(C++) Combine Timestamp Reply and Content File into a TimeStampData

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

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#include <CkBinData.h>
#include <CkAsn.h>
#include <CkXml.h>

void ChilkatSample(void)
    {
    // 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
    CkBinData bdTsr;
    bool success = bdTsr.LoadFile("qa_data/tsd/sample.tsr");
    if (success != true) {
        std::cout << "Failed to load timestamp reply file." << "\r\n";
        return;
    }

    // Load the tsr into an ASN.1 object.
    CkAsn asnTsr;
    success = asnTsr.LoadEncoded(bdTsr.getEncoded("base64"),"base64");
    if (success != true) {
        std::cout << asnTsr.lastErrorText() << "\r\n";
        return;
    }

    // Get the timestamp reply as XML.
    CkXml xmlTsr;
    xmlTsr.LoadXml(asnTsr.asnToXml());

    // 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..
    xmlTsr.RemoveChildByIndex(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..
    CkBinData bdContent;
    success = bdContent.LoadFile("qa_data/tsd/sample.p7m");
    if (success != true) {
        std::cout << "Failed to load content file." << "\r\n";
        return;
    }

    // Begin building the TimeStampData.  
    // We'll build as XML and then convert to ASN.1
    CkXml xml;
    xml.put_Tag("sequence");
    xml.UpdateChildContent("oid","1.2.840.113549.1.9.16.1.31");
    xml.UpdateAttrAt("contextSpecific",true,"tag","0");
    xml.UpdateAttrAt("contextSpecific",true,"constructed","1");
    xml.UpdateChildContent("contextSpecific|sequence|int","01");
    xml.UpdateChildContent("contextSpecific|sequence|octets",bdContent.getEncoded("base64"));
    xml.UpdateAttrAt("contextSpecific|sequence|contextSpecific",true,"tag","0");
    xml.UpdateAttrAt("contextSpecific|sequence|contextSpecific",true,"constructed","1");

    CkXml *xContext = xml.GetChildWithTag("contextSpecific|sequence|contextSpecific");
    xContext->AddChildTree(xmlTsr);
    delete xContext;

    // Convert the XML to ASN.1
    CkAsn tsd;
    tsd.LoadAsnXml(xml.getXml());

    // Write the timestamped data to a file.
    success = tsd.WriteBinaryDer("qa_output/sample.tsd");

    // Alternatively, get the tsd ASN.1 as base64..
    const char *tsdBase64 = tsd.getEncodedDer("base64_mime");
    std::cout << tsdBase64 << "\r\n";
    }