(VB.NET) Get Certificates from .p12 / .pfx

A PKCS12 (.p12 / .pfx) is a container for holding a certificate, its private key, and the certs in the chain of authentication up to and possibly including the root CA cert. A .p12 is not required to contain certain things. It will contain whatever the creator of the .p12 decided to include. It's possible to contain just a private key, just a cert, many certs without private keys, or many certs with many private keys. Usually, a .p12 contains one certificate, its associated private key, and certificates in the chain of authentication.

Note: This example requires Chilkat v11.0.0 or greater.

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Dim success As Boolean = False

Dim pfx As New Chilkat.Pfx

success = pfx.LoadPfxFile("qa_data/pfx/test.pfx","pfx_password")
If (success = False) Then
    Debug.WriteLine(pfx.LastErrorText)
    Exit Sub
End If


' Iterate over the certs contained in the PFX
Dim cert As New Chilkat.Cert
Dim numCerts As Integer = pfx.NumCerts
Dim i As Integer = 0
While i < numCerts

    pfx.CertAt(i,cert)

    Debug.WriteLine("--- " & i & " ---")
    Debug.WriteLine(cert.SubjectDN)
    ' Is this a root cert, or self-signed?
    Debug.WriteLine("Root: " & cert.IsRoot)
    Debug.WriteLine("Self-Signed: " & cert.SelfSigned)

    ' If this certificate is not the root (self-signed), then get the issuer.
    ' If the issuing certificate is contained in the PFX, then it will be found here..
    If (cert.SelfSigned <> True) Then
        Dim issuer As Chilkat.Cert = cert.FindIssuer()
        If (cert.LastMethodSuccess = False) Then
            Debug.WriteLine("Issuer not found.")
        Else
            Debug.WriteLine("Issuer: " & issuer.SubjectDN)

        End If

    End If

    i = i + 1
End While

' Usually, the user certificate is at index 0, its issuer is at index 1, etc. until we get to the root certificate.