(Delphi DLL) Calculate HRMC IRMark

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

Chilkat for Delphi Downloads

Chilkat non-ActiveX DLL for Delphi

Chilkat ActiveX DLL for Delphi

* The examples here use the non-ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Xml, XmlDSig, Crypt2;

...

procedure TForm1.Button1Click(Sender: TObject);
var
xml: HCkXml;
xdsig: HCkXmlDSig;
withComments: Boolean;
canonXml: PWideChar;
crypt: HCkCrypt2;
irmark: PWideChar;

begin
//  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 := CkXml_Create();
CkXml_putTag(xml,'GovTalkMessage');
CkXml_AddAttribute(xml,'xmlns','http://www.govtalk.gov.uk/CM/envelope');
CkXml_UpdateAttrAt(xml,'Body|Message',True,'xmlns','urn:g3.ge:dea:call:SendDocument:v1');
CkXml_UpdateChildContent(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>

Memo1.Lines.Add(CkXml__getXml(xml));

//  Canonicalize the XML (using C14N)
xdsig := CkXmlDSig_Create();
withComments := False;
canonXml := CkXmlDSig__canonicalizeXml(xdsig,CkXml__getXml(xml),'C14N',withComments);

//  Return the base64 SHA-1 HASH of the canonical XML.
crypt := CkCrypt2_Create();
CkCrypt2_putHashAlgorithm(crypt,'sha1');
CkCrypt2_putEncodingMode(crypt,'base64');
irmark := CkCrypt2__hashStringENC(crypt,canonXml);

Memo1.Lines.Add('IRMark = ' + irmark);

CkXml_Dispose(xml);
CkXmlDSig_Dispose(xdsig);
CkCrypt2_Dispose(crypt);

end;