JScript Source: verify.js

var xmldoc, xmldsig, infile;

DSIGNS = "xmlns:ds='http://www.w3.org/2000/09/xmldsig#'";
infile = "signature.verify.dsa.xml";

if (InitXML()) 
{
  alert("Verifying signature.\n");
  if (LoadXML(infile)) {
    VerifyXML();
  }
}

/////////  Helper functions: /////////
function alert(str) { WScript.echo(str); } 

///////// Set signature for signing. ////////
function InitXML()
{
   try {
     xmldoc = new ActiveXObject("Msxml2.DOMDOcument.5.0");
     xmldsig= new ActiveXObject("Msxml2.MXDigitalSignature.5.0");
   }
   catch (e) {
     alert("Installation of mxsml5 is required to run this app.\n");
     return false;
   }
   
   xmldoc.async = false;
   xmldoc.preserveWhiteSpace = true;
   xmldoc.validateOnParse = false;
   xmldoc.resolveExternals = false;
   return true;
}

function LoadXML(file)
{
   if (xmldoc == null) {
     alert("must instantiate xml dom\n");
     return false;
   }
  
   if (!xmldoc.load(file)) {
     alert("Can't load "+ file + "\n");
     return false;
   }
   xmldoc.setProperty("SelectionNamespaces", DSIGNS);
   xmldsig.signature = xmldoc.selectSingleNode(".//ds:Signature");
   return true;
}


function VerifyXML()
{
   if (!xmldsig.signature) {
      alert("Invalid signature.\n");
      return false;
   }

   var oKeyInfo = xmldoc.selectSingleNode(".//ds:KeyInfo/ds:KeyValue");
   if (!oKeyInfo) {
      alert("Invalid <KeyInfo> element.\n");
      return false;
   }

   var oKey = xmldsig.createKeyFromNode(oKeyInfo);
   if (!oKey)
   {
      alert("Failed to create key from <KeyInfo>\n");
      return false;
   }

   var oVerifiedKey = xmldsig.verify(oKey); 
   if (oVerifiedKey == null) {
      alert("Signature not verified.\n");
   }

   alert("Signature verified.\n");
   return true;
}

Try It!

1. Ensure that you have completed all the procedures in Getting Started with XML Digital Signatures.
2. Copy the XML signature resource file, and paste it into a text file. Save the file as signature.verify.dsa.xml.
3. Copy the JScript listing above, and paste it into a text file. Save the file as verify.js, in the same directory where you saved signature.verify.dsa.xml.
4. From a command prompt, navigate to this directory, then type "cscript verify.js".

   Note   Under operating systems other than Windows 2000 or Windows XP, you might need to install Windows Scripting Host (to run cscript.exe or wscript.exe), if it is not already installed.

5. Verify that your output is the same as that listed in the Output topic.