(Go) 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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    // 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 := chilkat.NewBinData()
    success := bdTsr.LoadFile("qa_data/tsd/sample.tsr")
    if success != true {
        fmt.Println("Failed to load timestamp reply file.")
        bdTsr.DisposeBinData()
        return
    }

    // Load the tsr into an ASN.1 object.
    asnTsr := chilkat.NewAsn()
    success = asnTsr.LoadEncoded(*bdTsr.GetEncoded("base64"),"base64")
    if success != true {
        fmt.Println(asnTsr.LastErrorText())
        bdTsr.DisposeBinData()
        asnTsr.DisposeAsn()
        return
    }

    // Get the timestamp reply as XML.
    xmlTsr := chilkat.NewXml()
    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..
    bdContent := chilkat.NewBinData()
    success = bdContent.LoadFile("qa_data/tsd/sample.p7m")
    if success != true {
        fmt.Println("Failed to load content file.")
        bdTsr.DisposeBinData()
        asnTsr.DisposeAsn()
        xmlTsr.DisposeXml()
        bdContent.DisposeBinData()
        return
    }

    // Begin building the TimeStampData.  
    // We'll build as XML and then convert to ASN.1
    xml := chilkat.NewXml()
    xml.SetTag("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")

    xContext := xml.GetChildWithTag("contextSpecific|sequence|contextSpecific")
    xContext.AddChildTree(xmlTsr)
    xContext.DisposeXml()

    // Convert the XML to ASN.1
    tsd := chilkat.NewAsn()
    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..
    tsdBase64 := tsd.GetEncodedDer("base64_mime")
    fmt.Println(*tsdBase64)

    bdTsr.DisposeBinData()
    asnTsr.DisposeAsn()
    xmlTsr.DisposeXml()
    bdContent.DisposeBinData()
    xml.DisposeXml()
    tsd.DisposeAsn()