How can I protect public API routes of unwanted malicious requests? - api

I am doing a Fullstack Web Project at the moment and am now looking into API security. I have implemented a user login which then allows the client to access most routes of my API. But there are unprotected routes as well which can and must be accessed without a login (e.g. sign up, login, ...).
One route for example returns whether a specific username or e-mail-adress is already taken by another user and is used during the sign up process. For someone with bad intentions this public route would be a great help to figure out which e-mail-addresses or usernames to try to hack or guess the password for because they can avoid credentials that aren‘t in use.
I know that this functionality is used very often by big companies to show the user whether he can use his desired username or not. How are they making sure there‘s no abuse? How can I protect my API and users from that?
I would appreciate any kind of help. Thanks a lot!

To limit API abuse rate limiting is a good practice. One way is to specify a maximum amount of API requests per IP address and after that ignore the requests.
A good article describing solutions to do so and also showing examples for an implementation in NodeJS can be found here.
Thanks to Gilbert Le Blanc for the help on this one.

Related

How to secure an REST API without login

I'm building a service that provide some readonly information that is going to be used in multiples websites, some with login and some public.
I dont want to make the api public to any website so I'm not sure what auth method i should use. I have some ideas but I don't want to reinvent the wheel.
I was thinking on have the backend of this sites request a token to my server using a secret/password/private_key then they should pass this token to their front end and pass it with each request to my server(their front end will comunicate directly with my API)
If your public non-authenticated API is accessible by your site, there's no way to stop other people from consuming this API and stealing your data.
You can stop other websites from directly taking data from your API (by not using CORS headers), but if your website is showing data from your API publicly, then assume anyone else can.
If your business relies on not being possible, rethink your business model. If data appears on the screen of a random user, it means that user can take that data and put it somewhere else. It's how the web works.
I totally agree with #Evert. Having said that, there are some ways you can use to make public API accessible to some and not to all. It will not be perfect, and using some kind of API tokens will be a better solution most of the time, but it might suit your needs.
First of all you can use firewall rules and allow connections from certain IPs only. Simple and will work as long as the source IPs do not change.
Another idea you can use: look at youtube and how private videos work. There is a secret in the URL. With enough entropy you can build publicly accessible URLs this way which can be used to share a simple link with friends, but will be hard to guess by others. There are drawbacks to this technique. You may only allow people to share their content this way, as they have always the rights to make the link public by pasting it into their tweeter/yt/other.

Simple RESTful API authentication

I'm building a single-page web application, fully based on RESTful API. I've seen several topics in that matter, but some things remain unclear for me.
I will need users to log in. Here are some of my ideas:
I can send e-mail and password to API and use basic auth. I'm not sure where should I keep password, should it be encrypted and if so: how?
Can I use built-in session system instead? Is it wrong to use cookies directly in the RESTful API? Why is it so popular to send credentials/keys to API itself instead of using cookies?
I thought about having one API key per user, return it in login action and keep it in localStorage. I guess it's not the greatest idea to have just one key per user?
Then, I came up with idea to have separate keys table and add random keys each time somebody logs in. On logout, the key would go away and no longer be valid. This is more secure than previous idea.
How is it solved in simple projects? I'd like to make it simple but not ridiculously inserure.
Please help.
The commonly approach is to use the header Authorization in REST. The state of the application must be on the client side with REST and shouldn'a be tied to a particularly client kind (browser with cookies)
I think that this link could be helpful:
Implementing authentication with tokens for RESTful applications : https://templth.wordpress.com/2015/01/05/implementing-authentication-with-tokens-for-restful-applications/
There is also à great question to à similar question here : https://softwareengineering.stackexchange.com/questions/141019/should-cookies-be-used-in-a-restful-api
Hope it helps,
Thierry

REST API - How to make logins via an API stateless and secure?

I'm struggling with an issue here. I've searched repeatedly for answers, but have been unable to find the exact answer I'm looking for. I'm attempting to build a secure authentication method for a REST api. My question is, how do we handle a login for a REST api?
Since a REST api is meant to be stateless every time, does that mean we need to store the client's username/password on the client's end (perhaps hashed), and send it in with every request? I'd be much more comfortable using a system like authentication tokens that are created upon logging in the first time, but does that go against the basic rules of REST, since this technically creates a "state" on the server?
What is the best and most practical method to handle this? As I wrote earlier, I'm struggling to come up with an answer to this; maybe that is due to this problem not having a clear answer, but I honestly don't know.
Thanks in advance.
That's also my understanding of REST: clients send login/password to the server along with every request. The server has to authenticate the client based on this information only. With regard to the Hypermedia principle of REST, having a user logged in is not an application state, in my understanding.

