How to implement a secure REST API with node.js - node.js

I start planning a REST API with node.js ,express and mongodb. The API provides data for a website (public and private area) and maybe later a mobile app. The frontend will be developed with AngularJS.
For some days I read a lot about securing REST APIs, but I don’t get to a final solution. As far as I understand is to use HTTPS to provide a basic security. But how I can protect the API in that use cases:
Only visitors/users of the website/app are allowed to get data for the public area of the website/app
Only authenticated and authorized users are allowed to get data for private area (and only data, where the user granted permissions)
At the moment I think about to only allow users with a active session to use the API. To authorize the users I will use passport and for permission I need to implement something for myself. All on the top of HTTPS.
Can somebody provide some best practice or experiences? Is there a lack in my “architecture”?

I've had the same problem you describe. The web site I'm building can be accessed from a mobile phone and from the browser so I need an api to allow users to signup, login and do some specific tasks. Furthermore, I need to support scalability, the same code running on different processes/machines.
Because users can CREATE resources (aka POST/PUT actions) you need to secure your api. You can use oauth or you can build your own solution but keep in mind that all the solutions can be broken if the password it's really easy to discover. The basic idea is to authenticate users using the username, password and a token, aka the apitoken. This apitoken can be generated using node-uuid and the password can be hashed using pbkdf2
Then, you need to save the session somewhere. If you save it in memory in a plain object, if you kill the server and reboot it again the session will be destroyed. Also, this is not scalable. If you use haproxy to load balance between machines or if you simply use workers, this session state will be stored in a single process so if the same user is redirected to another process/machine it will need to authenticate again. Therefore you need to store the session in a common place. This is typically done using redis.
When the user is authenticated (username+password+apitoken) generate another token for the session, aka accesstoken. Again, with node-uuid. Send to the user the accesstoken and the userid. The userid (key) and the accesstoken (value) are stored in redis with and expire time, e.g. 1h.
Now, every time the user does any operation using the rest api it will need to send the userid and the accesstoken.
If you allow the users to signup using the rest api, you'll need to create an admin account with an admin apitoken and store them in the mobile app (encrypt username+password+apitoken) because new users won't have an apitoken when they sign up.
The web also uses this api but you don't need to use apitokens. You can use express with a redis store or use the same technique described above but bypassing the apitoken check and returning to the user the userid+accesstoken in a cookie.
If you have private areas compare the username with the allowed users when they authenticate. You can also apply roles to the users.
Summary:
An alternative without apitoken would be to use HTTPS and to send the username and password in the Authorization header and cache the username in redis.

