How to restrict calls to api rest - javascript

Firstly, sorry for the format of this question. I know the rules for this site, but I haven't previous work nor investigation, because, basically, I don't know where to start...
I'm content with a tip for I start.
I'm searching how restrict calls to an api rest made in expressjs from (only) a native mobile app (ios and android). I thinking in a token, but I don't think it's a very safe idea, because any people can take the token and simulate to be the mobile app, or I'm wrong?
Thanks in advance!

You cannot restrict access to a REST api from only a native mobile app. The internet is wide open for access from any client so if you have a REST server, then any client can access it, whether mobile or not.
You can control access via authentication. So, usually what one would do is to require some sort of account access and then have your server watch for unexpected or unauthorized use and, if found, you disable that account.
You could also embed "secret" credentials in your mobile app and use those as the authorization over SSL, but a determined hacker could still get the credentials out of your app if they wanted to.

You can't restrict a public REST Api. Any request that your mobile users send can also be send by anyone.
Maybe you can keep a 'secret' string and attcah to http requests, but it can be easily exposed by sniffing http traffic or decompiling the apk.
Your last option is restricting access by IP, but I don't know if it's suitable with your case.

Of cource any one can simulate any APIs, it would just need a sniffer and the understanding of the right data format (like the format of the JSON object that is sent by your client app).
Anyone can go ahead, figure out how the WhatsApp works and simulate such an app. This can even happen when you are getting each user to Sign up first, then the "simulator" will just have to simulate that process too.
But, generally, what a developer wants is that :
People use his app
People use his REST APIs
Point 1 implies Point 2, but Point 2 does not imply Point 1. You cannot stop a hacker or someone from using your APIs without your App, you can just slow his simulator-development-process using some techniques.
Then you might ask, cant he flood your server with millions of request ? Of course he can. That a DoS attack. In theory, he can even use manny android simulators and install your App and then flood your server with millions of request.
Any one can use your APIs if you open it to the internet world.

Related

What Uniquely Identifies a Client Making a Request to Web API?

Let's say I write a piece of code that makes an http call to a web api, something like:
$http.get('www.myapi.com/api/controller/endpoint').then(function(resp){...})
I then give this code to two people that live in different cities and they hit my API from their respective houses (just from some browser). What information can my API get out of the http request that will allow me to tell apart person A and person B calling it? Is the IP always available? Is the MAC address ever available? What else is there?
How can person A pretend to be person B when calling my API?
Furthermore, what if person C calls my Web API from their own Web API (backend)? Will the same information be available, or what will be different?
This is a general question, but if you want to get specific, let's assume ASP.NET Web API 2 is receiving the http requests.
You're describing a desire for pre-authentication.
The IP will always be available. You could restrict the service to only those IP ranges. It's not a good way to do authentication.
Trying to get around having to perform authentication is not safe. You should use a proper authentication method. Combining IP restrictions with other methods is fine.
John Meyer's answer is essentially pre-shared token based user authentication. Having a valid token constitutes being constantly logged in. The token can be compromised far more easily than a typical token based user authentication that establishes a temporary token with a limited lifetime.
If you decide to go the pre-shared token route, please use a method that supports proper rotation or permutation of the token over time, such that it isn't vulnerable to replay attacks.
Your best option for this scenario is typical session-token based user authentication.
If you're actually not interested in who is using your service, only that they be uniquely identified, you can safely establish a session (or permanent, or arbitrary lifetime) cookie per user by the http Set-Cookie header that all clients should automatically respect and support, then use that as your method of tracking.
My team has accomplished this by requiring that an identification header be included on all requests. This does require some customization on the part of the calling party, but does not necessarily require that the user be logged in. Of course, the value of the header could be change by malicious users so if these calls need to be very secure you will need traditional authentication.
you seem really confused about this. what you are looking for is called authentication.
as you tagged C#, i am assuming you are developing your api in C#. I recommend checking Web Api.
there are a couple of authentication methods available these days. if you are developing a rest api, you can use json web tokens.
you can get a lot of information about the client calling your api via http headers.
I think you can always go with fully authenticated. I see your desire to go for a semi secured set of endpoints but I don't think any of the approach would serve you best. MAC, ip, user-agent, custom fields anything can be spoofed to be honest. Going with a bearer token or session token is your only bet here. For public apis you can limit user requests based on ip or you can try finding out whether a specific ip is trying to exploit you and thus block it but finding true identity might not be possible anyway.

