How do I check if a PDF Document contains a valid Adobe.PPKMS signature

‘This sample script demonstrates how to check if a PDF Document
‘contains a valid Adobe.PPKMS signature
‘Copyright 2015 Aloaha Limited
‘Redistribution without permission not allowed
‘Aloaha PDF Suite SDK License required. Please contact info@aloaha.com for an evaluation key.

On Error Resume Next
Dim pdf
Dim signer
Dim file
file = “c:\pdf\signed.pdf”

Set pdf = CreateObject(“aloahapdf.edit”)
MsgBox pdf.is_pdf_signed(CStr(file))
Set pdf = nothing