(VB.NET) Add S/MIME Signature using PFX

Add a digital signature to a MIME message using the certificate + private key from a PFX file.

Chilkat .NET Downloads Chilkat .NET Framework Chilkat for .NET Core

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

Dim mime As New Chilkat.Mime

' Load a PFX file into a certificate object.
Dim cert As New Chilkat.Cert
Dim pfxFilepath As String = "pfxFiles/something.pfx"
Dim pfxPassword As String = "secret"
Dim success As Boolean = cert.LoadPfxFile(pfxFilepath,pfxPassword)
If (success = False) Then
    Debug.WriteLine(cert.LastErrorText)
    Exit Sub
End If


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

mime.Charset = "utf-8"
mime.Encoding = "quoted-printable"


' Sign the MIME (adds a PKCS7 detached signature)
success = mime.AddDetachedSignature(cert)
If (success = False) Then
    Debug.WriteLine(mime.LastErrorText)
    Exit Sub
End If


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


Debug.WriteLine("success!")