CkPython

Calculate HRMC IRMark

See more XML Digital Signatures Examples

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

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CkPython

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)