BUG: "Access is denied" Error Message When Making HTTPS Requests with ServerXMLHTTP (302080)

CAUSE

Secure Sockets Layer (SSL) certificate support was added to the ServerXMLHTTP request object with the release of MSXML version 3.0 Service Pack 1. To make any SSL requests from the Web server, ServerXMLHTTP expects a client digital certificate to be installed, even if the target Web server does not require a client certificate.

RESOLUTION

To work around this problem, do one of the following:

Run the Active Server Pages (ASP) application in Microsoft Internet Information Server (IIS) and set the application protection level to Low (IIS Process).
If the ASP application is configured as out-of-process and the application protection level is set to Medium (Pooled) or High (Isolation), install a client certificate under the MY store of the IWAM_machinename user account.For additional information, click the article number below to view the article in the Microsoft Knowledge Base:
301429 HOWTO: Install Client Certificate on IIS Server for ServerXMLHTTP Request Object

MORE INFORMATION

If the client certificate is not properly installed, you may receive the following error message along with the main error message:

msxml3.dll (0x80072F0C) A certificate is required to complete client authentication

Steps to Reproduce Behavior

The test requires two Web servers, ServerA and ServerB. One server is a target Web server with a valid SSL server certificate installed, and the other is a client Web server.

Install a valid SSL server certificate on ServerA.

On ServerA, save the following code as Targetpage.asp:

<%@ Language="JScript" %>
<%
Response.Buffer=true ;


var oxmldom = Server.CreateObject("MSXML2.DOMDocument.3.0");
oxmldom.async=false;

oxmldom.loadXML("<msg><id>TargetPage</id></msg>");
Response.Write(oxmldom.xml);
%>

Save the following code as Client.asp on ServerB, and make sure that ServerB is set with Medium or High application protection.

<%@ Language="JScript" %>
<%
	try
	{
		var Req = Server.CreateObject("Msxml2.ServerXMLHTTP.3.0");
		var xmlDoc = Server.CreateObject("Msxml2.DOMDocument.3.0");
		
		xmlDoc.async = false;
		xmlDoc.loadXML("<msg><id>1</id></msg>");
		
		var URL = "https://targetserver/targetpage.asp";
		Req.open("POST", URL, false);
		Req.send(xmlDoc);

		Response.Write("<BR>Status = " + Req.status);
		Response.Write("<BR>responseText = " + Req.responseText);
	}
	catch( e )
	{	
		Response.Write( "Exception!!<BR>");
		Response.Write(e.number + "<BR>");
		Response.Write(e.description + "<BR>");
	}	
%>

In Microsoft Internet Explorer, run the ASP page (http://ServerB/client.asp).