read client certificate from httprequest C#

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I am trying to read an X509 certificate using Request.ClientCertificate but nothing is returned. The certificate is definitely being attached to the request because I can get the certificate information from the page sending the request.

I have tried reading the certificate from several different places but cannot seem to get it to work.

I started with code from this KB Article. In the requested page I tried to print out some information about the certificate but nothing was returned in the response.

This is running on IIS 5.1 and the communication is over SSL. This must be done using version 2 of the .Net framework

Why does the certificate seem to dissappear?

I wrote a identification web page a while back that looked for a client certificate and if found would display the certificate information. I believe that is what you are looking for... Here is the page:

<%@ Page Language="C#" Trace="false" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<%@ Import Namespace="System.Security.Cryptography.X509Certificates" %>
<%@ Import Namespace="System.Security.Cryptography" %>

<script runat="server">
    //protected void Page_Load(object sender, EventArgs e)
    //{ }

    void LoadCertInfo()
    {
        string para = "<div style='margin: 10px 0 0 0; font-weight: bold'>{0}</div>";
        string subpara = "<div style='margin-left: 15px; font-size: 90%'>{0}</div>";

        if (Page.Request.ClientCertificate.IsPresent)
        {
            Response.Write("<hr /><div style='width: 500px; margin: 20px auto'>");
            Response.Write("<h3 style='width: 500px; margin: 20px auto'>Client Certificate Information</h3>");
            try
            {
                X509Certificate2 x509Cert2 = new X509Certificate2(Page.Request.ClientCertificate.Certificate);

                Response.Write(string.Format(para, "Issued To:"));
                Response.Write(string.Format(subpara, x509Cert2.Subject));

                Response.Write(string.Format(para, "Issued By:"));
                Response.Write(string.Format(subpara, x509Cert2.Issuer));

                Response.Write(string.Format(para, "Friendly Name:"));
                Response.Write(string.Format(subpara, string.IsNullOrEmpty(x509Cert2.FriendlyName) ? "(None Specified)" : x509Cert2.FriendlyName));

                Response.Write(string.Format(para, "Valid Dates:"));
                Response.Write(string.Format(subpara, "From: " + x509Cert2.GetEffectiveDateString()));
                Response.Write(string.Format(subpara, "To: " + x509Cert2.GetExpirationDateString()));

                Response.Write(string.Format(para, "Thumbprint:"));
                Response.Write(string.Format(subpara, x509Cert2.Thumbprint));

                //Response.Write(string.Format(para, "Public Key:"));
                //Response.Write(string.Format(subpara, x509Cert2.GetPublicKeyString()));

                #region EKU Section - Retrieve EKU info and write out each OID
                X509EnhancedKeyUsageExtension ekuExtension = (X509EnhancedKeyUsageExtension)x509Cert2.Extensions["Enhanced Key Usage"];
                if (ekuExtension != null)
                {
                    Response.Write(string.Format(para, "Enhanced Key Usages (" + ekuExtension.EnhancedKeyUsages.Count.ToString() + " found)"));

                    OidCollection ekuOids = ekuExtension.EnhancedKeyUsages;
                    foreach (Oid ekuOid in ekuOids)
                        Response.Write(string.Format(subpara, ekuOid.FriendlyName + " (OID: " + ekuOid.Value + ")"));
                }
                else
                {
                    Response.Write(string.Format(para, "No EKU Section Data"));
                }
                #endregion // EKU Section

                #region Subject Alternative Name Section
                X509Extension sanExtension = (X509Extension)x509Cert2.Extensions["Subject Alternative Name"];
                if (sanExtension != null)
                {
                    Response.Write(string.Format(para, "Subject Alternative Name:"));
                    Response.Write(string.Format(subpara, sanExtension.Format(true)));
                }
                else
                {
                    Response.Write(string.Format(para, "No Subject Alternative Name Data"));
                }

                #endregion // Subject Alternative Name Section

                #region Certificate Policies Section
                X509Extension policyExtension = (X509Extension)x509Cert2.Extensions["Certificate Policies"];
                if (policyExtension != null)
                        {
                            Response.Write(string.Format(para, "Certificate Policies:"));
                            Response.Write(string.Format(subpara, policyExtension.Format(true)));
                        }
                        else
                        {
                            Response.Write(string.Format(para, "No Certificate Policies Data"));
                        }
                #endregion //Certificate Policies Section


