1

A self-signed certificate is used for authentication in the WCF application. The server specified:

<security mode="Message">
    <message clientCredentialType="Certificate"/>
</security>
...
<clientCertificate>
  <authentication certificateValidationMode="PeerOrChainTrust" revocationMode="NoCheck"/>
</clientCertificate>

The certificate is enabled correctly on the client:

<endpointBehaviors>
<behavior name="wsHttpCertificateBehavior">          
  <clientCredentials>
    <clientCertificate findValue="<Thumbprint>" storeName="My" storeLocation="LocalMachine" x509FindType="FindByThumbprint"/>    
  </clientCredentials>          
</behavior>
</endpointBehaviors>

On the client, the certificate is added to the trusted root certificates. When calling service methods, an error occurs: the calling user's identity was not verified by the service. I don't understand what else you need to specify for verification. If you remove the certificate and specify

<security mode= "None"/>

the client hangs when calling the service method. I don't understand why. I've been fighting this for a week. Please help me!

1 Answers1

0

This is a demo using X.509 self-signed certificate verification:

<system.serviceModel>
    <services>
      <service name="Microsoft.Samples.X509CertificateValidator.CalculatorService" behaviorConfiguration="CalculatorServiceBehavior">
        <!-- use host/baseAddresses to configure base address provided by host -->
        <host>
          <baseAddresses>
            <add baseAddress="http://localhost:8001/servicemodelsamples/service"/>
          </baseAddresses>
        </host>
        <!-- use base address specified above, provide one endpoint -->
        <endpoint address="certificate" binding="wsHttpBinding" bindingConfiguration="Binding" contract="Microsoft.Samples.X509CertificateValidator.ICalculator"/>
      </service>
    </services>

    <bindings>
      <wsHttpBinding>
        <!-- X509 certificate binding -->
        <binding name="Binding">
          <security mode="Message">
            <message clientCredentialType="Certificate"/>
          </security>
        </binding>
      </wsHttpBinding>
    </bindings>

    <behaviors>
      <serviceBehaviors>
        <behavior name="CalculatorServiceBehavior">
          <serviceDebug includeExceptionDetailInFaults="true"/>
          <serviceCredentials>
            <!-- 
            The serviceCredentials behavior allows one to specify authentication constraints on client certificates.
            -->
            <clientCertificate>
              <!-- 
              Setting the certificateValidationMode to Custom means that if the custom X509CertificateValidator
              does NOT throw an exception, then the provided certificate will be trusted without performing any
              validation beyond that performed by the custom validator. The security implications of this 
              setting should be carefully considered before using Custom in production code. 
              -->
              <authentication certificateValidationMode="Custom" customCertificateValidatorType="Microsoft.Samples.X509CertificateValidator.CustomX509CertificateValidator, service"/>
            </clientCertificate>
            <!-- 
            The serviceCredentials behavior allows one to define a service certificate.
            A service certificate is used by a client to authenticate the service and provide message protection.
            This configuration references the "localhost" certificate installed during the setup instructions.
            -->
            <serviceCertificate findValue="localhost" storeLocation="LocalMachine" storeName="My" x509FindType="FindBySubjectName"/>
          </serviceCredentials>
        </behavior>
      </serviceBehaviors>
    </behaviors>
    
  </system.serviceModel>

This is the configuration file of the service, we need to specify the location of the certificate.

serviceHost.Credentials.ClientCertificate.Authentication.CertificateValidationMode = System.ServiceModel.Security.X509CertificateValidationMode.Custom;
              
serviceHost.Credentials.ClientCertificate.Authentication.CustomCertificateValidator = new CustomX509CertificateValidator();

We custom verify the self-signed certificate.

public class CustomX509CertificateValidator : System.IdentityModel.Selectors.X509CertificateValidator
    {
        // This Validation function accepts any X.509 Certificate that is self-issued. As anyone can construct such
        // a certificate this custom validator is less secure than the default behavior provided by the
        // ChainTrust X509CertificateValidationMode. The security implications of this should be carefully 
        // considered before using this validation logic in production code. 
        public override void Validate(X509Certificate2 certificate)
        {
            // Check that we have been passed a certificate
            if (certificate == null)
                throw new ArgumentNullException("certificate");

            // Only accept self-issued certificates
            if (certificate.Subject != certificate.Issuer)
                throw new SecurityTokenException("Certificate is not self-issued");
        }
    }

If you need a complete example of this demo you can download it in this link:

https://www.microsoft.com/en-us/download/details.aspx?id=21459

Ding Peng
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  • Thank you very much. But there is another question. Connection failed: the certificate does not have a private key for messaging, or the process does not have access rights to the private key. The service configuration specifies an elevated access level: and This has no effect. [This section](http://learn.microsoft.com/dotnet/framework/wcf/feature-details/how-to-make-x-509-certificates-accessible-to-wcf) describes how to fix this problem, but for the local computer. How can I do this on Azure? – Alex Pertenava Nov 01 '20 at 23:21
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    You can refer to this link, I found a similar question on SO: https://stackoverflow.com/questions/13184586/wcf-error-it-is-likely-that-certificate-my-cert-may-not-have-a-private-key – Ding Peng Nov 05 '20 at 05:58
  • I don’t know Azure very much. I think this problem should be related to Azure. You can post this problem under the Azure tag. – Ding Peng Nov 05 '20 at 06:00
  • @ Ding Peng, The next morning, the problem disappeared... So, unfortunately, I can't say anything about this) But thank you for your answer, it helped solve another problem! – Alex Pertenava Nov 06 '20 at 09:36
  • I can't mark it because "Thanks for the feedback! Votes cast by those with less than 15 reputation are recorded, but do not change the publicly displayed post score." =) I'm just recently on SO =) – Alex Pertenava Nov 06 '20 at 10:11