Calling a WCF service from another WCF service - wcf

Question

I have a WCF service hosted on a windows service on my Server1. It also has IIS on this machine. I call the service from a web app and it works fine. But within this service, I have to call another WCF sevice (also hosted on a windows service) located on Server2. The security credentials are set to "Message" and "Username". I have an error like "SOAP protcol negociation failed". It's a problem with my server certificate public key that doesn't seem to be recognise. However, if I call the service on the Server2 from Server1 in a console app, it works fine.
I followed this tutorial to set up my certificates : http://www.codeproject.com/KB/WCF/wcf_certificates.aspx
Here's the config file from my service on Server1 that tries to call the second one :
<endpoint address=""
binding="wsHttpBinding"
contract="Microsoft.ServiceModel.Samples.ITraitement" />
<endpoint address="mex"
binding="mexHttpBinding"
contract="IMetadataExchange" />
</service>
</services>
<client>
<endpoint address="http://Server2:8000/servicemodelsamples/service"
behaviorConfiguration="myClientBehavior" binding="wsHttpBinding"
bindingConfiguration="MybindingCon" contract="Microsoft.ServiceModel.Samples.ICalculator"
name="">
<identity>
<dns value="ODWCertificatServeur" />
</identity>
</endpoint>
</client>
<bindings>
<wsHttpBinding>
<binding name="MybindingCon">
<security mode="Message">
<message clientCredentialType="UserName" />
</security>
</binding>
</wsHttpBinding>
</bindings>
<behaviors>
<serviceBehaviors>
<behavior name="ServiceTraitementBehavior">
<serviceMetadata httpGetEnabled="True"/>
<serviceDebug includeExceptionDetailInFaults="True" />
</behavior>
</serviceBehaviors>
<endpointBehaviors>
<behavior name="myClientBehavior">
<clientCredentials>
<clientCertificate findValue="MachineServiceTraitement" x509FindType="FindBySubjectName" storeLocation="LocalMachine" storeName="My" />
<serviceCertificate>
<authentication certificateValidationMode="ChainTrust" revocationMode="NoCheck"/>
</serviceCertificate>
</clientCredentials>
</behavior>
</endpointBehaviors>
</behaviors>
And here's the config file from the web app that calls the service on Server1 :
<system.serviceModel>
<bindings>
<wsHttpBinding>
<binding name="WSHttpBinding_ITraitement" closeTimeout="00:01:00"
openTimeout="00:01:00" receiveTimeout="00:10:00" sendTimeout="00:01:00"
bypassProxyOnLocal="false" transactionFlow="false" hostNameComparisonMode="StrongWildcard"
maxBufferPoolSize="524288" maxReceivedMessageSize="65536"
messageEncoding="Text" textEncoding="utf-8" useDefaultWebProxy="true"
allowCookies="false">
<readerQuotas maxDepth="32" maxStringContentLength="8192" maxArrayLength="16384"
maxBytesPerRead="4096" maxNameTableCharCount="16384" />
<reliableSession ordered="true" inactivityTimeout="00:10:00"
enabled="false" />
<security mode="Message">
<transport clientCredentialType="Windows" proxyCredentialType="None"
realm="" />
<message clientCredentialType="Windows" negotiateServiceCredential="true"
algorithmSuite="Default" establishSecurityContext="true" />
</security>
</binding>
</wsHttpBinding>
</bindings>
<client>
<endpoint address="http://localhost:8020/ServiceTraitementPC"
binding="wsHttpBinding" bindingConfiguration="WSHttpBinding_ITraitement"
contract="ITraitement" name="WSHttpBinding_ITraitement">
</endpoint>
</client>
Any idea why it works if if I call it in a console app and not from my service ? Maybe it has something to do with the certificateValidationMode="ChainTrust" ?

Answer 1

Well, finally it was just a matter of trusting the issuer of the certificate on the client machine. It was mentioned in the tutorial and I must have missed that step. Still wonder why it worked when calling from a console app, but... anyway, it works fine now.
Thanks !

Answer 2

When you call the service from the console app you are in the security context of the logged in user.
When you call the service from a service running in IIS, with default settings, you are in the security context of a local account NETWORK SERVICE.
The way to fix it is probably to set impersonate=true in the system.web section of your web.config.