生成的head：

Authorization:WECHATPAY2-SHA256-RSA2048 mchid="171***12",nonce_str="9d2640bee3dc439e877cbe0181e0b569",signature="jFKNe+YM/UmNkwRpXnodrJuqbHZl74DKPhUgkRuowSitPH6k91SVkWP4YeQ8PP9kfzgzLFlbOn8K0XQ2AQIqzsvGVDAvneTuqg/oAuXdUSFyvNLzRlyftoqILFx0lwSEhWWST62RUS7OK+y8CXdJ7OdnKsol66UgrvKEArZ+u9l/Nk7sz5ti1cmpMYiEHsr55Iri7yw3JnA8esy1CM2eHmG3XaYduVDHQMeHwALJb+gVyNK6ZjT/6dKgY08YYMnlooKbK22qfQ4w2pJw5aI+LfTkLDjyHUI7jxL2Z4HD/CuYgK/rWEE3s6hO3s4oW2k9np8cweSkdWqdH9P9Gq8SFg==",timestamp="1751437716",serial_no="5D1E3AA427034E38F36A7D75B81F4EDE420E65B9";Wechatpay-Serial:5D1E3AA***5B9;Accept:application/json;User-Agent:Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; .NET CLR 1.0.3705;);Content-Type:application/json;

调试过过程中，httpWebResponse = (HttpWebResponse)httpRequest.GetResponse();

返回 ：微信支付 商家转帐 请确认待处理的消息是否为加密后的密文

responseText = {"code":"PARAM_ERROR","message":"请确认待处理的消息是否为加密后的密文"}

请问哪里需要 加密。aasp.net4.5 使用什么方法 进行加密？

代码参考：https://developers.weixin.qq.com/community/develop/article/doc/00082cf0934a106b420a678d45b013

{

string requestBody ="

{\"appid\":\"wx48e923d9886gh\",\"out_bill_no\":\"preub15\",\"transfer_scene_id\":\"1000\",\"transfer_remark\":\"0\",\"openid\":\"oyQFh*******jBsdiwys6jt6tu4\",\"transfer_amount\":\"120\",\"total_num\":\"1\",\"user_name\":\"**堂\",\"user_recv_perception\":\"现金奖励\",\"transfer_scene_report_infos\":[{\"info_type\":\"佣金报酬\",\"info_content\":\"佣金提现报酬\"}]}";

string physicalApplicationPath =  HttpContext.Current.Request.PhysicalApplicationPath;

string pemPath = physicalApplicationPath + "config/apiclient_key.pem";

var pemContent = File.ReadAllText(pemPath)

                .Replace("-----BEGIN PRIVATE KEY-----", "")

                .Replace("-----END PRIVATE KEY-----", "")

.Replace("\n", "");

string method = "POST";

string timestamp = Convert.ToInt64((DateTime.UtcNow - new DateTime(1970, 1, 1, 0, 0, 0, 0)).TotalSeconds).ToString();

string nonce = Guid.NewGuid().ToString("N");

string url = "/v3/fund-app/mch-transfer/transfer-bills";

string message = $"{method}\n{url}\n{timestamp}\n{nonce}\n{requestBody}\n";

string signature = Sign( message,  pemContent);

             string CertSerialNo = "5D1E3AA**********81F0E65B9";

string token = $"WECHATPAY2-SHA256-RSA2048 " +

                           $"mchid=\"{this.mchid}\"," +

                           $"nonce_str=\"{nonce}\"," +

                           $"signature=\"{signature}\"," +

                           $"timestamp=\"{timestamp}\"," +

                           $"serial_no=\"{CertSerialNo}\"";

string Gateway = "https://api.mch.weixin.qq.com/v3/fund-app/mch-transfer/transfer-bills";

                // 3. 发送请求

                HttpWebRequest httpRequest = (HttpWebRequest)WebRequest.Create(Gateway);

httpRequest.Method = "POST";

httpRequest.Headers.Add("Authorization", token);

httpRequest.Headers.Add("Wechatpay-Serial", CertSerialNo);

httpRequest.Accept = "application/json";

httpRequest.UserAgent = "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; .NET CLR 1.0.3705;)";

httpRequest.ContentType = "application/json";

                HttpWebResponse httpWebResponse = null;

            // 写入请求体

Stream stream = null;

byte[] data = Encoding.UTF8.GetBytes(requestBody);

stream = httpRequest.GetRequestStream();

stream.Write(data, 0, data.Length);

stream.Close();

          // 4. 获取响应

httpWebResponse = (HttpWebResponse)httpRequest.GetResponse();

StreamReader streamReader = new StreamReader(httpWebResponse.GetResponseStream(), Encoding.UTF8);

                string text = streamReader.ReadToEnd().Trim();

streamReader.Close();

}

        protected string Sign(string message, string privateKey)

        {

            // SHA256withRSA

            //根据需要加签时的哈希算法转化成对应的hash字符节

            //byte[] bt = Encoding.GetEncoding("utf-8").GetBytes(str);

            byte[] bt =Encoding.UTF8.GetBytes(message);

            var sha256 = new SHA256CryptoServiceProvider();

            byte[] rgbHash = sha256.ComputeHash(bt);

            RSACryptoServiceProvider key = new RSACryptoServiceProvider();

            var _privateKey = RSAKeyConvert.RSAPrivateKeyJava2DotNet(privateKey);

            key.FromXmlString(_privateKey);

            RSAPKCS1SignatureFormatter formatter = new RSAPKCS1SignatureFormatter(key);

            formatter.SetHashAlgorithm("SHA256");//此处是你需要加签的hash算法，需要和上边你计算的hash值的算法一致，不然会报错。

            byte[] inArray = formatter.CreateSignature(rgbHash);

            return Convert.ToBase64String(inArray);

        }

protected string RSAPrivateKeyJava2DotNet(string privateKey)

{

RsaPrivateCrtKeyParameters privateKeyParam = (RsaPrivateCrtKeyParameters)PrivateKeyFactory.CreateKey(Convert.FromBase64String(privateKey));

return string.Format("<RSAKeyValue><Modulus>{0}</Modulus><Exponent>{1}</Exponent><P>{2}</P><Q>{3}</Q><DP>{4}</DP><DQ>{5}</DQ><InverseQ>{6}</InverseQ><D>{7}</D></RSAKeyValue>",

Convert.ToBase64String(privateKeyParam.Modulus.ToByteArrayUnsigned()),

Convert.ToBase64String(privateKeyParam.PublicExponent.ToByteArrayUnsigned()),

Convert.ToBase64String(privateKeyParam.P.ToByteArrayUnsigned()),

Convert.ToBase64String(privateKeyParam.Q.ToByteArrayUnsigned()),

Convert.ToBase64String(privateKeyParam.DP.ToByteArrayUnsigned()),

Convert.ToBase64String(privateKeyParam.DQ.ToByteArrayUnsigned()),

Convert.ToBase64String(privateKeyParam.QInv.ToByteArrayUnsigned()),

Convert.ToBase64String(privateKeyParam.Exponent.ToByteArrayUnsigned()));

}