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WindowsClientCredential.AllowedImpersonationLevel Property


Gets or sets the allowed impersonation level.

 property System::Security::Principal::TokenImpersonationLevel AllowedImpersonationLevel { System::Security::Principal::TokenImpersonationLevel get(); void set(System::Security::Principal::TokenImpersonationLevel value); };
public System.Security.Principal.TokenImpersonationLevel AllowedImpersonationLevel { get; set; }
member this.AllowedImpersonationLevel : System.Security.Principal.TokenImpersonationLevel with get, set
Public Property AllowedImpersonationLevel As TokenImpersonationLevel

Property Value

One of the TokenImpersonationLevel values.


The following example shows how to set this property.

// Create a service host.
EndpointAddress ea = new EndpointAddress("http://localhost/Calculator");
WSHttpBinding b = new WSHttpBinding(SecurityMode.Message);
b.Security.Message.ClientCredentialType = MessageCredentialType.Windows;

// Create a client. The code is not shown here. See the WCF samples
// for an example of the CalculatorClient code.

CalculatorClient cc = new CalculatorClient(b, ea);
// Get a reference to the Windows client credential object.
WindowsClientCredential winCred= cc.ClientCredentials.Windows;
Console.WriteLine("AllowedImpersonationLevel: {0}",
Console.WriteLine("AllowNtlm: {0}", winCred.AllowNtlm);
Console.WriteLine("Domain: {0}", winCred.ClientCredential.Domain);

// Change the AllowedImpersonationLevel.
winCred.AllowedImpersonationLevel =

Console.WriteLine("Changed AllowedImpersonationLevel: {0}",
// Open the calculator and use it.
//Console.WriteLine(cc.Add(11, 11));

//// Close the client.
' Create a service host.
Dim ea As New EndpointAddress("http://localhost/Calculator")
Dim b As New WSHttpBinding(SecurityMode.Message)
b.Security.Message.ClientCredentialType = _

' Create a client. The code is not shown here. See the WCF samples
' for an example of the CalculatorClient code.
Dim cc As New CalculatorClient(b, ea)
' Get a reference to the Windows client credential object.
Dim winCred As WindowsClientCredential = cc.ClientCredentials.Windows
Console.WriteLine("AllowedImpersonationLevel: {0}", _
Console.WriteLine("AllowNtlm: {0}", winCred.AllowNtlm)
Console.WriteLine("Domain: {0}", winCred.ClientCredential.Domain)

' Change the AllowedImpersonationLevel.
winCred.AllowedImpersonationLevel = _

Console.WriteLine("Changed AllowedImpersonationLevel: {0}", _
' Open the calculator and use it.
' cc.Open()
' Console.WriteLine(cc.Add(11, 11))
' Close the client.
' cc.Close()


This property specifies the impersonation level granted by the client to the server when using Windows SSPI Negotiate authentication. Note that the impersonation level obtained by the server when it impersonates the client token is not solely a function of this setting. It is also a function of the associated privileges and domain settings for the account in which the service is running.

The client must explicitly set the allowed impersonation level using this property.

When the client specifies anonymous impersonation the client always authenticates to the service as anonymous even when no impersonation is performed on the service. This is due to underlying Windows operating system behavior.

For more information about Windows impersonation, go to Impersonating and Reverting. For more information about impersonation using Windows Communication Foundation, see Delegation and Impersonation.

Applies to