.NET企业微信回调配置（数据回调URL和指令回调URL验证）

前言：

　　前段时间因为公司业务需求，需要将微信小程序与企业微信对接通，也就是把小程序绑定到对应的企业微信账号下，在该企业微信的用户可以将该小程序绑定到工作台中，然后可以在工作台中打开该小程序并授权。不过将微信小程序与企业微信对接通需要后台去做数据回调URL和指令回调URL验证，因为第一次接触这个然后企业微信文档写的也不是很详细，并且在全网没有找到一篇.NET相关企业微信回调配置验证有用的文章，所以这里把自己的配置详细过程分享出来，希望能够帮助更多的同学。

企业微信回调配置相关文档

回调配置：

主要讲的是回调配置的一些验证流程和请求接口。

https://work.weixin.qq.com/api/doc/90000/90135/90930

C#解密类库：

https://open.work.weixin.qq.com/wwopen/downloadfile/csharp.zip

.NET6完整示例代码

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企业微信回调配置验证完整流程

注意：配置回调服务时，需要能同时支持HttpGet以及HttpPost两种能力，注意接口一定要是https的安全域名地址。

• HttpGet接口用于验证数据回调URL有效性
• HttpPost接口用于验证指令回调URL有效性

所以我们可以只定义一个接口，通过企业微信请求过来的类型进行不同回调URL的有效性验证。

处理企业号的信息接口：

public class EnterpriseWechatCallbackController : Controller
{

    //企业微信后台开发者设置的token, corpID, EncodingAESKey
    private readonly string sToken = "追逐时光者";//企业微信后台，开发者设置的Token
    private readonly string sCorpID = "追逐时光者";//企业号corpid是企业号的专属编号（CorpID）[不同场景含义不同，详见文档说明（ToUserName：企业微信的CorpID，当为第三方应用回调事件时，CorpID的内容为suiteid）]
    private readonly string sEncodingAESKey = "追逐时光者";//企业微信后台，开发者设置的EncodingAESKey


    /// <summary>
    /// 处理企业号的信息
    /// get:数据回调URL验证;
    /// post:指令回调URL验证;
    /// </summary>
    public ActionResult EtWechatCommunication()
    {
        string httpMethod = Request.HttpMethod.ToUpper();

        if (httpMethod == "POST")
        {
            //获取请求中的xml数据
            string postString = GetXMLParameters(Request);

            string responseContent = "响应失败，未获取到xml中的请求参数";
            if (!string.IsNullOrEmpty(postString))
            {
                //指令响应回调
                responseContent = CommandCallback(Request, postString);
            }

            return Content(responseContent);
        }
        else
        {
            return EtWachatCheckVerifyURL();
        }
    }


    /// <summary>
    /// 数据回调URL验证
    /// </summary>
    /// <returns></returns>
    public ActionResult EtWachatCheckVerifyURL()
    {
        string signature = Request.QueryString["msg_signature"];//微信加密签名，msg_signature结合了企业填写的token、请求中的timestamp、nonce参数、加密的消息体
        string timestamp = Request.QueryString["timestamp"];//时间戳
        string nonce = Request.QueryString["nonce"];//随机数
        string httpMethod = Request.HttpMethod.ToUpper();

        if (httpMethod == "GET")//验证回调URL(注意：企业回调的url-该url不做任何的业务逻辑，仅仅微信查看是否可以调通)
        {
            try
            {
                //在1秒内响应GET请求，响应内容为上一步得到的明文消息内容decryptEchoString（不能加引号，不能带bom头，不能带换行符）
                string echostr = Request.QueryString["echostr"];//加密的随机字符串，以msg_encrypt格式提供。需要解密并返回echostr明文，解密后有random、msg_len、msg、$CorpID四个字段，其中msg即为echostr明文

                if (!IsNullOrWhiteSpace(signature) && !IsNullOrWhiteSpace(timestamp) && !IsNullOrWhiteSpace(nonce) && !IsNullOrWhiteSpace(echostr))
                {
                    string decryptEchoString = null;
                    if (CheckVerifyURL(sToken, signature, timestamp, nonce, sCorpID, sEncodingAESKey, echostr, ref decryptEchoString))
                    {
                        if (!string.IsNullOrEmpty(decryptEchoString))
                        {
                            //必须要返回解密之后的明文
                            return Content(decryptEchoString);
                        }
                    }
                }
                else
                {
                    return Content("fail");
                }
            }
            catch (Exception ex)
            {
                return Content("fail");
            }
        }

