Authorisation strategy for a first-party express based node API - node.js

I'm tackling the design of my first API and am struggling somewhat with authorisation concepts - I was hoping some kind people could give me some advice!
What I'm building:
An API that will eventually be accessed by third party apps and a mobile app.
A web-based 'client' (first-party single page app) that will use the API. (Should this first-party app be 'a part' of the API, or a completely separate node app?)
Technology I plan to use:
Node
Express
Passport
Mongodb with Mongoose
I'm not wed to express or passport, they just seem like the best options and are well documented - bit I wouldn't want a potential solution to be dismissed because of alternative dependencies. Same with Mongoose, I actually prefer the look of Monk (or even just Mongojs), but every tut seems to use mongoose, so seems like the safest option for a node beginner.
Authenticating a user is simple enough (I've gone through the fantastic Beer Locker tutorial), what I'm struggling with is ongoing authorisation. Naturally I don't want the user to have to input a username and password with every request they make - should this information be stored locally and sent with every request? (if so, how? I can't find any info on handling an API with a session) or should I be working with tokens of some sort? The small amount of reading I did on 'Digest' authorisation (including the Beer Locker tutorial follow-up) made it seem like it had security issues, at least with the Passport implementation (this I don't fully understand, but seems to relate to hashing passwords, which passport doesn't do as standard, and only MD5 is supported even if it's added?).
I have built a working API that I can authorise with 'Basic' (directly, through Postman), so I have the foundations in place - authorisation works, I just need the tools to take that to the next step and add sessions into the mix!
I've been trying to get my head around this for a couple of days now, but I fear I'm too stuck in a more traditional local web-app workflow - the whole API thing is throwing me somewhat.
Any help is hugely appreciated, even if it's just pointing me at an appropriate tutorial - the above set of requirements must be quite common!

I have come accross this problem too...
I can only recommend doing this for the beginning:
http://scotch.io/tutorials/javascript/easy-node-authentication-setup-and-local
tell me if it helped :)

As I understand you have done the authentication and the only thing you have to do now is store somewhere that the current user is authenticated, his name, roles etc to use later with other requests. In the Passport you will do it in the function callback (instead of the "If this function gets called..." comment).
Now you have to decide, you have two options:
Store the user information (name, roles etc.) on your server (in a session) and give the user some long code which will identify his session for the next requests
to store the information on your server you may use for example the express-session middleware
it would be probably best to save the session identifier in a cookie, but read some security issues before
Give the user something that would prove to you he/she is authenticated and which name, roles etc. he/she has
you can generate a token, that contains the user information (name, roles etc.) that the user will send with every request. to know this token is legit, you will have to sign it. more on this is on jwt.io and you can use express-jwt middleware.
you dont have to care about storage of session with this one
the token can be placed to a cookie too, but same security issues apply. it is still considered better that localstorage (more here)

