Visual FoxPro

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). Visual FoxPro

LOCAL lnSuccess
LOCAL loBdTsr
LOCAL loAsnTsr
LOCAL loXmlTsr
LOCAL loBdContent
LOCAL loXml
LOCAL loXContext
LOCAL loTsd
LOCAL lcTsdBase64

lnSuccess = 0

*  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('Chilkat.BinData')
lnSuccess = loBdTsr.LoadFile("qa_data/tsd/sample.tsr")
IF (lnSuccess <> 1) THEN
    ? "Failed to load timestamp reply file."
    RELEASE loBdTsr
    CANCEL
ENDIF

*  Load the tsr into an ASN.1 object.
loAsnTsr = CreateObject('Chilkat.Asn')
lnSuccess = loAsnTsr.LoadEncoded(loBdTsr.GetEncoded("base64"),"base64")
IF (lnSuccess <> 1) THEN
    ? loAsnTsr.LastErrorText
    RELEASE loBdTsr
    RELEASE loAsnTsr
    CANCEL
ENDIF

*  Get the timestamp reply as XML.
loXmlTsr = CreateObject('Chilkat.Xml')
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('Chilkat.BinData')
lnSuccess = loBdContent.LoadFile("qa_data/tsd/sample.p7m")
IF (lnSuccess <> 1) THEN
    ? "Failed to load content file."
    RELEASE loBdTsr
    RELEASE loAsnTsr
    RELEASE loXmlTsr
    RELEASE loBdContent
    CANCEL
ENDIF

*  Begin building the TimeStampData.  
*  We'll build as XML and then convert to ASN.1
loXml = CreateObject('Chilkat.Xml')
loXml.Tag = "sequence"
loXml.UpdateChildContent("oid","1.2.840.113549.1.9.16.1.31")
loXml.UpdateAttrAt("contextSpecific",1,"tag","0")
loXml.UpdateAttrAt("contextSpecific",1,"constructed","1")
loXml.UpdateChildContent("contextSpecific|sequence|int","01")
loXml.UpdateChildContent("contextSpecific|sequence|octets",loBdContent.GetEncoded("base64"))
loXml.UpdateAttrAt("contextSpecific|sequence|contextSpecific",1,"tag","0")
loXml.UpdateAttrAt("contextSpecific|sequence|contextSpecific",1,"constructed","1")

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

*  Convert the XML to ASN.1
loTsd = CreateObject('Chilkat.Asn')
loTsd.LoadAsnXml(loXml.GetXml())

*  Write the timestamped data to a file.
lnSuccess = 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