(Visual Basic 6.0) Get the Server Certificate, Certificate Chain, and Root CA Certificate

Demonstrates how to get the HTTP server certificate, its certificate chain, and the root CA certificate.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

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

Dim http As New ChilkatHttp

' We're getting the SSL/TLS certificate, so make sure to connect to the SSL/TLS port (443).
Dim sslCert As ChilkatCert
Set sslCert = http.GetServerSslCert("nationalgeographic.com",443)
If (http.LastMethodSuccess = 0) Then
    Debug.Print http.LastErrorText
    Exit Sub
End If

' Note: Prior to v9.5.0.50, this method would fail if the certificate chain could not 
' be completed to the root.  Starting in v9.5.0.50, the incomplete certificate chain 
' will be returned.  The certificate chain's ReachesRoot property can be examined to 
' see if the chain was completed to the root.
Dim certChain As ChilkatCertChain
Set certChain = sslCert.GetCertChain()
If (sslCert.LastMethodSuccess = 0) Then
    Debug.Print sslCert.LastErrorText

    Exit Sub
End If

Dim i As Long
i = 0
Dim numCerts As Long
numCerts = certChain.NumCerts
Do While i < numCerts
    Dim cert As ChilkatCert
    Set cert = certChain.GetCert(i)
    Debug.Print "SubjectDN " & i & ": " & cert.SubjectDN
    Debug.Print "IssuerDN " & i & ": " & cert.IssuerDN

    i = i + 1
Loop

' If the certificate chain reaches the root CA cert, then the last cert in the chain
' is the root CA cert.
If (certChain.ReachesRoot = 1) Then
    Dim caCert As ChilkatCert
    Set caCert = certChain.GetCert(numCerts - 1)
    Debug.Print "CA Root Cert: " & caCert.SubjectDN

End If