How to secure your Flutter Application?

· 5 min read
How to secure your Flutter Application?
How to secure your Flutter Application?

In this article, we will see about the most effective practices to minimize the risk for any security exploit in Flutter Apps. Also, we will put as many roadblocks to secure your flutter application created by the flutter app development company.

How to secure your Flutter Application?

One of the first things an attacker will look for when targeting an app is to see if they can intercept any of the data passing between it and your server’s backend.

Protecting the communication Layer

1) Employing strong encryption:

You can do this by making use of protocols like SSL and TLS, which are simple to add to your code and are very difficult to compromise. If you are dealing with particularly sensitive data, you may even want to go a little further and build a VPN-type solution right into your app.

2) Restricting network traffic.

One way to restrict network traffic or connection to an unsecured endpoint is through explicitly whitelisting your domain.

3) Certificate Pinning

SSL pinning solves the MITM (Man In The Middle) attack. In simple language, you will get a server certificate file from the backend developer and you will pin the certificate in every API call. So the HTTP client will take this certificate as a trustable one. Now if MITM happens and the app gets some bad certificate, the API calls will be broken due to a Handshake error.

4) Make Authentication Bulletproof

Besides your app’s data streams, the next most common attack vector to eliminate is any weakness in its authentication methods. So, the two-factor authentication with your server is both necessary and worth implementing. On top of that, you also need to pay attention to how you handle things like key exchanges. At a minimum, you should be using encryption to keep those transactions secure.

Protecting the Application:

1) Protecting the communication Layer

The compiled binaries and code of your apps can be reversed engineered. Some of the things that can be exposed include the strings, method and class names, and API keys. These data are either in their original form or in are in plain text.

-from the dart side what you can do is use the –obfuscate parameter when building your app.

flutter build appbundle --obfuscate --split-debug-info=/<directory>

and from the native side, you need to handle that by :

android

In your /android/app/build.gradle file, add the following:

android {
  ...
  buildTypes {
    release {
      signingConfig signingConfigs.release
      minifyEnabled true
      useProguard true
      proguardFiles 
getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
    }
  }
}

Create a ProGuard configuration file in /android/app/proguard-rules.pro:

# Flutter
-keep class io.flutter.app.** { *; }
-keep class io.flutter.plugin.**  { *; }
-keep class io.flutter.util.**  { *; }
-keep class io.flutter.view.**  { *; }
-keep class io.flutter.**  { *; }
-keep class io.flutter.plugins.**  { *; }

With ProGuard, it does not only obfuscate your code but also helps you shrink the size of your Android apps.

2) Jailbroken and rooted devices

Jailbroken iOS and rooted Android devices have more privileges. It may introduce malware to your user’s device that can circumvent the normal operations of the device. flutter_jailbreak_detection is a package that helps you detect if your app is currently running on a jailbroken or rooted device. It uses RootBeer on Android, and DTTJailbreakDetection on iOS. Also, it is so easy to use :

import 'package:flutter_jailbreak_detection/flutter_jailbreak_detection.dart';

bool jailbroken = await FlutterJailbreakDetection.jailbroken;
bool developerMode = await FlutterJailbreakDetection.developerMode; // android only.

3) Secure user data

For storing sensitive user data you should never use the shared preferences or SQLite. This is because it is easy to open on any device. So, you need to encrypt the stored data. For that, you can use flutter_secure_storage. This package uses Keystore for Android and Keychains for iOS.

4) Use local authentication

Suppose the user phone has been stolen and your application is installed on it and it has some payment information. To prevent any access to your app you should use Biometrics authentication by using this package.

Conclusion:

Thanks for being with us on a Flutter Journey!

So, in this article, we have seen the How to secure your Flutter Application. You can modify and experiment with it according to your own. Also, feel free to comment and provide any other suggestions regarding Flutter.

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