        return Content("fail");
    }

    /// <summary>
    /// 验证URL有效性
    /// </summary>
    /// <param name="token">企业微信后台，开发者设置的Token</param>
    /// <param name="signature">签名串，对应URL参数的msg_signature</param>
    /// <param name="timestamp">时间戳</param>
    /// <param name="nonce">随机数</param>
    /// <param name="corpId">ToUserName为企业号的CorpID</param>
    /// <param name="encodingAESKey">企业微信后台，开发者设置的EncodingAESKey</param>
    /// <param name="echostr">随机串，对应URL参数的echostr</param>
    /// <param name="retEchostr">解密之后的echostr，当return返回0时有效</param>
    /// <returns></returns>
    private bool CheckVerifyURL(string token, string signature, string timestamp, string nonce, string corpId, string encodingAESKey, string echostr, ref string retEchostr)
    {
        WXBizMsgCrypt wxcpt = new WXBizMsgCrypt(token, encodingAESKey, corpId);

        int result = wxcpt.VerifyURL(signature, timestamp, nonce, echostr, ref retEchostr);

        if (result != 0)
        {
            return false;//FAIL
        }

        //result==0表示验证成功、retEchostr参数表示明文
        //用户需要将retEchostr作为get请求的返回参数、返回给企业微信号
        return true;
    }

    /// <summary>
    /// 指令响应回调
    /// </summary>
    /// <param name="Request"></param>
    /// <param name="postString">post请求的xml参数</param>
    /// <returns></returns>
    private string CommandCallback(HttpRequestBase Request, string postString)
    {
        string signature = Request.QueryString["msg_signature"];//微信加密签名，msg_signature结合了企业填写的token、请求中的timestamp、nonce参数、加密的消息体
        string timestamp = Request.QueryString["timestamp"];//时间戳
        string nonce = Request.QueryString["nonce"];//随机数                             
        var xmlDoc = XDocument.Parse(postString);//xml数据转化

        try
        {
            //https://work.weixin.qq.com/api/doc/90001/90143/90613
            //在发生授权、通讯录变更、ticket变化等事件时，企业微信服务器会向应用的“指令回调URL”推送相应的事件消息。
            //消息结构体将使用创建应用时的EncodingAESKey进行加密（特别注意, 在第三方回调事件中使用加解密算法，receiveid的内容为suiteid），请参考接收消息解析数据包。 本章节的回调事件，服务商在收到推送后都必须直接返回字符串 “success”，若返回值不是 “success”，企业微信会把返回内容当作错误信息。
            if (xmlDoc.Root.Element("Encrypt") != null)
            {
                //将post请求的数据进行xml解析，并将<Encrypt> 标签的内容进行解密，解密出来的明文即是用户回复消息的明文
                //接收并读取POST过来的XML文件流
                string decryptionParame = null;  // 解析之后的明文

                // 注意注意:sCorpID
                // @param sReceiveId: 不同场景含义不同，详见文档说明（[消息加密时为 CorpId]ToUserName：企业微信的CorpID，当为第三方应用回调事件时，CorpID的内容为suiteid）

                WXBizMsgCrypt crypt = new WXBizMsgCrypt(sToken, sEncodingAESKey, xmlDoc.Root.Element("ToUserName").Value);
                var result = crypt.DecryptMsg(signature, timestamp, nonce, postString, ref decryptionParame);

                if (result != 0)
                {
                    return "fial";
                }

                //响应应答处理
                return new InstructionCallbackResponse().ReceiveResponse(decryptionParame, timestamp, signature,sToken, sEncodingAESKey, sCorpID);
            }
        }
        catch (Exception ex)
        {
            //LoggerHelper._.Debug("异常：" + ex.Message);
        }

        return "fail";
    }


    /// <summary>
    /// 验证是否为空
    /// </summary>
    /// <param name="strParame">验证参数</param>
    /// <returns></returns>
    private bool IsNullOrWhiteSpace(string strParame)
    {
        if (string.IsNullOrWhiteSpace(strParame))
        {
            return true;
        }
        else
        {
            return false;
        }
    }

