var Decrypter = require('aes-decrypter').Decrypter;
var fs = require('fs');
var keyContent = fs.readFileSync('something.key');
var encryptedBytes = fs.readFileSync('somithing.txt');

// keyContent is a string of the aes-keys content
var keyContent = fs.readFileSync(keyFile);

var view = new DataView(keyContent.buffer);
var key.bytes = new Uint32Array([
  view.getUint32(0),
  view.getUint32(4),
  view.getUint32(8),
  view.getUint32(12)
]);

key.iv = new Uint32Array([
  0, 0, 0, 0
]);

var d = new Decrypter(
  encryptedBytes,
  key.bytes,
  key.iv,
  function(err, decryptedBytes) {
    // err always null
});