填充不正确。AES Python加密

Question

我正在尝试使用python进行简单的加密。

这是加密：

from Crypto.Cipher import AES
from Crypto.Util.Padding import pad
from Crypto.Util.Padding import unpad
BLOCK_SIZE = 32

def encrypt(message):
    obj = AES.new(b'This is a key123', AES.MODE_CBC, b'This is an IV456')
    return obj.encrypt(pad(message, BLOCK_SIZE))

加密似乎可以正常工作，因为它返回以下内容：

b'V=\t7I\x99\xa5\x06*\xa1={\x95+\xc1h\xfeY\xc2\xb5\xcf3F:\x88\xa6g\x94d\x87\xd7U'

但是对于解密，我使用：

def decrypt(ciphertext):
    obj2 = AES.new(b'This is a key123', AES.MODE_CFB, b'This is an IV456')
    return obj2.decrypt(unpad(ciphertext, BLOCK_SIZE))

但它显示：

填充不正确

这是我要整理的整个文件：

import sys
from Crypto.Cipher import AES
import importlib
try:
    importlib.import_module('psutil')
except ImportError:
    import pip
    pip.main(['install', 'psutil'])
finally:
    globals()['psutil'] = importlib.import_module('psutil')

def collect_stats():
    try:
        cpu = psutil.cpu_percent(interval=1)
        memory = psutil.virtual_memory().percent
        disk = psutil.disk_usage('/').percent
        str_to_send_back = "{} {} {}".format(cpu, memory, disk)
        str_to_send_back = str_to_send_back.encode()
        str_to_send_back = encrypt(str_to_send_back)

    except Exception as e:
        print('Oops this error happened in collect_stats() inside client.py: ' + str(e))


def encrypt(message):
    obj = AES.new(b'This is a key123', AES.MODE_CBC, b'This is an IV456')
    return obj.encrypt(message)


def decrypt(ciphertext):
    obj2 = AES.new(b'This is a key123', AES.MODE_CFB, iv)
    return obj2.decrypt(ciphertext)

if __name__ == '__main__':
    collect_stats()

Answer 1

加密时，先进行填充，然后进行加密：

obj.encrypt(pad(message, BLOCK_SIZE))

这使我相信解密时，应该先解密，然后再解锁。所以：

obj2.decrypt(unpad(ciphertext, BLOCK_SIZE))

会成为：

unpad(obj2.decrypt(ciphertext), BLOCK_SIZE)