B4X

Use a Smart Card Certificate + Private Key for SSL/TLS Authentication

See more ScMinidriver Examples

Demonstrates how to use a certificate + private key located on a smart card for the TLS client certificate in an HTTPS request.

Note: This example only works on Windows. ScMinidriver is a Windows-specific smart card and USB token minidriver that enables smart card authentication and cryptographic operations within Windows operating systems.

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 scmd As ChilkatScMinidriver
scmd.Initialize

'  Reader names (smart card readers or USB tokens) can be discovered
'  via List Readers or Find Smart Cards
Dim readerName As String = "SCM Microsystems Inc. SCR33x USB Smart Card Reader 0"
success = scmd.AcquireContext(readerName)
If success = False Then
    Log(scmd.LastErrorText)
    Return
End If


'  If successful, the name of the currently inserted smart card is available:
Log("Card name: " & scmd.CardName)

'  If desired, perform regular PIN authentication with the smartcard.
'  For more details about smart card PIN authentication, see the Smart Card PIN Authentication Example
Dim retval As Int = scmd.PinAuthenticate("user", "000000")
If retval <> 0 Then
    Log("PIN Authentication failed.")
End If


'  You can find a cerficate using any of the following certificate parts:
'  "subjectDN" -- The full distinguished name of the cert.
'  "subjectDN_withTags" -- Same as above, but in a format that includes the subject part tags, such as the "CN=" in "CN=something"
'  "subjectCN" -- The common name part (CN) of the certificate's subject.
'  "serial" -- The certificate serial number.
'  "serial:issuerCN" -- The certificate serial number + the issuer's common name, delimited with a colon char.
'  These are the same certificate parts that can be retrieved by listing certificates on the smart card (or USB token).
'  See List Certificates on Smart Card Example
Dim certPart As String = "subjectCN"
Dim partValue As String = "BadSSL Client Certificate"

'  If the certificate is found, it is loaded into the cert object.
'  Note: We imported this certificate from a .p12/.pfx using this Example to Import a .pfx/.p12 onto a Smart Card
Dim cert As ChilkatCert
cert.Initialize("cert")
success = scmd.FindCert(certPart, partValue, cert)
If success = False Then
    Log("Failed to find the certificate.")
    scmd.DeleteContext
    Return
End If


Log("Successfully loaded the cert object from the smart card / USB token.")

'  Note: When successful, the cert object is internally linked to the ScMinidriver object's authenticated session.
'  The cert object can now be used to sign or do other cryptographic operations that occur on the smart card / USB token.
'  If your application calls PinDeauthenticate or DeleteContext, the cert will no longer be able to sign on the smart card
'  because the smart card ScMinidriver session will no longer be authenticated or deleted.

'  ------------------------------------------------------------------------------------------------------------

'  Send an HTTPS request to https://client.badssl.com
'  https://client.badssl.com (part of the badssl.com service) lets you test authentication using client SSL certificates. 
'  The client certificate can be downloaded from https://badssl.com/download/.
'  This server returns 200 OK if the correct client certificate is provided, and 400 Bad Request otherwise.

Dim http As ChilkatHttp
http.Initialize("http")

'  Provide the client certificate (linked internally to our authenticated smartcard session)
success = http.SetSslClientCert(cert)
If success = False Then
    Log(http.LastErrorText)
    scmd.DeleteContext
    Return
End If


Dim responseBody As String = http.QuickGetStr("https://client.badssl.com/")
If http.LastMethodSuccess = False Then
    Log(http.LastErrorText)
    scmd.DeleteContext
    Return
End If


Log("Response status code: " & http.LastStatus)
Log("Response body: ")
Log(responseBody)

'  ------------------------------------------------------------------------------------------------------------
'  Cleanup our ScMinidriver session...

'  When finished with operations that required authentication, you may if you wish, deauthenticate the session.
success = scmd.PinDeauthenticate("user")
If success = False Then
    Log(scmd.LastErrorText)
End If


'  Delete the context when finished with the card.
success = scmd.DeleteContext
If success = False Then
    Log(scmd.LastErrorText)
End If