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