Current workings for the encode/decode for AES-256.

encode-decode

var crypto = require('crypto');
var secret = crypto.randomBytes(24);

function encrypt(plaintext) {
    var encoded = new Buffer(plaintext, 'utf8', 'hex');
    var cipher = crypto.createCipher('aes-256-cbc', secret);
//    cipher.setAutoPadding(false);
    var ciphertext = cipher.update(encoded, 'hex');
    return ciphertext.toString('base64');
}

function decrypt(ciphertext) {
    var encoded = new Buffer(ciphertext, 'base64', 'hex')
    var decipher = crypto.createDecipher('aes-256-cbc', secret);
//    decipher.setAutoPadding(false);
    var plaintext = decipher.update(encoded, 'hex');
    return plaintext.toString('utf8');
}

var ciphertext = encrypt(new Buffer("The secret crow ate the pie of the bear.").toString('utf8'));

console.log("Cipher text is: " + ciphertext);
console.log("Plain text is: " + decrypt(ciphertext));