I would like to contribute this code as an structural solution for the question posed, according (I hope so) to the accepted answer. (You can very easily customize it).
// ------------------------------------------------------
// server.js
// .......................................................
// requires
var fs = require('fs');
var express = require('express');
var myBusinessLogic = require('../businessLogic/businessLogic.js');
// .......................................................
// security options
/*
1. Generate a self-signed certificate-key pair
openssl req -newkey rsa:2048 -new -nodes -x509 -days 3650 -keyout key.pem -out certificate.pem
2. Import them to a keystore (some programs use a keystore)
keytool -importcert -file certificate.pem -keystore my.keystore
*/
var securityOptions = {
key: fs.readFileSync('key.pem'),
cert: fs.readFileSync('certificate.pem'),
requestCert: true
};
// .......................................................
// create the secure server (HTTPS)
var app = express();
var secureServer = require('https').createServer(securityOptions, app);
// ------------------------------------------------------
// helper functions for auth
// .............................................
// true if req == GET /login
function isGETLogin (req) {
if (req.path != "/login") { return false; }
if ( req.method != "GET" ) { return false; }
return true;
} // ()
// .............................................
// your auth policy here:
// true if req does have permissions
// (you may check here permissions and roles
// allowed to access the REST action depending
// on the URI being accessed)
function reqHasPermission (req) {
// decode req.accessToken, extract
// supposed fields there: userId:roleId:expiryTime
// and check them
// for the moment we do a very rigorous check
if (req.headers.accessToken != "you-are-welcome") {
return false;
}
return true;
} // ()
// ------------------------------------------------------
// install a function to transparently perform the auth check
// of incoming request, BEFORE they are actually invoked
app.use (function(req, res, next) {
if (! isGETLogin (req) ) {
if (! reqHasPermission (req) ){
res.writeHead(401); // unauthorized
res.end();
return; // don't call next()
}
} else {
console.log (" * is a login request ");
}
next(); // continue processing the request
});
// ------------------------------------------------------
// copy everything in the req body to req.body
app.use (function(req, res, next) {
var data='';
req.setEncoding('utf8');
req.on('data', function(chunk) {
data += chunk;
});
req.on('end', function() {
req.body = data;
next();
});
});
// ------------------------------------------------------
// REST requests
// ------------------------------------------------------
// .......................................................
// authenticating method
// GET /login?user=xxx&password=yyy
app.get('/login', function(req, res){
var user = req.query.user;
var password = req.query.password;
// rigorous auth check of user-passwrod
if (user != "foobar" || password != "1234") {
res.writeHead(403); // forbidden
} else {
// OK: create an access token with fields user, role and expiry time, hash it
// and put it on a response header field
res.setHeader ('accessToken', "you-are-welcome");
res.writeHead(200);
}
res.end();
});
// .......................................................
// "regular" methods (just an example)
// newBook()
// PUT /book
app.put('/book', function (req,res){
var bookData = JSON.parse (req.body);
myBusinessLogic.newBook(bookData, function (err) {
if (err) {
res.writeHead(409);
res.end();
return;
}
// no error:
res.writeHead(200);
res.end();
});
});
// .......................................................
// "main()"
secureServer.listen (8081);
This server can be tested with curl:
echo "---- first: do login "
curl -v "https://localhost:8081/login?user=foobar&password=1234" --cacert certificate.pem
# now, in a real case, you should copy the accessToken received before, in the following request
echo "---- new book"
curl -X POST -d '{"id": "12341324", "author": "Herman Melville", "title": "Moby-Dick"}' "https://localhost:8081/book" --cacert certificate.pem --header "accessToken: you-are-welcome"

I just finished a sample app that does this in a pretty basic, but clear way. It uses mongoose with mongodb to store users and passport for auth management.
https://github.com/Khelldar/Angular-Express-Train-Seed

There are many questions about REST auth patterns here on SO. These are the most relevant for your question:
Securing my Node.js app's REST API?
RESTful Authentication
Basically you need to choose between using API keys (least secure as the key may be discovered by an unauthorized user), an app key and token combo (medium), or a full OAuth implementation (most secure).

If you want to secure your application, then you should definitely start by using HTTPS instead of HTTP, this ensures a creating secure channel between you & the users that will prevent sniffing the data sent back & forth to the users & will help keep the data exchanged confidential.
You can use JWTs (JSON Web Tokens) to secure RESTful APIs, this has many benefits when compared to the server-side sessions, the benefits are mainly:
1- More scalable, as your API servers will not have to maintain sessions for each user (which can be a big burden when you have many sessions)
2- JWTs are self contained & have the claims which define the user role for example & what he can access & issued at date & expiry date (after which JWT won't be valid)
3- Easier to handle across load-balancers & if you have multiple API servers as you won't have to share session data nor configure server to route the session to same server, whenever a request with a JWT hit any server it can be authenticated & authorized
4- Less pressure on your DB as well as you won't have to constantly store & retrieve session id & data for each request
5- The JWTs can't be tampered with if you use a strong key to sign the JWT, so you can trust the claims in the JWT that is sent with the request without having to check the user session & whether he is authorized or not, you can just check the JWT & then you are all set to know who & what this user can do.
Many libraries provide easy ways to create & validate JWTs in most programming languages, for example: in node.js one of the most popular is jsonwebtoken
Since REST APIs generally aims to keep the server stateless, so JWTs are more compatible with that concept as each request is sent with Authorization token that is self contained (JWT) without the server having to keep track of user session compared to sessions which make the server stateful so that it remembers the user & his role, however, sessions are also widely used & have their pros, which you can search for if you want.
One important thing to note is that you have to securely deliver the JWT to the client using HTTPS & save it in a secure place (for example in local storage).
You can learn more about JWTs from this link

