(Excel) Use Installed Cert on Windows for TLS Client Authentication

Demonstrates how to use a certificate that has already been installed on a Windows PC for TLS client authentication.

Download Excel Class Modules Chilkat Excel Class Modules

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

Dim http As Chilkat.Http
Set http = Chilkat.NewHttp

'  On Windows, a pre-installed certificate can be loaded in a number of different ways.
'  This example loads by the common name:
Dim cert As Chilkat.Cert
Set cert = Chilkat.NewCert

success = cert.LoadByCommonName("My ECA Medium Assurance Identity Certificate")
If (success <> True) Then
    Debug.Print cert.LastErrorText
    Exit Sub
End If

'  Make sure this certificate has a private key available.
'  It should be a private key such that when the certificate was installed, it was marked as "exportable"
'  so that authorized programs are able to access the private key.
If (cert.HasPrivateKey() <> True) Then
    Debug.Print "A private key is needed for TLS client authentication."
    Debug.Print "This certificate has no private key."
    Exit Sub
End If

'  Set the certificate to be used for mutual TLS authentication
'  (i.e. sets the client-side certificate for two-way TLS authentication)
success = http.SetSslClientCert(cert)
If (success <> True) Then
    Debug.Print http.LastErrorText
    Exit Sub
End If

'  At this point, the HTTP object instance is setup with the client-side cert, and any SSL/TLS
'  connection will automatically use it if the server demands a client-side cert.