Microsoft TS: Windows Communication Foundation velopment with Microsoft .NET Framework 4 Sample Questions:

1. You are implementing a Windows Communication Foundation (WCF) service contract named IContosoService in a class named ContosoService. The service occasionally fails due to an exception being thrown at the service.
You need to send the stack trace of any unhandled exceptions to clients as a fault message.
What should you do?

A) In the application configuration file on the service and all the clients, add the following
XML segment to the system.diagnostics/sources configuration section group.
<source name="System.ServiceModel" switchValue="Error" propagateActivity="true">
<listeners>
<add name="ServiceModelTraceListener"
initializeData="app_tracelog.svclog"
type="System.Diagnostics.XmlWriterTraceListener" />
</listeners>
</source>
B) For each OperationContract exposed by IContosoService, apply the following attribute.
[FaultContract(typeof(Exception))]
C) Apply the following attribute to the ContosoService class.
[ServiceBehavior(IncludeExceptionDetailInFaults = true)]
D) In the application configuration file on the client, add the following XML segment to the
system.serviceModel/behaviors configuration section group.
<endpointBehaviors>
<behavior name=" debug ">
< callback Debug includeExceptionDetailInFaults="true" />
</behavior>
</endpointBehaviors>
Associate the debug behavior with any endpoints that need to return exception details.

2. You are developing a Windows Communication Foundation (WCF) service that returns location information for authorized law enforcement agencies. The service contract is as follows.

Users are authenticated and impersonated. The system uses ASP.NET roles. The members of law enforcement are members of the LawEnforcement role.
You need to ensure that only members of the LawEnforcement role can call these methods.
What are two possible ways to achieve this goal (Each correct answer presents a complete solution? Choose two.)

A) Use the CurrentPrincipal property of the thread. Call the IsInRole method specifying LawEnforcement as a parameter.
B) Add a PrincipalPermissionAttribute to each method that should be available only to members of law enforcement. Set its SecurityAction to Demand and set the role equal to LawEnforcement.
C) Create a GenericPrincipal specifying Thread.CurrentPrincipal.Identity as the IIdentityParameter and LawEnforcement as the only value for the Roles parameter.
D) At the beginning of each method, enumerate each ClaimSet in a new WindowsClaimSet. Use the FindClaims method to locate a claim type named Role with a right named LawEnforcement.

3. You are maintaining a Windows Communication Foundation (WCF) service that uses a custom UserNamePassword class to authenticate clients. The service certificate is hosted in the deployment server store for trusted root certificate authorities and has a Subject value of TaxServiceKey. Other service certificates hosted on the server also use TaxServiceKey as a Subject value.
You need to ensure that the service identifies itself with a certificate whose subject name and distinguished names are TaxServiceKey.
Which code segment should you use?

A) HostInstance.Credentials.ServiceCertificate.SetCertificate( StoreLocation.LocalMachine, StoreName.My, X509FindType.FindBySubjectDistinguishedName, "CN=TaxServiceKey");
B) HostInstance.Credentials.ServiceCertificate.SetCertificate( StoreLocation.LocalMachine, StoreName.Root, X509FindType.FindBySubjectDistinguishedName, "CN=TaxServiceKey");
C) HostInstance.Credentials.ServiceCertificate.SetCertificate( StoreLocation.LocalMachine, StoreName.AuthRoot, X509FindType.FindBySubjectName, "CN=TaxServiceKey");
D) HostInstance.Credentials.ServiceCertificate.SetCertificate( StoreLocation.LocalMachine, StoreName.My, X509FindType.FindBySubjectName, "CN=TaxServiceKey");

4. A self-hosted Windows Communication Foundation (WCF) service uses a secure HTTP
binding with a custom principal permission mode. The binding requires users to provide their Windows logon credentials.
You need to retrieve the identity of the caller.
What are two possible properties you can use to achieve this goal? (Each correct answer presents a complete solution. Choose two.)

A) OperationContext.Current.ServiceSecurity Context.Primary Identity.Name
B) Thread.CurrentPrincipal.Identity-Name
C) ServiceSecurity Context.Current.Primary Identity.Name
D) HttpContext.Current.User.Identity.Name

5. A Windows Communication Foundation (WCF) client and service share the following service contract interface.
[ServiceContract]
public interface IContosoService {
[OperationContract]
void SavePerson(Person person);
}
They also use the following binding.
NetTcpBinding binding new NetTcpBinding { TransactionFlow = true };
The client calls the service with the following code
using (TransactionScope ts = new TransactionScope(TransactionScopeOption.Required))
{ IContosoService client = factoryCreateChannelO;
client SavePerson(person);
ConsoleWriteLine(
TransactionCurrentTransactionlnformation.
Distributedldentifier);
tsCompleteO;
}
The service has the following implementation for SavePerson
public void IContosoService SavePerson(Person person)
{ person.Saveo;
ConsoleWriteLine(TransactionCurrentTransactionlnformation.
Distributedidentifier);
}
The distributed identifiers do not match on the client and the server
You need to ensure that the client and server enlist in the same distributed transaction
What should you do?

A) Add the following attribute to the SavePerson operation on lContosoSernce [OperationBehavior(TransactionScopeRequired true)] Md the following attribute to the implementation of SavePerson. ITransactionFlow(TransactionFlowOptionAllowed)]
B) Add the following attributes to the SavePerson operation on lContosoService
[TransactionFlow(TransactionFlowOption Mandatory)]
[OperationBehavior(TransactionScopeRequired true)]
C) Add the following attributes to the SavePerson operation on IContosoService.
[OperationBehavior(TransactionScopeRequired = true)]
[TransactionFlow(TransactionFlowOption.
Mandatory)]
D) Add the following attribute to the SavePerson operation on lContosoService [TransactionFlow(TransactionFlowOption Allowed)] Add the following attribute to the implementation of SavePerson. [OperationBehavior(TransactionScopeRequired true)]

Solutions: