How to protect a public accessible API? - rest

I'm working in creating a FORM (kind of survey) to get user input, any user who visited the website can provide me information. This would means, the API is actually public accessible to anyone without any token or session (basically nothing)
I want to prevent people from getting my endpoint and create thousand/millions of requests (SPAM) to flood my service and database. I've tried to look over Stackoverflow and some post in medium, it's interesting that I don't find much about this.
Some said:
bundle my website as an hybrid app, supply accessToken to only "trusted device" for firing my api (but this is a pure webapp)
creating custom header and identify the header from my web server (hmm..?)
use CAPTCHA (this will only stop people spamming via the GUI, but spamming via script still possible)
Is this simply no better way to secure, since it's public?
Any thoughts to share?

have you read about Request Queue?
it might help you solve the issue
source 1
source 2

Related

What is the best approach to stop your platform's users to "sniff" the frontend requests to backend and modify them?

So I have a platform that works like this: Users can create accounts by logging in with their Google (I USE AUTH0) and then they can create "Projects" which contain lots of other unimportant stuff regarding my current problem (like todo lists, ability to upload files etc; they can also Edit the project by changing some of it's attributes like name, description, theme and so on). There is a home page where everyone can see each other's projects and access them (but not upload files, change the tasks in the to do lists; this is possible only by the person that owns it).
By using a tool like Burp, people can see the request made from frontend to backend, for example when accessing one of the projects, and modify it on the fly.
This is what it looks like inside Burp when they access one of the projects:
As you can see there is a Get request to /projects/idOfTheProject; they can replace the GET with DELETE for example and they will successfully delete it; they can also see what is sent to the backend when a project is edited (name changed, description, thumbnail picture etc) and change anything they want about it.
How should I prevent this?
What I've looked at so far:
a. JWT - Probably the best fitting for my situation, but required the most work to be done (as I already have my platform almost finished with no such a security measure implemented yet, so I may need to rewrite a lot of things in both backend and frontend)
b. Sending the user's id that initiated the action as well to the backend and verify if it has the necessary privileges - the worst solution as users can access each other's profile and see the id, then just change another field in the request's JSON
c. Have a sort of token for each user and send that instead of the user's id - in this way somebody can't get your token by just looking at the communication between frontend and backend (only if it is using YOUR account). That token should be taken maybe somewhere from the auth0 when they create their account? If they provide something like that; or I can just create it myself and store it alongside the other user variables. You would still see the requests in plain text but even if you modified something you would still have to "guess" the owner's token, which will be impossible.
For frontend I use NextJS and for backend Flask.
Thank you in advance!
The TL;DR is that you don’t. A determined user will always be able to see what requests are being sent out by the code running on their computer and over their network. What you are describing when asking how to prevent people from “sniffing” these requests is security through obscurity, which isn’t actually secure at all.
What you should do instead is have an authorization system on your backend which will check if the current user can perform a given action on a given resource. For example, verifying that a user is an administrator before allowing them to delete a blog post, or making sure that the current user is on the same account as another user before allowing the current user to see details about the other user.

API Authentication - Clients (consumers) vs. local users

I work for an ecommerce site and we are looking to expose much of our core functionality via a set of APIs. We plan on re-writing some of our own public facing applications (e.g. the main shop website and our mobile app) to call these new APIs also. We also want to offer some of these APIs out to third-parties who want to integrate with us.
My first question is - what is a suitable authentication method for these APIs? Everything I read is about OAuth, but am I right in saying that this doesn't fit in this case as we're not looking to use another log in system (e.g. Facebook, Google) but rather restrict access to our own API (so maybe an API key or JWT solution would be better?)
Secondly, our current website has it's own user accounts system. How do you offer /user endpoints (like GET user/1235/paymentmethods) in an API like this? Surely the actual user (website customer) needs to authenticate somehow in order for the given API consumer to access their data.
I've spent the last 2 days reading about this but I'm at a loss as to how to go about this! Any help much appreciated.

How to secure Rest Based API?

