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Sign Method


Digitally signs the message.

Syntax

  • Basic
object.Sign (Cert)
The Sign(object,Cert) syntax has these parts:
objectAn expression evaluating to an object of type SmtpMsg
CertRequired. A Variant value. Reference to ICertificate instance that holds your certificate and private key.

Remarks

Sign method will digitally sign your message before it's delivered to the recipient. You need valid certificate (and private key) in order to sign a message. Messages are signed using S/MIME version 3 specification.

Typical usage will be like this:
       ' initialize wodSmtp and create some message
       Dim Smtp1 As New wodSmtpCom
       Smtp1.CreateSimple "someone@somehost.com", "recipient@otherhost.com", "Subject goes here", "Text goes here"
 
       ' now initialize certificate and load your personal certificate
       Dim cert As New Certificate
       cert.LoadKey "c:\mbx\thawte.pfx", "your_password"
       cert.Load "c:\mbx\thawte.pfx", "your_password"
 
       'and sign the message
       Smtp1.Message.Sign cert
 
       ' optionally, save the message
       Smtp1.Message.Save App.Path & "\signed.eml"

above code will create new message and sign it using certificate stored in PFX file.

It is important that you DO NOT CHANGE message contents after signing it - meaning Sign method call should be LAST method/property used before you call SendMessage method. Failing to do so will cause clients to report 'message has been tampered' when they try to open it.

Note: currently wodSmtp does not support signing using (protected) certificates in Windows certificate store, but support for that will be added shortly, so that, for example, code like this will be valid:
       Dim cert As New CertLocation
       Smtp1.Message.Sign cert(CurrentUser).Item("My").Item("Thawte Freemail Member")


Platforms

Windows