If you want to have a completely locked down area of your webapplication which can only be accessed by administrators from your company, then SSL authorization maybe for you. It will insure that no one can make a connection to the server instance unless they have an authorized certificate installed in their browser. Last week I wrote an article on how to setup the server: Article
This is one of the most secure setups you will find as there are no username/passwords involved so no one can gain access unless one of your users hands the key files to a potential hacker.

Related

How to implement authentication in Next.js

I am new to Next.js and I am struggling with the authentication system using jwt token. I want to know what is the best / standard way to store the jwt token and routing with the authentication system. I have been trying different approaches, from different tutorials/articles, but do not quite understand it. Here are what I have tried.
When the user login, it sends username/password to a separated API server (ex. new project that handles backend stuff), the server will respond with the access-token, then in Next.js project, I set the cookie with that received token. In Next.js project, protected routes will be wrapped with a withAuth hoc, which will check for the token in a cookie. The problem with this approach is that it is vulnerable to XSS because the cookie has no httpOnly flag.
This is similar to 1.) but using localStorage, the problem is access-token could not be sent to the server on the first request. (This one I'm not sure, but in my understanding, in every HTTP request, I must stick my access-token manually, so what about requests that I have no control over? ex. first request or using <a> tag).
I wrote authentication backend inside Next.js server (custom express server). When the user login, the server will validate it and then set an httpOnly cookie. Then the problem is, with client-side routing (go to URL using Next.js Router), it could not check for token. For example, if a page is wrapped with withAuth hoc, but it cannot access the token inside cookies with javascript.
And I've seen a lot of people, in getInitialProps of the protected route, they only check for existence token in cookie / localStorage, then what if the token is being revoked or blacklisted, how do they handle it because they did not send the token to the server? Or do I have to send the token to the server in every client-side page change?
Since we are on quarantine I have enough time to answer this question. It will be a long answer.
Next.js uses the App component to initialize the pages. _app page is responsible for rendering our pages. We authenticate users on _app.js because anything that we return from getInitialProps can be accessed by all of the other pages. We authenticate user here, authentication decision will be passed to pages, from pages to header, so each page can decide if the user is authenticated or not. (Note that it could be done with redux without prop drilling but it would make the answer more complex)
static async getInitialProps({ Component, router, ctx }) {
let pageProps = {};
const user = process.browser
? await auth0.clientAuth()
: await auth0.serverAuth(ctx.req); // I explain down below
//this will be sent to all the components
const auth = { user, isAuthenticated: !!user };
if (Component.getInitialProps) {
pageProps = await Component.getInitialProps(ctx);
}
return { pageProps, auth };
}
render() {
const { Component, pageProps, auth } = this.props;
return <Component {...pageProps} auth={auth} />;
}
}
If we are on the browser and need to check if a user is authenticated, we just retrieve the cookie from the browser, which is easy. But we always have to verify the token. It is the same process used by browser and server. I will explain down below. But if we are on the server. we have no access to the cookies in the browser. But we can read from the "req" object because cookies are attached to the req.header.cookie. this is how we access to cookies on the server.
async serverAuth(req) {
// console.log(req.headers.cookie) to check
if (req.headers.cookie) {
const token = getCookieFromReq(req, "jwt");
const verifiedToken = await this.verifyToken(token);
