HttpListenerRequest.ClientCertificateError Property

Definition

Gets an error code that identifies a problem with the X509Certificate provided by the client.

public:
 property int ClientCertificateError { int get(); };
public int ClientCertificateError { get; }
member this.ClientCertificateError : int
Public ReadOnly Property ClientCertificateError As Integer

Property Value

An Int32 value that contains a Windows error code.

Exceptions

The client certificate has not been initialized yet by a call to the BeginGetClientCertificate(AsyncCallback, Object) or GetClientCertificate() methods

-or -

The operation is still in progress.

Examples

The following code example checks this property to determine whether the request includes a valid client certificate.

Console.WriteLine("Listening for {0} prefixes...", listener.Prefixes.Count);
HttpListenerContext context = listener.GetContext();
HttpListenerRequest request = context.Request;
Console.WriteLine("Received a request.");
// This server requires a valid client certificate
// for requests that are not sent from the local computer.

// Did the client omit the certificate or send an invalid certificate?
if (request.IsAuthenticated &&
    request.GetClientCertificate() == null ||
    request.ClientCertificateError != 0)
{
    // Send a 403 response.
    HttpListenerResponse badCertificateResponse = context.Response ;
    SendBadCertificateResponse(badCertificateResponse);
    Console.WriteLine("Client has invalid certificate.");
    continue;
}
Console.WriteLine("Listening for {0} prefixes...", listener.Prefixes.Count)
Dim context As HttpListenerContext = listener.GetContext()
Dim request As HttpListenerRequest = context.Request
Console.WriteLine("Received a request.")
' This server requires a valid client certificate
' for requests that are not sent from the local computer.

' Did the client omit the certificate or send an invalid certificate?
If request.IsAuthenticated AndAlso request.GetClientCertificate() Is Nothing OrElse request.ClientCertificateError <> 0 Then
    ' Send a 403 response.
    Dim badCertificateResponse As HttpListenerResponse = context.Response
    SendBadCertificateResponse(badCertificateResponse)
    Console.WriteLine("Client has invalid certificate.")
    Continue Do
End If

Remarks

This property contains a Windows error code returned by the Secure Channel (Schannel) Security Support Provider Interface (SSPI), which is used to validate the certificate. For more information about SSPI support for Schannel, see Creating a Secure Connection Using Schannel.

Applies to

See also