(VB.NET) Add a Document Timestamp Signature to an already-signed PDF

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Demonstrates how to add a document timestamp signature to an already-signed PDF.

Note: This example requires Chilkat v9.5.0.99 or greater.

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' This example requires the Chilkat API to have been previously unlocked.
' See Global Unlock Sample for sample code.

Dim pdf As New Chilkat.Pdf

' Load the PDF that has already been signed.
Dim success As Boolean = pdf.LoadFile("qa_data/pdf/helloWorld_signed.pdf")
If (success = False) Then
    Debug.WriteLine(pdf.LastErrorText)
    Exit Sub
End If


Dim json As New Chilkat.JsonObject

json.UpdateBool("invisibleSignature",True)
json.UpdateString("subFilter","/ETSI.RFC3161")

json.UpdateBool("timestampToken.enabled",True)

' In this example, we'll use a free TSA server (timestamp.digicert.com), but you may want to use your own timestamp authority server.
json.UpdateString("timestampToken.tsaUrl","http://timestamp.digicert.com")

' If the timestamp server requires a username/password, do the following.  Otherwise omit the following few lines of code.
json.UpdateString("timestampToken.tsaUsername","the_tsa_username")
json.UpdateString("timestampToken.tsaPassword","the_tsa_password")

' When requesting the timestamp token, ask the server to include its certificate in the timestamp token response.
' This allows for the timestamp server's certificate to be included in the LTV validation (i.e. if the timestamp server
' has an OCSP URL, then Chilkat will also do the OCSP request for the timestamp server's certificate.)
json.UpdateBool("timestampToken.requestTsaCert",True)


success = pdf.SignPdf(json,"c:/temp/qa_output/helloWorld_signed_2.pdf")
If (success = False) Then
    Debug.WriteLine(pdf.LastErrorText)
    Exit Sub
End If


Debug.WriteLine("Successfully added a Document Timestamp Signature to the PDF")