Is there any way to restrict post requests to my REST API only to requests coming from my own mobile app binary? This app will be distributed on Google Play and the Apple App Store so it should be implied that someone will have access to its binary and try to reverse engineer it.
I was thinking something involving the app signatures, since every published app must be signed somehow, but I can't figure out how to do it in a secure way. Maybe a combination of getting the app signature, plus time-based hashes, plus app-generated key pairs and the good old security though obscurity?
I'm looking for something as fail proof as possible. The reason why is because I need to deliver data to the app based on data gathered by the phone sensors, and if people can pose as my own app and send data to my api that wasn't processed by my own algorithms, it defeats its purpose.
I'm open to any effective solution, no matter how complicated. Tin foil hat solutions are greatly appreciated.
Any credentials that are stored in the app can be exposed by the user. In the case of Android, they can completely decompile your app and easily retrieve them.
If the connection to the server does not utilize SSL, they can be easily sniffed off the network.
Seriously, anybody who wants the credentials will get them, so don't worry about concealing them. In essence, you have a public API.
There are some pitfalls and it takes extra time to manage a public API.
Many public APIs still track by IP address and implement tarpits to simply slow down requests from any IP address that seems to be abusing the system. This way, legitimate users from the same IP address can still carry on, albeit slower.
You have to be willing to shut off an IP address or IP address range despite the fact that you may be blocking innocent and upstanding users at the same time as the abusers. If your application is free, it may give you more freedom since there is no expected level of service and no contract, but you may want to guard yourself with a legal agreement.
In general, if your service is popular enough that someone wants to attack it, that's usually a good sign, so don't worry about it too much early on, but do stay ahead of it. You don't want the reason for your app's failure to be because users got tired of waiting on a slow server.
Your other option is to have the users register, so you can block by credentials rather than IP address when you spot abuse.
Yes, It's public
This app will be distributed on Google Play and the Apple App Store so it should be implied that someone will have access to its binary and try to reverse engineer it.
From the moment its on the stores it's public, therefore anything sensitive on the app binary must be considered as potentially compromised.
The Difference Between WHO and WHAT is Accessing the API Server
Before I dive into your problem I would like to first clear a misconception about who and what is accessing an API server. I wrote a series of articles around API and Mobile security, and in the article Why Does Your Mobile App Need An Api Key? you can read in detail the difference between who and what is accessing your API server, but I will extract here the main takes from it:
The what is the thing making the request to the API server. Is it really a genuine instance of your mobile app, or is it a bot, an automated script or an attacker manually poking around your API server with a tool like Postman?
The who is the user of the mobile app that we can authenticate, authorize and identify in several ways, like using OpenID Connect or OAUTH2 flows.
Think about the who as the user your API server will be able to Authenticate and Authorize access to the data, and think about the what as the software making that request in behalf of the user.
So if you are not using user authentication in the app, then you are left with trying to attest what is doing the request.
Mobile Apps should be as much dumb as possible
The reason why is because I need to deliver data to the app based on data gathered by the phone sensors, and if people can pose as my own app and send data to my api that wasn't processed by my own algorithms, it defeats its purpose.
It sounds to me that you are saying that you have algorithms running on the phone to process data from the device sensors and then send them to the API server. If so then you should reconsider this approach and instead just collect the sensor values and send them to the API server and have it running the algorithm.
As I said anything inside your app binary is public, because as yourself said, it can be reverse engineered:
should be implied that someone will have access to its binary and try to reverse engineer it.
Keeping the algorithms in the backend will allow you to not reveal your business logic, and at same time you may reject requests with sensor readings that do not make sense(if is possible to do). This also brings you the benefit of not having to release a new version of the app each time you tweak the algorithm or fix a bug in it.
Runtime attacks
I was thinking something involving the app signatures, since every published app must be signed somehow, but I can't figure out how to do it in a secure way.
Anything you do at runtime to protect the request you are about to send to your API can be reverse engineered with tools like Frida:
Inject your own scripts into black box processes. Hook any function, spy on crypto APIs or trace private application code, no source code needed. Edit, hit save, and instantly see the results. All without compilation steps or program restarts.
Your Suggested Solutions
Security is all about layers of defense, thus you should add as many as you can afford and required by law(e.g GDPR in Europe), therefore any of your purposed solutions are one more layer the attacker needs to bypass, and depending on is skill-set and time is willing to spent on your mobile app it may prevent them to go any further, but in the end all of them can be bypassed.
Maybe a combination of getting the app signature, plus time-based hashes, plus app-generated key pairs and the good old security though obscurity?
Even when you use key pairs stored in the hardware trusted execution environment, all an attacker needs to do is to use an instrumentation framework to hook in the function of your code that uses the keys in order to extract or manipulate the parameters and return values of the function.