Related

Having one backend manage authentication for a webapp and react native app

Im planning on making an application that has two parts two it:
React native mobile app
Browser web-app for desktop users
I'm trying to plan out how im going to manage the backend authentication for this (Node.js, passport.js). Ideally, I can just have one backend manage it, regardless of which type of client.
Lets say im going to ONLY have google auth (for simplicity). I don't need to hit googles API's for any information (like profile, contacts, etc), I just want them to login with a google account. My understanding so far is that theres two main ways (especially since im using passport.js).
jwt based approach
session based approach
For either approach, my issue arises when it comes to the react native app. Since I'm not able to use the HttpOnly cookie, im not sure how to safely store data. e.g
In the jwt approach, if the server administers an access token and a refresh token, the react native client can just store them both in the same place e.g https://github.com/mcodex/react-native-sensitive-info. Which means the refresh token is just as susceptible as the access token, which defeats the point of a refresh token, so might as well just have the access token be long lived.
In the session based approach, react native can just store the session id some where (like react-native-sensitive-info above), and the same problem arises
My current thoughts on what should be done:
It seems like theres no way of getting around the security issue of storing information in react native, so as of now I feel like im just going to follow the JWT approach, and store the access + refresh token in react-native-sensitive-info. However, this does mean that the login endpoint is going to return the access + refresh token in the body of the request when the User-agent is mobile. When the user agent is web then we should be able to set an httponly cookie. The only thing that I can think of is if there is a malicious request that masks the user agent (is this possible?), and then can receive the access + refresh token in the body and will be able to do whatever with that.
Performance Aside
A session based storage approach seems much simpler overall. Yes it does store state on the backend, but if we did the JWT approach we would have to store peoples refresh tokens somewhere on the backend anyway (If theres ever a scenario where we need to invalidate peoples refresh tokens, e.g on logout or damage prevention).
This way, say we have a sessions table, when a user logs out, or if we want to invalidate sessions, all we have to do is delete rows from that table. In the JWT method, if we want to invalidate a refresh token, we have to have a blocklist table (which will only keep growing in size, since refresh tokens shouldn't expire, but I guess they can be dropped after a long period of time). However, if you have LOTS of users, the sessions table could get large, which could cause performance issues (but you could probably just drop sessions over a certain age)
/Aside
Questions:
Ive noticed mobile applications have NEVER asked me to relogin with OAuth. Does that mean they're constantly using their refresh token whenever the access token expires? If theres no clear way to store that in a secure way in mobile, do they just have super long lasting access tokens?
Is all of this thinking overkill? Is it fine to just store a super long-lasting access-token in react native and just use that all the time? Then when the user presses 'logout' we can drop that from local storage?
Would a third party auth system like auth0 manage all of this for me?
I'll try to share my experiencies in different kinds of app, this way things may get more clear.
Authentication Method
On most of the mobile applications (with web applications) I've worked with long term access tokens on the mobile side, most of applications don't require the user to login each time you open the app. Usually we store the token in a Secure Storage.
In some cases I've worked with a memory database (Redis) to put the user's session it's really fast and you don't need to query your main database each request (this was used for a high availability system, it may be overkill for most usecases)
Some very specific solutions may require more security, this will depend on your product (like banks, and transactions apps or apps the keep sensitive data) in these cases I would recommend you to login the user every time he closes the app or stays inactive for to long. (this kind of solution usually relies on fingerprint/faceId libs)
My personal opinion on this matter is to go with jwt, it's easy to maintain on the server side if you need to change backends and has a more defined pattern to follow, but that's my opinion and if you have high demand or some specific usecase this may change.
Storage
Talking about the storage options, there are some good suggestions on where to save data like tokens in a secure way on the react native docs,a good option I've used sometime would be:
https://github.com/emeraldsanto/react-native-encrypted-storage
but you can see more options and it advantages here:
https://reactnative.dev/docs/security#secure-storage
Third party libs
They usually helps with the basics if your projects has the budget and not a lot of customization on the authentication process, usually if it's a brand new project (on the back and front end) they work well.
Most of them will handle most of the hurdle for you like token renovation but you should mind the price scalability for these kind of approach
Wish success on your project.