    /// <summary>
    /// 获取post请求中的xml参数
    /// </summary>
    /// <returns></returns>
    private string GetXMLParameters(HttpRequestBase Request)
    {
        string replyMsg;
        using (Stream stream = Request.InputStream)
        {
            Byte[] postBytes = new Byte[stream.Length];
            stream.Read(postBytes, 0, (Int32)stream.Length);
            replyMsg = Encoding.UTF8.GetString(postBytes);
        }
        return replyMsg;
    }

}

指令回调响应应答处理：

    /// <summary>
    /// 指令回调响应应答处理
    /// </summary>
    public class InstructionCallbackResponse
    {
        /// <summary>
        /// 响应应答处理
        /// </summary>
        /// <param name="sMsg">解密参数</param>
        /// <param name="timestamp">时间戳</param>
        /// <param name="signature">签名</param>
        /// <param name="sToken">企业微信后台，开发者设置的Token</param>
        /// <param name="sEncodingAESKey">开发者设置的EncodingAESKey</param>
        /// <param name="sCorpID">业号corpid是企业号的专属编号（CorpID）</param>
        /// <returns></returns>
        public string ReceiveResponse(string sMsg, string timestamp, string signature, string sToken, string sEncodingAESKey, string sCorpID)
        {
            string responseMessage = "success";//响应内容   
            var xmlDoc = XDocument.Parse(sMsg);//xml数据转化

            //区分普通消息与第三方应用授权推送消息，MsgType有值说明是普通消息，反之则是第三方应用授权推送消息
            if (xmlDoc.Root.Element("MsgType") != null)
            {
                var msgType = (ResponseMsgType)Enum.Parse(typeof(ResponseMsgType), xmlDoc.Root.Element("MsgType").Value, true);
                switch (msgType)
                {
                    case ResponseMsgType.Text://文本消息
                        responseMessage = ResponseMessageText(xmlDoc, timestamp, signature,sToken,sEncodingAESKey,sCorpID);
                        break;
                    case ResponseMsgType.Image:
                        responseMessage = ResponseMessageImage();
                        break;
                    case ResponseMsgType.Voice:
                        responseMessage = ResponseMessageVoice();
                        break;
                    case ResponseMsgType.Video:
                        responseMessage = ResponseMessageVideo();
                        break;
                    case ResponseMsgType.News:
                        responseMessage = ResponseMessageNews();
                        break;
                }
            }
            else if (xmlDoc.Root.Element("InfoType") != null)
            {
                //第三方回调
                var infoType = (ResponseInfoType)Enum.Parse(typeof(ResponseInfoType), xmlDoc.Root.Element("InfoType").Value, true);

                switch (infoType)
                {
                    case ResponseInfoType.suite_ticket:
                        {
                            //LoggerHelper._.Warn("suite_ticket===>>>>>,进来了，获取到的SuiteTicket票据为" + xmlDoc.Root.Element("SuiteTicket").Value);
                        }
                        break;
                }
            }
            else
            {
                //其他情况
            }

            // result==0表示解密成功，sMsg表示解密之后的明文xml串
            //服务器未正确返回响应字符串 “success”
            return responseMessage;
        }


        #region 相关事件实现

        /// <summary>
        /// 消息文本回复
        /// </summary>
        /// <returns></returns>
        public string ResponseMessageText(XDocument xmlDoc, string timestamp, string nonce,string sToken,string sEncodingAESKey,string sCorpID)
        {
            string FromUserName = xmlDoc.Root.Element("FromUserName").Value;
            string ToUserName = xmlDoc.Root.Element("ToUserName").Value;
            string Content = xmlDoc.Root.Element("Content").Value;

            string xml = "<xml>";
            xml += "<ToUserName><![CDATA[" + ToUserName + "]]></ToUserName>";
            xml += "<FromUserName><![CDATA[" + FromUserName + "]]></FromUserName>";
            xml += "<CreateTime>" + GetCurrentTimeUnix() + "</CreateTime>";
            xml += "<MsgType><![CDATA[text]]></MsgType>";
            xml += "<Content><![CDATA[" + Content + "]]></Content>";
            xml += "</xml>";
            //"" + Content + "0";//回复内容 FuncFlag设置为1的时候，自动星标刚才接收到的消息，适合活动统计使用
            WXBizMsgCrypt wxcpt = new WXBizMsgCrypt(sToken, sEncodingAESKey, sCorpID);
            string sEncryptMsg = "";// 加密后的可以直接回复用户的密文;
            wxcpt.EncryptMsg(xml, timestamp, nonce, ref sEncryptMsg);

