(Lianja) 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
loBdTsr = createobject("CkBinData")
llSuccess = loBdTsr.LoadFile("qa_data/tsd/sample.tsr")
if (llSuccess <> .T.) then
    ? "Failed to load timestamp reply file."
    release loBdTsr
    return
endif

// Load the tsr into an ASN.1 object.
loAsnTsr = createobject("CkAsn")
llSuccess = loAsnTsr.LoadEncoded(loBdTsr.GetEncoded("base64"),"base64")
if (llSuccess <> .T.) then
    ? loAsnTsr.LastErrorText
    release loBdTsr
    release loAsnTsr
    return
endif

// Get the timestamp reply as XML.
loXmlTsr = createobject("CkXml")
loXmlTsr.LoadXml(loAsnTsr.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..
loXmlTsr.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..
loBdContent = createobject("CkBinData")
llSuccess = loBdContent.LoadFile("qa_data/tsd/sample.p7m")
if (llSuccess <> .T.) then
    ? "Failed to load content file."
    release loBdTsr
    release loAsnTsr
    release loXmlTsr
    release loBdContent
    return
endif

// Begin building the TimeStampData.  
// We'll build as XML and then convert to ASN.1
loXml = createobject("CkXml")
loXml.Tag = "sequence"
loXml.UpdateChildContent("oid","1.2.840.113549.1.9.16.1.31")
loXml.UpdateAttrAt("contextSpecific",.T.,"tag","0")
loXml.UpdateAttrAt("contextSpecific",.T.,"constructed","1")
loXml.UpdateChildContent("contextSpecific|sequence|int","01")
loXml.UpdateChildContent("contextSpecific|sequence|octets",loBdContent.GetEncoded("base64"))
loXml.UpdateAttrAt("contextSpecific|sequence|contextSpecific",.T.,"tag","0")
loXml.UpdateAttrAt("contextSpecific|sequence|contextSpecific",.T.,"constructed","1")

loXContext = loXml.GetChildWithTag("contextSpecific|sequence|contextSpecific")
loXContext.AddChildTree(loXmlTsr)
release loXContext

// Convert the XML to ASN.1
loTsd = createobject("CkAsn")
loTsd.LoadAsnXml(loXml.GetXml())

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

// Alternatively, get the tsd ASN.1 as base64..
lcTsdBase64 = loTsd.GetEncodedDer("base64_mime")
? lcTsdBase64


release loBdTsr
release loAsnTsr
release loXmlTsr
release loBdContent
release loXml
release loTsd