return verifiedToken;
}
return undefined;
}
here is getCookieFromReq(). remember we have to think functional.
const getCookieFromReq = (req, cookieKey) => {
const cookie = req.headers.cookie
.split(";")
.find((c) => c.trim().startsWith(`${cookieKey}=`));
if (!cookie) return undefined;
return cookie.split("=")[1];
};
Once we get the cookie, we have to decode it, extract the expiration time to see if it is valid or not. this part is easy. Another thing we have to check is if the signature of the jwt is valid. Symmetric or asymmetric algorithms are used to sign the jwt. You have to use private keys to validate the signature of symmetric algorithms. RS256 is the default asymmetric algorithms for APIs. Servers that use RS256, provide you with a link to get jwt to use the keys to validate the signature. You can either use [jwks-rsa][1] or you can do on your own. You have to create a certificate and then verify if the token is valid.
Assume that our user authenticated now. You said, "And I've seen a lot of people, in getInitialProps of the protected route, they only check for existence token in cookie / localStorage,". We use protected routes to give access only to the authorized users. In order to access those routes, users have to show their jwt tokens and express.js uses middlewares to check if the user's token is valid. Since you have seen a lot of examples, I will skip this part.
"then what if the token is being revoked or blacklisted, how do they handle it because they did not send the token to the server? Or do I have to send the token to a server in every client-side page changing?"
with verifying token process we are 100% sure if the token is valid or not. When a client asks the server to access some secret data, the client has to send the token to the server. Imagine when you mount the component, component asks the server to get some data from the protected routes. The server will extract the req object, take the jwt and use it to fetch data from the protected routes. Implementation of the fetching data for browser and server are different. And if the browser makes a request, it just needs the relative path but the server needs an absolute path. As you should know fetching data is done getInitialProps() of the component and this function executed on both client and server. here is how you should implement it. I just attached the getInitialProps() part.
MyComponent.getInitialProps = async (ctx) => {
const another = await getSecretData(ctx.req);
//reuslt of fetching data is passed to component as props
return { superValue: another };
};
const getCookieFromReq = (req, cookieKey) => {
const cookie = req.headers.cookie
.split(";")
.find((c) => c.trim().startsWith(`${cookieKey}=`));
if (!cookie) return undefined;
return cookie.split("=")[1];
};
const setAuthHeader = (req) => {
const token = req ? getCookieFromReq(req, "jwt") : Cookies.getJSON("jwt");
if (token) {
return {
headers: { authorization: `Bearer ${token}` },
};
}
return undefined;
};
export const getSecretData = async (req) => {
const url = req ? "http://localhost:3000/api/v1/secret" : "/api/v1/secret";
return await axios.get(url, setAuthHeader(req)).then((res) => res.data);
};
[1]: https://www.npmjs.com/package/jwks-rsa
With the introduction of Next.JS v8, there are examples placed in the NextJS example page. The basic idea to follow is:
JWT
Using cookies to store the token (you may choose to further encrypt it or not)
Sending the cookies as authorization headers
OAuth
Using a third-party authentication service such as OAuth2.0
Using Passport
This question might need an updated answer, now middlewares are there in Next.js 12 (october 2021): https://nextjs.org/docs/middleware
I am drafting a comprehensive answer to explain auth in Next.js more deeply, you can follow the progress there on GitHub
Here I'll try to propose a summary for Next.js, using middlewares.
Verifying the token after auth and redirecting accordingly
Most of the answer from #Yilmaz from april 2020 is still relevant. However, previously, we had to use getInitialProps in _app to process the request OR a custom server.
This is no longer the case.. Using a middleware let's you achieve a similar purpose, with cleaner code. Because middleware are specifically designed for such use cases.