            //返回
            return sEncryptMsg;
        }

        /// <summary>
        /// 图片消息
        /// </summary>
        /// <returns></returns>

        public string ResponseMessageImage()
        {
            return "success";
        }

        /// <summary>
        /// 语音消息
        /// </summary>
        /// <returns></returns>
        public string ResponseMessageVoice()
        {
            return "success";
        }

        /// <summary>
        /// 视频消息
        /// </summary>
        /// <returns></returns>
        public string ResponseMessageVideo()
        {
            return "success";
        }

        /// <summary>
        /// 图文消息
        /// </summary>
        /// <returns></returns>
        public string ResponseMessageNews()
        {
            return "success";
        }

        #endregion

        /// <summary>
        /// 获取当前时间戳
        /// </summary>
        /// <returns></returns>
        public static string GetCurrentTimeUnix()
        {
            TimeSpan cha = (DateTime.Now - TimeZone.CurrentTimeZone.ToLocalTime(new System.DateTime(1970, 1, 1)));
            long t = (long)cha.TotalSeconds;
            return t.ToString();
        }
    }

消息类型枚举（enumType）：

第三方应用授权推送消息类型（ResponseInfoType）

/// <summary>
    /// 第三方应用授权推送消息类型
    /// </summary>
    public enum ResponseInfoType
    {
        /// <summary>
        /// 推送suite_ticket 企业微信服务器会定时（每十分钟）推送ticket。ticket会实时变更，并用于后续接口的调用。
        /// </summary>
        suite_ticket =1,

        /// <summary>
        /// 授权成功通知
        /// </summary>
        create_auth = 2,

        /// <summary>
        /// 成员通知事件
        /// </summary>
        change_contact = 3
    }

普通消息响应类型（ResponseMsgType）

/// <summary>
    /// 普通消息响应类型
    /// </summary>
    public enum ResponseMsgType
    {
        /// <summary>
        /// 文本消息
        /// </summary>
        Text = 0,
        /// <summary>
        /// 图文消息
        /// </summary>
        News = 1,
        /// <summary>
        /// 图片消息
        /// </summary>
        Image = 3,
        /// <summary>
        /// 语音消息
        /// </summary>
        Voice = 4,
        /// <summary>
        /// 视频消息
        /// </summary>
        Video = 5
    }

C#解密类库

WXBizMsgCrypt

 public class WXBizMsgCrypt
    {
        string m_sToken;
        string m_sEncodingAESKey;
        string m_sReceiveId;

        //-40001 ： 签名验证错误
        //-40002 :  xml解析失败
        //-40003 :  sha加密生成签名失败
        //-40004 :  AESKey 非法
        //-40005 :  corpid 校验错误
        //-40006 :  AES 加密失败
        //-40007 ： AES 解密失败
        //-40008 ： 解密后得到的buffer非法
        //-40009 :  base64加密异常
        //-40010 :  base64解密异常

        enum WXBizMsgCryptErrorCode
        {
            WXBizMsgCrypt_OK = 0,
            WXBizMsgCrypt_ValidateSignature_Error = -40001,
            WXBizMsgCrypt_ParseXml_Error = -40002,
            WXBizMsgCrypt_ComputeSignature_Error = -40003,
            WXBizMsgCrypt_IllegalAesKey = -40004,
            WXBizMsgCrypt_ValidateCorpid_Error = -40005,
            WXBizMsgCrypt_EncryptAES_Error = -40006,
            WXBizMsgCrypt_DecryptAES_Error = -40007,
            WXBizMsgCrypt_IllegalBuffer = -40008,
            WXBizMsgCrypt_EncodeBase64_Error = -40009,
            WXBizMsgCrypt_DecodeBase64_Error = -40010
        };

        //构造函数
        // @param sToken: 企业微信后台，开发者设置的Token
        // @param sEncodingAESKey: 企业微信后台，开发者设置的EncodingAESKey
        // @param sReceiveId: 不同场景含义不同，详见文档说明（[消息加密时为 CorpId]ToUserName：企业微信的CorpID，当为第三方应用回调事件时，CorpID的内容为suiteid）
        public WXBizMsgCrypt(string sToken, string sEncodingAESKey, string sReceiveId)
        {
            m_sToken = sToken;
            m_sReceiveId = sReceiveId;
            m_sEncodingAESKey = sEncodingAESKey;
        }