Securing API with Node

I'm trying to build my first API to be consumed by a mobile application built with Ionic.
Before starting I'm looking into the architecture and I can not understand exactly how to make secure my API routes.
Let's say I have an endpoint like http://myapi/v1/get-items and my application doesn't need an user to be authenticated to view those items in the mobile app.
How should I protect that route from external queries, using Postman for example?
I wish that route to be not accessible unless is not requested by the application.
Looking on Google I can find many solution using basic authentication but all of those require an user to log in... What if my app doesn't have users to log in?
I'm a bit confused but I think there is a solution and I don't know it yet...
I hope you can help me to understand it.
EDIT:
My Question is totally different from the following: How to implement a secure REST API with node.js
I'm looking for solution that DO NOT require a User Authentication.
If you don't want to use User Auth through something like Passport then you can institute a whitelist in your Node API instead. express-ipfilter is an express middleware module that allows you to filter requests based on the request IP.
Requiring a login would be the cleanest and safest way to make sure your api remains private. However, if you want to keep external users out of your services without requiring a login, you will need to "sign" your requests. By that I mean doing something like encrypting a current timestamp on the client using a key known to both the server and the client app, adding that encrypted string as a header, receiving that header in your server, decrypting it and checking that it's not too old of a timestamp before you return a response.
It's not really safe (if someone can see the code they can see the encryption key) but it's an obstacle and it down't require logging in. See this for an example on encryption/decryption

How to Secure ASP.NET Web API with Cross Domain AJAX Calls?

I want to create an API at www.MyDomain.com that is accessible from public websites www.Customer1.com and www.Customer2.com. These public websites display each customers inventory and do not have any login features. They will use AJAX calls to read data from my API.
How can I secure the API so that it can be accessed via AJAX from different domains but no one can access the API to be able to scrape all of my customers data and all of their inventory?
I have tried thinking of different solutions on my own but they would all either require people to login to the public websites (which isn't an option) or it would require some secret "key" to be displayed publicly in the browser source code which could then be easily stolen.
Any ideas would be greatly appreciated.
Thanks!
P.S. Are their any obstacles that I am going to run into using Javascript & CORS that I need to look into now?
Anything that is accessible without authentication from a browser is by definition insecure, so you can't stop that. Your best bet is to have to have a relationship with the owner of customer1.com and customer2.com - the server apps for those two websites would make an HTTP call to you and authenticate with your service. Going this way also avoids the CORS issues you're talking about.
If you've already designed the client functionality, you can still probably do it without much change to the javascript - have it point to customer1.com for its AJAX call instead of your API, and customer1.com would accept this request and just act as a proxy to your API. Aside from the authentication, the rest of the request and response could just be pass-throughs to your API.
You can use Microsoft.AspNet.WebApi.Cors.
It's just need add ONE line at webapi config to use CORS in ASP.NET WEB API:
config.EnableCors("*","*","*");
View this for detail.
The simplest way to provide a minimum security here is to provide some kind of token system. Each app has its own token, or combination of tokens which it must pass to the server to be verified. How you generate this tokens is up to you and other than being linked to app's access, doesn't have to mean anything.
Provide a way for each API implementer to open an account with you. This way you will know who is accessing what and in some cases you can block/stop service.
For instance, a token can just be an MD5 hash:
7f138a09169b250e9dcb378140907378
In the database, this hash is linked to their account. On each request, they send this token with what they want. It is verified first to be valid, then the request is fore filled. If the token is invalid, then you can decide how to deal with it. Either don't return anything or return an "access denied" (or anything you want).
One thing to avoid is having a single token for everyone, though this can be a starting point. The reason for this is if some unauthorized app gets a hold of this token and exploits it, you have to change the token for everyone, not just the app that somehow leaked the token. You also can't control if someone has access to something or not.
Since you listed ASP.NET, I can also point you to WCF, which is fairly complex but has all the tools that you need to setup a comprehensive web service to service both you and your clients.
I hope this gives you a starting point!
EDIT:
There are security concerns here in the case that someone leaks their token key somehow. Make sure that you setup a way in which the app/your service do not expose the the token in anyway. Also have a flexible way of blocking a token, both by your clients in you, if it so happens that a token is exploited.

