(Go) IMAP Download and Verify Signed (S/MIME) Email

Demonstrates how to download and verify digitally signed S/MIME email.

Note: This example requires Chilkat v11.0.0 or greater.

Chilkat Go Downloads Go Package for Windows, MacOS, Linux, Alpine Linux, Solaris

    success := false

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

    imap := Imap_Ref.html">chilkat.NewImap()

    // Connect to an IMAP server.
    // Use TLS
    imap.SetSsl(true)
    imap.SetPort(993)
    success = imap.Connect("imap.example.com")
    if success == false {
        fmt.Println(imap.LastErrorText())
        imap.DisposeImap()
        return
    }

    success = imap.Login("myLogin","myPassword")
    if success == false {
        fmt.Println(imap.LastErrorText())
        imap.DisposeImap()
        return
    }

    // Select an IMAP mailbox
    success = imap.SelectMailbox("Inbox")
    if success == false {
        fmt.Println(imap.LastErrorText())
        imap.DisposeImap()
        return
    }

    // We can choose to fetch UIDs or sequence numbers.
    fetchUids := true

    // Get the message IDs of all the emails in the mailbox
    messageSet := MessageSet_Ref.html">chilkat.NewMessageSet()
    success = imap.QueryMbx("ALL",fetchUids,messageSet)
    if success == false {
        fmt.Println(imap.LastErrorText())
        imap.DisposeImap()
        messageSet.DisposeMessageSet()
        return
    }

    email := Email_Ref.html">chilkat.NewEmail()
    cert := Cert_Ref.html">chilkat.NewCert()

    i := 0
    for i < messageSet.Count() {

        uid := messageSet.GetId(i)
        fmt.Println("uid: ", *uid)

        success = imap.FetchEmail(false,*uid,true,email)
        if success == false {
            fmt.Println(imap.LastErrorText())
            imap.DisposeImap()
            messageSet.DisposeMessageSet()
            email.DisposeEmail()
            cert.DisposeCert()
            return
        }

        // The security layers of signed and/or encrypted emails
        // are automatically "unwrapped" when loaded into
        // a Chilkat email object.
        // An application only needs to check to see if an email
        // was received signed or encrypted, and then examine
        // the success/failure.  For example:
        if email.ReceivedSigned() == true {

            fmt.Println("This email was signed.")

            // Check to see if the signatures were verified.
            if email.SignaturesValid() == true {
                fmt.Println("Digital signature(s) verified.")
                fmt.Println("Signer: ", email.SignedBy())

                // Get the certificate used for signing.
                success = email.LastSignerCert(0,cert)

                if success == false {
                    fmt.Println("Failed to get signing certificate object.")
                } else {
                    fmt.Println("Signing cert: ", cert.SubjectCN())
                }

            } else {
                fmt.Println("Digital signature verification failed.")
            }

        }

        i = i + 1
    }

    // Disconnect from the IMAP server.
    success = imap.Disconnect()

    imap.DisposeImap()
    messageSet.DisposeMessageSet()
    email.DisposeEmail()
    cert.DisposeCert()