(Visual Basic 6.0) 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.

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 dsig As New ChilkatXmlDSig
Dim sbXml As New ChilkatStringBuilder

Dim success As Long
success = sbXml.LoadFile("c:/aaworkarea/elias/3/face_f09006808443a699d1b.xml","utf-8")
If (success <> 1) Then
    Debug.Print "Failed to load XML file."
    Exit Sub
End If

success = dsig.LoadSignatureSb(sbXml)
If (success <> 1) Then
    Debug.Print dsig.LastErrorText
    Exit Sub
End If

' Get the KeyInfo XML.
Dim xmlKeyInfo As ChilkatXml
Set xmlKeyInfo = dsig.GetKeyInfo()
If (dsig.LastMethodSuccess <> 1) 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>
Dim certBase64 As String
certBase64 = xmlKeyInfo.GetChildContent("*:X509Data|*:X509Certificate")
If (xmlKeyInfo.LastMethodSuccess <> 1) Then
    Debug.Print "No X509Certificate found in the KeyInfo."
    Exit Sub
End If

' Load a certificate object w/ the base64.
Dim cert As New ChilkatCert
success = cert.LoadFromBase64(certBase64)
If (success <> 1) 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