HOW TO: Use ASP to Force SSL for Specific Pages

It is frequently good security practice to require Secure Sockets Layer (SSL) for certain pages on a Web site. Although this can be configured through the Internet Services Manager (ISM) in the Microsoft Management Console (MMC), you can also use Active Server Pages (ASP) to force SSL for specific pages without making changes in the MMC.

Prerequisites

This article assumes the following conditions:

• IIS is running on standard ports:
  • HTTP = Port 80
  • HTTPS = Port 443
• IIS has a valid SSL certificate installed.
• The Web site or virtual server that is used does not use HTTP/1.1 host headers for name resolution.

Forcing SSL using ASP

To force SSL using ASP, follow these steps:

1. Click Start, click Run, type Notepad, and then click OK.
2. Paste the following code into a blank Notepad document. On the File menu, click Save As, and then save the following code in the root of your Web server as an include file named ForceSSL.inc:

   <%
      If Request.ServerVariables("SERVER_PORT")=80 Then
         Dim strSecureURL
         strSecureURL = "https://"
         strSecureURL = strSecureURL & Request.ServerVariables("SERVER_NAME")
         strSecureURL = strSecureURL & Request.ServerVariables("URL")
         Response.Redirect strSecureURL
      End If
   %>
   					

3. For each page that requires SSL, paste the following code at the top of the page to reference the include file from the previous step:

   <%@Language="VBSCRIPT"%>
   <!--#include virtual="/ForceSSL.inc"-->
   					

   When each page is browsed, the ASP code that is contained in the include file detects the port to determine if HTTP is used. If HTTP is used, the browser will be redirected to the same page by using HTTPS.