Detect if user is accessing my network (WIFI) using NodeJS

My question is a NodeJS newbie question. I would like to somehow detect if a user is accessing my network (Wifi) and I would like to indicate the users presence in my network.
How would I go about identifying the user presence. I'm completely clueless as I was unable to find any library that could help me detect this in Node. Is this even possible? If so could you point me to the appropriate libraries and the approach that I need to use.
If you run a router like a Linksys, etc. that can support DD-WRT, you can flash that firmware and then use either SNMP or web page scraping to get connected clients. There are node.js libraries for SNMP and there are a ton of examples of web page scraping with Node.JS.
Alternatively, you could get really complicated and add in RADIUS authentication to your DD-WRT installation and watch for an authentication event.
Another option, you could send ICMP (Ping) packets to every potential address that your router would acknowledge. e.g. if it's 192.168.1.1 on a 255.255.255.0 subnet, you would have 253 addresses to ping. Of course, the connecting user's machine would have to have ICMP responses turned on (which they typically do by default).
I hope one of these suggestions helps.

How it is possible to not expose you secret key with a Javascript OAuth library?

Looking at Twitter OAuth Libraries, I saw this note:
Be cautious when using JavaScript with OAuth. Don't expose your keys.
Then, looking at jsOAuth examples, I noticed that the keys are exposed in the code.
So my question is: How it is possible to not expose your keys when you use an OAuth library in Javascript?
Thanks.
UPDATE: Ok, maybe jsOAuth is not the right library to use, but how it is possible to do authentication with OAuth on a full Javascript web site?
As said in the documentation linked by you:
Written in JavaScript, jsOAuth aims to be a fully featured open source OAuth library for use in Adobe AIR, Appcelerator Titanium and PhoneGAP. In fact, anywhere that javascript can be used and has cross-domain XMLHttpRequests. For security reasons jsOAuth doesn't run in the browser. Browsers are only mentioned here for running the test suite. If you need jsOAuth in the browser, write an extension.
A good answer to your added question is available here:
Secure OAuth in Javascript
The only really reasonable way, right now, to do OAuth 1 in the browser, is to route API-calls via your server.
There simply is no way, as far as I have understood it, around this. If you do OAuth 1.0a calls through JavaScript from the browser -> You will HAVE to expose your consumer secret and access token secret, to at least the end user.
You cannot store these credentials in:
a cookie, the user can find them.
local storage, the user can find them (better than cookie though, since it does not entail sending a cookie back and forth all the time over HTTP)
in javascript, the user can find them (although this is probably your best bet since it is easier to obscure).
If it were only the access token secret that was exposed to the end user, that would be bearable - since it is in fact he/she who have authenticated your application. But losing your consumer secret is really not so hot, it means that your application is eligible for identity theft. I.e someone else could write an app that claims to be your app.
Even if you made it work securely in the browser, you are hampered by cross domain security blocks.
You could also make a script that sends all necessary values and parameters to the server to do the signing with.
The signed URL can then be sent back to the client (browser) that in turn does the actual request.
I have implemented OAuth 1.0a on the Twitter API that way using jsonp requests.
The benefit of this is that the response body is not relayed via your server, saving bandwidth.
That way you can have your cookie and eat it too.

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