Basic HTTP authentication with Node and Express 4

Question

It looks like implementing basic HTTP authentication with Express v3 was trivial:

app.use(express.basicAuth('username', 'password'));

Version 4 (I'm using 4.2) removed the basicAuth middleware, though, so I'm a little stuck. I have the following code, but it doesn't cause the browser to prompt the user for credentials, which is what I'd like (and what I imagine the old method did):

app.use(function(req, res, next) {
    var user = auth(req);

    if (user === undefined || user['name'] !== 'username' || user['pass'] !== 'password') {
        res.writeHead(401, 'Access invalid for user', {'Content-Type' : 'text/plain'});
        res.end('Invalid credentials');
    } else {
        next();
    }
});

Answer 1

Simple Basic Auth with vanilla JavaScript (ES6)

app.use((req, res, next) => {

  // -----------------------------------------------------------------------
  // authentication middleware

  const auth = {login: 'yourlogin', password: 'yourpassword'} // change this

  // parse login and password from headers
  const b64auth = (req.headers.authorization || '').split(' ')[1] || ''
  const [login, password] = Buffer.from(b64auth, 'base64').toString().split(':')

  // Verify login and password are set and correct
  if (login && password && login === auth.login && password === auth.password) {
    // Access granted...
    return next()
  }

  // Access denied...
  res.set('WWW-Authenticate', 'Basic realm="401"') // change this
  res.status(401).send('Authentication required.') // custom message

  // -----------------------------------------------------------------------

})

_{note: This "middleware" can be used in any handler. Just remove next() and reverse the logic. See the 1-statement example below, or the edit history of this answer.}

Why?

• req.headers.authorization contains the value "Basic <base64 string>", but it can also be empty and we don't want it to fail, hence the weird combo of || ''
• Node doesn't know atob() and btoa(), hence the Buffer

ES6 -> ES5

const is just var .. sort of
(x, y) => {...} is just function(x, y) {...}
const [login, password] = ...split() is just two var assignments in one

source of inspiration (uses packages)

---

super simplesuper short:b64auth

  // parse login and password from headers
  const b64auth = (req.headers.authorization || '').split(' ')[1] || ''
  const strauth = Buffer.from(b64auth, 'base64').toString()
  const splitIndex = strauth.indexOf(':')
  const login = strauth.substring(0, splitIndex)
  const password = strauth.substring(splitIndex + 1)

  // using shorter regex by @adabru
  // const [_, login, password] = strauth.match(/(.*?):(.*)/) || []

Basic auth in one statement

...on the other hand, if you only ever use one or very few logins, this is the bare minimum you need: (you don't even need to parse the credentials at all)

function (req, res) {
//btoa('yourlogin:yourpassword') -> "eW91cmxvZ2luOnlvdXJwYXNzd29yZA=="
//btoa('otherlogin:otherpassword') -> "b3RoZXJsb2dpbjpvdGhlcnBhc3N3b3Jk"

  // Verify credentials
  if (  req.headers.authorization !== 'Basic eW91cmxvZ2luOnlvdXJwYXNzd29yZA=='
     && req.headers.authorization !== 'Basic b3RoZXJsb2dpbjpvdGhlcnBhc3N3b3Jk')        
    return res.status(401).send('Authentication required.') // Access denied.   

  // Access granted...
  res.send('hello world')
  // or call next() if you use it as middleware (as snippet #1)
}

---

PS: do you need to have both "secure" and "public" paths? Consider using express.router instead.

var securedRoutes = require('express').Router()

securedRoutes.use(/* auth-middleware from above */)
securedRoutes.get('path1', /* ... */) 

app.use('/secure', securedRoutes)
app.get('public', /* ... */)

// example.com/public       // no-auth
// example.com/secure/path1 // requires auth

Answer 2

TL;DR:

☒ express.basicAuth is gone
☒ basic-auth-connect is deprecated
☒ basic-auth doesn't have any logic
☒ http-auth is an overkill
☑ express-basic-auth is what you want

More info:

Since you're using Express then you can use the express-basic-auth middleware.

