Running a Checksum Validation of Android & iOS Apps

Last updated June 3, 2024 by Appdome

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

What is Checksum?

A checksum, otherwise known as “hash”, is a sequence of numbers and letters used for checking data for errors. A checksum is produced by running a program that puts the original file through an algorithm such as MD5, SHA-1, and SHA-256/512. By executing a cryptographic hash function, the algorithm produces the checksum as an input of a fixed length.

Why Should Developers use Checksum Validation??

A checksum validation is used when you received a file and would like to verify that the original file has not been modified or tampered with. If you know the checksum of the original file, running a checksum validation that results in a checksum of the same length proves that no changes were made to your copy. Any change made to the original file, be it one character or one digit, will result in producing an entirely different checksum.

Prerequisites for Using Checksum Validation:

To use Appdome’s mobile app security build system to Validate Checksum , you’ll need:

Validate Checksum on Mobile apps using Appdome

On Appdome, follow these 3 simple steps to create self-defending Mobile Apps that Validate Checksum 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, or .apk or .aab for Android
    4. Checksum Validation Compatible With: Obj-C, Java, JS, C#, C++, Swift, Kotlin, Flutter, React Native, Unity, Xamarin, and more
  2. Build the feature: Checksum Validation.

    1. Building Checksum Validation by using Appdome’s DEV-API:

      1. Create and name the Fusion Set (security template) that will contain the Checksum Validation feature as shown below:
      2. fusion set that contains Checksum Validation

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

      3. Follow the steps in Sections 2.2.1-2.2.2 of this article, Building the Checksum Validation feature via Appdome Console, to add the Checksum Validation feature to this Fusion Set.

      4. 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): fusion Set Detail Summary image

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

      5. 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, Circle 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 Checksum Validation feature via Appdome Console

      To build the Checksum Validation protection by using Appdome Console, follow the instructions below.

      1. Where: Inside the Appdome Console, go to Build > Security Tab > ONEShield™ section.
      2. When you select the Checksum Validation you'll notice that your Fusion Set you created in step 2.1.1 now bears the icon of the protection category that contains Checksum Validation

        Fusion Set applied Checksum Validation

        Figure 4: Fusion Set that displays the newly added Checksum Validation protection

      3. Click Build My App at the bottom of the Build Workflow (shown in Figure 3).
    Congratulations!  The Checksum Validation protection is now added to the mobile app

Using Threat-Events™ for Checksum Intelligence and Control in Mobile Apps

Appdome Threat-Events™ provides consumable in-app mobile app attack intelligence and defense control when Checksum is detected. To consume and use Threat-Events™ for Checksum in Mobile Apps, use AddObserverForName in Notification Center, and the code samples for Threat-Events™ for Checksum shown below.

The specifications and options for Threat-Events™ for Checksum are:

Threat-Event™ Elements Validate Checksum Method Detail
Appdome Feature Name Checksum Validation
Threat-Event Mode
OFF, IN-APP DEFENSE Appdome detects, defends and notifies user (standard OS dialog) using customizable messaging.
ON, IN-APP DETECTION Appdome detects the attack or threat and passes the event in a standard format to the app for processing (app chooses how and when to enforce).
ON, IN-APP DEFENSE Uses Appdome Enforce mode for any attack or threat and passes the event in a standard format to the app for processing (gather intel on attacks and threats without losing any protection).
Certified Secure™ Threat Event Check x
Visible in ThreatScope™ x
Developer Parameters for Validating Checksum Threat-Event™
Threat-Event NAME
Threat-Event DATA reasonData
Threat-Event CODE reasonCode
Threat-Event REF
Threat-Event SCORE
currentThreatEventScore Current Threat-Event score
threatEventsScore Total Threat-events score
Threat-Event Context Keys
message Message displayed for the user on event
externalID The external ID of the event which can be listened via Threat Events
osVersion OS version of the current device
deviceModel Current device model
deviceManufacturer The manufacturer of the current device
fusedAppToken The task ID of the Appdome fusion of the currently running app
kernelInfo Info about the kernel: system name, node name, release, version and machine.
carrierPlmn PLMN of the device
deviceID Current device ID
reasonCode Reason code of the occured event
buildDate Appdome fusion date of the current application
devicePlatform OS name of the current device
carrierName Carrier name of the current device
updatedOSVersion Is the OS version up to date
deviceBrand Brand of the device
deviceBoard Board of the device
buildUser Build user
buildHost Build host
sdkVersion Sdk version
timeZone Time zone
deviceFaceDown Is the device face down
locationLong Location longitude conditioned by location permission
locationLat Location latitude conditioned by location permission
locationState Location state conditioned by location permission
wifiSsid Wifi SSID
wifiSsidPermissionStatus Wifi SSID permission status

With Threat-Events™ enabled (turned ON), Mobile developers can get detailed attack intelligence and granular defense control in Mobile applications and create amazing user experiences for all mobile end users when Checksum is detected.

The following is a code sample for native Mobile apps, which uses all values in the specification above for Checksum Validation:


Using Appdome, there are no development or coding prerequisites to build secured Mobile Apps by using Checksum Validation. There is no SDK and no library to code or implement in the app and no gateway to deploy in your network. All protections are built into each app and the resulting app is self-defending and self-protecting.

Releasing and Publishing Mobile Apps with Checksum Validation

After successfully securing your app by using Appdome, there are several available options to complete your project, depending on your app lifecycle or workflow. These include:

Related Articles:

If you have any questions, please send them our way at support.appdome.com or via the chat window on the Appdome platform.

Thank you!

Thanks for visiting Appdome! Our mission is to secure every app on the planet by making mobile app security easy. We hope we’re living up to the mission with your project.

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