(PureBasic) Calculate HRMC IRMark

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

Chilkat PureBasic Module Download

Chilkat PureBasic Module

IncludeFile "CkXml.pb"
IncludeFile "CkXmlDSig.pb"
IncludeFile "CkCrypt2.pb"

Procedure 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.
    xml.i = CkXml::ckCreate()
    If xml.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkXml::setCkTag(xml, "GovTalkMessage")
    CkXml::ckAddAttribute(xml,"xmlns","http://www.govtalk.gov.uk/CM/envelope")
    CkXml::ckUpdateAttrAt(xml,"Body|Message",1,"xmlns","urn:g3.ge:dea:call:SendDocument:v1")
    CkXml::ckUpdateChildContent(xml,"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>

    Debug CkXml::ckGetXml(xml)

    ;  Canonicalize the XML (using C14N)
    xdsig.i = CkXmlDSig::ckCreate()
    If xdsig.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    withComments.i = 0
    canonXml.s = CkXmlDSig::ckCanonicalizeXml(xdsig,CkXml::ckGetXml(xml),"C14N",withComments)

    ;  Return the base64 SHA-1 HASH of the canonical XML.
    crypt.i = CkCrypt2::ckCreate()
    If crypt.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkCrypt2::setCkHashAlgorithm(crypt, "sha1")
    CkCrypt2::setCkEncodingMode(crypt, "base64")
    irmark.s = CkCrypt2::ckHashStringENC(crypt,canonXml)

    Debug "IRMark = " + irmark


    CkXml::ckDispose(xml)
    CkXmlDSig::ckDispose(xdsig)
    CkCrypt2::ckDispose(crypt)


    ProcedureReturn
EndProcedure