See the docs:

• https://www.npmjs.com/package/express-basic-auth

Example:

const app = require('express')();
const basicAuth = require('express-basic-auth');
 
app.use(basicAuth({
    users: { admin: 'supersecret123' },
    challenge: true // <--- needed to actually show the login dialog!
}));

Answer 3

A lot of the middleware was pulled out of the Express core in v4, and put into separate modules. The basic auth module is here: https://github.com/expressjs/basic-auth-connect

Your example would just need to change to this:

var basicAuth = require('basic-auth-connect');
app.use(basicAuth('username', 'password'));

Answer 4

I used the code for the original basicAuth to find the answer:

app.use(function(req, res, next) {
    var user = auth(req);

    if (user === undefined || user['name'] !== 'username' || user['pass'] !== 'password') {
        res.statusCode = 401;
        res.setHeader('WWW-Authenticate', 'Basic realm="MyRealmName"');
        res.end('Unauthorized');
    } else {
        next();
    }
});

Answer 5

I changed in express 4.0 the basic authentication with http-auth, the code is:

var auth = require('http-auth');

var basic = auth.basic({
        realm: "Web."
    }, function (username, password, callback) { // Custom authentication method.
        callback(username === "userName" && password === "password");
    }
);

app.get('/the_url', auth.connect(basic), routes.theRoute);

Answer 6

There seems to be multiple modules to do that, some are deprecated.

This one looks active:
https://github.com/jshttp/basic-auth

Here's a use example:

// auth.js

var auth = require('basic-auth');

var admins = {
  '[email protected]': { password: 'pa$$w0rd!' },
};


module.exports = function(req, res, next) {

  var user = auth(req);
  if (!user || !admins[user.name] || admins[user.name].password !== user.pass) {
    res.set('WWW-Authenticate', 'Basic realm="example"');
    return res.status(401).send();
  }
  return next();
};




// app.js

var auth = require('./auth');
var express = require('express');

var app = express();

// ... some not authenticated middlewares

app.use(auth);

// ... some authenticated middlewares

Make sure you put the auth middleware in the correct place, any middleware before that will not be authenticated.

Answer 7

We can implement the basic authorization without needing any module

//1.
var http = require('http');

//2.
var credentials = {
    userName: "vikas kohli",
    password: "vikas123"
};
var realm = 'Basic Authentication';

//3.
function authenticationStatus(resp) {
    resp.writeHead(401, { 'WWW-Authenticate': 'Basic realm="' + realm + '"' });
    resp.end('Authorization is needed');

};

//4.
var server = http.createServer(function (request, response) {
    var authentication, loginInfo;

    //5.
    if (!request.headers.authorization) {
        authenticationStatus (response);
        return;
    }

    //6.
    authentication = request.headers.authorization.replace(/^Basic/, '');

    //7.
    authentication = (new Buffer(authentication, 'base64')).toString('utf8');

    //8.
    loginInfo = authentication.split(':');

    //9.
    if (loginInfo[0] === credentials.userName && loginInfo[1] === credentials.password) {
        response.end('Great You are Authenticated...');
         // now you call url by commenting the above line and pass the next() function
    }else{

    authenticationStatus (response);

}

});
 server.listen(5050);

Source:- http://www.dotnetcurry.com/nodejs/1231/basic-authentication-using-nodejs

Answer 8

function auth (req, res, next) {
  console.log(req.headers);
  var authHeader = req.headers.authorization;
  if (!authHeader) {
      var err = new Error('You are not authenticated!');
      res.setHeader('WWW-Authenticate', 'Basic');
      err.status = 401;
      next(err);
      return;
  }
  var auth = new Buffer.from(authHeader.split(' ')[1], 'base64').toString().split(':');
  var user = auth[0];
  var pass = auth[1];
  if (user == 'admin' && pass == 'password') {
      next(); // authorized
  } else {
      var err = new Error('You are not authenticated!');
      res.setHeader('WWW-Authenticate', 'Basic');      
      err.status = 401;
      next(err);
  }
}
app.use(auth);

Answer 9

Express has removed this functionality and now recommends you use the basic-auth library.

Here's an example of how to use:

var http = require('http')
var auth = require('basic-auth')

// Create server
var server = http.createServer(function (req, res) {
  var credentials = auth(req)

  if (!credentials || credentials.name !== 'aladdin' || credentials.pass !== 'opensesame') {
    res.statusCode = 401
    res.setHeader('WWW-Authenticate', 'Basic realm="example"')
    res.end('Access denied')
  } else {
    res.end('Access granted')
  }
})

// Listen
server.listen(3000)

To send a request to this route you need to include an Authorization header formatted for basic auth.

Sending a curl request first you must take the base64 encoding of name:pass or in this case aladdin:opensesame which is equal to YWxhZGRpbjpvcGVuc2VzYW1l

Your curl request will then look like:

 curl -H "Authorization: Basic YWxhZGRpbjpvcGVuc2VzYW1l" http://localhost:3000/