我必须在c#中开发一个应用程序,以获取基于我提供的DNS(例如* .google.com)发布的SSL证书信息,如有效期,以便如果到期日期临近,我可以主动处理它.如果我将DNS提供为* .google.com,那么我需要获取该域的SSL证书信息的详细信息.
我试过跟随http://awesomeideas.net/page/Cert-Expiry-Check.aspx,但我觉得它是存储在本地系统中的证书.我也尝试使用HttpWebRequest获取SSL证书的详细信息,但它要求我输入一个有效的URI,在我的情况下是不可用的.我只有DNS名称
下面是我用HttpWebRequest获取信息的代码.但它要求我输入https：//*.domain.com类型的有效URI
Uri uri = new Uri(DNSEntry); HttpWebRequest request = (HttpWebRequest)WebRequest.Create(uri); request.Method = WebRequestMethods.Http.Get; HttpWebResponse response = (HttpWebResponse)request.GetResponse(); X509Certificate cert1 = request.ServicePoint.Certificate; X509Certificate2 cert = new X509Certificate2(cert1); DateTime dtCertExpiry = Convert.ToDateTime(cert.NotAfter.ToString());
解决方法
我尝试使用以下它工作正常：
string strDNSEntry是您需要SSL的DNS
public X509Certificate2 DownloadSslCertificate(string strDNSEntry)
{
X509Certificate2 cert = null;
using (TcpClient client = new TcpClient())
{
//ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3;
client.Connect(strDNSEntry,443);
SslStream ssl = new SslStream(client.GetStream(),false,new RemoteCertificateValidationCallback(ValidateServerCertificate),null);
try
{
ssl.AuthenticateAsClient(strDNSEntry);
}
catch (AuthenticationException e)
{
log.Debug(e.Message);
ssl.Close();
client.Close();
return cert;
}
catch (Exception e)
{
log.Debug(e.Message);
ssl.Close();
client.Close();
return cert;
}
cert = new X509Certificate2(ssl.RemoteCertificate);
ssl.Close();
client.Close();
return cert;
}
}
public static bool ValidateServerCertificate(object sender,X509Certificate certificate,X509Chain chain,SslPolicyErrors sslPolicyErrors)
{
if (sslPolicyErrors == SslPolicyErrors.None)
return true;
Console.WriteLine("Certificate error: {0}",sslPolicyErrors);
// Do not allow this client to communicate with unauthenticated servers.
return false;
}
