OperationBehaviorAttribute.Impersonation Property

public:
 property System::ServiceModel::ImpersonationOption Impersonation { System::ServiceModel::ImpersonationOption get(); void set(System::ServiceModel::ImpersonationOption value); };

public System.ServiceModel.ImpersonationOption Impersonation { get; set; }

member this.Impersonation : System.ServiceModel.ImpersonationOption with get, set

Public Property Impersonation As ImpersonationOption

Property Value

One of the ImpersonationOption values. The default is NotAllowed.

Examples

The following service code example requires impersonation by setting the Impersonation property to Required.

using System;
using System.Collections.Generic;
using System.ServiceModel;
using System.Threading;

namespace Microsoft.WCF.Documentation
{
 [ServiceContract(
 Name="SampleHello",
 Namespace="http://microsoft.wcf.documentation"
 )]
 public interface IHello
 {
 [OperationContract]
 string Hello(string greeting);
 }

 public class HelloService : IHello
 {

 public HelloService()
 {
 Console.WriteLine("Service object created: " + this.GetHashCode().ToString());
 }

 ~HelloService()
 {
 Console.WriteLine("Service object destroyed: " + this.GetHashCode().ToString());
 }

 [OperationBehavior(Impersonation=ImpersonationOption.Required)]
 public string Hello(string greeting)
 {
 Console.WriteLine("Called by: " + Thread.CurrentPrincipal.Identity.Name);
 Console.WriteLine("IsAuthenticated: " + Thread.CurrentPrincipal.Identity.IsAuthenticated.ToString());
 Console.WriteLine("AuthenticationType: " + Thread.CurrentPrincipal.Identity.AuthenticationType.ToString());

 Console.WriteLine("Caller sent: " + greeting);
 Console.WriteLine("Sending back: Hi, " + Thread.CurrentPrincipal.Identity.Name);
 return "Hi, " + Thread.CurrentPrincipal.Identity.Name;
 }
 }
}

Imports System.ServiceModel
Imports System.Threading

Namespace Microsoft.WCF.Documentation
 <ServiceContract(Name:="SampleHello", Namespace:="http://microsoft.wcf.documentation")> _
 Public Interface IHello
 <OperationContract> _
 Function Hello(ByVal greeting As String) As String
 End Interface

 Public Class HelloService
 Implements IHello

 Public Sub New()
 Console.WriteLine("Service object created: " & Me.GetHashCode().ToString())
 End Sub

 Protected Overrides Sub Finalize()
 Console.WriteLine("Service object destroyed: " & Me.GetHashCode().ToString())
 End Sub

 <OperationBehavior(Impersonation:=ImpersonationOption.Required)> _
 Public Function Hello(ByVal greeting As String) As String Implements IHello.Hello
 Console.WriteLine("Called by: " & Thread.CurrentPrincipal.Identity.Name)
 Console.WriteLine("IsAuthenticated: " & Thread.CurrentPrincipal.Identity.IsAuthenticated.ToString())
 Console.WriteLine("AuthenticationType: " & Thread.CurrentPrincipal.Identity.AuthenticationType.ToString())

 Console.WriteLine("Caller sent: " & greeting)
 Console.WriteLine("Sending back: Hi, " & Thread.CurrentPrincipal.Identity.Name)
 Return "Hi, " & Thread.CurrentPrincipal.Identity.Name
 End Function
 End Class
End Namespace

The following code example shows using the ClientCredentials property to set the client application credentials prior to invoking the operation that requires those credentials for impersonation.

using System;
using System.ServiceModel;
using System.ServiceModel.Channels;
using System.Security.Principal;
using System.Threading;

namespace Microsoft.WCF.Documentation
{
 public class Client
 {
 public void Run()
 {
 // Picks up configuration from the config file.
 SampleHelloClient wcfClient = new SampleHelloClient();
 try
 {
 // Set the client credentials to permit impersonation. You can do this programmatically or in the configuration file.
 wcfClient.ClientCredentials.Windows.AllowedImpersonationLevel = TokenImpersonationLevel.Impersonation;

 // Make calls using the proxy.
 Console.ForegroundColor = ConsoleColor.White;
 Console.WriteLine("Enter a greeting to send and press ENTER: ");
 Console.Write(">>> ");
 Console.ForegroundColor = ConsoleColor.Green;
 string greeting = Console.ReadLine();
 Console.ForegroundColor = ConsoleColor.White;
 Console.WriteLine("Called service with: \r\n\t" + greeting);
 Console.WriteLine("Service returned: " + wcfClient.Hello(greeting));
 Console.ForegroundColor = ConsoleColor.Blue;
 Console.Write("Press ");
 Console.ForegroundColor = ConsoleColor.Red;
 Console.Write("ENTER");
 Console.ForegroundColor = ConsoleColor.Blue;
 Console.Write(" to exit...");
 Console.ReadLine();
 wcfClient.Close();
 }
 catch (TimeoutException timeProblem)
 {
 Console.WriteLine("The service operation timed out. " + timeProblem.Message);
 wcfClient.Abort();
 Console.Read();
 }
 catch (CommunicationException commProblem)
 {
 Console.WriteLine("There was a communication problem. " + commProblem.Message);
 wcfClient.Abort();
 Console.Read();
 }
 }
 public static void Main()
 {
 Client client = new Client();
 client.Run();
 }
 }
}

Imports System.ServiceModel
Imports System.ServiceModel.Channels
Imports System.Security.Principal
Imports System.Threading

Namespace Microsoft.WCF.Documentation
 Public Class Client
 Public Sub Run()
 ' Picks up configuration from the config file.
 Dim wcfClient As New SampleHelloClient()
 Try
 ' Set the client credentials to permit impersonation. You can do this programmatically or in the configuration file.
 wcfClient.ClientCredentials.Windows.AllowedImpersonationLevel = TokenImpersonationLevel.Impersonation

 ' Make calls using the proxy.
 Console.ForegroundColor = ConsoleColor.White
 Console.WriteLine("Enter a greeting to send and press ENTER: ")
 Console.Write(">>> ")
 Console.ForegroundColor = ConsoleColor.Green
 Dim greeting = Console.ReadLine()
 Console.ForegroundColor = ConsoleColor.White
 Console.WriteLine("Called service with: " & vbCrLf & vbTab & greeting)
 Console.WriteLine("Service returned: " & wcfClient.Hello(greeting))
 Console.ForegroundColor = ConsoleColor.Blue
 Console.Write("Press ")
 Console.ForegroundColor = ConsoleColor.Red
 Console.Write("ENTER")
 Console.ForegroundColor = ConsoleColor.Blue
 Console.Write(" to exit...")
 Console.ReadLine()
 wcfClient.Close()
 Catch timeProblem As TimeoutException
 Console.WriteLine("The service operation timed out. " & timeProblem.Message)
 wcfClient.Abort()
 Console.Read()
 Catch commProblem As CommunicationException
 Console.WriteLine("There was a communication problem. " & commProblem.Message)
 wcfClient.Abort()
 Console.Read()
 End Try
 End Sub
 Public Shared Sub Main()
 Dim client As New Client()
 client.Run()
 End Sub
 End Class
End Namespace

Remarks

Use the Impersonation property (together with a binding configuration that supports impersonation) to enable specified methods (those marked with the Impersonation property set to Allowed or Required) to execute under the caller's identity. For details, including how impersonation is performed when using Allowed together with the ServiceAuthorizationBehavior.ImpersonateCallerForAllOperations property, see Delegation and Impersonation and How to: Impersonate a Client on a Service.

There may be specific scenarios when impersonation is not supported. For more information, see Unsupported Scenarios.