(Ruby) Calculate HRMC IRMark

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

Chilkat Ruby Downloads

install from rubygems.org
gem install chilkat
or download... Ruby Library for Windows, MacOS, Linux, Alpine Linux

require 'chilkat'

# 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.
xml = Chilkat::CkXml.new()
xml.put_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>

print xml.getXml() + "\n";

# Canonicalize the XML (using C14N)
xdsig = Chilkat::CkXmlDSig.new()
withComments = false
canonXml = xdsig.canonicalizeXml(xml.getXml(),"C14N",withComments)

# Return the base64 SHA-1 HASH of the canonical XML.
crypt = Chilkat::CkCrypt2.new()
crypt.put_HashAlgorithm("sha1")
crypt.put_EncodingMode("base64")
irmark = crypt.hashStringENC(canonXml)

print "IRMark = " + irmark + "\n";