mirror of
https://github.com/jxxghp/MoviePilot.git
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366 lines
13 KiB
Python
366 lines
13 KiB
Python
#!/usr/bin/env python
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# -*- encoding:utf-8 -*-
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"""
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企业微信回调消息的签名验证、加解密和 XML 编解码。
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版权所有 (c) 1998-2014 Tencent Inc.，沿用原示例的接口和错误码。
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"""
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import base64
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import hashlib
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import logging
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import random
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import socket
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import struct
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import time
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import xml.etree.cElementTree as ET
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from typing import NoReturn, Optional, cast
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from Crypto.Cipher import AES
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# 成功
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WXBizMsgCrypt_OK = 0
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# 消息签名校验失败
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WXBizMsgCrypt_ValidateSignature_Error = -40001
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# XML 消息解析失败
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WXBizMsgCrypt_ParseXml_Error = -40002
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# 签名计算失败
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WXBizMsgCrypt_ComputeSignature_Error = -40003
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# AES 密钥格式无效
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WXBizMsgCrypt_IllegalAesKey = -40004
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# 接收方标识不匹配
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WXBizMsgCrypt_ValidateCorpid_Error = -40005
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# AES 加密失败
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WXBizMsgCrypt_EncryptAES_Error = -40006
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# AES 解密失败
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WXBizMsgCrypt_DecryptAES_Error = -40007
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# 解密正文结构无效
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WXBizMsgCrypt_IllegalBuffer = -40008
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# Base64 编码失败
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WXBizMsgCrypt_EncodeBase64_Error = -40009
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# Base64 解码失败
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WXBizMsgCrypt_DecodeBase64_Error = -40010
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# 回复 XML 生成失败
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WXBizMsgCrypt_GenReturnXml_Error = -40011
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class FormatException(Exception):
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"""
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企业微信编码密钥的格式错误。
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"""
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pass
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def throw_exception(message: str, exception_class: type[Exception] = FormatException) -> NoReturn:
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"""
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抛出指定的消息格式异常，不返回结果。
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:param message: 异常携带的错误说明
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:param exception_class: 要构造并抛出的异常类型，默认为 FormatException
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"""
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raise exception_class(message)
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class SHA1:
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"""
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计算企业微信的消息签名接口
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"""
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@staticmethod
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def getSHA1(token: Optional[str], timestamp: str | int | None, nonce: Optional[str], encrypt: Optional[str]) -> tuple[int, Optional[str]]:
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"""
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按企业微信协议排序四个字段并计算 SHA1 签名。
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:param token: 企业微信回调配置的令牌
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:param timestamp: 回调时间戳；参与字符串排序时应传入文本
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:param nonce: 回调随机串
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:param encrypt: Base64 密文文本
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:return: 错误码与十六进制签名；计算失败时签名为 None
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"""
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try:
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sortlist = [token, timestamp, nonce, encrypt]
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sortlist.sort()
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sha = hashlib.sha1()
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# 其余三项只能为 str 或 None；排序成功已排除 None 和整数时间戳。
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sha.update("".join(cast(list[str], sortlist)).encode())
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return WXBizMsgCrypt_OK, sha.hexdigest()
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except Exception as e:
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logger = logging.getLogger()
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logger.error(e)
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return WXBizMsgCrypt_ComputeSignature_Error, None
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class XMLParse:
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"""
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提供提取消息格式中的密文及生成回复消息格式的接口
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"""
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# xml消息模板
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AES_TEXT_RESPONSE_TEMPLATE = """<xml>
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<Encrypt><![CDATA[%(msg_encrypt)s]]></Encrypt>
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<MsgSignature><![CDATA[%(msg_signaturet)s]]></MsgSignature>
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<TimeStamp>%(timestamp)s</TimeStamp>
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<Nonce><![CDATA[%(nonce)s]]></Nonce>
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</xml>"""
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@staticmethod
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def extract(xmltext: str | bytes) -> tuple[int, Optional[str]]:
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"""
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读取 XML 数据包中的 Encrypt 字段。
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:param xmltext: 企业微信回调的 XML 文本或字节
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:return: 错误码与密文文本；解析失败时密文为 None
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"""
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try:
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xml_tree = ET.fromstring(xmltext)
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encrypt = xml_tree.find("Encrypt")
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if encrypt is None:
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raise AttributeError("'NoneType' object has no attribute 'text'")
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return WXBizMsgCrypt_OK, encrypt.text
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except Exception as e:
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logger = logging.getLogger()
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logger.error(e)
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return WXBizMsgCrypt_ParseXml_Error, None
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def generate(self, encrypt: str, signature: Optional[str], timestamp: str, nonce: str) -> str:
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"""
