(Node.js) S/MIME Encrypt .eml without Sending

See more Email Object Examples

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

var os = require('os');
if (os.platform() == 'win32') {  
  var chilkat = require('@chilkat/ck-node23-win64'); 
} else if (os.platform() == 'linux') {
    if (os.arch() == 'arm') {
        var chilkat = require('@chilkat/ck-node23-linux-arm');
    } else if (os.arch() == 'arm64') {
        var chilkat = require('@chilkat/ck-node23-linux-arm64');
    } else {
        var chilkat = require('@chilkat/ck-node23-linux-x64');
    }
} else if (os.platform() == 'darwin') {
  var chilkat = require('@chilkat/ck-node23-mac-universal');
}

function chilkatExample() {

    var success = false;

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

    var email = new chilkat.Email();

    success = email.LoadEml("c:/temp/email/unencrypted.eml");
    if (success == false) {
        console.log(email.LastErrorText);
        return;
    }

    // The email content is encrypted using AES with a 256-bit key, operating in GCM mode, which provides authenticated encryption.
    email.Pkcs7CryptAlg = "aes-gcm";
    email.Pkcs7KeyLength = 256;
    email.OaepPadding = true;
    email.OaepHash = "sha256";
    email.OaepMgfHash = "sha256";

    var cert = new chilkat.Cert();
    success = cert.LoadFromFile("c/temps/cert/recipient.cer");
    if (success == false) {
        console.log(cert.LastErrorText);
        return;
    }

    email.SendEncrypted = true;
    email.SetEncryptCert(cert);

    var sbSmime = new chilkat.StringBuilder();

    // The mailman object applies the encryption by rendering the email according to the instructions (property settings) provided in the email object.
    // No email is sent.
    var mailman = new chilkat.MailMan();
    success = mailman.RenderToMimeSb(email,sbSmime);
    if (success == false) {
        console.log(mailman.LastErrorText);
        return;
    }

    success = sbSmime.WriteFile("c:/temp/encryptedEmail.eml","utf-8",false);
    if (success == false) {
        console.log(mailman.LastErrorText);
        return;
    }

    console.log("Success!");

}

chilkatExample();