Delphi ActiveX

SII Chile - FRMA Signature Computation and Add to XML

See more XML Digital Signatures Examples

Compute the FRMA signature of a <DA> element enclosed inside a <CAF> element of the XML to be signed. Delphi ActiveX

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

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Integer;
xml: TChilkatXml;
daXml: IChilkatXml;
sbFlattened: TChilkatStringBuilder;
privKey: TPrivateKey;
rsa: TChilkatRsa;
sig: WideString;

begin
success := 0;

// This example assumes the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

// Also see:  Compute the FRMT Signature and Add to XML

xml := TChilkatXml.Create(Self);

// Load the unsigned XML that contains the following:

// <DTE version="1.0">
//   <Documento ID="F60T33">
//         <TED version="1.0">
//             <DD>
// 		...
//                 <CAF version="1.0">
//                     <DA>
// 			...
//                     </DA>
// 			... The FRMA will be added here ...
//                 </CAF>
//                 ...
//             </DD>
//             ... The FRMT will be added here in another example ...
//         </TED>
//   </Documento>
// </DTE>

success := xml.LoadXmlFile('qa_data/xml_dsig/sii_cl/test_0.xml');
if (success = 0) then
  begin
    Memo1.Lines.Add('Failed to load initial XML file.');
    Exit;
  end;

// Get a reference to the "DA" element
daXml := xml.FindChild('Documento|TED|DD|CAF|DA');
if (xml.LastMethodSuccess = 0) then
  begin
    Memo1.Lines.Add('Failed to find DA element');
    Exit;
  end;

//  We need to get the "flattened" DA XML where:
//    - No whitespace between elements.
//    - The 5 pre-defined entities are converted.
//    - The text is encoded in the ISO-8859-1 character set (Latin-1), 
sbFlattened := TChilkatStringBuilder.Create(Self);
daXml.EmitCompact := 1;
daXml.EmitXmlDecl := 0;
daXml.GetXmlSb(sbFlattened.ControlInterface);

// Compute the SHA-1 message digest of the iso-8859-1 byte representation, 
// and sign it with our RSA private key, getting the result in base64 format.

privKey := TPrivateKey.Create(Self);
success := privKey.LoadAnyFormatFile('qa_data/rsa/rsaPrivKey_pkcs8.pem','');
if (success = 0) then
  begin
    Memo1.Lines.Add(privKey.LastErrorText);
    Exit;
  end;

rsa := TChilkatRsa.Create(Self);
rsa.UsePrivateKey(privKey.ControlInterface);

rsa.EncodingMode := 'base64';
rsa.Charset := 'iso-8859-1';
sig := rsa.SignStringENC(sbFlattened.GetAsString(),'sha1');

// Add the FRMA signature element to the XML.
xml.UpdateChildContent('Documento|TED|DD|CAF|FRMA',sig);
xml.UpdateAttrAt('Documento|TED|DD|CAF|FRMA',1,'algoritmo','SHA1withRSA');

// See what we have:
xml.EmitCompact := 0;
xml.EmitXmlDecl := 1;
Memo1.Lines.Add(xml.GetXml());

xml.SaveXml('qa_data/xml_dsig/sii_cl/test_1.xml');
end;