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组装企业微信要求的加密回复 XML。
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:param encrypt: Base64 编码后的消息密文
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:param signature: 计算得到的安全签名
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:param timestamp: 秒级时间戳文本
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:param nonce: 回复随机串
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:return: 包含密文、签名、时间戳和随机串的 XML 文本
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"""
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resp_dict = {
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'msg_encrypt': encrypt,
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'msg_signaturet': signature,
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'timestamp': timestamp,
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'nonce': nonce,
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}
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resp_xml = self.AES_TEXT_RESPONSE_TEMPLATE % resp_dict
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return resp_xml
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class PKCS7Encoder:
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"""
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按企业微信约定的 32 字节分组长度填充和移除 PKCS7 补位。
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"""
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# 企业微信协议使用 32 字节补位分组，与 AES 的 16 字节分组不同。
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block_size = 32
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def encode(self, text: bytes) -> bytes:
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"""
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为明文字节追加 PKCS7 补位，已对齐时仍追加完整分组。
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:param text: 要填充的明文字节
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:return: 长度为 32 字节整数倍的填充结果
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"""
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text_length = len(text)
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# 计算需要填充的位数
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amount_to_pad = self.block_size - (text_length % self.block_size)
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if amount_to_pad == 0:
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amount_to_pad = self.block_size
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# 获得补位所用的字符
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pad = chr(amount_to_pad)
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return text + (pad * amount_to_pad).encode()
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@staticmethod
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def decode(decrypted: str) -> str:
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"""
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按末尾字符值移除补位，保留原示例的切片行为。
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:param decrypted: 含末尾补位字符的解密文本
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:return: 去掉补位后的文本；补位值不在 1 至 32 时返回空字符串
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"""
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pad = ord(decrypted[-1])
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if pad < 1 or pad > 32:
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pad = 0
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return decrypted[:-pad]
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class Prpcrypt(object):
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"""
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提供接收和推送给企业微信消息的加解密接口
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"""
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def __init__(self, key: bytes) -> None:
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"""
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保存已解码的 AES 密钥与 CBC 模式。
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:param key: 企业微信提供的 32 字节 AES 密钥，前 16 字节同时用作初始向量
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"""
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self.key = key
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# 设置加解密模式为AES的CBC模式
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self.mode = AES.MODE_CBC
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def encrypt(self, text: str, receiveid: Optional[str]) -> tuple[int, Optional[bytes]]:
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"""
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按随机前缀、消息长度、正文和接收方标识组装明文，再进行 AES-CBC 加密。
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:param text: 待加密的回复正文
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:param receiveid: 企业微信接收方标识，本实现不接受 None
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:return: 错误码与 Base64 密文字节；加密调用失败时密文为 None
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"""
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# 16位随机字符串添加到明文开头
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plaintext = text.encode()
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plaintext = self.get_random_str() + struct.pack("I", socket.htonl(len(plaintext))) + plaintext
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if receiveid is None:
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raise AttributeError("'NoneType' object has no attribute 'encode'")
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plaintext += receiveid.encode()
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# 使用自定义的填充方式对明文进行补位填充
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pkcs7 = PKCS7Encoder()
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plaintext = pkcs7.encode(plaintext)
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# 加密
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cryptor = AES.new(self.key, self.mode, self.key[:16])
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try:
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ciphertext = cryptor.encrypt(plaintext)
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# 使用BASE64对加密后的字符串进行编码
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return WXBizMsgCrypt_OK, base64.b64encode(ciphertext)
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except Exception as e:
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logger = logging.getLogger()
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logger.error(e)
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return WXBizMsgCrypt_EncryptAES_Error, None
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def decrypt(self, text: str | bytes, receiveid: Optional[str]) -> tuple[int, Optional[bytes]]:
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"""
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解密企业微信密文，提取正文并核对接收方。
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:param text: Base64 编码的密文
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:param receiveid: 预期的企业微信接收方标识
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:return: 错误码与正文字节；解密、内容拆分或接收方校验失败时正文为 None
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"""
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try:
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cryptor = AES.new(self.key, self.mode, self.key[:16])
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# 使用BASE64对密文进行解码，然后AES-CBC解密
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plain_text: bytes = cryptor.decrypt(base64.b64decode(text))
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except Exception as e:
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logger = logging.getLogger()
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logger.error(e)
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return WXBizMsgCrypt_DecryptAES_Error, None
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try:
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pad = plain_text[-1]
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# 去掉补位字符串
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# 去除16位随机字符串
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content = plain_text[16:-pad]
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xml_len = socket.ntohl(struct.unpack("I", content[: 4])[0])
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xml_content = content[4: xml_len + 4]
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from_receiveid = content[xml_len + 4:]
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except Exception as e:
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logger = logging.getLogger()
