Python爬虫进阶必备 | 关于AES 的案例分析与总结

pip3 install pycryptodome 
# 豆瓣源安装：pip3 install -i https://pypi.douban.com/simple pycryptodome

from Crypto.PublicKey import RSA
from Crypto.Cipher import AES
from Crypto.Signature import PKCS1_v1_5
from Crypto.Hash import SHA256

import base64
from Crypto.Cipher import AES

class UseAES:
    """
    AES
    除了MODE_SIV模式key长度为：32, 48, or 64,
    其余key长度为16, 24 or 32
    详细见AES内部文档
    CBC模式传入iv参数
    本例使用常用的ECB模式
    """
    def __init__(self, key):
        if len(key) > 32:
            key = key[:32]
        self.key = self.to_16(key)

    @staticmethod
    def to_16(key):
        """
        转为16倍数的bytes数据
        :param key:
        :return:
        """
        key = bytes(key, encoding="utf8")
        while len(key) % 16 != 0:
            key += b'\0'
        return key  # 返回bytes

    def aes(self):
        return AES.new(self.key, AES.MODE_ECB)  # 初始化加密器

    def encrypt(self, text):
        aes = self.aes()
        return str(base64.encodebytes(aes.encrypt(self.to_16(text))),
                   encoding='utf8').replace('\n', '')  # 加密

    def decode_bytes(self, text):
        aes = self.aes()
        return str(aes.decrypt(base64.decodebytes(bytes(
            text, encoding='utf8'))).rstrip(b'\0').decode("utf8"))  # 解密

if __name__ == '__main__':
    aes_test = UseAES("xianyuxuepython")
    a = aes_test.encrypt("咸鱼学Python")
    print(a)
    b = aes_test.decode_bytes(a)
    print(b)

#!/usr/bin/env python
# -*- coding=utf-8 -*-
import base64
from Crypto.Cipher import AES
import random


def pkcs7padding(text):
    """
    明文使用PKCS7填充
    最终调用AES加密方法时，传入的是一个byte数组，要求是16的整数倍，因此需要对明文进行处理
    :param text: 待加密内容(明文)
    :return:
    """
    bs = AES.block_size  # 16
    length = len(text)
    bytes_length = len(bytes(text, encoding='utf-8'))
    # tips：utf-8编码时，英文占1个byte，而中文占3个byte
    padding_size = length if(bytes_length == length) else bytes_length
    padding = bs - padding_size % bs
    # tips：chr(padding)看与其它语言的约定，有的会使用'\0'
    padding_text = chr(padding) * padding
    return text + padding_text


def pkcs7unpadding(text):
    """
    处理使用PKCS7填充过的数据
    :param text: 解密后的字符串
    :return:
    """
    length = len(text)
    unpadding = ord(text[length-1])
    return text[0:length-unpadding]


def encrypt(key, content):
    """
    AES加密
    key,iv使用同一个
    模式cbc
    填充pkcs7
    :param key: 密钥
    :param content: 加密内容
    :return:
    """
    key_bytes = bytes(key, encoding='utf-8')
    iv = key_bytes
    cipher = AES.new(key_bytes, AES.MODE_CBC, iv)
    # 处理明文
    content_padding = pkcs7padding(content)
    # 加密
    encrypt_bytes = cipher.encrypt(bytes(content_padding, encoding='utf-8'))
    # 重新编码
    result = str(base64.b64encode(encrypt_bytes), encoding='utf-8')
    return result


def decrypt(key, content):
    """
    AES解密
     key,iv使用同一个
    模式cbc
    去填充pkcs7
    :param key:
    :param content:
    :return:
    """
    key_bytes = bytes(key, encoding='utf-8')
    iv = key_bytes
    cipher = AES.new(key_bytes, AES.MODE_CBC, iv)
    # base64解码
    encrypt_bytes = base64.b64decode(content)
    # 解密
    decrypt_bytes = cipher.decrypt(encrypt_bytes)
    # 重新编码
    result = str(decrypt_bytes, encoding='utf-8')
    # 去除填充内容
    result = pkcs7unpadding(result)
    return result


def get_key(n):
    """
    获取密钥 n 密钥长度
    :return:
    """
    c_length = int(n)
    source = 'ABCDEFGHJKMNPQRSTWXYZabcdefhijkmnprstwxyz2345678'
    length = len(source) - 1
    result = ''
    for i in range(c_length):
        result += source[random.randint(0, length)]
    return result

en_16 = 'abcdefgj10124567'
encrypt_en = encrypt(aes_key, en_16)
print(encrypt_en)