(VB.NET UWP/WinRT) Add EncapsulatedTimestamp to Already-Signed XML

See more XML Digital Signatures Examples

Demonstrates how to add an EncapsulatedTimestamp to an existing XML signature.

Note: This example requires Chilkat v9.5.0.90 or greater.

Chilkat Universal Windows Platform (UWP) / WinRT Downloads Chilkat for the Universal Windows Platform (UWP)

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

' Note: We cannot load the already-signed XML into a Chilkat XML object because it would re-format the XML when re-emitted.
' (i.e. indentation and whitespace could change, and it would invalidate the existing signature.)
' We must use a StringBuilder.
Dim sbXml As New Chilkat.StringBuilder
Dim success As Boolean = sbXml.LoadFile("qa_data/xml_dsig_valid_samples/encapsulatedTimestamp_not_yet_added.xml","utf-8")
If (success = False) Then
    Debug.WriteLine("Failed to load the XML file.")
    Exit Sub
End If


Dim dsig As New Chilkat.XmlDSig
success = dsig.LoadSignatureSb(sbXml)
If (success = False) Then
    Debug.WriteLine(dsig.LastErrorText)
    Exit Sub
End If


If (dsig.HasEncapsulatedTimeStamp() = True) Then
    Debug.WriteLine("This signed XML already has an EncapsulatedTimeStamp")
    Exit Sub
End If


' Specify the timestamping authority URL
Dim json As New Chilkat.JsonObject
json.UpdateString("timestampToken.tsaUrl","http://timestamp.digicert.com")
json.UpdateBool("timestampToken.requestTsaCert",True)

' Call AddEncapsulatedTimeStamp to add the EncapsulatedTimeStamp to the signature.
' Note: If the signed XML contains multiple signatures, the signature modified is the one 
' indicated by the dsig.Selector property.
Dim sbOut As New Chilkat.StringBuilder
success = dsig.AddEncapsulatedTimeStamp(json,sbOut)
If (success = False) Then
    Debug.WriteLine(dsig.LastErrorText)
    Exit Sub
End If


sbOut.WriteFile("qa_output/addedEncapsulatedTimeStamp.xml","utf-8",False)

' The EncapsulatedTimeStamp can be validated when validating the signature by adding the VerifyEncapsulatedTimeStamp
' keyword to UncommonOptions.  See here:

' ----------------------------------------
' Verify the signatures we just produced...
Dim verifier As New Chilkat.XmlDSig
success = verifier.LoadSignatureSb(sbOut)
If (success <> True) Then
    Debug.WriteLine(verifier.LastErrorText)
    Exit Sub
End If


' Add "VerifyEncapsulatedTimeStamp" to the UncommonOptions to also verify any EncapsulatedTimeStamps
verifier.UncommonOptions = "VerifyEncapsulatedTimeStamp"

Dim numSigs As Integer = verifier.NumSignatures
Dim verifyIdx As Integer = 0
While verifyIdx < numSigs
    verifier.Selector = verifyIdx
    Dim verified As Boolean = verifier.VerifySignature(True)
    If (verified <> True) Then
        Debug.WriteLine(verifier.LastErrorText)
        Exit Sub
    End If

    verifyIdx = verifyIdx + 1
End While
Debug.WriteLine("All signatures were successfully verified.")