VB.NET

RSA Sign using a Private Key on a USB Token or Smartcard

See more Apple Keychain Examples

Create an RSA signature using a private key stored on a USB token or smartcard.

Note: On MacOS and iOS, this example requires Chilkat v10.1.2 or later when the Apple Keychain is used as the underlying means to do the signing.

VB.NET

Dim success As Boolean = False

' Assuming the smartcard/USB token is installed with the correct drivers from the manufacturer,
' this code can work on multiple platforms including Windows, MacOS, Linux, and iOS.

' Chilkat automatically detects and determines the way in which the HSM is used,
' which can be by PKCS11, Apple Keychain, Microsoft CNG / Crypto API, or ScMinidriver.

Dim cert As New Chilkat.Cert

' Set the token/smartcard PIN prior to loading.
cert.SmartCardPin = "123456"

' Specify the certificate by its common name.
success = cert.LoadFromSmartcard("cn=chilkat-rsa-2048")
If (success = False) Then
    Debug.WriteLine(cert.LastErrorText)
    Exit Sub
End If


Debug.WriteLine("Signing with cert: " & cert.SubjectCN)

' Create data to be hashed and signed.
Dim bd As New Chilkat.BinData
Dim i As Integer
For i = 0 To 100
    bd.AppendEncoded("000102030405060708090A0B0C0D0E0F","hex")
Next

Dim rsa As New Chilkat.Rsa

' Use the certificate's private key for signing.
success = rsa.SetX509Cert(cert,True)
If (success = False) Then
    Debug.WriteLine(rsa.LastErrorText)
    Exit Sub
End If


' Sign the SHA-256 hash of the contents of bd.
Dim bdSig As New Chilkat.BinData
success = rsa.SignBd(bd,"sha256",bdSig)
If (success = False) Then
    Debug.WriteLine(rsa.LastErrorText)
    Exit Sub
End If


' The RSA signature is equal in length to the size of the RSA key.
Debug.WriteLine("Output signature size in bits = " & (bdSig.NumBytes * 8))

' We can save the signature for later verification..
bdSig.WriteFile("rsaSignatures/test1.sig")

' See the example to verify the RSA signature:
' Verfies an RSA Signature