C# 判断域名证书是否过期

定义一个基础类

public class DomainName
{
    public string GUID { get; set; }

    public string Domain { get; set; }

    public bool IsChecked { get; set; }

    public bool IsExpired { get; set; }

    public string Message { get; set; }

    public List<string> SupportedSslProtocols { get; set; } = new List<string>();

    public string DisplayText
    {
        get
        {
            if (IsChecked)
            {
                return this.Domain + " **** Checked.";
            }
            else
            {
                return this.Domain + " **** Unchecked.";

            }

        }
    }
}

　　调用https请求方法

 private bool SendHttpRequest(string url)
 {
     bool result = false;

     var httpclientHandler = new HttpClientHandler();

     httpclientHandler.ServerCertificateCustomValidationCallback = (senderx, cert, chain, sslPolicyErrors)
         => ValidateCertificate(senderx, cert, chain, sslPolicyErrors);

     string domainUrl = url;

     using (var httpClient = new HttpClient(httpclientHandler))
     {
         try
         {
             var response = httpClient.GetAsync(domainUrl).Result;

             result = true;
         }
         catch (Exception ex)
         {
             result = false;
         }
     }

     return result;
 }

检查证书核心代码

 private DomainName domainNameEntity = new DomainName();

 private bool ValidateCertificate(HttpRequestMessage senderx, X509Certificate certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors)
 {
     bool result = false;
     domainNameEntity.IsChecked = true;

     var expirationDate = DateTime.Parse(certificate.GetExpirationDateString(), CultureInfo.InvariantCulture);
     var effectiveDate = DateTime.Parse(certificate.GetEffectiveDateString(), CultureInfo.InvariantCulture);

     if (certificate == null)
     {
         result = true;
         domainNameEntity.IsExpired = false;
         domainNameEntity.Message = "The Cert is valid.EffectiveDate : from " + effectiveDate + "  to " + expirationDate;
     }
     else
     {
         // 已过期
         if (expirationDate <= DateTime.Today)
         {
             domainNameEntity.IsExpired = true;
             domainNameEntity.Message = "The Cert has expired.! EffectiveDate : from " + effectiveDate + "  to " + expirationDate;
         }
         //还有十五天过期，则给出提示
         else if (expirationDate - DateTime.Today < TimeSpan.FromDays(15))
         {
             domainNameEntity.IsExpired = false;
             domainNameEntity.Message = "It's time to renew the certificate! EffectiveDate : from " + effectiveDate + "  to " + expirationDate;
         }

         //无错误
         if (sslPolicyErrors == SslPolicyErrors.None)
         {
             domainNameEntity.IsExpired = false;
             domainNameEntity.Message = "The Cert is valid. EffectiveDate : from " + effectiveDate + "  to " + expirationDate;

             return true;
         }
         else
         {
             domainNameEntity.IsExpired = false;
             domainNameEntity.Message = $"Cert errors: {sslPolicyErrors.ToString()}";
         }
     }

     return result;
 }