(Visual Basic 6.0) Verify XAdES with External File Reference

Demonstrates how to validate an XML digital signature that contains a reference to an external file. (This is one way of doing it..)

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

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

' Load the XAdES file to be validated..
Dim sbXml As New ChilkatStringBuilder
Dim success As Long
success = sbXml.LoadFile("qa_data/xml_dsig_valid_samples/externalFile/test.pdf.XAdES","utf-8")
If (success = 0) Then
    Debug.Print "Failed to load XAdES input file."
    Exit Sub
End If

Dim validator As New ChilkatXmlDSig

' Specify a set of absolute or relative directory paths to be searched for any external file references.
' Directory paths are separated by semicolon chars.
validator.ExternalRefDirs = "qa_data/externalFiles;qa_data/xml_dsig_valid_samples/externalFile;c:/someOtherDir"

success = validator.LoadSignatureSb(sbXml)
If (success = 0) Then
    Debug.Print validator.LastErrorText
    Exit Sub
End If

' Validate signatures as usual..
Dim i As Long
i = 0
Do While i < validator.NumSignatures
    validator.Selector = i

    Dim valid As Long
    valid = validator.VerifySignature(1)
    Debug.Print "Signature " & (i + 1) & " and all reference digests OK = " & valid

    i = i + 1
Loop