        //验证URL
        // @param sMsgSignature: 签名串，对应URL参数的msg_signature
        // @param sTimeStamp: 时间戳，对应URL参数的timestamp
        // @param sNonce: 随机串，对应URL参数的nonce
        // @param sEchoStr: 随机串，对应URL参数的echostr
        // @param sReplyEchoStr: 解密之后的echostr，当return返回0时有效
        // @return：成功0，失败返回对应的错误码
        public int VerifyURL(string sMsgSignature, string sTimeStamp, string sNonce, string sEchoStr, ref string sReplyEchoStr)
        {
            int ret = 0;
            if (m_sEncodingAESKey.Length != 43)
            {
                return (int)WXBizMsgCryptErrorCode.WXBizMsgCrypt_IllegalAesKey;
            }
            ret = VerifySignature(m_sToken, sTimeStamp, sNonce, sEchoStr, sMsgSignature);
            if (0 != ret)
            {
                return ret;
            }
            sReplyEchoStr = "";
            string cpid = "";
            try
            {
                sReplyEchoStr = Cryptography.AES_decrypt(sEchoStr, m_sEncodingAESKey, ref cpid); //m_sReceiveId);
            }
            catch (Exception)
            {
                sReplyEchoStr = "";
                return (int)WXBizMsgCryptErrorCode.WXBizMsgCrypt_DecryptAES_Error;
            }
            if (cpid != m_sReceiveId)
            {
                sReplyEchoStr = "";
                return (int)WXBizMsgCryptErrorCode.WXBizMsgCrypt_ValidateCorpid_Error;
            }
            return 0;
        }

        // 检验消息的真实性，并且获取解密后的明文
        // @param sMsgSignature: 签名串，对应URL参数的msg_signature
        // @param sTimeStamp: 时间戳，对应URL参数的timestamp
        // @param sNonce: 随机串，对应URL参数的nonce
        // @param sPostData: 密文，对应POST请求的数据
        // @param sMsg: 解密后的原文，当return返回0时有效
        // @return: 成功0，失败返回对应的错误码
        public int DecryptMsg(string sMsgSignature, string sTimeStamp, string sNonce, string sPostData, ref string sMsg)
        {
            if (m_sEncodingAESKey.Length != 43)
            {
                return (int)WXBizMsgCryptErrorCode.WXBizMsgCrypt_IllegalAesKey;
            }
            XmlDocument doc = new XmlDocument();
            XmlNode root;
            string sEncryptMsg;
            try
            {
                doc.LoadXml(sPostData);
                root = doc.FirstChild;
                sEncryptMsg = root["Encrypt"].InnerText;

                LoggerHelper._.Info("进来解密了，解密密文sEncryptMsg为：" + sEncryptMsg);
            }
            catch (Exception)
            {
                return (int)WXBizMsgCryptErrorCode.WXBizMsgCrypt_ParseXml_Error;
            }
            //verify signature
            int ret = 0;
            ret = VerifySignature(m_sToken, sTimeStamp, sNonce, sEncryptMsg, sMsgSignature);

            LoggerHelper._.Info("进来解密了，解密结果：" + ret);

            if (ret != 0)
                return ret;
            //decrypt
            string cpid = "";
            try
            {
                sMsg = Cryptography.AES_decrypt(sEncryptMsg, m_sEncodingAESKey, ref cpid);
            }
            catch (FormatException)
            {
                sMsg = "";
                return (int)WXBizMsgCryptErrorCode.WXBizMsgCrypt_DecodeBase64_Error;
            }
            catch (Exception)
            {
                sMsg = "";
                return (int)WXBizMsgCryptErrorCode.WXBizMsgCrypt_DecryptAES_Error;
            }
            if (cpid != m_sReceiveId)
                return (int)WXBizMsgCryptErrorCode.WXBizMsgCrypt_ValidateCorpid_Error;
            return 0;
        }

