B4X

Examine KeyInfo Certificate in XML Signature

See more XML Digital Signatures Examples

This example loads signed XML and gets the signing certificate, assuming the certificate is contained in X509Certificate within the KeyInfo. B4X

Dim success As Boolean = False

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

Dim dsig As ChilkatXmlDSig
dsig.Initialize
Dim sbXml As ChilkatStringBuilder
sbXml.Initialize

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


success = dsig.LoadSignatureSb(sbXml)
If success <> True Then
    Log(dsig.LastErrorText)
    Return
End If


'  Get the KeyInfo XML.
Dim xmlKeyInfo As ChilkatXml = dsig.GetKeyInfo
If dsig.LastMethodSuccess <> True Then
    Log(dsig.LastErrorText)
    Return
End If


Log(xmlKeyInfo.GetXml)
Log("----")

'  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 = xmlKeyInfo.GetChildContent("*:X509Data|*:X509Certificate")
If xmlKeyInfo.LastMethodSuccess <> True Then
    Log("No X509Certificate found in the KeyInfo.")
    Return
End If


'  Load a certificate object w/ the base64.
Dim cert As ChilkatCert
cert.Initialize("cert")
success = cert.LoadFromBase64(certBase64)
If success <> True Then
    Log(cert.LastErrorText)
    Return
End If


'  Examine the cert..
Log("SubjectDN: " & cert.SubjectDN)
Log("IssuerDN: " & cert.IssuerDN)
Log("SerialNumber as Decimal: " & cert.SerialDecimal)