(Visual Basic 6.0) Verify XML Digital Signature

Verifies XML signatures in an XML file.

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.

Dim sbXml As New ChilkatStringBuilder
Dim success As Long
success = sbXml.LoadFile("qa_data/xml_dsig_verify/csioz_sample.xml","utf-8")
If (success <> 1) Then
    Debug.Print "Failed to load XML file."
    Exit Sub
End If

Dim dsig As New ChilkatXmlDSig

' First load the XML containing the signatures to be verified.
success = dsig.LoadSignatureSb(sbXml)
If (success <> 1) Then
    Debug.Print dsig.LastErrorText
    Exit Sub
End If

' It's possible that an XML document can contain multiple signatures.
' Each can be verified as follows:
Dim i As Long
i = 0
Do While i < dsig.NumSignatures
    ' Select the Nth signature by setting the Selector property.
    dsig.Selector = i

    ' The bVerifyReferenceDigests argument determines if we want
    ' to also verify each reference digest.  If set to 0,
    ' then only the SignedInfo part of the Signature is verified.
    Dim bVerifyReferenceDigests As Long
    bVerifyReferenceDigests = 1
    Dim bVerified As Long
    bVerified = dsig.VerifySignature(bVerifyReferenceDigests)
    Debug.Print "Signature " & (i + 1) & " verified = " & bVerified

    i = i + 1
Loop