node-2fa

Easy 2-Factor Integration For Node.js

There are a number of applications which support 2-Factor Authentication, namely

- Authy iPhone | Android | Chrome | Linux | OS X | BlackBerry
- Google Authenticator iPhone | Android
- Microsoft Authenticator Windows Phone | Android

This module uses notp which implements TOTP (RFC 6238)
(the _Authenticator_ standard), which is based on HOTP (RFC 4226)
to provide codes that are exactly compatible with all other _Authenticator_ apps and services that use them.

Usage
=====

``bash
npm install node-2fa --save
`

`javascript
const twofactor = require("node-2fa");

const newSecret = twofactor.generateSecret({ name: "My Awesome App", account: "johndoe" });
/*
{ secret: 'XDQXYCP5AC6FA32FQXDGJSPBIDYNKK5W',
uri: 'otpauth://totp/My%20Awesome%20App:johndoe?secret=XDQXYCP5AC6FA32FQXDGJSPBIDYNKK5W&issuer=My%20Awesome%20App',
qr: 'https://chart.googleapis.com/chart?chs=166x166&chld=L|0&cht=qr&chl=otpauth://totp/My%20Awesome%20App:johndoe%3Fsecret=XDQXYCP5AC6FA32FQXDGJSPBIDYNKK5W%26issuer=My%20Awesome%20App'
}
*/

const newToken = twofactor.generateToken("XDQXYCP5AC6FA32FQXDGJSPBIDYNKK5W");
// => { token: '630618' }

twofactor.verifyToken("XDQXYCP5AC6FA32FQXDGJSPBIDYNKK5W", "630618");
// => { delta: 0 }

twofactor.verifyToken("XDQXYCP5AC6FA32FQXDGJSPBIDYNKK5W", "00");
// => null
`

API

$3

returns an object containing a 32-character secret (keep user specific, store in DB), a uri (if you want to make your own QR / barcode) and a direct link to a QR code served via HTTPS by the Google Chart API

options is an object containing name which is the name of your app that will show up when the user scans the QR code and account which can be the username and will also show up in the user's app. Both parameters are optional

$3

returns an object containing a 6-character token

$3

checks if a time-based token matches a token from secret key within a +/- _window_ (default: 4) minute window

returns either null if the token does not match, or an object containing delta key, which is an integer of how for behind / forward the code time sync is in terms of how many new codes have been generated since entry

ex.
{delta: -1} means that the client entered the key too late (a newer key was meant to be used).
{delta: 1} means the client entered the key too early (an older key was meant to be used).
{delta: 0}` means the client was within the time frame of the current key.

_n_-Minute Window

The window is set to 4 by default. Each token is valid for a total of _n_ minutes to account for time drift.