Delphi ActiveX

Add EncapsulatedTimestamp to Already-Signed XML

See more XML Digital Signatures Examples

Demonstrates how to add an EncapsulatedTimestamp to an existing XML signature.

Note: This example requires Chilkat v9.5.0.90 or greater.

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;
sbXml: TChilkatStringBuilder;
dsig: TChilkatXmlDSig;
json: TChilkatJsonObject;
sbOut: TChilkatStringBuilder;
verifier: TChilkatXmlDSig;
numSigs: Integer;
verifyIdx: Integer;
verified: Integer;

begin
success := 0;

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

// Note: We cannot load the already-signed XML into a Chilkat XML object because it would re-format the XML when re-emitted.
// (i.e. indentation and whitespace could change, and it would invalidate the existing signature.)
// We must use a StringBuilder.
sbXml := TChilkatStringBuilder.Create(Self);
success := sbXml.LoadFile('qa_data/xml_dsig_valid_samples/encapsulatedTimestamp_not_yet_added.xml','utf-8');
if (success = 0) then
  begin
    Memo1.Lines.Add('Failed to load the XML file.');
    Exit;
  end;

dsig := TChilkatXmlDSig.Create(Self);
success := dsig.LoadSignatureSb(sbXml.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(dsig.LastErrorText);
    Exit;
  end;

if (dsig.HasEncapsulatedTimeStamp() = 1) then
  begin
    Memo1.Lines.Add('This signed XML already has an EncapsulatedTimeStamp');
    Exit;
  end;

// Specify the timestamping authority URL
json := TChilkatJsonObject.Create(Self);
json.UpdateString('timestampToken.tsaUrl','http://timestamp.digicert.com');
json.UpdateBool('timestampToken.requestTsaCert',1);

// Call AddEncapsulatedTimeStamp to add the EncapsulatedTimeStamp to the signature.
// Note: If the signed XML contains multiple signatures, the signature modified is the one 
// indicated by the dsig.Selector property.
sbOut := TChilkatStringBuilder.Create(Self);
success := dsig.AddEncapsulatedTimeStamp(json.ControlInterface,sbOut.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(dsig.LastErrorText);
    Exit;
  end;

sbOut.WriteFile('qa_output/addedEncapsulatedTimeStamp.xml','utf-8',0);

// The EncapsulatedTimeStamp can be validated when validating the signature by adding the VerifyEncapsulatedTimeStamp
// keyword to UncommonOptions.  See here:

// ----------------------------------------
// Verify the signatures we just produced...
verifier := TChilkatXmlDSig.Create(Self);
success := verifier.LoadSignatureSb(sbOut.ControlInterface);
if (success <> 1) then
  begin
    Memo1.Lines.Add(verifier.LastErrorText);
    Exit;
  end;

// Add "VerifyEncapsulatedTimeStamp" to the UncommonOptions to also verify any EncapsulatedTimeStamps
verifier.UncommonOptions := 'VerifyEncapsulatedTimeStamp';

numSigs := verifier.NumSignatures;
verifyIdx := 0;
while verifyIdx < numSigs do
  begin
    verifier.Selector := verifyIdx;
    verified := verifier.VerifySignature(1);
    if (verified <> 1) then
      begin
        Memo1.Lines.Add(verifier.LastErrorText);
        Exit;
      end;
    verifyIdx := verifyIdx + 1;
  end;

Memo1.Lines.Add('All signatures were successfully verified.');
end;