        //将企业号回复用户的消息加密打包
        // @param sReplyMsg: 企业号待回复用户的消息，xml格式的字符串
        // @param sTimeStamp: 时间戳，可以自己生成，也可以用URL参数的timestamp
        // @param sNonce: 随机串，可以自己生成，也可以用URL参数的nonce
        // @param sEncryptMsg: 加密后的可以直接回复用户的密文，包括msg_signature, timestamp, nonce, encrypt的xml格式的字符串,当return返回0时有效
        // return：成功0，失败返回对应的错误码
        public int EncryptMsg(string sReplyMsg, string sTimeStamp, string sNonce, ref string sEncryptMsg)
        {
            if (m_sEncodingAESKey.Length != 43)
            {
                return (int)WXBizMsgCryptErrorCode.WXBizMsgCrypt_IllegalAesKey;
            }
            string raw = "";
            try
            {
                raw = Cryptography.AES_encrypt(sReplyMsg, m_sEncodingAESKey, m_sReceiveId);
            }
            catch (Exception)
            {
                return (int)WXBizMsgCryptErrorCode.WXBizMsgCrypt_EncryptAES_Error;
            }
            string MsgSigature = "";
            int ret = 0;
            ret = GenarateSinature(m_sToken, sTimeStamp, sNonce, raw, ref MsgSigature);
            if (0 != ret)
                return ret;
            sEncryptMsg = "";

            string EncryptLabelHead = "<Encrypt><![CDATA[";
            string EncryptLabelTail = "]]></Encrypt>";
            string MsgSigLabelHead = "<MsgSignature><![CDATA[";
            string MsgSigLabelTail = "]]></MsgSignature>";
            string TimeStampLabelHead = "<TimeStamp><![CDATA[";
            string TimeStampLabelTail = "]]></TimeStamp>";
            string NonceLabelHead = "<Nonce><![CDATA[";
            string NonceLabelTail = "]]></Nonce>";
            sEncryptMsg = sEncryptMsg + "<xml>" + EncryptLabelHead + raw + EncryptLabelTail;
            sEncryptMsg = sEncryptMsg + MsgSigLabelHead + MsgSigature + MsgSigLabelTail;
            sEncryptMsg = sEncryptMsg + TimeStampLabelHead + sTimeStamp + TimeStampLabelTail;
            sEncryptMsg = sEncryptMsg + NonceLabelHead + sNonce + NonceLabelTail;
            sEncryptMsg += "</xml>";
            return 0;
        }

        public class DictionarySort : System.Collections.IComparer
        {
            public int Compare(object oLeft, object oRight)
            {
                string sLeft = oLeft as string;
                string sRight = oRight as string;
                int iLeftLength = sLeft.Length;
                int iRightLength = sRight.Length;
                int index = 0;
                while (index < iLeftLength && index < iRightLength)
                {
                    if (sLeft[index] < sRight[index])
                        return -1;
                    else if (sLeft[index] > sRight[index])
                        return 1;
                    else
                        index++;
                }
                return iLeftLength - iRightLength;

            }
        }
        //Verify Signature
        private static int VerifySignature(string sToken, string sTimeStamp, string sNonce, string sMsgEncrypt, string sSigture)
        {
            string hash = "";
            int ret = 0;
            ret = GenarateSinature(sToken, sTimeStamp, sNonce, sMsgEncrypt, ref hash);
            if (ret != 0)
                return ret;
            if (hash == sSigture)
                return 0;
            else
            {
                return (int)WXBizMsgCryptErrorCode.WXBizMsgCrypt_ValidateSignature_Error;
            }
        }

        public static int GenarateSinature(string sToken, string sTimeStamp, string sNonce, string sMsgEncrypt, ref string sMsgSignature)
        {
            //校验规则：https://work.weixin.qq.com/api/doc#90000/90139/90968/%E6%B6%88%E6%81%AF%E4%BD%93%E7%AD%BE%E5%90%8D%E6%A0%A1%E9%AA%8C

            ArrayList AL = new ArrayList();
            AL.Add(sToken);
            AL.Add(sTimeStamp);
            AL.Add(sNonce);
            AL.Add(sMsgEncrypt);
            AL.Sort(new DictionarySort());
            string raw = "";
            for (int i = 0; i < AL.Count; ++i)
            {
                raw += AL[i];
            }

            SHA1 sha;
            ASCIIEncoding enc;
            string hash = "";
            try
            {
                sha = new SHA1CryptoServiceProvider();
                enc = new ASCIIEncoding();
                byte[] dataToHash = enc.GetBytes(raw);
                byte[] dataHashed = sha.ComputeHash(dataToHash);
                hash = BitConverter.ToString(dataHashed).Replace("-", "");
                hash = hash.ToLower();
            }
            catch (Exception)
            {
                return (int)WXBizMsgCryptErrorCode.WXBizMsgCrypt_ComputeSignature_Error;
            }
            sMsgSignature = hash;
            return 0;
        }

