Delphi DLL

Combine Timestamp Reply and Content File into a TimeStampData

See more ASN.1 Examples

Demonstrates how to combine a timestamp reply (RFC 3161) with a data file (any type of file) to create a TimeStampData structure (RFC 5544). Delphi DLL

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Xml, Asn, BinData;

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
bdTsr: HCkBinData;
asnTsr: HCkAsn;
xmlTsr: HCkXml;
bdContent: HCkBinData;
xml: HCkXml;
xContext: HCkXml;
tsd: HCkAsn;
tsdBase64: PWideChar;

begin
success := False;

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

// Also see this example:
// Send a TimeStamp Request to a TimeStamp Authority and get the Response

// Load a timestamp reply file
bdTsr := CkBinData_Create();
success := CkBinData_LoadFile(bdTsr,'qa_data/tsd/sample.tsr');
if (success <> True) then
  begin
    Memo1.Lines.Add('Failed to load timestamp reply file.');
    Exit;
  end;

// Load the tsr into an ASN.1 object.
asnTsr := CkAsn_Create();
success := CkAsn_LoadEncoded(asnTsr,CkBinData__getEncoded(bdTsr,'base64'),'base64');
if (success <> True) then
  begin
    Memo1.Lines.Add(CkAsn__lastErrorText(asnTsr));
    Exit;
  end;

// Get the timestamp reply as XML.
xmlTsr := CkXml_Create();
CkXml_LoadXml(xmlTsr,CkAsn__asnToXml(asnTsr));

// The timestamp reply XML begins like this:
// We'll want to remove the 1st "sequence" subtree.

//     <?xml version="1.0" encoding="utf-8"?>
//     <sequence>
//         <sequence>       <---- Remove this sub-tree.
//             <int>00</int>
//             <sequence>
//                 <utf8>Operation Okay</utf8>
//             </sequence>
//         </sequence>
//         <sequence>   
//             <oid>1.2.840.113549.1.7.2</oid>
//             <contextSpecific tag="0" constructed="1">
//             ...

// Remove the 1st sub-tree..
CkXml_RemoveChildByIndex(xmlTsr,0);

// In this example, the data file we're combining with the timestamp into a timestampData is a .p7m.
// However, it can be any type of file (text or binary), it doesn't matter..
bdContent := CkBinData_Create();
success := CkBinData_LoadFile(bdContent,'qa_data/tsd/sample.p7m');
if (success <> True) then
  begin
    Memo1.Lines.Add('Failed to load content file.');
    Exit;
  end;

// Begin building the TimeStampData.  
// We'll build as XML and then convert to ASN.1
xml := CkXml_Create();
CkXml_putTag(xml,'sequence');
CkXml_UpdateChildContent(xml,'oid','1.2.840.113549.1.9.16.1.31');
CkXml_UpdateAttrAt(xml,'contextSpecific',True,'tag','0');
CkXml_UpdateAttrAt(xml,'contextSpecific',True,'constructed','1');
CkXml_UpdateChildContent(xml,'contextSpecific|sequence|int','01');
CkXml_UpdateChildContent(xml,'contextSpecific|sequence|octets',CkBinData__getEncoded(bdContent,'base64'));
CkXml_UpdateAttrAt(xml,'contextSpecific|sequence|contextSpecific',True,'tag','0');
CkXml_UpdateAttrAt(xml,'contextSpecific|sequence|contextSpecific',True,'constructed','1');

xContext := CkXml_GetChildWithTag(xml,'contextSpecific|sequence|contextSpecific');
CkXml_AddChildTree(xContext,xmlTsr);
CkXml_Dispose(xContext);

// Convert the XML to ASN.1
tsd := CkAsn_Create();
CkAsn_LoadAsnXml(tsd,CkXml__getXml(xml));

// Write the timestamped data to a file.
success := CkAsn_WriteBinaryDer(tsd,'qa_output/sample.tsd');

// Alternatively, get the tsd ASN.1 as base64..
tsdBase64 := CkAsn__getEncodedDer(tsd,'base64_mime');
Memo1.Lines.Add(tsdBase64);

CkBinData_Dispose(bdTsr);
CkAsn_Dispose(asnTsr);
CkXml_Dispose(xmlTsr);
CkBinData_Dispose(bdContent);
CkXml_Dispose(xml);
CkAsn_Dispose(tsd);

end;