Python中的AES-128 CBC解密

Question

我正在尝试在python中实现此代码(我是python的新手),它给了我以下错误:

AttributeError:'str'对象没有属性'decode'

如果我们删除.decode ('hex')只是为了避免这样的错误:

from itertools import product
from Crypto.Cipher import AES
import Crypto.Cipher.AES

key = ('2b7e151628aed2a6abf7158809cf4f3c').decode('hex')
IV = ('000102030405060708090a0b0c0d0e0f').decode('hex')
plaintext1 = ('6bc1bee22e409f96e93d7e117393172a').decode('hex')
plaintext2 = ('ae2d8a571e03ac9c9eb76fac45af8e51').decode('hex')
plaintext3 = ('30c81c46a35ce411e5fbc1191a0a52ef').decode('hex')
cipher = AES.new(key, AES.MODE_CBC, IV)
ciphertext = cipher.encrypt(plaintext1 + plaintext2 + plaintext3)
(ciphertext).encode('hex')
decipher = AES.new(key, AES.MODE_CBC, IV)
plaintext = decipher.decrypt(ciphertext)
(plaintext).encode('hex')

但它给了我以下错误:

ValueError:IV必须长度为16个字节

因为算法需要.decode ('hex')我必须删除的

from itertools import product
from Crypto.Cipher import AES
import Crypto.Cipher.AES

key = ('2b7e151628aed2a6abf7158809cf4f3c')
IV = ('000102030405060708090a0b0c0d0e0f')
plaintext1 = ('6bc1bee22e409f96e93d7e117393172a')
plaintext2 = ('ae2d8a571e03ac9c9eb76fac45af8e51')
plaintext3 = ('30c81c46a35ce411e5fbc1191a0a52ef')
cipher = AES.new(key,AES.MODE_CBC,IV)
ciphertext = cipher.encrypt(plaintext1 + plaintext2 + plaintext3)
(ciphertext).encode('hex')
decipher = AES.new(key,AES.MODE_CBC,IV)
plaintext = decipher.decrypt(ciphertext)
(plaintext).encode('hex')

有没有人知道如何使这个代码工作？

Answer 1

您使用的是Python 3,而不是Python 2.您不能decode()在Python 3中使用字符串,它们已经是文本,因此'hex'无法以这种方式应用字节到字节的编解码器.

binascii改为使用模块:

from binascii import hexlify, unhexlify

key = unhexlify('2b7e151628aed2a6abf7158809cf4f3c')
IV = unhexlify('000102030405060708090a0b0c0d0e0f')
plaintext1 = unhexlify('6bc1bee22e409f96e93d7e117393172a')
plaintext2 = unhexlify('ae2d8a571e03ac9c9eb76fac45af8e51')
plaintext3 = unhexlify('30c81c46a35ce411e5fbc1191a0a52ef')

和

ciphertext_hex = hexlify(ciphertext)
# ...
plaintext_hex = hexlify(plaintext)

因此,要从十六进制字符串解码为字节,使用binascii.unhexlify(),并编码回十六进制,请使用binascii.hexlify().请注意,您无法就地转换数据,您必须将结果存储回变量(或打印出值等).

演示:

>>> from Crypto.Cipher import AES
>>> import Crypto.Cipher.AES
>>> from binascii import hexlify, unhexlify
>>> key = unhexlify('2b7e151628aed2a6abf7158809cf4f3c')
>>> IV = unhexlify('000102030405060708090a0b0c0d0e0f')
>>> plaintext1 = unhexlify('6bc1bee22e409f96e93d7e117393172a')
>>> plaintext2 = unhexlify('ae2d8a571e03ac9c9eb76fac45af8e51')
>>> plaintext3 = unhexlify('30c81c46a35ce411e5fbc1191a0a52ef')
>>> cipher = AES.new(key,AES.MODE_CBC,IV)
>>> ciphertext = cipher.encrypt(plaintext1 + plaintext2 + plaintext3)
>>> hexlify(ciphertext)
b'7649abac8119b246cee98e9b12e9197d5086cb9b507219ee95db113a917678b273bed6b8e3c1743b7116e69e22229516'
>>> decipher = AES.new(key,AES.MODE_CBC,IV)
>>> plaintext = decipher.decrypt(ciphertext)
>>> plaintext == plaintext1 + plaintext2 + plaintext3  # test if decryption was successful
True
>>> hexlify(plaintext)
b'6bc1bee22e409f96e93d7e117393172aae2d8a571e03ac9c9eb76fac45af8e5130c81c46a35ce411e5fbc1191a0a52ef'