Here, I suppose you get a JWT access token using an asymetrical algorithm like RS256, exactly like in this previous answer.
Here is a possible implementation:
import { NextFetchEvent, NextRequest, NextResponse } from "next/server";
const removeCookie = (res: NextResponse, cookieName: string) => {
res.headers.append("Set-Cookie", `${cookieName}=; Max-Age=-1; Path=/`);
return res;
};
export default async function middleware(
req: NextRequest,
ev: NextFetchEvent
) {
const { pathname } = req.nextUrl;
const isPublic = isPublicRoute(pathname);
if (isPublic) {
return NextResponse.next();
}
const accessToken = req.cookies[TOKEN_PATH];
if (!accessToken) {
return NextResponse.redirect(LOGIN_HREF);
}
const isValidToken = await checkAccessToken(accessToken);
if (!isValidToken) {
let res = NextResponse.redirect(LOGIN_HREF);
res = removeCookie(res, TOKEN_PATH);
return res;
}
return NextResponse.next();
}
How to verify the token
In my example, the checkAccessToken should verify the token (not decode, verify the signature).
This is where things are the most complicated imo.
When using the RSA256 algorithm
You also get a PUBLIC certificate (in addition to the SECRET key that must be... kept secret). Eventhough you do the check in the middleware, which is private and server-only code, that's good news because it means you could even use it in the browser, in theory.
So, you can either fetch the token validation endpoint provided by your auth server, or verify the token yourself.
Fetching is not the recommended option because it might break Vercel/Next edge capabilities and add latency, according to the documentation.
I must admit that I did not succeed to verify the token yet using Next.js :) I'll update this answer if I manage to have a code sample that works.
When using a symmetrical encryption
You have only a PRIVATE secret passphrase. It means that the decoding have to happen server-side (good news, you are writing a middleware).
Login/logout
This doesn't change with middlewares. You store your access token as an httpOnly cookie. When logging out, you unset this cookie.
Managing those Set-Cookies headers are the responsibility of your auth server.
This is a basic workflow but it should work. You can then add a refresh token in the mix with a similar approach.
About token revokation
If you verify the token in your middleware, there is no immediate revokation mechanism for the access token. Because there is no call to a database.
Therefore, in this scenario, you'd want to opt-in for short lived access token (eg 5 minutes) coupled with a refresh token. You can revoke the refresh token, so basically revoking works but takes a few minutes.
If a 3rd party server verifies the token: then it could check for blacklisted tokens.
Caveats
Also, some piece of advice: most articles, tutorials etc. online are focused on server-to-server communication. Or client-to-API. They completely suck when it comes to check authentication before accessing web pages.
For instance, setting the Authorization header is not possible in the browser. It works only when communicating with an API. Cookies are mandatory for web pages.
Even then, if this API is meant to be called from a browser, it should preferably accept a cookie.
When discussing with experts on the field, you need to always clarify the Next.js use case.
Open questions: about session-based authentication
Some frameworks seem to prefer relying on the database. They store a hashed token in the db, which acts as a session. If you want to check auth, you need a server that will check the user's token against the stored token (= checking that there is an active session with this token).
I am thinking of Meteor for instance.
I couldn't find the name of this mechanism and its actual relation to JWT however. Are they simply variations of the JWT approach?
Next.js official authentication doc is not showing middlewares at the time of writing, but instead use getServerSideProps. I really don't like this pattern.
It uses a kind of session system but I am not clear about the internals of it, I am not even sure of the name (is that session-based auth?).
Vercel edge handles examples shows how to secure an API route, but not a page (at the time of writing)

