How to: Create a Custom Principal Identity
The PrincipalPermissionAttribute is a declarative means of controlling access to service methods. When using this attribute, the PrincipalPermissionMode enumeration specifies the mode for performing authorization checks. When this mode is set to Custom, it enables the user to specify a custom IPrincipal class returned by the CurrentPrincipal property. This topic illustrates the scenario when Custom is used in combination with a custom authorization policy and a custom principal.
For more information about using the PrincipalPermissionAttribute, see How to: Restrict Access with the PrincipalPermissionAttribute Class.
Example
namespace CustomMode
{
public class Test
{
public static void Main()
{
try
{
ShowPrincipalPermissionModeCustom ppwm = new ShowPrincipalPermissionModeCustom();
ppwm.Run();
}
catch (Exception exc)
{
Console.WriteLine("Error: {0}", exc.Message);
Console.ReadLine();
}
}
}
class ShowPrincipalPermissionModeCustom
{
[ServiceContract]
interface ISecureService
{
[OperationContract]
string Method1(string request);
}
[ServiceBehavior]
class SecureService : ISecureService
{
[PrincipalPermission(SecurityAction.Demand, Role = "everyone")]
public string Method1(string request)
{
return String.Format("Hello, \"{0}\"", Thread.CurrentPrincipal.Identity.Name);
}
}
public void Run()
{
Uri serviceUri = new Uri(@"http://localhost:8006/Service");
ServiceHost service = new ServiceHost(typeof(SecureService));
service.AddServiceEndpoint(typeof(ISecureService), GetBinding(), serviceUri);
List<IAuthorizationPolicy> policies = new List<IAuthorizationPolicy>();
policies.Add(new CustomAuthorizationPolicy());
service.Authorization.ExternalAuthorizationPolicies = policies.AsReadOnly();
service.Authorization.PrincipalPermissionMode = PrincipalPermissionMode.Custom;
service.Open();
EndpointAddress sr = new EndpointAddress(
serviceUri, EndpointIdentity.CreateUpnIdentity(WindowsIdentity.GetCurrent().Name));
ChannelFactory<ISecureService> cf = new ChannelFactory<ISecureService>(GetBinding(), sr);
ISecureService client = cf.CreateChannel();
Console.WriteLine("Client received response from Method1: {0}", client.Method1("hello"));
((IChannel)client).Close();
Console.ReadLine();
service.Close();
}
public static Binding GetBinding()
{
WSHttpBinding binding = new WSHttpBinding(SecurityMode.Message);
binding.Security.Message.ClientCredentialType = MessageCredentialType.Windows;
return binding;
}
class CustomAuthorizationPolicy : IAuthorizationPolicy
{
string id = Guid.NewGuid().ToString();
public string Id
{
get { return this.id; }
}
public ClaimSet Issuer
{
get { return ClaimSet.System; }
}
public bool Evaluate(EvaluationContext context, ref object state)
{
object obj;
if (!context.Properties.TryGetValue("Identities", out obj))
return false;
IList<IIdentity> identities = obj as IList<IIdentity>;
if (obj == null || identities.Count <= 0)
return false;
context.Properties["Principal"] = new CustomPrincipal(identities[0]);
return true;
}
}
class CustomPrincipal : IPrincipal
{
IIdentity identity;
public CustomPrincipal(IIdentity identity)
{
this.identity = identity;
}
public IIdentity Identity
{
get { return this.identity; }
}
public bool IsInRole(string role)
{
return true;
}
}
}
}
Namespace CustomMode
Public Class Test
Public Shared Sub Main()
Try
Dim ppwm As New ShowPrincipalPermissionModeCustom()
ppwm.Run()
Catch exc As Exception
Console.WriteLine("Error: {0}", exc.Message)
Console.ReadLine()
End Try
End Sub
End Class
Friend Class ShowPrincipalPermissionModeCustom
<ServiceContract> _
Private Interface ISecureService
<OperationContract> _
Function Method1(ByVal request As String) As String
End Interface
<ServiceBehavior> _
Private Class SecureService
Implements ISecureService
<PrincipalPermission(SecurityAction.Demand, Role:="everyone")> _
Public Function Method1(ByVal request As String) As String Implements ISecureService.Method1
Return String.Format("Hello, ""{0}""", Thread.CurrentPrincipal.Identity.Name)
End Function
End Class
Public Sub Run()
Dim serviceUri As New Uri("http://localhost:8006/Service")
Dim service As New ServiceHost(GetType(SecureService))
service.AddServiceEndpoint(GetType(ISecureService), GetBinding(), serviceUri)
Dim policies As New List(Of IAuthorizationPolicy)()
policies.Add(New CustomAuthorizationPolicy())
service.Authorization.ExternalAuthorizationPolicies = policies.AsReadOnly()
service.Authorization.PrincipalPermissionMode = PrincipalPermissionMode.Custom
service.Open()
Dim sr As New EndpointAddress(serviceUri, EndpointIdentity.CreateUpnIdentity(WindowsIdentity.GetCurrent().Name))
Dim cf As New ChannelFactory(Of ISecureService)(GetBinding(), sr)
Dim client As ISecureService = cf.CreateChannel()
Console.WriteLine("Client received response from Method1: {0}", client.Method1("hello"))
CType(client, IChannel).Close()
Console.ReadLine()
service.Close()
End Sub
Public Shared Function GetBinding() As Binding
Dim binding As New WSHttpBinding(SecurityMode.Message)
binding.Security.Message.ClientCredentialType = MessageCredentialType.Windows
Return binding
End Function
Private Class CustomAuthorizationPolicy
Implements IAuthorizationPolicy
Private id_Renamed As String = Guid.NewGuid().ToString()
Public ReadOnly Property Id() As String Implements System.IdentityModel.Policy.IAuthorizationComponent.Id
Get
Return Me.id_Renamed
End Get
End Property
Public ReadOnly Property Issuer() As ClaimSet Implements IAuthorizationPolicy.Issuer
Get
Return ClaimSet.System
End Get
End Property
Public Function Evaluate(ByVal context As EvaluationContext, ByRef state As Object) As Boolean Implements IAuthorizationPolicy.Evaluate
Dim obj As Object = Nothing
If (Not context.Properties.TryGetValue("Identities", obj)) Then
Return False
End If
Dim identities As IList(Of IIdentity) = TryCast(obj, IList(Of IIdentity))
If obj Is Nothing OrElse identities.Count <= 0 Then
Return False
End If
context.Properties("Principal") = New CustomPrincipal(identities(0))
Return True
End Function
End Class
Private Class CustomPrincipal
Implements IPrincipal
Private identity_Renamed As IIdentity
Public Sub New(ByVal identity As IIdentity)
Me.identity_Renamed = identity
End Sub
Public ReadOnly Property Identity() As IIdentity Implements IPrincipal.Identity
Get
Return Me.identity_Renamed
End Get
End Property
Public Function IsInRole(ByVal role As String) As Boolean Implements IPrincipal.IsInRole
Return True
End Function
End Class
End Class
End Namespace
Compiling the Code
References to the following namespaces are needed to compile the code: