Pascal (Lazarus/Delphi)

Examine KeyInfo Certificate in XML Signature

See more XML Digital Signatures Examples

This example loads signed XML and gets the signing certificate, assuming the certificate is contained in X509Certificate within the KeyInfo. Pascal (Lazarus/Delphi)

program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.StringBuilder,
  Chilkat.Xml,
  Chilkat.XmlDSig,
  Chilkat.Cert;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  success: Boolean;
  dsig: TXmlDSig;
  sbXml: TStringBuilder;
  xmlKeyInfo: TXml;
  certBase64: string;
  cert: TCert;

begin
  success := False;

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

  dsig := TXmlDSig.Create;
  sbXml := TStringBuilder.Create;

  success := sbXml.LoadFile('c:/aaworkarea/elias/3/face_f09006808443a699d1b.xml','utf-8');
  if (success <> True) then
    begin
      WriteLn('Failed to load XML file.');
      Exit;
    end;

  success := dsig.LoadSignatureSb(sbXml);
  if (success <> True) then
    begin
      WriteLn(dsig.LastErrorText);
      Exit;
    end;

  //  Get the KeyInfo XML.
  xmlKeyInfo := dsig.GetKeyInfo();
  if (dsig.LastMethodSuccess <> True) then
    begin
      WriteLn(dsig.LastErrorText);
      Exit;
    end;

  WriteLn(xmlKeyInfo.GetXml());
  WriteLn('----');

  //  Assuming the X509Certificate is in the KeyInfo, it will look like this:

  //    <ds:KeyInfo Id="...">
  //      <ds:KeyValue>
  //      ...  
  //      <ds:X509Data>
  //        <ds:X509Certificate>MIIHAz...</ds:X509Certificate>
  //      </ds:X509Data>
  //    </ds:KeyInfo>
  certBase64 := xmlKeyInfo.GetChildContent('*:X509Data|*:X509Certificate');
  if (xmlKeyInfo.LastMethodSuccess <> True) then
    begin
      WriteLn('No X509Certificate found in the KeyInfo.');
      Exit;
    end;

  //  Load a certificate object w/ the base64.
  cert := TCert.Create;
  success := cert.LoadFromBase64(certBase64);
  if (success <> True) then
    begin
      WriteLn(cert.LastErrorText);
      Exit;
    end;

  //  Examine the cert..
  WriteLn('SubjectDN: ' + cert.SubjectDN);
  WriteLn('IssuerDN: ' + cert.IssuerDN);
  WriteLn('SerialNumber as Decimal: ' + cert.SerialDecimal);

  xmlKeyInfo.Free;


  dsig.Free;
  sbXml.Free;
  cert.Free;

end;

// ---------------------------------------------------------------------------

begin

  try
    RunDemo;
  except
    on E: Exception do
      WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
  end;

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.