Binary Code Obfuscation, Anti-Reversing - Android & iOS

Learn to Prevent Code Obfuscation in Mobile apps, in mobile CI/CD with a Data-Driven DevSecOps™ build system.

Why is Obfuscation Efficient Against Reverse Engineering?

How does Appdome Implement Binary Code Obfuscation?

In iOS, the application’s executable manifests as binary code. Appdome shuffles the code around, so that when the reverse engineering tool attempts to determine the target of a reference, it will appear as though it points to some arbitrary location. On a large scale, this renders the code completely unintelligible. However, the application must contain enough binary code to make the shuffling effective, otherwise it is advisable to use Appdome Flow Relocation as an alternative.

In Android, shared-libraries constitute the native-code part of the app. Appdome uses the loading mechanism of shared libraries in Android and modifies it so encrypted libraries can be loaded. Then, when integrating Binary Code Obfuscation, the native libraries that come with the application get encrypted by using a unique key.

When an attacker attempts to open the protected libraries in a reverse engineering tool, the applications will fail at recognizing the file as binary code.

Prerequisites to Using Binary Code Obfuscation:

To use Appdome’s mobile app security build system to Prevent Code Obfuscation , you’ll need:

• Appdome account (create a free Appdome account here)
• A license for Binary Code Obfuscation
• Mobile App (.ipa For iOS device or .apk or .aab For Mobile)
• Signing Credentials (see Signing Secure Android apps and Signing Secure iOS apps)

Prevent Code Obfuscation on Mobile apps using Appdome

On Appdome, follow these 3 simple steps to create self-defending Mobile Apps that Prevent Code Obfuscation without an SDK or gateway:

1. Upload the Mobile App to Appdome.

   1. Upload an app to Appdome’s Mobile App Security Build System

   2. Upload Method: Appdome Console or DEV-API
   3. Mobile App Formats: .ipa For iOS device or .apk or .aab
   4. Binary Code Obfuscation Compatible With: Obj-C, C+, Java, JS, C#, C++, Swift, Kotlin, Flutter, React Native, Unity, Xamarin, and more

2. Build the feature: Binary Code Obfuscation.

   1. Building Binary Code Obfuscation by using Appdome’s DEV-API:

      1. Create and name the Fusion Set (security template) that will contain the Binary Code Obfuscation feature as shown below:
      

      Figure 1: Fusion Set that will contain the Binary Code Obfuscation feature
      Note: Naming the Fusion Set to correspond to the protection(s) selected is for illustration purposes only (not required).

      2. Follow the steps in Sections 2.2.1-2.2.2 of this article, Building the Binary Code Obfuscation feature via Appdome Console, to add the Binary Code Obfuscation feature to this Fusion Set.

      3. Open the Fusion Set Detail Summary by clicking the “...” symbol on the far-right corner of the Fusion Set, as shown in Figure 1 above, and get the Fusion Set ID from the Fusion Set Detail Summary (as shown below):

         Figure 2: Fusion Set Detail Summary
         Note: Annotating the Fusion Set to identify the protection(s) selected is optional only (not mandatory).

      4. Follow the instructions below to use the Fusion Set ID inside any standard mobile DevOps or CI/CD toolkit like Bitrise, App Center, Jenkins, Travis, Team City, Cirlce CI or other system:

         1. Build an API for the app – for instructions, see the tasks under Appdome API Reference Guide
         2. Look for sample APIs in Appdome’s GitHub Repository

   2. Building the Binary Code Obfuscation feature via Appdome Console

      To build the Binary Code Obfuscation protection by using Appdome Console, follow the instructions below.

      1. Where: Inside the Appdome Console, go to Build > Security Tab > TOTALCode™ Obfuscation section
      2. How: Toggle (turn ON) Binary Code Obfuscation, as shown below.
         If needed, Customize the Threat Notification to be displayed to the mobile end-user in a standard OS dialog notification when Appdome Prevents Code Obfuscation.

         Figure 3: Prevent Code Obfuscation option
         Note: The App Compromise Notification contains an easy to follow default remediation path for the mobile app end user. You can customize this message as required to achieve brand specific support, workflow or other messaging.

      3. When you select the Binary Code Obfuscation you'll notice that your Fusion Set you created in step 2.1.1 now bears the icon of the protection category that contains Binary Code Obfuscation

         

         Figure 4: Fusion Set that displays the newly added Binary Code Obfuscation protection

      4. Extra Configuration with Binary Code Obfuscation:

         1. Favor App’s Size

            Automatically detect and exclude publicly available elements from being obfuscated, to reduce overall application package size.

      5. Click Build My App at the bottom of the Build Workflow (shown in Figure 3).

   Congratulations!  The Binary Code Obfuscation protection is now added to the mobile app

3. Certify the Binary Code Obfuscation feature in Mobile Apps.

   After building Binary Code Obfuscation, Appdome generates a Certified Secure™ certificate to guarantee that the Binary Code Obfuscation protection has been added and is protecting the app. To verify that the Binary Code Obfuscation protection has been added to the mobile app, locate the protection in the Certified Secure™ certificate as shown below:

   Figure 5: Certified Secure™ certificate

   Each Certified Secure™ certificate provides DevOps and DevSecOps organizations the entire workflow summary, audit trail of each build, and proof of protection that Binary Code Obfuscation has been added to each Mobile app. Certified Secure provides instant and in-line DevSecOps compliance certification that Binary Code Obfuscation and other mobile app security features are in each build of the mobile app