cryptography using node.js having issues

newbie question re: nodejs and cryto

var crypto = require('crypto');

var User = {
  user1: { name: 'bob', salt: 'randomSalt', password: sha1('mypass', this.salt) }
};

function sha1(pass, salt) {
  return crypto.createHmac('sha1', salt).update(p开发者_运维知识库ass).digest('hex');
}

Why do I have console.log(User.user1.password == sha1('mypass', 'randomSalt') //false ?

Answering to myself:

"classic" javascript gotcha :

the context (this) has changed when sha1 is called from the object. Therefore, this.salt is "undefined"

This should work:

var crypto = require("crypto");
function sha1(pass, salt) {
  return crypto.createHmac('sha1', salt).update(pass).digest('hex');
}
var User = { name:'Robin', salt:'mysalt'}
User.password = sha1('mypass', User.salt);
// 'cfbc41a870bb7ddd3d7fcc774dd6d2d5850d5340'