Hi Everyone,

SSL双向认证内容，更加安全的连接；

1、这里将证书安装到“证书 - 当前用户” --> “个人” --> “证书”中；（不会操作的小伙伴百度搜一下吧，我后期维护后再放自己的链接）
原因是：如果安装到本地计算机了，对于当前用户来说无法越级查找敏感信息。在代码中断点调试后可以确认 --> 证书可以获取，但是获取不到证书中的PrivateKey的，会报异常；

2、MMC中找到客户端证书并双击 / “详细信息” -> 获取指纹：

代码片段如下（注意使用Using，可以释放资源）

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Security.Cryptography.X509Certificates;
using System.Threading.Tasks;
using log4net;

namespace Helper
{
    public class ServiceHelper
    {
        private static readonly ILog logger = LogManager.GetLogger("ServiceHelper");
        //private readonly string _clientCertificateThumbprint = AppSettingHelper.Read("ServiceClientCertificateThumbprint");
        private readonly string _clientCertificateThumbprint = "上面图片获取的客户端证书指纹";//Client Thumbprint.

        /// <summary>
        /// 请求Https并携带客户端证书
        /// </summary>
        /// <param name="content">Request Body</param>
        /// <param name="url">Target URL</param>
        /// <param name="headers">Request Headers</param>
        /// <param name="method">Post、Get.....</param>
        /// <returns></returns>
        public async Task<string> RequestServiceAPI(string content, string url, Dictionary<string, string> headers, string method = "Post")
        {
            try
            {
                string result = string.Empty;

                #region 方式1：通过mmc安装Client Certificate方式

               
                ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3 | SecurityProtocolType.Tls |
                                                       (SecurityProtocolType)768 | (SecurityProtocolType)3072 |
                                                       (SecurityProtocolType)0x300 | (SecurityProtocolType)0xC00;

                ServicePointManager.ServerCertificateValidationCallback = (sender, certificate, chain, sslPolicyErrors) => true; //获取或设置用于验证服务器证书的回调
                
#if !DEBUG
                X509Store store = new X509Store(StoreName.My, StoreLocation.LocalMachine); //从 "本地计算机" 安装的Client Certificate中进行查找;//不能使用CurrentUser
#else
                X509Store store = new X509Store(StoreName.My, StoreLocation.CurrentUser);//从 "计算机当前用户" 安装的Client Certificate中进行查找;也可以使用LocalMachine
#endif
                store.Open(OpenFlags.ReadOnly | OpenFlags.OpenExistingOnly);
                
                X509Certificate2 clientCer ;

                try
                {
                    //do not use "store.Certificates.Find()" --> Performance
                    //Case must be omitted;
                    //Find By certificate thumbprint.
                    clientCer = store.Certificates.Cast<X509Certificate2>().FirstOrDefault(c => c.Thumbprint.Equals(_clientCertificateThumbprint, StringComparison.OrdinalIgnoreCase));

                    if (clientCer == null)
                    {
                        logger.Info($"Class : {nameof(ServiceHelper)} Method : {nameof(RequestServiceAPI)}; Error : Client certificate with \"{_clientCertificateThumbprint}\" thumbprint not found.");
                        return null;
                    }
                }
                catch
                {
                    logger.Info($"Class : {nameof(ServiceHelper)} Method : {nameof(RequestServiceAPI)}; Error : Client certificate with \"{_clientCertificateThumbprint}\" thumbprint not found.");
                    return null;
                }
                finally
                {
                    store.Close();
                }

                #endregion


#region 方式2：通过路径获取Client Certificate方式；
//try
//{
    //string certificatePath = @"....\ClientCertificateFile.pfx";//使用相对路径或者绝对路径，
    //string certPassword = "******"; //客户端证书对应的明文密码；

    //ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3|SecurityProtocolType.Tls| (SecurityProtocolType)768|(SecurityProtocolType)3072|(SecurityProtocolType)0x300|(SecurityProtocolType)0xC00;//根据当前framework版本中的枚举进行设置；

    //ServicePointManager.ServerCertificateValidationCallback = (sender, certificate, chain, sslPolicyErrors) => true;//获取或设置用于验证服务器证书的回调，根据实际情况true或false；

    clientCer对象就是请求时携带上去的客户端证书
    //X509Certificate2 clientCer = new X509Certificate2(certificatePath, certPassword, X509KeyStorageFlags.MachineKeySet|X509KeyStorageFlags.PersistKeySet|X509KeyStorageFlags.Exportable);
//catch (Exception ex)
//{
    //logger.Error($"Get Client certificate Error : {ex}.");
    //return null;
//}
#endregion


                byte[] bytes = System.Text.Encoding.UTF8.GetBytes(content);

                HttpWebRequest request = (HttpWebRequest) WebRequest.Create(url);
                request.ClientCertificates.Add(clientCer);
                request.ContentType = "application/json";
                request.Method = method;
                request.ContentLength = bytes.Length;
                if (headers != null && headers.Count > 0)
                {
                    foreach (var item in headers)
                    {
                        request.Headers.Add(item.Key, item.Value);
                    }
                }

                using (Stream requestStream = request.GetRequestStream())
                {
                    requestStream.Write(bytes, 0, bytes.Length);
                    requestStream.Close();
                }

                using (HttpWebResponse response = (HttpWebResponse) await request.GetResponseAsync())
                {
                    using (Stream responseStream = response.GetResponseStream())
                    {
                        if (responseStream != null)
                        {
                            using (StreamReader reader = new StreamReader(responseStream, System.Text.Encoding.UTF8))
                            {
                                result = reader.ReadToEnd().Trim();
                                request.Abort();
                            }
                        }
                    }
                }
                
                return result;
            }
            catch (Exception ex)
            {
                logger.Info($"Class : {nameof(ServiceHelper)} Method : {nameof(RequestServiceAPI)} happen exception. error: {ex.Message}");
                return null;
            }
        }


    }
}

超详细的Asp.net使用SSL双向认证，一篇就够了：
https://blog.csdn.net/qq_39797713/article/details/126130544