(JavaScript) IMAP Download and Verify Signed MIME

Downloads the original MIME of a digitally signed email and saves the .p7s signature along with other MIME parts. It then imports the email into a Chilkat email object to unwrap the S/MIME and verify the signature, and subsequently saves the attachments if they haven't been saved already.

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

Note

This example is intended for running within a Chilkat.Js embedded JavaScript engine. All Chilkat JavaScript examples require Chilkat v11.4.0 or greater.

var success = false;

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

var imap = new CkImap();

// Connect to an IMAP server.
// Use TLS
imap.Ssl = true;
imap.Port = 993;
success = imap.Connect("imap.example.com");
if (success == false) {
    console.log(imap.LastErrorText);
    return;
}

success = imap.Login("myLogin","myPassword");
if (success == false) {
    console.log(imap.LastErrorText);
    return;
}

// Select an IMAP mailbox
success = imap.SelectMailbox("Inbox");
if (success == false) {
    console.log(imap.LastErrorText);
    return;
}

// Download the 1st email (as MIME) in the Inbox by sequence number.
var sbMime = new CkStringBuilder();
success = imap.FetchSingleAsMimeSb(1,false,sbMime);
if (success == false) {
    console.log(imap.LastErrorText);
    return;
}

// Load it into a MIME object and check to see if it is signed
var mime = new CkMime();
mime.LoadMimeSb(sbMime);
var alreadySavedParts = false;
if (mime.ContainsSignedParts() == true) {

    // This will save the .p7s and other parts...
    var st = new CkStringTable();
    success = mime.PartsToFiles("c:/temp/qa_output",st);
    if (success == true) {
        var numFiles = st.Count;
        var i = 0;
        while (i < numFiles) {
            console.log("Created: " + st.StringAt(i));
            i = i+1;
        }

        alreadySavedParts = true;
    }

}

// Load the MIME into an Email object.  This unwraps the security layers and verifies signatures.
var email = new CkEmail();
email.SetFromMimeSb(sbMime);

if (email.ReceivedSigned == true) {

    console.log("This email was signed.");

    // Check to see if the signatures were verified.
    if (email.SignaturesValid == true) {
        console.log("Digital signature(s) verified.");

        console.log("Signer: " + email.SignedBy);

        // The certificate used for signing may be obtained
        // by calling email.GetSignedByCert.
        var cert = new CkCert();
        success = email.LastSignerCert(i,cert);
        if (success == false) {
            console.log("Failed to get signing certificate object.");
        }
        else {
            console.log("Signing cert: " + cert.SubjectCN);
        }

    }

}
else {
    console.log("Digital signature verification failed.");
}

if (alreadySavedParts !== true) {
    email.SaveAllAttachments("c:/temp/qa_output");
}