(Excel) 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.

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' 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 Chilkat.StringBuilder
Set sbXml = Chilkat.NewStringBuilder

success = sbXml.LoadFile("qa_data/xml_dsig_valid_samples/encapsulatedTimestamp_not_yet_added.xml","utf-8")
If (success = False) Then
    Debug.Print "Failed to load the XML file."
    Exit Sub
End If

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

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

' Specify the timestamping authority URL
Dim json As Chilkat.JsonObject
Set json = Chilkat.NewJsonObject
Dim success As Boolean
success = json.UpdateString("timestampToken.tsaUrl","http://timestamp.digicert.com")
success = 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 Chilkat.StringBuilder
Set sbOut = Chilkat.NewStringBuilder
success = dsig.AddEncapsulatedTimeStamp(json,sbOut)
If (success = False) Then
    Debug.Print dsig.LastErrorText
    Exit Sub
End If

success = 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 Chilkat.XmlDSig
Set verifier = Chilkat.NewXmlDSig
success = verifier.LoadSignatureSb(sbOut)
If (success <> True) Then
    Debug.Print verifier.LastErrorText
    Exit Sub
End If

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


numSigs = verifier.NumSignatures

verifyIdx = 0
Do While verifyIdx < numSigs
    verifier.Selector = verifyIdx

    verified = verifier.VerifySignature(True)
    If (verified <> True) Then
        Debug.Print verifier.LastErrorText
        Exit Sub
    End If

    verifyIdx = verifyIdx + 1
Loop
Debug.Print "All signatures were successfully verified."