Transport Security with Certificate Authentication

  • Article

The following scenario shows a Windows Communication Foundation (WCF) client and service secured by an X.509 certificate. Each client has a certificate that can be used for client Secure Sockets Layer (SSL) authentication and is trusted by the service. This example shows a request/reply message pattern.

For more information about using a certificate with a service, see Working with Certificates and How to: Configure a Port with an SSL Certificate.

Secure transfer using certificates

Characteristic Description

Security Mode

Transport

Interoperability

With existing Web service clients and services.

Authentication (Server)

Authentication (Client)

Yes (using HTTPS)

Yes (using a certificate)

Integrity

Yes

Confidentiality

Yes

Transport

HTTPS

Binding

WSHttpBinding

Service

The following code and configuration are meant to run independently. Do one of the following:

  • Create a stand-alone service using the code with no configuration.

  • Create a service using the supplied configuration, but do not define any endpoints.

Code

The following code shows how to create a service endpoint that uses a transport security and a certificate.

' Create the binding. 
Dim binding As New WSHttpBinding()
binding.Security.Mode = SecurityMode.Transport
binding.Security.Transport.ClientCredentialType = HttpClientCredentialType.Certificate

' Create the URI for the endpoint.
Dim httpUri As New Uri("https://localhost/Calculator")

' Create the service and add an endpoint.
Dim myServiceHost As New ServiceHost(GetType(ServiceModel.Calculator), httpUri)
myServiceHost.AddServiceEndpoint(GetType(ServiceModel.ICalculator), binding, "")

' Open the service.
myServiceHost.Open()
Console.WriteLine("Listening...")
Console.ReadLine()

' Close the service.
myServiceHost.Close()

// Create the binding. 
WSHttpBinding binding = new WSHttpBinding();
binding.Security.Mode = SecurityMode.Transport;
binding.Security.Transport.ClientCredentialType = HttpClientCredentialType.
    Certificate;

// Create the URI for the endpoint.
Uri httpUri = new Uri("https://localhost/Calculator");

// Create the service and add an endpoint.
ServiceHost myServiceHost =
    new ServiceHost(typeof(ServiceModel.Calculator), httpUri);
myServiceHost.AddServiceEndpoint(
    typeof(ServiceModel.ICalculator), binding, "");

// Open the service.
myServiceHost.Open();
Console.WriteLine("Listening...");
Console.ReadLine();

// Close the service.
myServiceHost.Close();

Configuration

The following configuration can be used instead of the code to set up the service:

<bindings>
    <wsHttpBinding>
        <binding name="CertificateWithTransport">
            <security mode="Transport">
                <transport clientCredentialType="Certificate"/>
            </security>
        </binding>
    </wsHttpBinding>
</bindings>
<services>
    <service name="ServiceModel.Calculator" 
             behaviorConfiguration="credentialConfig" >
    <endpoint address=""
              binding="wsHttpBinding"
              bindingConfiguration="CertificateWithTransport" 
              contract="ServiceModel.ICalculator" />
     </service>
</services>
<behaviors>
    <serviceBehaviors>
        <behavior name="credentialConfig">
            <serviceCredentials>
                <clientCertificate trustedStoreLocation="LocalMachine" 
                                   revocationMode="Online"/>
            </serviceCredentials>
        </behavior>
    </serviceBehaviors>
</behaviors>

Client

The following code and configuration are meant to run independently. Do one of the following:

  • Create a stand-alone client using the code (and client code).

  • Create a client that does not define any endpoint addresses. Instead, use the client constructor that takes the configuration name as an argument. For example:

    Dim cc As New CalculatorClient("EndpointConfigurationName")

    CalculatorClient cc = new CalculatorClient("EndpointConfigurationName");

Code

The following code creates the client. The binding is configured to use the transport mode security, with the TCP transport, with the client credential type set to Windows.

' Create the binding.
Dim myBinding As New WSHttpBinding()
myBinding.Security.Mode = SecurityMode.Transport
myBinding.Security.Transport.ClientCredentialType = _
    HttpClientCredentialType.Certificate

' Create the endpoint address. Note that the machine name 
' must match the subject or DNS field of the X.509 certificate
' used to authenticate the service. 
Dim ea As New EndpointAddress("https://localhost/Calculator")

' Create the client. The code for the calculator 
' client is not shown here. See the sample applications
' for examples of the calculator code.
Dim cc As New CalculatorClient(myBinding, ea)

' The client must specify a certificate trusted by the server.
cc.ClientCredentials.ClientCertificate.SetCertificate( _
StoreLocation.CurrentUser, StoreName.My, X509FindType.FindBySubjectName, "contoso.com")

' Begin using the client.
Try
    cc.Open()

    Console.WriteLine(cc.Add(100, 11))
    Console.ReadLine()

    ' Close the client.
    cc.Close()
Catch tex As TimeoutException
    Console.WriteLine(tex.Message)
    cc.Abort()
Catch cex As CommunicationException
    Console.WriteLine(cex.Message)
    cc.Abort()
Finally
    Console.WriteLine("Closed the client")
    Console.ReadLine()
End Try

// Create the binding.
WSHttpBinding myBinding = new WSHttpBinding();
myBinding.Security.Mode = SecurityMode.Transport;
myBinding.Security.Transport.ClientCredentialType =
    HttpClientCredentialType.Certificate;

// Create the endpoint address. Note that the machine name 
// must match the subject or DNS field of the X.509 certificate
// used to authenticate the service. 
EndpointAddress ea = new
    EndpointAddress("https://localhost:8006/Calculator");

// Create the client. The code for the calculator 
// client is not shown here. See the sample applications
// for examples of the calculator code.
CalculatorClient cc =
    new CalculatorClient(myBinding, ea);

// The client must specify a certificate trusted by the server.
cc.ClientCredentials.ClientCertificate.SetCertificate(
    StoreLocation.CurrentUser,
    StoreName.My,
    X509FindType.FindBySubjectName,
    "contoso.com");

// Begin using the client.
Console.WriteLine(cc.Add(100, 1111));
try
{
    cc.Open();

    // Close the client.
    cc.Close();
}

Configuration

The following configuration code is for the client, and likewise specifies the certificate location and values used to find it.

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <system.serviceModel>
    <behaviors>
      <endpointBehaviors>
        <behavior name="credentialConfiguration">
          <clientCredentials>
            <clientCertificate findValue="Contoso.com"
                      storeLocation="CurrentUser" 
                      x509FindType="FindBySubjectName" />
          </clientCredentials>
        </behavior>
      </endpointBehaviors>
    </behaviors>
    <bindings>
      <wsHttpBinding>
        <binding name="WSHttpBinding_ICalculator">
          <security mode="Transport">
            <transport clientCredentialType="Certificate" />
          </security>
        </binding>
      </wsHttpBinding>
    </bindings>
    <client>
      <endpoint address="https://machineName/Calculator"
                behaviorConfiguration="credentialConfiguration"
                binding="wsHttpBinding"
                bindingConfiguration="WSHttpBinding_ICalculator"
                contract="ICalculator"
                name="WSHttpBinding_ICalculator" />
    </client>
  </system.serviceModel>
</configuration>

See Also

Concepts

Security Overview