Meteor: Endpoint for images fetched from S3 - How to authenticate connection?

We have encrypted images stored in S3 that we need to serve to clients, meaning that we cannot give clients S3 URLs for the img src. The files are also potentially large, so idealy we would like to not go through js.
With no serverside routing available we were going down the route of having a separate express setup in Meteor, and this works, since the router on the client side doesn't interfere with
We could add the Auth token to the src url and poke the DB, but we're wary of doing so as it would expose the token in the DOM and in copy pasta cooked up by the users.
Is there a good way of getting this to work properly? Is it posible to configure other routers to serve up the angular app on a specific URL maybe?
Any input welcome :)
app = Express();
app.get('/order/:orderID/image/:UUID', function(mainReq, mainRes) {
// TODO: security check, but not getting current loggedin user info
// There are no cookies, only the DDP connection is authenticated (?)
console.log(Meteor.userId()); // fails
// S3 fetch and decrypt here
});
The answer is:
It's not possible using out of the box Meteor. If you wanna restrict HTTP requests, you're on your own.
Meteor doesn't use cookies (on purpose and for good reason; https://blog.meteor.com/why-meteor-doesnt-use-session-cookies-e988544f52c9), but instead only ever authenticate the DDP websocket connection, and hence any HTTP request to the server is not authed in any way. There are a few packages that tries to handle these things, and this article explains a way of putting the auth token (and the user ID) into the url: https://blog.kayla.com.au/server-side-route-authentication-in-meteor/
The problem with this is that you then expose the token in the DOM, and any browser extension would be able to read it, and the user would be able to copy/paste the url and send it to others. This could end up in session hijacking.
If you wanna authenticate HTTP requests, you will have to wither find a package that write a cookie (and prevents CSRF attacks if you're doing actions) or have the user supply the username/password each time.
For my situation it is sufficient to have the client side write a cookie with the auth token on login on the client. It will then be sent with the request and can be checked server side. Since all I'm doing is send back a picture, it's not nessaccary to prevent CSRF for me, so beware of that while reading the snippets below og how to have the client send a cookie to the server:
Accounts.onLogin(() => {
removeExistingCookie(cookieName);
document.cookie = "loginToken=" + localStorage['Meteor.loginToken'] + "; domain=" + document.location.hostname + "; path=/; expires=" + expiryTime + ";secure"
});
Then you'll have to parse the cookie header on the server and auth the request on the server using something like this
let cookieParser = Npm.require('cookie-parser');
app = Express();
app.use(cookieParser());
app.get('/order/:orderID/image/:UUID', function(mainReq, mainRes) {
let loginToken = mainReq.cookies["loginToken"];
if (!loginToken) {
mainRes.status(404).send();
return;
}
let hashedToken = Accounts._hashLoginToken(loginToken),
sessionBelongsToUser = Meteor.users.findOne(
{
'services.resume.loginTokens.hashedToken': hashedToken,
});
if (!sessionBelongsToUser) {
mainRes.status(404).send();
return;
}

Allow connection only for authorised socket in sails.js

I am trying to implement some kind of security for socket.io clients in the sails.js backend (using version 0.12.x). To achieve this, I try to either prevent successful handshake for clients without a proper cookie (no authorised session beforehand) or like for HTTP request using passport.js to see if the client is authenticated.
In Sails.js documentation I've found that this should be possible, but I could not find any hint, how to do it really. On the other hand, looking for examples on the internet, people mostly don't use security for sockets, or use some old version of sails.js (<0.10).
The closest what I found until now, is for the config/sockets.js:
beforeConnect: function(handshake, cb) {
if (handshake.headers.cookie) {
console.log(handshake);
// TODO: check session authorization
} else {
return cb(null, false);
}
return cb(null, true);
},
This should check the cookie sent with the handshake, if it has a proper session. I have a hard time figuring out, how can I map the sid from the cookie to current sessions in sails.js, for deciding if the connection should be allowed.
Questions:
What is the best security practice for socket.io, if only a small number of clients is allowed (some 40-50 dynamic generated users should be allowed for connection), and nobody else?
How can I map the sails.sid from the cookie to active sessions?
What other configs could be a shortcut to my goal (e.g. setting some policies, that socket.io request use the same middleware as http)?
Thanks for any hint, link or suggestions.
What is the best security practice for socket.io, if only a small
number of clients is allowed (some 40-50 dynamic generated users
should be allowed for connection), and nobody else?
I don't know what is best. But there are two common approaches: token- and cookie based authentication.
Here is a nice visualization of both taken from https://auth0.com/blog/auth-with-socket-io/
I really like the token approach because there is no need for a session store. Hence the server application is decoupled from the client and also stateless.
How can I map the sails.sid from the cookie to active sessions?
Token approach: check out jsonwebtoken. When a user signs in you generate a token and send it to the client:
res.json({
user: user,
token: jwToken.issue({id : user.id })
});
Further you need a policy that checks if a token exists and validate it:
jwToken.verify(token, function (err, token) {
if (err) return res.json(401, {err: 'Invalid Token!'});
req.token = token;
next();
});
I found a complete tutorial that might help you: https://thesabbir.com/how-to-use-json-web-token-authentication-with-sails-js/
How to configure it with sails: you basically just send the token with each socket.io request and check the token inside a policy:
SailsJS - using sails.io.js with JWT

