(Node.js) IMAP Download and Verify Signed (S/MIME) Email

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

Install Chilkat for Node.js and Electron using npm at Chilkat npm packages for Node.js Chilkat npm packages for Electron on Windows, Linux, MacOSX, and ARM

var os = require('os');
if (os.platform() == 'win32') {  
    if (os.arch() == 'ia32') {
        var chilkat = require('@chilkat/ck-node21-win-ia32');
    } else {
        var chilkat = require('@chilkat/ck-node21-win64'); 
    }
} else if (os.platform() == 'linux') {
    if (os.arch() == 'arm') {
        var chilkat = require('@chilkat/ck-node21-arm');
    } else if (os.arch() == 'x86') {
        var chilkat = require('@chilkat/ck-node21-linux32');
    } else {
        var chilkat = require('@chilkat/ck-node21-linux64');
    }
} else if (os.platform() == 'darwin') {
    if (os.arch() == 'arm64') {
        var chilkat = require('@chilkat/ck-node21-mac-m1');
    } else {
        var chilkat = require('@chilkat/ck-node21-macosx');
    }
}

function chilkatExample() {

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

    var imap = new chilkat.Imap();

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

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

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

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

    // Get the message IDs of all the emails in the mailbox
    // messageSet: MessageSet
    var messageSet = imap.Search("ALL",fetchUids);
    if (imap.LastMethodSuccess !== true) {
        console.log(imap.LastErrorText);
        return;
    }

    // Scan for emails with attachments, and save the attachments
    // to a sub-directory.
    var i = 0;
    while (i < messageSet.Count) {

        var uid = messageSet.GetId(i);
        console.log("uid: " + uid);

        // email: Email
        var email = imap.FetchSingle(uid,true);

        // 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) {

            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.
                // cert: Cert
                var cert = email.GetSignedByCert();
                if (email.LastMethodSuccess !== true) {
                    console.log("Failed to get signing certificate object.");
                }
                else {
                    console.log("Signing cert: " + cert.SubjectCN);

                }

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

        }

        i = i+1;
    }

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


}

chilkatExample();