(CkPython) Calculate HRMC IRMark

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

Chilkat Python Downloads

install with pip
pip3 install chilkat
or download... Python Module for Windows, MacOS, Linux, Alpine Linux

import 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()
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())

# Canonicalize the XML (using C14N)
xdsig = chilkat.CkXmlDSig()
withComments = False
canonXml = xdsig.canonicalizeXml(xml.getXml(),"C14N",withComments)

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

print("IRMark = " + irmark)