Android Hardware-backed Keystore
The availability of a trusted execution environment in a system on a chip (SoC) offers an opportunity for Android devices to provide hardware-backed, strong security services to the Android OS, to platform services, and even to third-party apps.
While it can be defeated I still recommend you to use it, because not all hackers have the skill set or are willing to spend the time on it, and I would recommend you to read this series of articles about Mobile API Security Techniques to learn about some complementary/similar techniques to the ones you described. This articles will teach you how API Keys, User Access Tokens, HMAC and TLS Pinning can be used to protect the API and how they can be bypassed.
Possible Better Solutions
Nowadays I see developers using Android SafetyNet to attest what is doing the request to the API server, but they fail to understand it's not intended to attest that the mobile app is what is doing the request, instead it's intended to attest the integrity of the device, and I go in more detail on my answer to the question Android equivalent of ios devicecheck. So should I use it? Yes you should, because it is one more layer of defense, that in this case tells you that your mobile app is not installed in a rooted device, unless SafetyNet has been bypassed.
Is there any way to restrict post requests to my REST API only to requests coming from my own mobile app binary?
You can allow the API server to have an high degree of confidence that is indeed accepting requests only from your genuine app binary by implementing the Mobile App Attestation concept, and I describe it in more detail on this answer I gave to the question How to secure an API REST for mobile app?, specially the sections Securing the API Server and A Possible Better Solution.
Do you want to go the Extra Mile?
In any response to a security question I always like to reference the excellent work from the OWASP foundation.
For APIS
OWASP API Security Top 10
The OWASP API Security Project seeks to provide value to software developers and security assessors by underscoring the potential risks in insecure APIs, and illustrating how these risks may be mitigated. In order to facilitate this goal, the OWASP API Security Project will create and maintain a Top 10 API Security Risks document, as well as a documentation portal for best practices when creating or assessing APIs.
For Mobile Apps
OWASP Mobile Security Project - Top 10 risks
The OWASP Mobile Security Project is a centralized resource intended to give developers and security teams the resources they need to build and maintain secure mobile applications. Through the project, our goal is to classify mobile security risks and provide developmental controls to reduce their impact or likelihood of exploitation.
OWASP - Mobile Security Testing Guide:
The Mobile Security Testing Guide (MSTG) is a comprehensive manual for mobile app security development, testing and reverse engineering.
No. You're publishing a service with a public interface and your app will presumably only communicate via this REST API. Anything that your app can send, anyone else can send also. This means that the only way to secure access would be to authenticate in some way, i.e. keep a secret. However, you are also publishing your apps. This means that any secret in your app is essentially being given out also. You can't have it both ways; you can't expect to both give out your secret and keep it secret.
Though this is an old post, I thought I should share the updates from Google in this regard.
You can actually ensure that your Android application is calling the API using the SafetyNet mobile attestation APIs. This adds a little overhead on the network calls and prevents your application from running in a rooted device.
I found nothing similar like SafetyNet for iOS. Hence in my case, I checked the device configuration first in my login API and took different measures for Android and iOS. In case of iOS, I decided to keep a shared secret key between the server and the application. As the iOS applications are a little bit difficult to reversed engineered, I think this extra key checking adds some protection.
Of course, in both cases, you need to communicate over HTTPS.
As the other answers and comments imply, you cant truly restrict API access to only your app but you can take different measures to reduce the attempts. I believe the best solution is to make requests to your API (from native code of course) with a custom header like "App-Version-Key" (this key will be decided at compile time) and make your server check for this key to decide if it should accept or reject. Also when using this method you SHOULD use HTTPS/SSL as this will reduce the risk of people seeing your key by viewing the request on the network.
Regarding Cordova/Phonegap apps, I will be creating a plugin to do the above mentioned method. I will update this comment when its complete.
there is nothing much you can do. cause when you let some one in they can call your APIs. the most you can do is as below:
since you want only and only your application (with a specific package name and signature) calls your APIs, you can get the signature key of your apk pragmatically and send is to sever in every API call and if thats ok you response to the request. (or you can have a token API that your app calls it every beginning of the app and then use that token for other APIs - though token must be invalidated after some hours of not working with)
then you need to proguard your code so no one sees what you are sending and how you encrypt them. if you do a good encrypt decompiling will be so hard to do.
even signature of apk can be mocked in some hard ways but its the best you can do.
Someone have looked at Firebase App Check ?
https://firebase.google.com/docs/app-check
Is there any way to restrict post requests to my REST API only to requests coming from my own mobile app binary?
I'm not sure if there is an absolute solution.
But, you can reduce unwanted requests.
