AuthenticationSchemeSelector Delegate


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Selects the authentication scheme for an HttpListener instance.

Namespace:   System.Net
Assembly:  System (in System.dll)

Public Delegate Function AuthenticationSchemeSelector (
	httpRequest As HttpListenerRequest
) As AuthenticationSchemes


Type: System.Net.HttpListenerRequest

The HttpListenerRequest instance for which to select an authentication scheme.

Return Value

Type: System.Net.AuthenticationSchemes

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

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.

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

' Set up a listener.
Dim listener As New HttpListener()
Dim prefixes As HttpListenerPrefixCollection = listener.Prefixes

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

' Start listening for requests and process them 
' synchronously.

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

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
        Return AuthenticationSchemes.IntegratedWindowsAuthentication
    End If
End Function

.NET Framework
Available since 2.0
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