(Delphi DLL) Verify XAdES with External File Reference

Demonstrates how to validate an XML digital signature that contains a reference to an external file. (This is one way of doing it..)

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, XmlDSig, StringBuilder;

...

procedure TForm1.Button1Click(Sender: TObject);
var
sbXml: HCkStringBuilder;
success: Boolean;
validator: HCkXmlDSig;
i: Integer;
valid: Boolean;

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

// Load the XAdES file to be validated..
sbXml := CkStringBuilder_Create();
success := CkStringBuilder_LoadFile(sbXml,'qa_data/xml_dsig_valid_samples/externalFile/test.pdf.XAdES','utf-8');
if (success = False) then
  begin
    Memo1.Lines.Add('Failed to load XAdES input file.');
    Exit;
  end;

validator := CkXmlDSig_Create();

// Specify a set of absolute or relative directory paths to be searched for any external file references.
// Directory paths are separated by semicolon chars.
CkXmlDSig_putExternalRefDirs(validator,'qa_data/externalFiles;qa_data/xml_dsig_valid_samples/externalFile;c:/someOtherDir');

success := CkXmlDSig_LoadSignatureSb(validator,sbXml);
if (success = False) then
  begin
    Memo1.Lines.Add(CkXmlDSig__lastErrorText(validator));
    Exit;
  end;

// Validate signatures as usual..
i := 0;
while i < CkXmlDSig_getNumSignatures(validator) do
  begin
    CkXmlDSig_putSelector(validator,i);

    valid := CkXmlDSig_VerifySignature(validator,True);
    Memo1.Lines.Add('Signature ' + IntToStr(i + 1) + ' and all reference digests OK = ' + IntToStr(Ord(valid)));

    i := i + 1;
  end;

CkStringBuilder_Dispose(sbXml);
CkXmlDSig_Dispose(validator);

end;