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VB.NET Requires Chilkat v10.1.2+

RSA Sign using Private Key of Certificate Type A3 (smart card / token)

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Demonstrates RSA signing data using the private key of a certificate type A3 (smart card, token).

Note: This is a Windows-only example.

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VB.NET
Dim success As Boolean = False

'  First get the A3 certificate that was installed on the Windows system.
Dim certStore As New Chilkat.CertStore

Dim thumbprint As String = "12c1dd8015f3f03f7b1fa619dc24e2493ca8b4b2"

'  This is specific to Windows because it is opening the Windows Current-User certificate store.
Dim bReadOnly As Boolean = True
success = certStore.OpenCurrentUserStore(bReadOnly)
If (success <> True) Then
    Debug.WriteLine(certStore.LastErrorText)
    Exit Sub
End If


'  Find the certificate with the desired thumbprint
'  (There are many ways to locate a certificate.  This example chooses to find by thumbprint.)
Dim json As New Chilkat.JsonObject
json.UpdateString("thumbprint",thumbprint)

Dim cert As New Chilkat.Cert
success = certStore.FindCert(json,cert)
If (success = False) Then
    Debug.WriteLine("Failed to find the certificate.")
    Exit Sub
End If


Debug.WriteLine("Found: " & cert.SubjectCN)

Dim rsa As New Chilkat.Rsa

'  Provide the cert's private key
Dim bUsePrivateKey As Boolean = True
success = rsa.SetX509Cert(cert,bUsePrivateKey)
If (success <> True) Then
    Debug.WriteLine(rsa.LastErrorText)
    Exit Sub
End If


'  Now we're ready to sign..
Dim fac As New Chilkat.FileAccess

'  Get bytes to be signed..
Dim inData() As Byte = fac.ReadEntireFile("in.dat")
Dim signature() As Byte = rsa.SignBytes(inData,"SHA-256")
If (rsa.LastMethodSuccess <> True) Then
    Debug.WriteLine(rsa.LastErrorText)
    Exit Sub
End If


Debug.WriteLine("Signature created.")