We intend to develop rest based api. I explored the topic but it seems, you can secure api when your client is an app (So there are many ways, public key - private key etc). What about websites / mobile website, if we are accessing rest based api in website which do not use any login for accessing contents ( login would be optional ) then how could we restrict other people from accessing rest based api ?
Does it make sense using Oauth2.0 ? I don't have clear idea of that.
More clear question could be ,How can we secure get or post request exposed over web for the website which doesn't use any login ?
If it's simple get request or post request , which will return you json data on specific input, now i have mobile website , who will access those data using get request or post request to fetch data. Well, some else can also access it , problem is i am not using Login, user can access data directly. But how can we restrict other people from accessing that data.
What do you think is the difference between securing a website that is not using REST vs one that is using REST API?
OAuth provides authorisation capabilities for your site, in a REST architecture this means a user of the mobile application will have to provide their credentials before being allowed to access the resource. The application can then decide on if that user has access to the requested resource. However you've said your website doesn't need use authorisation.
You can use certificates however good luck managing the certificate for each client. My take on it is for your explanation you don't need to secure your website because you will never be able to manage a trust relationship between the client and the server. There are some options though:
You build your own client application that you ship out to people which can verify itself with the server using a packaged certificate with the client. E.g. iOS has this kind of feature if you build for that device.
You provide a capability to download a certificate that is 'installed' in the browser and used when communicating to your REST API
Use something like a handshaking protocol so when a client wants to make the first request it says; 'hi I'm a client can we chat?' And the server responds with 'yes for the next X minutes we can however make sure you send me this key everytime you tell me something YYYYYY' (you can use something like SecureUDID or equivalent for other devices than iOS).
There are probably others but you get the basic idea. Again in my opinion if your resource doesn't need authorisation then you don't need to secure that REST API. Can I ask what kind of data are you exposing via this REST API or functionality your providing? That might help provide a better answer.
You want authorization: only some agents (mobile clients) and/or users should be allowed to access those APIs.
To solve that problem, you need identification: a way for the server to tell who is who (or what), so the right decision can be made.
There are many different way to provide some form of identification, depending how much you care about security.
The simplest is a user agent string, specific to your mobile clients. But it can be faked easily. Slightly harder to fake are client based 'secrets' - embed some kind of secret or key in your mobile client code. You can make it really complicated and secret, but as ramsinb pointed out, you can't get security this way as it would require you to be able to guarantee that the secret you're shipping with the client (wether it's code, algorithm or any other fancy construct) can't be compromised or reverse engineered. Not happening when you don't control the client.
From there, 3 choices:
Security isn't really required, don't bother
Security isn't really required, but you still want to limit access to your API to either legit users/agents or people ready to invest some time hacking your protection - go with a specific user agent or a client embedded secret - don't invest much into it as it won't block people who really want access to get it anyway
Security IS required - and then I don't think there is a way around authentication, wether it's login/password, user specific (device specific?) keys, OpenID, etc... No matter what, you'll have to add to the user burden to some extent, although you can limit that burden by allowing authentication to persist (cookies, storage....)

