gistfile1.txt

var crypto = require('crypto');

var cipher = crypto.createCipher( process.argv[2], 'tacos' );

//aes-gcm 256
//key size must be 32
var cipher = crypto.createCipheriv('aes-256-gcm', '3zTvzr3p67VC61jmV54rIYu1545x4TlY', 'X6sIq117H0vR');
var cipher = crypto.createCipher('aes-256-gcm', '3zTvzr3p67VC61jmV54rIYu1545x4TlY');

//aes-gcm 128
//key size must be 16
var cipher = crypto.createCipheriv('aes-128-gcm', '3zTvzr3p67VC61jm', 'X6sIq117H0vR');
var cipher = crypto.createCipher('aes-128-gcm', '3zTvzr3p67VC61jm');
 
cipher.write('bob');

console.log( cipher.final() );