Saturday, 3 July 2010

X.509 error when running simple WCF services

I was running through some tutorials and hit a problem when adding new endpoints to a WCF service. The Visual Studio service runner showed the following error:
System.InvalidOperationException: Cannot load the X.509 certificate identity specified in the configuration.
   at System.ServiceModel.Description.ConfigLoader.LoadIdentity(IdentityElement element)
   at System.ServiceModel.Description.ConfigLoader.LoadServiceDescription(ServiceHostBase host, ServiceDescription description, ServiceElement serviceElement, Action`1 addBaseAddress)
   at System.ServiceModel.ServiceHostBase.LoadConfigurationSectionInternal(ConfigLoader configLoader, ServiceDescription description, ServiceElement serviceSection)
   at System.ServiceModel.ServiceHostBase.LoadConfigurationSectionInternal(ConfigLoader configLoader, ServiceDescription description, String configurationName)
   at System.ServiceModel.ServiceHostBase.ApplyConfiguration()
   at System.ServiceModel.ServiceHostBase.InitializeDescription(UriSchemeKeyedCollection baseAddresses)
   at System.ServiceModel.ServiceHost.InitializeDescription(Type serviceType, UriSchemeKeyedCollection baseAddresses)
   at System.ServiceModel.ServiceHost..ctor(Type serviceType, Uri[] baseAddresses)
   at Microsoft.Tools.SvcHost.ServiceHostHelper.CreateServiceHost(Type type, ServiceKind kind)
   at Microsoft.Tools.SvcHost.ServiceHostHelper.OpenService(ServiceInfo info)
The problem lay in the App.config <identity> block of some of the newly added endpoints. Originally they looked something like this:
    <certificatereference x509findtype="FindBySubjectDistinguishedName" storelocation="LocalMachine" storename="My" />
Adding a <dns> element fixed the issue:
    <dns value="localhost" />
    <certificatereference x509findtype="FindBySubjectDistinguishedName" storelocation="LocalMachine" storename="My" />
The <dns> element is described as:
“Specifies the DNS of an X.509 certificate used to authenticate a service. This element contains an attribute value that is a string, and contains the actual identity.”
See the MSDN documentation:


  1. Thank you so very, very much!!!

    The MSDN documentation makes it so clear.

    1. Hi Guy,

      I'm glad you found this useful, especially after such a long time!


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