This script configures the FTPS Service in IIS to use client certificate authentication

ftps_ClientCertAuth_IIS.vbs

' This is a Robert McMurray's script, all the credit goes to him :)
' https://blogs.msdn.microsoft.com/robert_mcmurray/2012/04/26/configuring-ftp-client-certificate-authentication-in-ftp-7/
'
' Please change the following two variables before running it

Set strSiteName = "FTP"
Set strSserverCertHash = "884301293bad5ab538c0cfddcba7371cedfca647"

Set adminManager = CreateObject("Microsoft.ApplicationHost.WritableAdminManager")
adminManager.CommitPath = "MACHINE/WEBROOT/APPHOST"
Set sitesSection = adminManager.GetAdminSection("system.applicationHost/sites", "MACHINE/WEBROOT/APPHOST")
Set sitesCollection = sitesSection.Collection

siteElementPos = FindElement(sitesCollection, "site", Array("name", strSiteName ))
If (addElementPos = -1) Then
   WScript.Echo "Element not found!"
   WScript.Quit
End If
Set siteElement = sitesCollection.Item(siteElementPos)

Set ftpServerElement = siteElement.ChildElements.Item("ftpServer")
Set securityElement = ftpServerElement.ChildElements.Item("security")

Set sslClientCertificatesElement = securityElement.ChildElements.Item("sslClientCertificates")
sslClientCertificatesElement.Properties.Item("clientCertificatePolicy").Value = "CertRequire"
sslClientCertificatesElement.Properties.Item("useActiveDirectoryMapping").Value = True

Set authenticationElement = securityElement.ChildElements.Item("authentication")
Set clientCertAuthenticationElement = authenticationElement.ChildElements.Item("clientCertAuthentication")
clientCertAuthenticationElement.Properties.Item("enabled").Value = True

Set sslElement = securityElement.ChildElements.Item("ssl")
sslElement.Properties.Item("serverCertHash").Value = strSserverCertHash
sslElement.Properties.Item("controlChannelPolicy").Value = "SslRequire"
sslElement.Properties.Item("dataChannelPolicy").Value = "SslRequire"

adminManager.CommitChanges

Function FindElement(collection, elementTagName, valuesToMatch)
   For i = 0 To CInt(collection.Count) - 1
      Set element = collection.Item(i)
      If element.Name = elementTagName Then
         matches = True
         For iVal = 0 To UBound(valuesToMatch) Step 2
            Set property = element.GetPropertyByName(valuesToMatch(iVal))
            value = property.Value
            If Not IsNull(value) Then
               value = CStr(value)
            End If
            If Not value = CStr(valuesToMatch(iVal + 1)) Then
               matches = False
               Exit For
            End If
         Next
         If matches Then
            Exit For
         End If
      End If
   Next
   If matches Then
      FindElement = i
   Else
      FindElement = -1
   End If
End Function