(Node.js) Calculate HRMC IRMark

Demonstrates how to calculate an IRmark for an HMRC GovTalkMessage XML document.

Install Chilkat for Node.js and Electron using npm at

Chilkat npm packages for Node.js
Chilkat npm packages for Electron
on Windows, Linux, MacOSX, and ARM

var os = require('os');
if (os.platform() == 'win32') {  
    if (os.arch() == 'ia32') {
        var chilkat = require('@chilkat/ck-node21-win-ia32');
    } else {
        var chilkat = require('@chilkat/ck-node21-win64'); 
    }
} else if (os.platform() == 'linux') {
    if (os.arch() == 'arm') {
        var chilkat = require('@chilkat/ck-node21-arm');
    } else if (os.arch() == 'x86') {
        var chilkat = require('@chilkat/ck-node21-linux32');
    } else {
        var chilkat = require('@chilkat/ck-node21-linux64');
    }
} else if (os.platform() == 'darwin') {
    if (os.arch() == 'arm64') {
        var chilkat = require('@chilkat/ck-node21-mac-m1');
    } else {
        var chilkat = require('@chilkat/ck-node21-macosx');
    }
}

function chilkatExample() {

    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    // First build a sample (but incomplete) GovTalkMessage.
    // You can replace this code with a call to LoadXml or LoadXmlFile..
    // 
    // Note: The online tool at https://tools.chilkat.io/xmlCreate.cshtml
    // can be used to generate XML code that creates a given XML document.
    var xml = new chilkat.Xml();
    xml.Tag = "GovTalkMessage";
    xml.AddAttribute("xmlns","http://www.govtalk.gov.uk/CM/envelope");
    xml.UpdateAttrAt("Body|Message",true,"xmlns","urn:g3.ge:dea:call:SendDocument:v1");
    xml.UpdateChildContent("Body|Message","................");

    // This is the XML created:
    // <?xml version="1.0" encoding="utf-8" ?>
    // <GovTalkMessage xmlns="http://www.govtalk.gov.uk/CM/envelope">
    //     <Body>
    //         <Message xmlns="urn:g3.ge:dea:call:SendDocument:v1">................</Message>
    //     </Body>
    // </GovTalkMessage>

    console.log(xml.GetXml());

    // Canonicalize the XML (using C14N)
    var xdsig = new chilkat.XmlDSig();
    var withComments = false;
    var canonXml = xdsig.CanonicalizeXml(xml.GetXml(),"C14N",withComments);

    // Return the base64 SHA-1 HASH of the canonical XML.
    var crypt = new chilkat.Crypt2();
    crypt.HashAlgorithm = "sha1";
    crypt.EncodingMode = "base64";
    var irmark = crypt.HashStringENC(canonXml);

    console.log("IRMark = " + irmark);

}

chilkatExample();