Configuring WCF client binding to use X509 certificate in dotnet core 2.2

user_45031 0
Viewed 3835

I'm trying to convert an old WCF client to dotnet core. I successfully generated my proxies from the wsdl and have been trying to configure them so I can successfully call the endpoint. It appears, based on some googling, that under dotnet core I need to configure my WCF client from code.

Here's the WCF configuration section from the web.config of the old application:

<system.serviceModel>
  <serviceHostingEnvironment aspNetCompatibilityEnabled="true" />
  <behaviors>
    <endpointBehaviors>
      <behavior name="clientEndpointCredential">
        <clientCredentials>
          <clientCertificate storeName="My" storeLocation="LocalMachine" x509FindType="FindBySubjectName" findValue="CERTNAME" />
        </clientCredentials>
      </behavior>
    </endpointBehaviors>
  </behaviors>
  <bindings>
    <basicHttpBinding>
      <binding name="OUR_Customer_OUTBinding" closeTimeout="00:01:00" openTimeout="00:01:00" receiveTimeout="00:10:00" sendTimeout="00:01:00" allowCookies="false" bypassProxyOnLocal="false" hostNameComparisonMode="StrongWildcard" maxBufferSize="2147483647" maxBufferPoolSize="2147483647" maxReceivedMessageSize="2147483647" messageEncoding="Text" textEncoding="utf-8" transferMode="Buffered" useDefaultWebProxy="true">
        <readerQuotas maxDepth="32" maxStringContentLength="5242880" maxArrayLength="16384" maxBytesPerRead="4096" maxNameTableCharCount="16384" />
        <security mode="Transport">
          <transport clientCredentialType="Certificate" proxyCredentialType="None" realm="" />
        </security>
      </binding>
    </basicHttpBinding>
  </bindings>
  <client>
    <endpoint address="https://the-full-url" behaviorConfiguration="clientEndpointCredential" binding="basicHttpBinding" bindingConfiguration="OUR_Customer_OUTBinding" contract="CustomerInterface.OUR_Customer_OUT" name="HTTPS_Port" />
  </client>
  <diagnostics>
    <messageLogging logEntireMessage="true" logMalformedMessages="true" logMessagesAtServiceLevel="true" logMessagesAtTransportLevel="false" maxMessagesToLog="3000" />
  </diagnostics>
</system.serviceModel>

Here's what I've come up with to configure it in dotnet core:

private OUR_Customer_OUTClient GetCustomerClient()
{
    TimeSpan Minutes(int minutes) => new TimeSpan(0, minutes, 0);

    var binding = new BasicHttpBinding();
    binding.Name = "OUR_Customer_OUTBinding";
    binding.AllowCookies = false;
    binding.SendTimeout = Minutes(1);
    binding.ReceiveTimeout = Minutes(10);
    binding.OpenTimeout = Minutes(1);
    binding.CloseTimeout = Minutes(1);
    binding.MaxBufferPoolSize = 2147483647;
    binding.MaxReceivedMessageSize = 2147483647;
    binding.TextEncoding = Encoding.UTF8;
    binding.TransferMode = TransferMode.Buffered;
    binding.BypassProxyOnLocal = false;
    binding.UseDefaultWebProxy = true;
    binding.Security.Mode = BasicHttpSecurityMode.Transport;
    binding.Security.Transport.ClientCredentialType = HttpClientCredentialType.Certificate;
    binding.Security.Transport.ProxyCredentialType = HttpProxyCredentialType.None;

    var endpointAddress = new EndpointAddress("https://the-full-url");

    var client = new OUR_Customer_OUTClient(binding, endpointAddress);
    client.ClientCredentials.ClientCertificate.SetCertificate(
        StoreLocation.LocalMachine,
        StoreName.My,
        X509FindType.FindBySubjectName,
        "CERTNAME");
    return client;
}

And here's the code I'm using to call the endpoint (dotnet core proxies don't yet support synchronous calls):

SearchResponse searchResponse = Task.Run(() => GetCustomerClient().SearchAsync(message)).Result;

However, I'm getting the following error:

The HTTP request is unauthorized with client authentication scheme 'Anonymous'. The authentication header received from the server was 'Basic realm="XISOAPApps"'

Can anyone see anything wrong with my approach or suggest ways I could use to debug this? I'm a WCF newbie and am tearing my hair out at this point.

.net-core wcf-security wcf-binding wcf
2 Answers

For the benefit of any others who may be unlucky enough to hit the same problem, the central issue turned out to be that the X509 certificate was not being sent. (The endpoint we were hitting accepted either a certificate or basic auth, thus the 401.)

The reason the certificate wasn't being sent was because the dotnet core networking stack is stricter than the .NET one, and requires the certificate to either have its Enhanced Key Usage set to ClientAuthentication (1.3.6.1.5.5.7.3.2) or have no EKU at all (see the source code here). Ours wasn't - it was set to Server Authentication. So the certificate was quietly discarded, despite having been loaded up successfully.

This github issue provides further details.

user_450310

Your code snippets seem good. We may have one more thing to do. when server authenticates the client with a certificate, we should establish the trust relationship each other, please refer to the below link.
https://docs.microsoft.com/en-us/dotnet/framework/wcf/feature-details/transport-security-with-certificate-authentication
Besides, we should provider an Identity flag to identity the server, like below.

<client>
    <endpoint address="http://vabqia593vm:4434/Service1.svc" binding="wsHttpBinding" bindingConfiguration="WSHttpBinding_IService1" contract="ServiceReference1.IService1" name="WSHttpBinding_IService1" behaviorConfiguration="mybeh">
        <identity>
            <dns value="vabqia130vm"/>
        </identity>
    </endpoint>
</client>

We could generate client proxy class by Micorosoft WCF Web Service Reference Provider.(Add Connected Services). Feel free to let me know if there is anything I can help with.
Abraham

user_101632510
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