Use an App Check:
The "Firebase App Check" can be used cross-platform (https://firebase.google.com/docs/app-check) - credit to #Xande-Rasta-Moura
iOS: https://developer.apple.com/documentation/devicecheck
Android: https://android-developers.googleblog.com/2013/01/verifying-back-end-calls-from-android.html
Use BasicAuth (for API requests)
Allow a user-agent header for mobile devices only (for API requests)
Use a robots.txt file to reduce bots
User-agent: *
Disallow: /
I am a doctor who is seeking a solution for my patients. I often receive medical CDs from my patients which contain their radiological data. What I need is a web solution which I can integrate with my web site. But the caveat is that I dont want this to happen via Choose File. Most of my patients are old people who doesnt know much about internet or computers. So I want a single button on my web site which will copy the entire CD in the CD drive and send it to me without any user intervention. Is it possible?
Update:
OK thank you all. I did not intend to break copyright issues. Actually, I thought a user who will hit that "button" will also give permission to access their files. I completely understand your concerns and I completely agree however - as an end-user - this is the problem requiring a solution in my case. After the COVID none of my patients can come to clinical visits and I need to see their follow-up. In neurosurgery, this is very important. I do not know if it is OK to send links (and sorry if it is not) here but for example, this web site makes something similar to my idea but it is not free and it is so complicated for my -low socioeconomic - patient profile.
My target population mostly deals with brain tumors and their level of concern for copyright issues is so low for that reason. I don't mean taking everything from them without their will but this is the case. So again thank you all for enlightening me and I am again sorry if I break the rules of this website.
Introduction
I'm going to go through the reasons as to why the specification as stated, cannot be implemented, and also as to why older technologies that may have allowed this implementation cannot be used.
Do note that even older technologies, would have required some sort of installation or agreement from the user- as a minimum 1 click.
Also note: It is possible to get files from a users system, but you still have to get their agreement through an action or prompt from their part!**
As to what you could do? Tukan already covers some nice alternatives but if I do think of something I will add it!
Basic Explanation
The most basic explanation is that this would be a giant unprecedented security hole. It would mean that browsers would allow a site to access files from a users computer hardware (DVD) without the permission of the user or the active actions of the user.
In your case you do have a valid non-malicious use for it. Imagine however all the malicious websites that would use this mechanism to steal stuff off the DVD/CD that is in the users tray. Imagine the privacy issues, security breaches, and even minor stuff like copyright issues.
Finally, and even worse, if the specific requested allowed access to the whole file system (including all drives like C:), a malicious site could steal everything on a user's system.
The positive (and negative for you) is that browsers have been incrementally locked down over the years and technologies/plugins/extensions/features have been incrementally either locked down, or deprecated/removed. Such technologies include: active X, java applets, and flash.
Finally, browsers like chrome and internet explorer themselves now'a'days run in sandboxes. See for example the article (and this is from 2013!!): Sandboxes Explained: How They’re Already Protecting You and How to Sandbox Any Program
They’re restricted to running in your browser and accessing a limited set of resources — they can’t view your webcam without permission or read your computer’s local files. If websites you visit weren’t sandboxed and isolated from the rest of your system, visiting a malicious website would be as bad as installing a virus.
Other programs on your computer are also sandboxed. For example,
Google Chrome and Internet Explorer both run in a sandbox themselves.
These browsers are programs running on your computer, but they don’t
have access to your entire computer. They run in a low-permission
mode. Even if the web page found a security vulnerability and managed
to take control of the browser, it would then have to escape the
browser’s sandbox to do real damage.
Active X (Deprecated) (Internet Explorer)
Let's start by saying that Active X would require the user to change their Internet Explorer Security Settings so we can strike it off immediately.
If a user did change their settings (see: Enable ActiveX controls in Internet Explorer ) and Enable for IE 11, a developer could use active x to access files on a users system.
Also note Active X is deprecated and rumour has it that it may not be around for long.
Java Signed Applets
Java Signed Applets could access the local file system.
However, Applets are no longer supported in firefox and chrome. They do run in Internet Explorer though IE is deprecated as well (since people are moving to Edge).
There's a very well written answer on the topic here: How do I run Java applets? [duplicate] and Why is the Java plugin (JRE) disabled in Chrome?
Adobe Flash (Previously Macromedia)
First off, flash has been removed from most Internet Browsers and is officially considered dead. Additionally, after Flash Player 10 it was possible to load a file but the user had to select it himself through a dialog (see: Can Flash action script read and write local file system? ).
FileSystem and FileWriter APIs
You can read and write using this API. However, it again requires the user to interact with the webpage and to select the files themselves.
References
Is it possible to access local file via javascript?
Sandboxes Explained: How They’re Already Protecting You and How to Sandbox Any Program
Enable ActiveX controls in Internet Explorer , Enable for IE 11, and active x to access files on a users system
Java Signed Applets could access the local file system, How do I run Java applets? [duplicate], Why is the Java plugin (JRE) disabled in Chrome?
