Visual Basic 6.0

RSA Signature with Certificate's Private Key from PFX

See more RSA Examples

Demonstrates how to use a certificate's private key from a PFX file to create an RSA signature. Visual Basic 6.0

Dim success As Long
success = 0

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

' Create an instance of a certificate store object, load a PFX file,
' locate the certificate we need, and use it for signing.
' (a PFX file may contain more than one certificate.)
Dim certStore As New ChilkatCertStore

' The 1st argument is the filename, the 2nd arg is the 
' PFX file's password:
success = certStore.LoadPfxFile("chilkat.pfx","test")
If (success = 0) Then
    Debug.Print certStore.LastErrorText
    Exit Sub
End If

' Find the certificate by the subject common name:
Dim jsonCN As New ChilkatJsonObject
success = jsonCN.UpdateString("CN","cert common name")

Dim cert As New ChilkatCert
success = certStore.FindCert(jsonCN,cert)
If (success = 0) Then
    Debug.Print certStore.LastErrorText
    Exit Sub
End If

Dim privKey As New PrivateKey
success = cert.GetPrivateKey(privKey)
If (success = 0) Then
    Debug.Print cert.LastErrorText
    Exit Sub
End If

Dim rsa As New ChilkatRsa

success = rsa.UsePrivateKey(privKey)
If (success = 0) Then
    Debug.Print rsa.LastErrorText
    Exit Sub
End If

' Encode the signature as a hex string
rsa.EncodingMode = "hex"

Dim strData As String
strData = "This is the string to be signed."

' Sign the string using the sha-1 hash algorithm.
' Other valid choices are "sha-256", "md2" and "md5".
Dim hexSig As String
hexSig = rsa.SignStringENC(strData,"sha-1")

Debug.Print hexSig

Debug.Print "Success!"