    }

Cryptography

    public class Cryptography
    {
        public static UInt32 HostToNetworkOrder(UInt32 inval)
        {
            UInt32 outval = 0;
            for (int i = 0; i < 4; i++)
                outval = (outval << 8) + ((inval >> (i * 8)) & 255);
            return outval;
        }

        public static Int32 HostToNetworkOrder(Int32 inval)
        {
            Int32 outval = 0;
            for (int i = 0; i < 4; i++)
                outval = (outval << 8) + ((inval >> (i * 8)) & 255);
            return outval;
        }
        /// <summary>
        /// 解密方法
        /// </summary>
        /// <param name="Input">密文</param>
        /// <param name="EncodingAESKey"></param>
        /// <returns></returns>
        /// 
        public static string AES_decrypt(String Input, string EncodingAESKey, ref string corpid)
        {
            byte[] Key;
            Key = Convert.FromBase64String(EncodingAESKey + "=");
            byte[] Iv = new byte[16];
            Array.Copy(Key, Iv, 16);
            byte[] btmpMsg = AES_decrypt(Input, Iv, Key);

            int len = BitConverter.ToInt32(btmpMsg, 16);
            len = IPAddress.NetworkToHostOrder(len);


            byte[] bMsg = new byte[len];
            byte[] bCorpid = new byte[btmpMsg.Length - 20 - len];
            Array.Copy(btmpMsg, 20, bMsg, 0, len);
            Array.Copy(btmpMsg, 20 + len, bCorpid, 0, btmpMsg.Length - 20 - len);
            string oriMsg = Encoding.UTF8.GetString(bMsg);
            corpid = Encoding.UTF8.GetString(bCorpid);


            return oriMsg;
        }

        public static String AES_encrypt(String Input, string EncodingAESKey, string corpid)
        {
            byte[] Key;
            Key = Convert.FromBase64String(EncodingAESKey + "=");
            byte[] Iv = new byte[16];
            Array.Copy(Key, Iv, 16);
            string Randcode = CreateRandCode(16);
            byte[] bRand = Encoding.UTF8.GetBytes(Randcode);
            byte[] bCorpid = Encoding.UTF8.GetBytes(corpid);
            byte[] btmpMsg = Encoding.UTF8.GetBytes(Input);
            byte[] bMsgLen = BitConverter.GetBytes(HostToNetworkOrder(btmpMsg.Length));
            byte[] bMsg = new byte[bRand.Length + bMsgLen.Length + bCorpid.Length + btmpMsg.Length];

            Array.Copy(bRand, bMsg, bRand.Length);
            Array.Copy(bMsgLen, 0, bMsg, bRand.Length, bMsgLen.Length);
            Array.Copy(btmpMsg, 0, bMsg, bRand.Length + bMsgLen.Length, btmpMsg.Length);
            Array.Copy(bCorpid, 0, bMsg, bRand.Length + bMsgLen.Length + btmpMsg.Length, bCorpid.Length);

            return AES_encrypt(bMsg, Iv, Key);

        }
        private static string CreateRandCode(int codeLen)
        {
            string codeSerial = "2,3,4,5,6,7,a,c,d,e,f,h,i,j,k,m,n,p,r,s,t,A,C,D,E,F,G,H,J,K,M,N,P,Q,R,S,U,V,W,X,Y,Z";
            if (codeLen == 0)
            {
                codeLen = 16;
            }
            string[] arr = codeSerial.Split(',');
            string code = "";
            int randValue = -1;
            Random rand = new Random(unchecked((int)DateTime.Now.Ticks));
            for (int i = 0; i < codeLen; i++)
            {
                randValue = rand.Next(0, arr.Length - 1);
                code += arr[randValue];
            }
            return code;
        }

        private static String AES_encrypt(String Input, byte[] Iv, byte[] Key)
        {
            //var aes = new RijndaelManaged();
#if NET45
            var aes = new RijndaelManaged();
#else
            var aes = Aes.Create();
#endif
            //秘钥的大小，以位为单位
            aes.KeySize = 256;
            //支持的块大小
            aes.BlockSize = 128;
            //填充模式
            aes.Padding = PaddingMode.PKCS7;
            aes.Mode = CipherMode.CBC;
            aes.Key = Key;
            aes.IV = Iv;
            var encrypt = aes.CreateEncryptor(aes.Key, aes.IV);
            byte[] xBuff = null;