Express JS routing based authentication

I have created node js app using express framework.
I have created middleware for restricting access to some routes.
Middleware actually works fine. but i have difficulties in displaying data.
Suppose In My app i have created route for display list of countries('/country/master')i.e html page which is using internally different/default route ('/country/') to get data from mongoDB.
In this case user will not able to see data cause i have not given permission to "/" routes. but i want to display data but not allow him to make use of "/" route to check data.
How can i deal with this case ????
The answer depends on your authentication strategy i.e. are you using session identifiers, access tokens, etc.
In either case I suggest that you break out the credential exchange (aka login) from the authentication. They should be separate middleware functions. Below is an example of what this looks like.
While this answers your question, specific to ExpressJS, it does leave out a lot of other details that matter when you are building an authentication system (like how to securely store passwords). I work at Stormpath, we provide user management as an API so that you don't have to worry about all the security details! It's very easy to integrate our API into your application, using the express-stormpath module. You'll have a fully featured user database in minutes, without having to setup mongo or a user table.
All that said, here's the example:
/* pseudo example of building your own authentication middleware */
function usernamePasswordExchange(req,res,next){
var username = req.body.username;
var password = req.body.password;
callToAuthService(username,password,function(err,user){
if(err){
next(err); // bad password, user doesn’t exist, etc
}else{
/*
this part depends on your application. do you use
sessions or access tokens? you need to send the user
something that they can use for authentication on
subsequent requests
*/
res.end(/* send something */);
}
});
}
function authenticate(req,res,next){
/*
read the cookie, access token, etc.
verify that it is legit and then find
the user that it’s associated with
*/
validateRequestAndGetUser(req,function(err,user){
if(err){
next(err); // session expired, tampered, revoked
}else{
req.user = user;
next();
}
});
}
app.post('/login',usernamePasswordExchange);
app.get('/protected-resource',authenticate,function(req,res,next){
/*
If we are here we know the user is authenticated and we
can know who the user is by referencing req.user
*/
});
You can positioning of middleware in you app.for example:-
app.get('/country/master',function(req,res){
})
app.use(function(req,res){
your middle ware for providing authentication
})
// other routes where authentication should be enabled
app.get('other urls')

How should I implement a token based authorization API in Node.js and Redis?