JWT - What is the best way to use jsonwebtoken ? I'm lost

I’m learning to code for one year now. I mainly learned how to deal with a rest API (Node/Express on back-end and Vue on front-end).
I get to the point where I want to develop the ideas I have for app.
For this, I first wanted to develop the backend to have a authentification process that I could use as a boilerplate for other project I would have.
But now I’m completely lost with Jsonwebtoken and how to exactly use it in order to make something secure as well as user-friendly.
So far I understand that a rest API should be stateless (I.e. nothing should be store server-side and should therefore not have DB calls -as for sessions- to grant access to data).
In this respect, I’ve noted different strategies :
Short-lived JWT : (+) this is very secure since you theoretically have to log in every time you want to access the server (-) very bad user experience
Long-lived JWT : (+) user-friendly (persistent login) (-) very insecure (no way to check if JWT was stolen)
Short-lived JWT with Long-lived Refresh Token…
That’s where I get confused…
From every articles/tutorials I’ve read, the refresh token should be linked somehow with a DB (e.g. to store the refresh token key or the blacklisted token…). I’ve also seen a tutorial that partly linked the secret key (to verify the token) with the hashed password stored in the DB. This is kind of smart since previous token will automatically be considered as invalid as of the moment the user changes his password… But this once again mean a DB call…
My point is that I’m coming to the conclusion that
(1) there’s no perfect way to handle authentification process in secure and user-friendly way…
(2) DB calls cannot be avoided to have something a bit secure...
And considering that conclusion, I definitely can’t understand the use of refresh token…
If refresh tokens required DB calls, you could get to the same result with only one main token…
You could for instance store a JWT ID in the token and in the DB… If those two id match upon validation of the token, you issue a new token with a new id that overwrites the previous one… Now if you use an old one, it will never be validated… Then, since you have called the DB to validate the token (most certainly the USER table), you could check in the sametime if, for example, the user is an admin or not (no need to store it in the JWT)… Finally, you could use the « hashed password » trick described above to enhance security…
So… What am I missing ? What is the best strategy ?
I’ll be happy to have your comments on this (or a link to a very good article - I’ve a lot of these though…)
Thank you very much for your help
PS: and I’m not even talking about how to send the token to the server (with cookie but risk of CSRF attach or with header but subject to XSS attack if token is stored client-side)… In this respect I’ve seen multiple tutorial that use JWT through cookie with cerf key stored client side as well as inside the jet => both should be send.
PS2: I hope I'm clear since I'm french-speaking native :-)
So you have asked quite a few questions in this one question. It will be quite difficult for anyone to give a thoughtful answer here, but I shall try. Before that, full disclaimer, that I am the author of a new library called SuperTokens that I believe would provide you the best solution for session management. It's possible that you may have already read our blog: https://hackernoon.com/all-you-need-to-know-about-user-session-security-ee5245e6bdad. It's best if we can chat about this so that I can give you a full detailed explanation about everything you have asked (I would love to help out). Join our discord: https://discord.gg/zVcVeev
Now to answer your question(s):
You should always only use short lived JWTs
Doing a database call for authentication is not a problem, but as everything else, we try and optimise things, so doing fewer db calls, is better. If you go with JWT access tokens and Opaque Refresh tokens, then for most APIs, you do not need to do a db call. However, if you link the secret key of the JWT with the hashed password, then you would have to a db call for every API - which is OK, but I feel unnecessary since you are going to use short lived JWTs anyways (a few hours to a day max)
You mentioned token theft - this is a tricky issue, but according to RFC 6819, you can use the concept of rotating refresh token to detect theft. Of course, actually doing so can be tricky as you have to take care of many race conditions and network failure issues - see https://hackernoon.com/the-best-way-to-securely-manage-user-sessions-91f27eeef460
About why we need refresh tokens: Say you do not have a refresh token, then you would have just one token that you could treat as both, an access and a refresh token. You could still make it short lived (when it's an access token), and then after it expires, treat it as a refresh token - which also has some lifetime. The problem with this is that it's not very clean (point of expiring a token is that it is useless afterwards), and that you are exposing the refresh token over the network every single API call - reducing security. I know you can have HTTPS, but there are HTTPS MITM attacks as well - see the blog post, part 1.
In terms of storage, one neat trick could be to split the access token into two - one to store in secure, httponly cookie, and one to store in localstorage. For every API call, send both to the server (cookies will be sent automatically anyways), and then the server would combine the two and go about authenticating. This would prevent both, CSRF and XSS attacks on sessions!
Now, you could either implement this whole thing on your own, or then use our library that does all these things out of the box: https://github.com/supertokens/supertokens-node-mysql-ref-jwt.
To discuss this more, or any other questions you have, join our discord server.
PS: I know I used this for advertising my lib, but I hope I did answer your question. It is genuinely difficult to give a good explanation to your questions without having a conversation.

Should I use cookies, sessions, or user accounts?

