AuthenticationSchemeSelector Delegate

Definition

Namespace:

System.Net

Assembly:

System.Net.HttpListener.dll

Selects the authentication scheme for an HttpListener instance.

public delegate System::Net::AuthenticationSchemes AuthenticationSchemeSelector(HttpListenerRequest ^ httpRequest);

public delegate System.Net.AuthenticationSchemes AuthenticationSchemeSelector(HttpListenerRequest httpRequest);

type AuthenticationSchemeSelector = delegate of HttpListenerRequest -> AuthenticationSchemes

Public Delegate Function AuthenticationSchemeSelector(httpRequest As HttpListenerRequest) As AuthenticationSchemes 

Parameters

httpRequest

HttpListenerRequest

The HttpListenerRequest instance for which to select an authentication scheme.

Return Value

AuthenticationSchemes

One of the AuthenticationSchemes values that indicates the method of authentication to use for the specified client request.

Examples

The following example uses an instance of this type to set the AuthenticationSchemeSelectorDelegate property.

// Set up a listener.
HttpListener listener = new HttpListener();
HttpListenerPrefixCollection prefixes = listener.Prefixes;
prefixes.Add(@"http://localhost:8080/");
prefixes.Add(@"http://contoso.com:8080/");

// Specify the authentication delegate.
listener.AuthenticationSchemeSelectorDelegate =
    new AuthenticationSchemeSelector (AuthenticationSchemeForClient);

// Start listening for requests and process them
// synchronously.
listener.Start();

' Set up a listener.
Dim listener As New HttpListener()
Dim prefixes As HttpListenerPrefixCollection = listener.Prefixes
prefixes.Add("http://localhost:8080/")
prefixes.Add("http://contoso.com:8080/")

' Specify the authentication delegate.
listener.AuthenticationSchemeSelectorDelegate = New AuthenticationSchemeSelector(AddressOf AuthenticationSchemeForClient)

' Start listening for requests and process them 
' synchronously.
listener.Start()

The following example shows the implementation of the method invoked by the AuthenticationSchemeSelector delegate in the previous example.

static AuthenticationSchemes AuthenticationSchemeForClient(HttpListenerRequest request)
{
    Console.WriteLine("Client authentication protocol selection in progress...");
    // Do not authenticate local machine requests.
    if (request.RemoteEndPoint.Address.Equals (IPAddress.Loopback))
    {
        return AuthenticationSchemes.None;
    }
    else
    {
        return AuthenticationSchemes.IntegratedWindowsAuthentication;
    }
}

Private Shared Function AuthenticationSchemeForClient(ByVal request As HttpListenerRequest) As AuthenticationSchemes
    Console.WriteLine("Client authentication protocol selection in progress...")
    ' Do not authenticate local machine requests.
    If request.RemoteEndPoint.Address.Equals(IPAddress.Loopback) Then
        Return AuthenticationSchemes.None
    Else
        Return AuthenticationSchemes.IntegratedWindowsAuthentication
    End If
End Function

Remarks

Delegates of this type are used by HttpListener instances to select an authentication scheme based on the characteristics of a request.

An AuthenticationSchemeSelector delegate is passed an HttpListenerRequest object for each incoming request that has not provided authentication information. The method invoked by the delegate uses the HttpListenerRequest object and any other available information to decide which authentication scheme to require. The delegate is specified by using the AuthenticationSchemeSelectorDelegate property.

Extension Methods

GetMethodInfo(Delegate)

Gets an object that represents the method represented by the specified delegate.