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logger.error(e)
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return WXBizMsgCrypt_IllegalBuffer, None
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if from_receiveid.decode('utf8') != receiveid:
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return WXBizMsgCrypt_ValidateCorpid_Error, None
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return 0, xml_content
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@staticmethod
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def get_random_str() -> bytes:
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"""
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生成加密明文前缀使用的 16 位十进制随机数字。
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:return: 16 个数字字符组成的字节串
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"""
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return str(random.randint(1000000000000000, 9999999999999999)).encode()
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class WXBizMsgCrypt(object):
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"""
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验证企业微信回调并封装加解密错误码。
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"""
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def __init__(self, sToken: Optional[str], sEncodingAESKey: Optional[str], sReceiveId: Optional[str]) -> None:
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"""
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解码并验证企业微信配置的 AES 密钥。
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:param sToken: 回调签名使用的令牌
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:param sEncodingAESKey: 去掉末尾填充符的 Base64 密钥文本
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:param sReceiveId: 企业微信接收方标识
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:raises FormatException: 密钥缺失、无法解码或解码结果不是 32 字节
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"""
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try:
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if sEncodingAESKey is None:
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raise TypeError("unsupported operand type(s) for +: 'NoneType' and 'str'")
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self.key = base64.b64decode(sEncodingAESKey + "=")
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assert len(self.key) == 32
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except Exception as err:
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print(str(err))
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throw_exception("[error]: EncodingAESKey unvalid !", FormatException)
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self.m_sToken = sToken
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self.m_sReceiveId = sReceiveId
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def VerifyURL(self, sMsgSignature: str, sTimeStamp: str | int, sNonce: str, sEchoStr: str) -> tuple[int, Optional[bytes]]:
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"""
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核对 URL 验证请求的签名，再解密返回验证内容。
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:param sMsgSignature: URL 查询参数 msg_signature
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:param sTimeStamp: URL 查询参数 timestamp，应传入文本以便参与签名排序
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:param sNonce: URL 查询参数 nonce
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:param sEchoStr: URL 查询参数 echostr 的密文
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:return: 错误码与解密后的验证字节；校验失败时内容为 None
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"""
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sha1 = SHA1()
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ret, signature = sha1.getSHA1(self.m_sToken, sTimeStamp, sNonce, sEchoStr)
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if ret != 0:
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return ret, None
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if not signature == sMsgSignature:
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return WXBizMsgCrypt_ValidateSignature_Error, None
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pc = Prpcrypt(self.key)
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ret, sReplyEchoStr = pc.decrypt(sEchoStr, self.m_sReceiveId)
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return ret, sReplyEchoStr
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def EncryptMsg(self, sReplyMsg: str, sNonce: str, timestamp: Optional[str] = None) -> tuple[int, Optional[str]]:
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"""
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加密回复正文并生成带签名的 XML 数据包。
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:param sReplyMsg: 待回复的 XML 消息文本
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:param sNonce: 回复随机串，可沿用请求的 nonce
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:param timestamp: 秒级时间戳文本；None 使用当前时间
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:return: 错误码与完整加密回复 XML；加密或签名失败时 XML 为 None
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"""
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pc = Prpcrypt(self.key)
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ret, encrypted = pc.encrypt(sReplyMsg, self.m_sReceiveId)
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if ret != 0:
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return ret, None
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# encrypt 的成功分支只返回 base64 bytes，失败时不可对 None 解码。
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encrypt = cast(bytes, encrypted).decode('utf8')
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if timestamp is None:
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timestamp = str(int(time.time()))
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# 生成安全签名
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sha1 = SHA1()
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ret, signature = sha1.getSHA1(self.m_sToken, timestamp, sNonce, encrypt)
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if ret != 0:
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return ret, None
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xmlParse = XMLParse()
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return ret, xmlParse.generate(encrypt, signature, timestamp, sNonce)
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def DecryptMsg(self, sPostData: str | bytes, sMsgSignature: str, sTimeStamp: str, sNonce: str) -> tuple[int, Optional[bytes]]:
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"""
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验证 XML 与消息签名，再解密正文并检查接收方。
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:param sPostData: POST 请求携带的加密 XML 数据
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:param sMsgSignature: URL 查询参数 msg_signature
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:param sTimeStamp: URL 查询参数 timestamp 文本
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:param sNonce: URL 查询参数 nonce
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:return: 错误码与原始正文字节；解析、签名或解密失败时正文为 None
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"""
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# 验证安全签名
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xmlParse = XMLParse()
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ret, encrypt = xmlParse.extract(sPostData)
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if ret != 0:
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return ret, None
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sha1 = SHA1()
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ret, signature = sha1.getSHA1(self.m_sToken, sTimeStamp, sNonce, encrypt)
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if ret != 0:
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return ret, None
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if not signature == sMsgSignature:
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return WXBizMsgCrypt_ValidateSignature_Error, None
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pc = Prpcrypt(self.key)
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# SHA1 成功已证明密文为字符串；空字段会在签名计算阶段返回错误。
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ret, xml_content = pc.decrypt(cast(str, encrypt), self.m_sReceiveId)
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return ret, xml_content
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