(Excel) ConvertToSignedPk

Demonstrates how to digitally sign MIME to create an "opaque" signature. The MIME is converted to an application/x-pkcs7-mime which is a PKCS7 signature that includes both the original MIME message and the signature. This is different than AddDetachedSignaturePk, where the signature is appended to the MIME. This example demonstrates how to use the certificate and its corresponding private key when they are stored in separate files -- a .cer for the certificate, and a .pem for the private key.

Download Excel Class Modules Chilkat Excel Class Modules

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

Dim mime As Chilkat.Mime
Set mime = Chilkat.NewMime

' Load the certificate from a .cer file.
Dim cert As Chilkat.Cert
Set cert = Chilkat.NewCert

success = cert.LoadFromFile("aaworkarea/myCert.cer")
If (success = False) Then
    Debug.Print cert.LastErrorText
    Exit Sub
End If

' Load the private key from an encrypted PEM file.
' (A private key can be loaded from other file formats also..)
Dim privKey As Chilkat.PrivateKey
Set privKey = Chilkat.NewPrivateKey
success = privKey.LoadEncryptedPemFile("aaworkarea/myPrivateKey.pem","myPassword")
If (success = False) Then
    Debug.Print privKey.LastErrorText
    Exit Sub
End If

success = mime.SetBodyFromPlainText("This is the plain-text MIME body.")

' Convert the MIME to application/x-pkcs7-mime, which
' is PKCS7 containing both the original content and the signature.
success = mime.ConvertToSignedPk(cert,privKey)
If (success = False) Then
    Debug.Print mime.LastErrorText
    Exit Sub
End If

' Save the S/MIME to a file.
success = mime.SaveMime("aaworkarea/opaqueSignedMime.txt")
If (success = False) Then
    Debug.Print mime.LastErrorText
    Exit Sub
End If

Debug.Print "success!"