JailMonkey Unveiled: A Deep Dive into React Native’s Device Security Checks for Bulletproof Mobile Applications

Sugand singh
3 min readNov 23, 2023

Introduction:

In the ever-evolving landscape of mobile app development, ensuring the security of your application is paramount. React Native, a popular framework for building cross-platform mobile apps, provides developers with powerful tools to create robust applications. However, the security of these apps can be compromised if they run on jailbroken or rooted devices. In this blog post, we’ll explore the concept of JailMonkey in React Native and how it helps developers enhance the security of their applications.

Understanding JailMonkey:

JailMonkey is a React Native library designed to detect potential security threats on a user’s device. It includes several checks to determine if a device is jailbroken (iOS) or rooted (Android). Let’s delve into some key security checks provided by JailMonkey

Installing JailMonkey

To get started, you need to install the jail-monkey library. Open your terminal or command prompt and navigate to your React Native project directory. Run the following command:

yarn add jail-monkey

or

npm install jail-monkey

In React Native 0.60 and higher, linking is automatic. So you don’t need to runreact-native link.

If you’re on a Mac and developing for iOS, you need to install the pods (via Cocoapods) to complete the linking.

npx pod-install ios
  1. isJailBroken:This check is specific to iOS devices and is used to detect whether the device has been jailbroken. Jailbreaking removes the limitations imposed by Apple on iOS devices, allowing users to install unauthorized apps and make system-level changes. The isJailBroken function in JailMonkey helps developers identify if the app is running on a jailbroken iOS device
import JailMonkey from 'jail-monkey';

if (JailMonkey.isJailBroken()) {
Handle the case where the device is jailbroken
}

2. canMockLocation: Some users attempt to fake their GPS location, which can be a security concern for certain applications. ThecanMockLocation function in JailMonkey checks whether the device has mock location settings enabled, helping developers identify potential location spoofing.

import JailMonkey from 'jail-monkey';

if (JailMonkey.canMockLocation()) {
Handle the case where mock location is detected

3.trustFall:

TrustFall is a comprehensive security check provided by JailMonkey. It combines various methods to detect common signs of a compromised environment. This includes checking for the presence of specific files or processes that are indicative of a rooted or jailbroken device.


import JailMonkey from 'jail-monkey';

if (JailMonkey.trustFall()) {
Handle the case where a compromised environment is detected
}

4.isDebuggedMode: Running an app in debug mode can expose sensitive information and make it easier for malicious actors to reverse engineer the code. TheisDebuggedMode function in JailMonkey helps developers identify if the app is running in a debuggable environment.

import JailMonkey from 'jail-monkey';

if (JailMonkey.isDebuggedMode()) {
Handle the case where the app is running in debug mode
}

Conclusion:

In the world of mobile app development, ensuring the security of your application is a continuous challenge. Integrating libraries like JailMonkey into your React Native projects can provide an additional layer of defense against potential threats. By utilizing functions like isJailBroken, canMockLocation, trustFall, andisDebuggedMode, developers can proactively identify and respond to security risks, ultimately creating a safer and more secure user experience.

Remember, while these tools enhance the security of your application, it’s crucial to adopt a holistic approach to security, including encryption, secure communication protocols, and regular security audits, to fortify your app against a wide range of potential threats.

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Sugand singh

Experienced React Native dev, UI/UX expert, performance optimizer. Keeping up with mobile trends. Let's build mobile magic!