Delphi DLL

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 DLL

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

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
sbXml: HCkStringBuilder;
dsig: HCkXmlDSig;
json: HCkJsonObject;
sbOut: HCkStringBuilder;
verifier: HCkXmlDSig;
numSigs: Integer;
verifyIdx: Integer;
verified: Boolean;

begin
success := False;

// 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 := CkStringBuilder_Create();
success := CkStringBuilder_LoadFile(sbXml,'qa_data/xml_dsig_valid_samples/encapsulatedTimestamp_not_yet_added.xml','utf-8');
if (success = False) then
  begin
    Memo1.Lines.Add('Failed to load the XML file.');
    Exit;
  end;

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

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

// Specify the timestamping authority URL
json := CkJsonObject_Create();
CkJsonObject_UpdateString(json,'timestampToken.tsaUrl','http://timestamp.digicert.com');
CkJsonObject_UpdateBool(json,'timestampToken.requestTsaCert',True);

// 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 := CkStringBuilder_Create();
success := CkXmlDSig_AddEncapsulatedTimeStamp(dsig,json,sbOut);
if (success = False) then
  begin
    Memo1.Lines.Add(CkXmlDSig__lastErrorText(dsig));
    Exit;
  end;

CkStringBuilder_WriteFile(sbOut,'qa_output/addedEncapsulatedTimeStamp.xml','utf-8',False);

// 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 := CkXmlDSig_Create();
success := CkXmlDSig_LoadSignatureSb(verifier,sbOut);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkXmlDSig__lastErrorText(verifier));
    Exit;
  end;

// Add "VerifyEncapsulatedTimeStamp" to the UncommonOptions to also verify any EncapsulatedTimeStamps
CkXmlDSig_putUncommonOptions(verifier,'VerifyEncapsulatedTimeStamp');

numSigs := CkXmlDSig_getNumSignatures(verifier);
verifyIdx := 0;
while verifyIdx < numSigs do
  begin
    CkXmlDSig_putSelector(verifier,verifyIdx);
    verified := CkXmlDSig_VerifySignature(verifier,True);
    if (verified <> True) then
      begin
        Memo1.Lines.Add(CkXmlDSig__lastErrorText(verifier));
        Exit;
      end;
    verifyIdx := verifyIdx + 1;
  end;

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

CkStringBuilder_Dispose(sbXml);
CkXmlDSig_Dispose(dsig);
CkJsonObject_Dispose(json);
CkStringBuilder_Dispose(sbOut);
CkXmlDSig_Dispose(verifier);

end;