Security Risks of having an API for registering a new user

I have this question in mind and I wanted to get other developer's opinion on this issue.
For creating a user (like in Facebook or creating an account in Gmail), some people suggested to have an public/private (means we don't tell developers how to use it) action in API for it. I, however, think it is a security risk as even if it is not documented, a hacker can simple see the calls and http requests when our front-end app is using that api action to create a new user (using a web debugger like fiddler) and can find the url to that action so simple ! like this POST ~/api/user/create
and then he/she can send thousands of requests to create user, users needs to be verified but still he/she is adding a lot of junk users in our database and puts a lot of pressure on our servers.
So the question is how do we handle this? Allow this only on our website or what?
Thanks
You can use CAPTCHA to verify that's a real user.

secure the code in google chrome extension

I want to write a google chrome extension, that should make a request to my website to send and get some data, so, actually I should do an ajax request like it is written here https://developer.chrome.com/extensions/xhr.html
var xhr = new XMLHttpRequest();
xhr.open("GET", "http://api.example.com/data.json", true);
I wanted ask if there is a way to somehow secure the code or prevent others from using my api, because actually the other users can see the source code of the extension when they install it and so use my api without me being aware of it.
EDIT:
If I need to make some sort of authentication, than how can I authenticate the user before making the ajax call ? for authentication I will need to send a request to my server , but for that I should send , e.g. username and password, that should be saved somewhere in the extension's files, which, in fact, can be seen by the users, when they install the extension.
Thanks
Don't trust the browser, take steps to authenticate the user instead. So, in this case, you could require that YOU enter in a password that is used to communicate with your server.
Your Google extension would simple require you to enter in a password before it attempts to use AJAX to communicate with your server.
Be aware that you should build in means of protecting yourself from brute-force attacks. So, do things like lock everything down if there are more than some small number of wrong passwords, etc.
You could also consider using the password to simply decrypt the destination of the XHR, but if you go this route, you should store this very carefully, because this will be brute-forceable offline.
EDIT
Trying to lock down an API so that only a single application can use it is just not practical nor technically possible, so you're only hope of doing this is to authenticate the user using the API, regardless of the accessing software he is using. You could have the user sign an agreement that legally limits them to only your extension, but I suspect this will go largely unenforceable and will consume your time tracking abusers down.
If you don't want unauthorized people even knowing where the API is, you could perform authentication using an out-of-band mechanism: over the telephone, email, SMS, or simply, another API that will grant the user a password or token that requests to your API must be accompanied with.
During this out-of-band process, you could also grant the user, a unique URI (the API access point) that is only valid per authenticated session (https://api.totally-cool-extension.com/api/ijyeDvB5dYvSiWG97OLuTAoNWwbhuZ0/, for example). Any requests to your server on OTHER URIs simply won't work. However, this isn't theoretically much different than using the same API access point, and having a good password. It just changes the number of places in your architecture that will be performing authentication and/or authorization checks.
<aside>My vote would be to reduce the number of authorization/authentication points to as few as possible so that you can spend more time on getting that one place correct rather than having multiple places and possibly multiple logic flaws or other things that could lead to vulnerabilities.</aside>
You could also explore using Public Key Infrastructure and/or one-time passwords schemes or device-based token generators, etc., but in the end, you'll be allowing authenticated and authorized users to use your API. And, thanks to the Internet, this will not remain an undisclosed URI for long.
And, more importantly, it will not prevent someone from using the data on their own. Even with all these measures in place, it would be trivial for an authorized user to collect this data as it is being streamed to your extension. Or, if you employ point-to-point encryption, they could screen-scrap or use some form of JS introspection on your very code or even extract the data from their computer's memory.
I know you were looking for a silver bullet here, but it doesn't exist.
I think you are doing it wrong. You should never trust what's going on on internet users PC's. Never!
Move the line of trust one step inward, make your API public and then design the security where you have perfect control - server side.
I could not get correct aspect of your use case
Few Points:
Your extension code is always traceable( Any one who has installed extension can view the code)
If you are looking for security through complicated or obfuscated coding patterns you end up slow down of understanding process not the whole.
If your target is to ensure users who install your extension should be able to access and inert all other users( Who have gained illegal access or downloaded and edited code) have a session shared key per installation.
Please explain further use case so i can help you better.