AES的模式
mode = random.choice((AES.MODE_CBC, AES.MODE_CFB, AES.MODE_ECB, AES.MODE_OFB))
if not key:
print('Something is wrong.')
else:
print('key:', key)
print('mode:', mode)
print('Before encryption:', text)
#明文必須以位元組串形式,且長度為16的倍數
text_encoded = text.encode()
text_length = len(text_encoded)
padding_length = 16 - text_length%16
text_encoded = text_encoded + b'0'*padding_length
text_encrypted = AESencrypt(key, mode, text_encoded)
print('After encryption:', text_encrypted)
text_decrypted =AESdecrypt(key, mode, text_encrypted)
print('After decryption:', text_decrypted.decode()[:-padding_length])
二 運作結果
E:\python\python可以這樣學\第18章 密碼學程式設計\code>python AES_test.py
('key:', 'D5pcO6iu0HIbj3I2')
('mode:', 1)
('Before encryption:', 'Python3.5 is excellent.')
('After encryption:', '\xf4\x15\x9f\xaf\xea\xd0\n\x03\xfdf\xf6}9\xaa\xa34\xb4\x1eL2\x0e \x16\xa5 \xff?\x8bA\x8e\xdd\xa8')
('After decryption:', u'Python3.5 is excellent.')