I'm working in a web app which handle resources from a Mongo database, for such resources I'd like to offer an API, so a future mobile application can seize it or consume it from a raw client.
However I'd like to have web app consuming same API, here is where I get a bit confused about how to properly implement this.
Here is what I've done so far:
API Auth:
app.route('/api/auth/')
.post(function (request,response) {
var email = request.body.email;
var password = request.body.password;
var login = new Account({"local.email":email,"local.password":password});
Account.findOne({"local.email":email}, function (err,user) {
if (err) {
response.send(500);
}
if (!user) {
response.send(404);
}
else {
user.validPassword(password, function (err,matched) {
if (err) {
response.send(500);
}
if (matched) {
var uuidToken = uuid.v4();
redisClient.set(uuidToken,user._id,redis.print);
redisClient.expire(user._id,100);
response.send(uuid);
}
else {
response.send(403);
}
});
}
});
});
So basically I receive consumers username and password, I authenticate it against database, If it matches I reply a token, (actually an UUID). That token gets stored at Redis paired with the user id in databse. Every future request to any API route will verify for such token existance.
Here I wonder:
How should I manage the token TTL, and renewal upon future requests?
How can I control requests per time windows limits?
Is there any security caveat in the approach I'm taking?
Website Auth:
Basically I perform SAME username-password authentication against database and I then:
1. Start a new server session.
2. Naturally, offer back a cookie with session ID.
3. I create then the Redis UUID and user ID record, which API will check. I guess this is OK as there's any sense in requesting POST /api/auth authenticating again.
Here I wonder:
Is this a best approach?
Should I include any token salt to distinguish a pure API consuming request from a request from web app?
Is there any security caveat in the approach I'm taking?
Should I include more tokens?
This is example of POST /login:
app.route('/login')
.post(function (request,response,next) {
var email = request.body.email;
var password = request.body.password;
var login = new Account({"local.email":email,"local.password":password});
Account.findOne({"local.email":email}, function (err,user) {
if (err) {
response.redirect('/error');
}
if (!user) {
var cookie = request.cookies.userAttempts;
if (cookie === undefined) {
response.cookie('userAttempts',1);
}
else {
response.cookie('userAttempts',(++cookie));
}
response.redirect('/');
}
else {
user.validPassword(password, function (err,matched) {
if (err) {
// Redirect error site or show err message.
response.redirect('/error');
}
if (matched) {
var session = request.session;
session.userid = user._id;
var uuidToken = uuid.v4();
redisClient.set(uuidToken,user._id,redis.print);
redisClient.expire(uuidToken,900);
response.cookie('email',email);
response.redirect('/start');
}
else {
var cookie = request.cookies.passwordAttemps;
if (cookie === undefined)
response.cookie('passwordAttemps',1);
else {
var attemps = ++request.cookies.attemps
response.cookie('passwordAttemps', attemps)
}
response.redirect('/');
}
});
}
});
})
I think I could get rid of using and writing a typical session implementation and depend somehow on the similar token based auth the API has.
What you have there is on the right track and basically replaces some of the functionality of cookies. There are a few things to consider though, and you've touched on some of them already.
While using a UUID (v4 I'm guessing?) is good in that it's nondeterministic and "random", on its own the token is worthless. Should redis lose data the token no longer has any context. Nor can you enforce expirations without help from redis. Compare this to a JWT which can carry context on its own, can be decrypted by anybody with the correct key, can handle expirations, and can enforce further common application level constraints (issuer, audience, etc).
Rate limiting. There are a number of ways to handle this and few of them are tied directly to your choice of token scheme aside from the fact that you'd probably use the token as the key to identify a user across requests in the rate limiter.
Transparently passing the token in both a web app and on other clients (mobile app, desktop app, etc) can be a huge pain. In order to access private resources the user will need to pass the token in the request somewhere, likely the headers, and in the case of a web app this means manual intervention on your part to include the token in each request. This means hand coded ajax requests for all authenticated requests. While this can be annoying, at least it's possible to do, and if you're writing a single page app it's likely you'd do that anyways. The same can be said for any mobile or desktop client. Since you already have to make the HTTP request directly in code anyways, why does it matter? Now imagine the scenario where an HTTP GET endpoint, which returns an html page, can only be accessed with proper authentication. In the case of a web app the user is very likely going to access this via a browser redirect or by typing it directly into the URL bar. How is the token added to the request? Other than using cookies, which you're explicitly not using because mobile and desktop clients do not implement them, this is not really possible. However, if your API clients can always modify the HTTP request structure this isn't really a problem.
Now for a shameless plug, our team has a library we use for this. It's mostly used internally and as such is pretty opinionated on its dependencies (express, redis), but hopefully it can help you here. In fact, that library is pretty much just a JWT wrapper around what you have in place. If you decide to use it and notice any issues or deficiencies feel free to file any issues on github. Otherwise there are a whole bunch of other JWT based session management modules on npm that look promising. I would check those out regardless as there are very likely better modules out there than ours. Again, ours is used internally and came about from a pretty specific set of use cases so the chances that it captures all of yours are pretty slim. On the other hand, it sounds like you're using a similar stack so maybe the shoe fits.
If you do use ours it may seem odd that there's a split in the API surface on that module in that you can choose to store data directly in the JWT claims or in redis. This was deliberate and I think your examples illustrate a good use case for both sides. Typically what we do is store the user's email and name in the JWT claims, then store more dynamic session data in redis on their session. For example, upon logging in you'd add the issuer, audience, and user's email to the JWT claims but leave off anything related to "userAttempts". Then upon failed attempts you would add or modify the "userAttempts" on the session data stored in redis related to that JWT. Once a JWT is set it's not possible to modify its contents without generating a new one, so be aware that if you decide to keep relatively dynamic data in the JWT you'll have a constant exchange of old and new JWT's between the server and client.

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