I'm trying to develop a website for reviewing TV series, and I want to limit the rating for a show to one rating per user, and I kind of have no idea where to start, since I'm very new to web development. I'm using Vue.js on the front-end; Node.js with Express on the back-end.
From what I understand, cookies should not be suitable for this purpose since they can be deleted by the user, am I right?
I've also read about sessions and how they are stored on the server rather than the browser (but I also don't know what sessions are or how to implement them).
There's also the user registration system possibility. So, which one of these methods should I use for this purpose?
If you could also tell me about where to start (direct me to tutorials, code snippets, ..) I would be really grateful. Thanks.
Like said by Mr. Anonymous, you need User Accounts. However you could achieve this using in your case, for example, expressjs/session to create sessions and passport.js for the user authentication part.
Here there is a simple tutorial using these two libraries and mongo-db for saving user data.
If you want implement your own session library (only for learning purpose), you can follow these advices.
You need to use all 3 and if your new to web development this will take you some time to get right. You will need user registration, a login system, and when users log in you will create sessions ( which internally use cookies) and if you want them to login with "remember me" you need to explicitly use cookies.
Sessions
This is how express/your-web-app will remember that a user is logged in. Under the hood its using cookies on the users machine that map to ids stored in memory on your server. Without sessions and cookies your users will have to log in on every page....You don't have to worry about how sessions use cookies yourself. There is express middleware libraries that handle this for you so you just interact with sessions like any other object, but its good to know that sessions internally use cookies. You can find lots of articles expanding on this.
Cookies
You will explicitly have to create cookies if you want to give your users the "Remember Me" login option. If you don't care about that then you can force them to log in and then create a session so they wont have to log in again for 20 mins or however long you want.
User Accounts
User accounts are records in a database that uniquely identify each user. The sessions and cookies all point back to this. That is where your store your users information such as their username, email, and whether or not they have already voted on a TV series. When a user logs in you lookup their identity in your database and if you find one you then create a session so they don't have log in again as they navigate your site for a set amount of time.
Recommendation
Start small. Forget about Vue.js for now and use plain HTML until you understand these basic components sessions, cookies, and how to build a login and registration page. If, and I respectfully mean if, you get that working then you can work on making it look pretty and fancy in the front using Vue.js.

Authentication middleware in Express NodeJS - Best practice

I'm writing my first Express NodeJS app and I want to know what is the best practice when it comes to authentication middlewares?
I'm using access tokens and cookies (which are composed from user id and some random bytes) for each new user, and for some routes I want only given users to have access to it.
Is a good idea to access database from a middleware? Or where should I check if a given user has access to a given resource?
Thank you!
There are many modules built for authentication purpose for nodejs applications. However, the most commonly used module for nodejs/expressjs is Passport. If you wish to stay isolated from such libraries, nodejs has built-in libraries for encryption etc, for example, check this out.
For sessions and cookies, using signed cookies is always a good practice. Check out this SO post. There are many good practices for maintaining security (say, using https over http, token based authentication, etc.) followed throughout the development grounds, which you'll learn as you go on. Here is a short tutorial of JWT(JSON Web Tokens) for a good introduction to token based authentication in JSON you can check out.
Happy coding :)

PassportJS authentication and mongodb database collection best practices?

I am working in a project and actually the first time using nodejs, express and mongodb. For the authentication i am using passport.js which look pretty flexible and easy to integrate it.
I really like the idea of Serializing and Deserializing but my concern is about the user object which is always ON and can be used on every request.
My project involve subscriptions, user profile and maybe a small ticked system.
So my user schema it contains user credentials, user info like address, phone, email and also information about the subscription. Some of this information is embedded documents with in same schema. It seems weird that all this info is always ready even i do not needed, even the bcrypt password is always on the request call.
My question is, do you think is best practice to separate the user credentials from the user object and play with relationships soi can call the user info when i need it with normal controller model way?
Thanks in advance
if you are referring to sessions you should really only be sending a small piece of data with the request such as a user id. The entire user document should not be going across with every request.
It's common practice to separate user credentials from the rest of the user data, because the credentials need to be stored in a very secure manner - so much so that it dictates different infrastructure.
I work at Stormpath and we provide this as a service. We store the password for you, with very high levels of encryption. We have a great integration for Express, you check it out here:
https://github.com/stormpath/stormpath-express

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