Can Flash action script read and write local file system?
As Andrew mentioned this SO is used for Q&A from/to developers. I'll try to give you a general idea what could be done.
Who should do it?
I think you need some freelancer who would create a code for you.
The mechanism you are describing is not possible due to security issues.
Web page should not have access to the HW, as you would like, without user
interaction.
What is then feasible?
I think what is feasible is an application (thick - meaning .exe file) which would be executed by your patients which would search for a CD/DVD drive, pack it and send it via secure channel to your server. They would need to download it and execute it.
If you have elderly patients you need to visually confirm that the data has been send using some clear message.
Something like: Thank you for sending the data to Dr. Jones. All data has been received.
Secure channel can be for example: ftps, sftp, https, etc.
On your side you would a have a daemon which would serve as endpoint for your patient's data. After receiving the data it should be moved immediately outside the uploading folder.
Edit
One more option that came into my mind would be to distribute a tailored USB key to your patients with such application, which would be executed upon insertion.
We are creating our first google glass app and I had some security questions that came up that I can't seem to find a definitive answer to on the web. They are as follows:
What apps are available for us to be able to wipe the glass (factory reset) remotely if they are ever misplaced or lost?
Is there an app or a way to automatically wipe the glass maybe at a certain time everyday of the data that is one them?
When we do a factory reset, is the data securely wiped from the device? Or like a PC is the data still there for possible usage if the device memory is hacked into directly?
If we pass data over the network, is it passed using some sort of encryption currently? Or do we have to take this into account when developing our app?
Is there a way to allow multiple people to use the device without having to wipe the device and setup with another account? The only way we were able to login using 2 different accounts was for the first person to factory reset it and allow the next person to login using their account. What we were envisioning was a way for the device to securely authenticate and allow multiple users to use it differently somehow without having to reset it.
The only current way to lock the device that I found is to create the swipe/tap pattern that is included. Are there any apps that allow for a more secure type of login?
If anyone can help on any of the questions, that would help out a lot.
Thanks!
The MyGlass webapp and mobile app allow you to do a remote device reset. From the mobile app, you can go to Settings while the webapp does it from the MyGlass -> Device Info page.
There is no way to do an automatic reset every day that I'm aware of. What are you trying to do here? Just reset it to a known state every day for development?
At this time, you probably can't count on it being a secure reset.
This is a pretty vague question. Google hasn't provided details on the sharing protocol, but it is a safe bet that this is done using SSL on some level. From their servers to yours using the Mirror API must be done using HTTPS. Of course, if you're doing the network data passing yourself, then it's up to you.
No, this isn't possible at this time. Glass is a very personal device. More so than phones, and most phones don't have a profile feature!
I'm not aware of any, but I'm not sure how much more secure you can get and still be usable. Can you elaborate on what you're envisioning?
i have developed Java ME game and now i want to upload it to some of the sites for mobile games. After i finished it, i began to read papers for the producing the final .jar file and .jad file . I mean things like pre-verification , obfuscation , and signing with certificate. My question is specifiaclly for these certificates. If i upload my game and it is not certified ( it is not signed with certificate), will people install it on their phones? I have to mention that i think that i do NOT use some specific java ME api that require an app to be signed in order to used by the phone(I have read that one such api is httpconnection api - well, my game does not use such kind of api). The only thing that i doubt is the usage of RecordStore to store some information, but i think the java me RecordStore does not require the midlets to be signed. Anyway, i will ask in short - if my game is not signed , will people install it on their phone at all? (Just to mention, that the only thing that my game does in general is : paint, re-paint the screen , take the users input from keys, touch screen and use of RecordStore, nothing supernatural for phone game).
Thanks
The only thing signing does for you, is to remove the security popups you'll otherwise encounter whenever the app tries to access e.g. camera, sms, internet connection or filesystem.
No, you don't need to sign your game, and yes people will install it whether it's signed or not.
Signing is Compulsory for .sis and .sisx files.
J2me games Don't require signing.
I came across this line from the Nokia dev site. It seems to suggest that there are two ways of getting rid of those annoying confirmation messages when accessing protected services in j2me. Does anybody have any clue as to what might be the other method apart form signing?
"This document describes how to code sign a Java ME app using Thawte. This is one of two mechanisms for avoiding security messages when accessing secured APIs."
http://www.developer.nokia.com/Community/Wiki/Thawte_signing_for_Java_ME
Those Messages are because of your Application is not Signed with the required certificates.
Please look at to my answer here.
Not everyone can access the all API's of the Phone. To give a security to phone, Nokia has put those restrictions. Otherwise it may easy to create Mobile Virus too like computer virus.