How to use the same facebook application for different websites

I'm developing a small CMS in PHP and we're putting on social integration.
The content is changed by a single administrator who as right for publishing news, events and so on...
I'd to add this feature, when the admin publishes something it's already posted on facebook wall. I'm not very familiar with facebook php SDK, and i'm a little bit confused about it.
If (make it an example) 10 different sites are using my CMS, do I have to create 10 different facebook application? (let's assume the 10 websites are all in different domains and servers)
2nd, is there a way for authenticating with just PHP (something like sending username&password directly) so that the user does not need to be logged on facebook?
thanks
You might want to break up your question in to smaller understandable units. Its very difficult to understand what you are driving at.
My understanding of your problem could be minimal, but here goes...
1_ No you do not create 10 different facebook application. Create a single facebook application and make it a service entry point. So that all your cms sites could talk to this one site to interact with facebook. ( A REST service layer).
2_ Facebook api does not support username and password authentication. They only support oauth2.0. Although Oauth is not trivial, but since they have provided library for that, implementing authentication is pretty trivial.
Please read up on http://developers.facebook.com/docs/.
Its really easy and straight forward and well explained.
Your question is so vague and extensive that it cannot be answered well here.
If you experience any specific implementation problems, this is the right place.
However to answer atleast a part of your question:
The most powerful tool when working with facebook applications is the Graph API.
Its principle is very simple. You can do almonst any action on behalf of any user or application. You have to generate a token first that identifies the user and the proper permissions. Those tokens can be made "permanent" so you can do background tasks. Usually they are only active a very short time so you can perform actions while interacting with the user. The process of generating tokens involves the user so that he/she has to confirm the privileges you are asking for.
For websites that publish something automatically you would probably generate a permanent token one time that is active as long as you remove the app in your privacy settings.
Basically yuo can work with any application on any website. There is no limitation. However there are two ways of generating tokens. One involves on an additional request and one is done client side, which is bound to one domain oyu specifiedin your apps settings.
Addendum:
#ArtoAle
you are right about every app beeing assighend to exactly one domain. however once you obtained a valid token it doesnt matter from where or who you use it within the graph api.
let me expalin this a little bit:
it would make no sense since it is you doing the request. there is no such thing as "where the request is coming from". of course there is the "referer" header information, but it can be freely specified and is not used in any context of this.
the domain you enter in your apps settings only restricts where facebook redirects the user to.
why?
this ensures that some bad guy cannot set up a website on any domain and let the user authorize an app and get an access token with YOUR application.
so this setting ensures that the user and the access token are redirected back to YOUR site and not to another bad site.
but there is an alternative. if you use the control flow for desktop applications you don't get an access token right after the user has been redirected back. you get a temporary SESSION-TOKEN that you can EXCCHANGE for an access token. this exchange is done server side over the REST api and requires your application secret. So at this point it is ensured that it is YOU who gets the token.
This method can be done on any domain or in case of desktop applications on no domain at all.
This is a quote from the faceboo docs:
To convert sessions, send a POST
request to
https://graph.facebook.com/oauth/exchange_sessions
with a comma-separated list of
sessions you want to convert:
curl client_id=your_app_id \
-F client_secret=your_app_secret \
-F sessions=2.DbavCpzL6Yc_XGEI0Ip9GA__.3600.1271649600-12345,2.aBdC...
\
https://graph.facebook.com/oauth/exchange_sessions
The response from the request is a
JSON array of OAuth access tokens in
the same order as the sessions given:
[ {
"access_token": "...",
"expires": 1271649600, }, ... ]
However you don't need this method as its a bit more complex. For your use case i would suggest using a central point of authorization.
So you would specify your ONE domain as a redirect url. This domain is than SHARED between your websites. there you can obtain the fully valid access token and seamlessly redirect the user back to your specific project website and pass along the access token.
This way you can use the traditional easy authentication flow that is probably also more future proof.
The fact remains. Once the access token is generated you can perform any action from any domain, there is no difference as ther is literally no "domain" where the request is coming from (see above).
apart from that, if you want some nice javascript features to work - like the comments box or like button, you need to setup up open graph tags correctly.
if you have some implementation problems or as you said "domain errors" please describe them more clearly, include the steps you made and if possible an error message.

Authorizing REST Requests

I'm working on a REST service that has a few requirements:
It has to be secure.
Users should not be able to forge requests.
My current proposed solution is to have a custom Authorization header that look like this (this is the same way that the amazon web services work):
Authorization: MYAPI username:signature
My question is how to form the signature. When the user logs into the service they are given a secret key which they should be able to use to sign requests. This will stop other users submitting requests on their behalf, but will not stop them forging requests.
The application that will be using this service is an iPhone application, so I was thinking we could have a public key embedded in the application which we can do an additional signature with, but does this mean we'll have to have two signatures, one for the user key and one for the app key?
Any advice would be greatly appreciated, I'd quite like to get this right the first time.
The answer is simple: It cannot be done. As soon as you ship any solution to the end user, he or she can allways attack the server it is communicating with. The most common version of this problem is cheating with hi-score lists in Flash games. You can make it harder by embedding some sort of encryption in the client and obfuscating the code... But all compiled and obfuscated code can allways be decompiled and unobfuscated. It is just a matter of how much time and money you are willing to spend and likewise for the potential attacker.
So your concern is not how to try to prevent the user from sending faulty data to your system. It is how to prevent the user from damaging your system. You have to design your interfaces so that all damage done by faulty data only affects the user sending it.
What's wrong with HTTP Digest Authentication?
I think the simplest way to do this right would be to use HTTPS client authentication. Apple's site has a thread on this very subject.
Edit: to handle authorization, I would create a separate resource (URI) on the server for each user, and only permit that (authenticated) user to manipulate this resource.
Edit (2014): Apple changed their forum software in the past six years; the thread is now at https://discussions.apple.com/thread/1643618
There is a better discussion of this here:
Best Practices for securing a REST API / web service