python 实现aes256加密

 # ------------------------------- # -*- coding: utf-8 -*- # @Author：jianghan # @Time：2020/11/25 14:46 # @File: crypt.py # Python版本：3.6.8 # ------------------------------- """ 1、 填充字符串和明文字符串最后一位不能相同 2、 字符串编码默认是utf-8， key和iv默认为英文字符；字符串不支持其他编码或key/iv不支持为中文字符 """ from enum import Enum, unique from Crypto.Cipher import AES @unique class Mode(Enum): CBC = AES.MODE_CBC ECB = AES.MODE_ECB @unique class Padding(Enum): """ 定义填充的字符串 """ SPACE = ' ' # 空格 class AES256Crypto: def __init__(self, key, mode=Mode.ECB, padding=Padding.SPACE, iv=None): """ :param key: 密钥， 32byte 长度字符串 :param mode: 加密模式， 来源 class Mode :param iv: 16byte 长度字符串 :param padding: 填充的字符串， 来源class Padding """ self.padding = self.check_padding(padding) self.key = self.padding_key(key) self.iv = self.padding_iv(iv) if iv else None self.mode = self.check_mode(mode) def check_mode(self, mode): """ 核对 mode """ if mode not in Mode.__members__.values(): raise Exception(f'mode {mode} not allowed!') if mode == Mode.CBC and not self.iv: raise Exception(f'iv is required') return mode def check_padding(self, padding): """ 核对 padding """ if padding not in Padding.__members__.values(): raise Exception(f'mode {padding} not allowed!') return padding def padding_ret_byte(self, text, _len=16): """ 填充并转成 bytes """ text = text.encode() remainder = len(text) % _len remainder = _len if remainder == 0 else remainder text += (_len - remainder) * self.padding.value.encode() return text def padding_iv(self, iv: str): """ 补全iv 并转成 bytes""" if len(iv.encode()) > 16: raise Exception(f'iv {iv} must <= 16bytes') return self.padding_ret_byte(iv) def padding_key(self, key: str): """ 补全key 并转成 bytes """ if len(key.encode()) > 32: raise Exception(f'key {key} must <= 32bytes') return self.padding_ret_byte(key, _len=32) def encrypt(self, text, encode=None): """ 加密 :param text: 待加密字符串 :param encode: 传入base64里面的方法 :return: 若encode=None则不进行base加密处理，返回bytes类型数据 """ text = self.padding_ret_byte(text) # 注意：加密中的和解密中的AES.new()不能使用同一个对象，所以在两处都使用了AES.new() text = AES.new(key=self.key, mode=self.mode.value, iv=self.iv).encrypt(text) if encode: return encode(text).decode() return text def decrypt(self, text, decode=None): """ 解密 """ if decode: if type(text) == str: text = text.encode() text = decode(bytes(text)) else: if type(text) != bytes: raise Exception(text) text = AES.new(key=self.key, mode=self.mode.value, iv=self.iv).decrypt(text) text = text.strip(self.padding.value.encode()) return text.decode()

 import json # 这是一段待加密的字符串 text = '{"upi": "1341343", "overdue": "2020-11-26 00:00:00"}' key = 't6LtKa3tD5X6qaJ6qOrAW3XmobFrY6ob' iv = 'NjtP47eSECuOm3s6' aes = AES256Crypto(key, Mode.CBC, Padding.SPACE, iv) text_1 = aes.encrypt(text) # b'\xe7\x1d\xeae\xff\xc7\xc2\xd7\x8c\xf6\xe7\x82u\x7f\x168\xbc\x90\xad\x1e\x85M\xcb\xb0\xb4Ho\x1b\xe4\xec\x9d\x1d\xf93\xeb\x9b\xe7\xa3\xdd$\x8cEa\xab\xf7K~\x91H\xc3]5\xc4\x1a\xd4w[\x83\xb2"FC\x9f\x9d' text_2 = aes.decrypt(text_1) # '{"upi": "1341343", "overdue": "2020-11-26 00:00:00"}' import base64 text_3 = aes.encrypt(text, encode=base64.b16encode) # 'E71DEA65FFC7C2D78CF6E782757F1638BC90AD1E854DCBB0B4486F1BE4EC9D1DF933EB9BE7A3DD248C4561ABF74B7E9148C35D35C41AD4775B83B22246439F9D' text_4 = aes.decrypt(text_3, decode=base64.b16decode) # '{"upi": "1341343", "overdue": "2020-11-26 00:00:00"}'