FIX: You cannot access a website that does not support TLS v1.0 when you enable HTTPS inspection and set HTTPSiClientProtocols

Symptoms

Consider the following scenario:

• In a Microsoft Forefront Threat Management Gateway (TMG) 2010 environment, you enable HTTPS Inspection.

• You set the HTTPSiClientProtocols Const SE_VPS_VALUE value to 160. This value is mentioned in article 982876 in the Microsoft Knowledge Base.

• You try to access an HTTPS website that does not support TLS v1.0.

In this scenario, you cannot access the website.

Cause

The issue occurs because TMG 2010 sends a client "hello" message that offers TLS. However, because the web server does not support TLS, it rejects the message and closes the connection. In this scenario, the client typically falls back to SSL v3.0. However, TMG does not fall back to SSL v3.0 when HTTPS Inspection is enabled.

Resolution

To resolve this issue, install the software update that is described in the following article in the Microsoft Knowledge Base:

2517957 Software Update 1 Rollup 4 for Forefront Threat Management Gateway (TMG) 2010 Service Pack 1To enable this fix, follow these steps:

1. Start Notepad.

2. Copy and paste the following script into Notepad:

   ''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
   '
   ' Copyright (c) Microsoft Corporation. All rights reserved.
   ' THIS CODE IS MADE AVAILABLE AS IS, WITHOUT WARRANTY OF ANY KIND. THE ENTIRE
   ' RISK OF THE USE OR THE RESULTS FROM THE USE OF THIS CODE REMAINS WITH THE
   ' USER. USE AND REDISTRIBUTION OF THIS CODE, WITH OR WITHOUT MODIFICATION, IS
   ' HEREBY PERMITTED.
   ''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
   
   ''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
   ' This script disables the use of old client protocols like PCT and SSLv2
   ''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
   
   Const SE_VPS_GUID = "{143F5698-103B-12D4-FF34-1F34767DEabc}"
   Const SE_VPS_NAME = "HTTPSiDontUseOldClientProtocols"
   Const SE_VPS_VALUE = TRUE
   Sub SetValue()
       ' Create the root object.
       Dim root
       ' The FPCLib.FPC root object
       Set root = CreateObject("FPC.Root")
       'Declare the other objects that are needed.
       Dim array       ' An FPCArray object
       Dim VendorSets
       ' An FPCVendorParametersSets collection
       Dim VendorSet
       ' An FPCVendorParametersSet object
       Set array = root.GetContainingArray
       Set VendorSets = array.VendorParametersSets
       On Error Resume Next
       Set VendorSet = VendorSets.Item( SE_VPS_GUID )
       If Err.Number <> 0 Then
           Err.Clear        ' Add the item.
           Set VendorSet = VendorSets.Add( SE_VPS_GUID )
           CheckError
           WScript.Echo "New VendorSet added... " & VendorSet.Name
       Else
           WScript.Echo "Existing VendorSet found... value- " &  VendorSet.Value(SE_VPS_NAME)
       End If
       if VendorSet.Value(SE_VPS_NAME)  <>  SE_VPS_VALUE Then
           Err.Clear
           VendorSet.Value(SE_VPS_NAME) = SE_VPS_VALUE
           If Err.Number <> 0 Then
               CheckError
           Else
               VendorSets.Save false, true
               CheckError
               If Err.Number = 0 Then
                   WScript.Echo "Done with " & SE_VPS_NAME & ", saved!"
               End If
           End If
       Else
           WScript.Echo "Done with " & SE_VPS_NAME & ", no change!"
       End If
   End Sub
   Sub CheckError()
       If Err.Number <> 0 Then
           WScript.Echo "An error occurred: 0x" & Hex(Err.Number) & " " & Err.Description
           Err.Clear
       End If
   End Sub
   SetValue

3. Save the Notepad file by using the .vbs file name extension. For example, use the following name when you save this file:

   EnableHTTPSiDontUseOldClientProtocols.vbs

4. At a command prompt, run the script. For example, use the following syntax to run the script:

   cscript.exe EnableHTTPSiDontUseOldClientProtocols.vbs

Status

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.