B4X

Get Certificates within XML Signature

See more XML Digital Signatures Examples

Demonstrates how to get the certificates contained within an XML signature. 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 sbXml As ChilkatStringBuilder
sbXml.Initialize

'  Load XML containing one or more signatures.
success = sbXml.LoadFile("qa_data/xml_dsig_valid_samples/multipleSigners/sp.pdf.XAdES.xml", "utf-8")
If success = False Then
    Log("Failed to load the XML file..")
    Return
End If


Dim dsig As ChilkatXmlDSig
dsig.Initialize

'  First load the XML containing the signatures to be verified.
'  Note that this particular Signature already contains the RSA public key that will be used
'  for verification.
success = dsig.LoadSignatureSb(sbXml)
If success = False Then
    Log(dsig.LastErrorText)
    Return
End If


'  For each signature, verify and also get the certificate(s) contained within each Signature.
Dim i As Int = 0
Dim saCerts As ChilkatStringArray
saCerts.Initialize
Dim cert As ChilkatCert
cert.Initialize("cert")

Log("numSignatures = " & dsig.NumSignatures)

Do While i < dsig.NumSignatures
    '  Select the Nth signature by setting the Selector property.
    dsig.Selector = i

    Dim bVerifyReferenceDigests As Boolean = True
    Dim bVerified As Boolean = dsig.VerifySignature(bVerifyReferenceDigests)
    Log("Signature " & (i + 1) & " verified = " & bVerified)

    '  Get the certificates embedded in this signature.
    saCerts.Clear
    success = dsig.GetCerts(saCerts)
    If success = True Then
        Dim j As Int = 0
        Do While j < saCerts.Count
            success = cert.LoadFromBase64(saCerts.GetString(j))
            If success = True Then
                Log("    " & cert.SubjectDN)
            End If

            j = j + 1
        Loop
    End If


    i = i + 1
Loop