            using (var ms = new MemoryStream())
            {
                using (var cs = new CryptoStream(ms, encrypt, CryptoStreamMode.Write))
                {
                    byte[] xXml = Encoding.UTF8.GetBytes(Input);
                    cs.Write(xXml, 0, xXml.Length);
                }
                xBuff = ms.ToArray();
            }
            String Output = Convert.ToBase64String(xBuff);
            return Output;
        }

        private static String AES_encrypt(byte[] Input, byte[] Iv, byte[] Key)
        {
            //var aes = new RijndaelManaged();
#if NET45
            var aes = new RijndaelManaged();
#else
            var aes = Aes.Create();
#endif
            //秘钥的大小，以位为单位
            aes.KeySize = 256;
            //支持的块大小
            aes.BlockSize = 128;
            //填充模式
            //aes.Padding = PaddingMode.PKCS7;
            aes.Padding = PaddingMode.None;
            aes.Mode = CipherMode.CBC;
            aes.Key = Key;
            aes.IV = Iv;
            var encrypt = aes.CreateEncryptor(aes.Key, aes.IV);
            byte[] xBuff = null;

            #region 自己进行PKCS7补位，用系统自己带的不行
            byte[] msg = new byte[Input.Length + 32 - Input.Length % 32];
            Array.Copy(Input, msg, Input.Length);
            byte[] pad = KCS7Encoder(Input.Length);
            Array.Copy(pad, 0, msg, Input.Length, pad.Length);
            #endregion

            #region 注释的也是一种方法，效果一样
            //ICryptoTransform transform = aes.CreateEncryptor();
            //byte[] xBuff = transform.TransformFinalBlock(msg, 0, msg.Length);
            #endregion

            using (var ms = new MemoryStream())
            {
                using (var cs = new CryptoStream(ms, encrypt, CryptoStreamMode.Write))
                {
                    cs.Write(msg, 0, msg.Length);
                }
                xBuff = ms.ToArray();
            }

            String Output = Convert.ToBase64String(xBuff);
            return Output;
        }

        private static byte[] KCS7Encoder(int text_length)
        {
            int block_size = 32;
            // 计算需要填充的位数
            int amount_to_pad = block_size - (text_length % block_size);
            if (amount_to_pad == 0)
            {
                amount_to_pad = block_size;
            }
            // 获得补位所用的字符
            char pad_chr = chr(amount_to_pad);
            string tmp = "";
            for (int index = 0; index < amount_to_pad; index++)
            {
                tmp += pad_chr;
            }
            return Encoding.UTF8.GetBytes(tmp);
        }
        /**
         * 将数字转化成ASCII码对应的字符，用于对明文进行补码
         * 
         * @param a 需要转化的数字
         * @return 转化得到的字符
         */
        static char chr(int a)
        {

            byte target = (byte)(a & 0xFF);
            return (char)target;
        }
        private static byte[] AES_decrypt(String Input, byte[] Iv, byte[] Key)
        {
            //RijndaelManaged aes = new RijndaelManaged();
#if NET45
            var aes = new RijndaelManaged();
#else
            var aes = Aes.Create();
#endif
            aes.KeySize = 256;
            aes.BlockSize = 128;
            aes.Mode = CipherMode.CBC;
            aes.Padding = PaddingMode.None;
            aes.Key = Key;
            aes.IV = Iv;
            var decrypt = aes.CreateDecryptor(aes.Key, aes.IV);
            byte[] xBuff = null;
            using (var ms = new MemoryStream())
            {
                using (var cs = new CryptoStream(ms, decrypt, CryptoStreamMode.Write))
                {
                    byte[] xXml = Convert.FromBase64String(Input);
                    byte[] msg = new byte[xXml.Length + 32 - xXml.Length % 32];
                    Array.Copy(xXml, msg, xXml.Length);
                    cs.Write(xXml, 0, xXml.Length);
                }
                xBuff = decode2(ms.ToArray());
            }
            return xBuff;
        }
        private static byte[] decode2(byte[] decrypted)
        {
            int pad = (int)decrypted[decrypted.Length - 1];
            if (pad < 1 || pad > 32)
            {
                pad = 0;
            }
            byte[] res = new byte[decrypted.Length - pad];
            Array.Copy(decrypted, 0, res, 0, decrypted.Length - pad);
            return res;
        }
    }

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