Create S/MIME Signed-Data Message

Download Chilkat MIME ActiveX

This Visual Basic sample program shows how to create an S/MIME signed-data message. A file is loaded into a MIME message as an attachment, a digital certificate is located and then used to create an x-pkcs7-mime signed-data message.

' Converts any kind of file into an S/MIME message with
' an attached (opaque) digital signature.
Private Sub Command1_Click()

        Dim mime As New ChilkatMime

   
        mime.UnlockComponent "Anything for 30-day trial"
        mime.SetBodyFromPlainText "This is a message containing a GIF image file."
        mime.AppendPartFromFile "dude.gif"
        mime.SaveMime "unsigned.txt"

        ' Locate a certificate in the Current User Store (in the registry)
        ' There are many different ways of locating and using certificates
        ' using Cert, CertStore and CreateCS.
        Dim ccs As New ChilkatCreateCS
        Dim certStore As ChilkatCertStore
        Dim cert As ChilkatCert

        Set certStore = ccs.OpenCurrentUserStore()
        Set cert = certStore.FindCertForEmail("matt@chilkatsoft.com")

        ' Use the certificate for signing.
        ' This creates a signed message.
        mime.ConvertToSigned cert
        mime.SaveMime "signed.txt"

        ' You can always convert MIME to XML
        ' XML is easier to parse, and you can always convert back from XML to MIME.
        mime.SaveXml "signed.xml"

End Sub