                // Example on how to enumerate all extensions
                //foreach (X509Extension extension in x509Cert2.Extensions)
                //    Response.Write(string.Format(para, extension.Oid.FriendlyName + "(" + extension.Oid.Value + ")"));
            }
            catch (Exception ex)
            {
                Response.Write(string.Format(para, "An error occured:"));
                Response.Write(string.Format(subpara, ex.Message));
                Response.Write(string.Format(subpara, ex.StackTrace));
            }
            finally
            {
                Response.Write("</div>");
            }
        }
    }
</script>
<html>
  <head runat="server">
    <title><% Page.Response.Write(System.Environment.MachineName); %></title>
  </head>
  <body>
      <% LoadCertInfo();  %>
  </body>
</html>

read client certificate from httprequest C#, I wrote a identification web page a while back that looked for a client certificate and if found would display the certificate information. I believe� Gets the current request's client security certificate. ContentEncoding: Gets or sets the character set of the entity-body. ContentLength: Specifies the length, in bytes, of content sent by the client. ContentType: Gets or sets the MIME content type of the incoming request. Cookies: Gets a collection of cookies sent by the client

Ok it isn't completely clear but you have a website which requires the clients to authenticate themselves using certificates? Because thats what the Request.ClientCertificate property is for.

I say this because there's something odd about your question.

"I can get the certificate information from the page sending the request."

Pages in general do not really send requests the clients do.

To get the server cert you could open the X509Store and sift through the certs to find the one with the CN you need.

Making an HttpWebRequest with Client Certificates, Making an HttpWebRequest with Client Certificates | Test your C# code online with .NET Fiddle code editor. Open the store to be able to read from it. 18. store . Configure your server for certificate authentication, be it IIS, Kestrel, Azure Web Apps, or whatever else you're using. Proxy and load balancer scenarios. Certificate authentication is a stateful scenario primarily used where a proxy or load balancer doesn't handle traffic between clients and servers.

I'm not sure what you need the client certificate for, but if you're using it for your own custom authentication or authorization, you may want to consider using the web server's security infrastructure instead of implementing your own. For example, you can configure IIS to require client certificates, map the certs to user accounts, and use Windows-based authentication. Of course, this doesn't necessarily work for your problem domain.

Get client certificate, So, how can I get client certificate when I process request? Read(ReadBuf, 0, 1024); if (0 != count) { Console.WriteLine(new Well, it's the standard HttpRequest[Base] from the HttpContext[Base]. So another way: System. An HttpClientCertificate object containing information about the client's security certificate settings. Examples. The following code example sends the client's certificate settings back to the client in an HTML page.

You have to configure your local IIS to accept (or require) client certificates.

HttpWebRequest with Client Certificate Authentication, HttpWebRequest with Client Certificate Authentication. by Dave Scheele on September 30th, 2006 | ~ 4 minute read. The .NET Framework HttpWebRequest � I am not sure I can install the certificate in the IIS user, but go on setting, computer certificate, on the certificate I press right-click and all activities, manage private key, and added the IIS_USER to complete control and read. – Perry Sep 17 '16 at 5:45

Using client certificates in .NET part 5: working with client certificates , In this post we'll go through how to attach a client certificate… we looked at a couple pf examples on how to work with digital certificates in C# code. You can read it from the address you see in the browser when starting� HttpClient is a base class for sending HTTP requests and receiving HTTP responses from a resource identified by a URI.. C# HttpClient status code. HTTP response status codes indicate whether a specific HTTP request has been successfully completed.

SSL Certificate Based Authentication In Web API Project, In addition, SSL client certificates can be used to authenticate clients. SSL Client To use client certificates with SSL, you need a way to distribute signed certificates to your users. Read more articles on Security in .NET:. Making an HttpWebRequest with Client Certificates | Test your C# code online with .NET Fiddle code editor.

The HttpWebRequest and Using Client Certificates, The HttpWebRequest and Using Client Certificates GetResponse(); //get the response stream to read the response from “A client certificate is a type of digital certificate that is used by client systems to make authenticated requests to a remote server. Client certificates play a key role in many mutual authentication designs, providing strong assurances of a requester’s identity.”

Comments
  • I didn't see this before asking essentially the same question just a few minutes ago. It's a little disheartening you don't have an answer yet...
  • What point in the lifecycle are you attempting to retreive it? Page OnInit, OnLoad, Master Page, Global.asax, etc?
  • I try to retrieve it in the Page_Load method
  • How is this the top answer? The OP said he is already using Page.Request.ClientCertificate.Certificate but it is returning null. This does nothing to help solve the issue.
  • the "page sending the request" is the client in this case. It attaches an X509 certificate to the request for the page that I try to use the Request.ClientCertificate property in