错误:证书链已处理，但在根错误中终止.Net框架4.7

openssl s_client -connect example.com:443 -showcerts

<configuration>
  <system.web>
    <httpRuntime targetFramework="4.7" />
  </system.web>
  <system.webServer>
    <security>
      <access sslFlags="Ssl, SslNegotiateCert" />
    </security>
  </system.webServer>
</configuration>

using System;
using System.Net;
using System.Net.Security;
using System.Security.Cryptography.X509Certificates;

public class CustomSslStream : SslStream
{
    public CustomSslStream(Stream innerStream, bool leaveInnerOpen) : base(innerStream, leaveInnerOpen)
    {
    }

    public override void AuthenticateAsClient(string host, X509CertificateCollection clientCertificates, SslProtocols enabledSslProtocols, bool checkCertificateRevocation)
    {
        ServicePointManager.ServerCertificateValidationCallback = ValidateCertificate;
        base.AuthenticateAsClient(host, clientCertificates, enabledSslProtocols, checkCertificateRevocation);
    }

    private bool ValidateCertificate(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors)
    {
        // 自定义验证逻辑
        return true; // 或者根据验证结果返回true或false
    }
}