Delphi DLL

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 DLL

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, StringBuilder, PrivateKey, Rsa, Xml;

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
xml: HCkXml;
daXml: HCkXml;
sbFlattened: HCkStringBuilder;
privKey: HCkPrivateKey;
rsa: HCkRsa;
sig: PWideChar;

begin
success := False;

// 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 := CkXml_Create();

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

// Get a reference to the "DA" element
daXml := CkXml_FindChild(xml,'Documento|TED|DD|CAF|DA');
if (CkXml_getLastMethodSuccess(xml) = False) 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 := CkStringBuilder_Create();
CkXml_putEmitCompact(daXml,True);
CkXml_putEmitXmlDecl(daXml,False);
CkXml_GetXmlSb(daXml,sbFlattened);

// 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 := CkPrivateKey_Create();
success := CkPrivateKey_LoadAnyFormatFile(privKey,'qa_data/rsa/rsaPrivKey_pkcs8.pem','');
if (success = False) then
  begin
    Memo1.Lines.Add(CkPrivateKey__lastErrorText(privKey));
    Exit;
  end;

rsa := CkRsa_Create();
CkRsa_UsePrivateKey(rsa,privKey);

CkRsa_putEncodingMode(rsa,'base64');
CkRsa_putCharset(rsa,'iso-8859-1');
sig := CkRsa__signStringENC(rsa,CkStringBuilder__getAsString(sbFlattened),'sha1');

// Add the FRMA signature element to the XML.
CkXml_UpdateChildContent(xml,'Documento|TED|DD|CAF|FRMA',sig);
CkXml_UpdateAttrAt(xml,'Documento|TED|DD|CAF|FRMA',True,'algoritmo','SHA1withRSA');

CkXml_Dispose(daXml);

// See what we have:
CkXml_putEmitCompact(xml,False);
CkXml_putEmitXmlDecl(xml,True);
Memo1.Lines.Add(CkXml__getXml(xml));

CkXml_SaveXml(xml,'qa_data/xml_dsig/sii_cl/test_1.xml');

CkXml_Dispose(xml);
CkStringBuilder_Dispose(sbFlattened);
CkPrivateKey_Dispose(privKey);
CkRsa_Dispose(rsa);

end;