Custom HTTPHandler is not getting called - asp.net

Question

I'm trying to make a HTTPHandler that will authenticate certain static resources, PDF Files in this case.
I've added the following to my web.config:
<configuration>
<system.web>
<httpHandlers>
<clear />
<add path="*.pdf" verb="*" validate="true" type="AuthenticatedStaticResourceHandler" />
</httpHandlers>
</system.web>
</configuration>
Here's my HTTPHandler class:
Imports Microsoft.VisualBasic
Public Class AuthenticatedStaticResourceHandler
Implements IHttpHandler
Public Sub ProcessRequest(ByVal context As HttpContext) Implements IHttpHandler.ProcessRequest
Dim resource As String = String.Empty
Select Case context.Request.HttpMethod
Case "GET"
resource = context.Server.MapPath(context.Request.FilePath)
If Helpers.User.CanAccessPath(context.Request.FilePath, context.User.Identity.Name) Then
SendContentTypeAndFile(context, resource)
Else
FormsAuthentication.RedirectToLoginPage()
End If
End Select
End Sub
Public ReadOnly Property IsReusable As Boolean Implements IHttpHandler.IsReusable
Get
Return False
End Get
End Property
Private Function SendContentTypeAndFile(ByVal context As HttpContext, ByVal file As String) As HttpContext
context.Response.ContentType = GetContentType(file)
context.Response.TransmitFile(file)
context.Response.End()
Return context
End Function
Private Function GetContentType(ByVal filename As String) As String
'Used to set the encoding for the reponse stream
Dim resource As String = String.Empty
Dim file As System.IO.FileInfo = New System.IO.FileInfo(filename)
If file.Exists Then
Select Case file.Extension.Remove(0, 1).ToLower()
Case "pdf"
resource = "application/pdf"
Case "jpg"
resource = "image/jpg"
Case "gif"
resource = "image/gif"
Case "png"
resource = "image/png"
Case "css"
resource = "text/css"
Case "js"
resource = "text/javascript"
Case Else
resource = String.Empty
End Select
End If
Return IIf(resource.Length > 0, resource, Nothing)
End Function
End Class
I've set a breakpoint on the Select Case context.Request.HttpMethod line in ProcessRequest, however when I try to access http://localhost/subfolder/subfolder/some.pdf the breakpoint is not triggered. Further, the example PDF I'm attempting to access is buried in a folder that I should not have access to, yet the PDF is served.
This leads me to believe that my HTTPHandler is not being called.
Am I missing something? What am I doing incorrectly?

Answer 1

Most likely, you have to add one extra part to your web.config to support all versions of IIS.
For IIS7 and higher, you need to register your handler in the system.webServer section:
<system.webServer>
<handlers>
<add ... />
</handlers>
</system.webServer>