(Excel) Examine KeyInfo Certificate in XML Signature

This example loads signed XML and gets the signing certificate, assuming the certificate is contained in X509Certificate within the KeyInfo.

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

Dim dsig As Chilkat.XmlDSig
Set dsig = Chilkat.NewXmlDSig
Dim sbXml As Chilkat.StringBuilder
Set sbXml = Chilkat.NewStringBuilder


success = sbXml.LoadFile("c:/aaworkarea/elias/3/face_f09006808443a699d1b.xml","utf-8")
If (success <> True) Then
    Debug.Print "Failed to load XML file."
    Exit Sub
End If

success = dsig.LoadSignatureSb(sbXml)
If (success <> True) Then
    Debug.Print dsig.LastErrorText
    Exit Sub
End If

' Get the KeyInfo XML.

Set xmlKeyInfo = dsig.GetKeyInfo()
If (dsig.LastMethodSuccess <> True) Then
    Debug.Print dsig.LastErrorText
    Exit Sub
End If

Debug.Print xmlKeyInfo.GetXml()
Debug.Print "----"

' Assuming the X509Certificate is in the KeyInfo, it will look like this:

'   <ds:KeyInfo Id="...">
'     <ds:KeyValue>
'     ...  
'     <ds:X509Data>
'       <ds:X509Certificate>MIIHAz...</ds:X509Certificate>
'     </ds:X509Data>
'   </ds:KeyInfo>

certBase64 = xmlKeyInfo.GetChildContent("*:X509Data|*:X509Certificate")
If (xmlKeyInfo.LastMethodSuccess <> True) Then
    Debug.Print "No X509Certificate found in the KeyInfo."
    Exit Sub
End If

' Load a certificate object w/ the base64.
Dim cert As Chilkat.Cert
Set cert = Chilkat.NewCert
success = cert.LoadFromBase64(certBase64)
If (success <> True) Then
    Debug.Print cert.LastErrorText
    Exit Sub
End If

' Examine the cert..
Debug.Print "SubjectDN: "; cert.SubjectDN
Debug.Print "IssuerDN: "; cert.IssuerDN
Debug.Print "SerialNumber as Decimal: "; cert.SerialDecimal