How to Use App Store Signature Validation in iOS Apps
This Knowledge Base article describes how to use Appdome’s AI/ML in your CI/CD pipeline to continuously deliver plugins that Validate App Store Signature in iOS apps.
Why Should Developers Prevent the Running of non-authorized apps?
Fraudsters and other cyber-criminals often use various methods and techniques to create fake apps by copying or cloning existing popular apps and then repackaging, re-signing, and re-distributing those apps on alternative, malicious or non-approved app stores. It is fairly easy for malicious actors to publish fake, malicious or pirated apps on app stores other than Apple’s App Store. They only need to download a target app (such as your app) on a Jailbroken mobile device, modify the app, and then repackage, re-sign, and re-distribute the fake or pirated mobile app to any app store they want.
How does Appdome Prevent the Running of non-Authorized Apps?
Appdome App Store Validation validates that apps signed for Apple App Store cannot be distributed through any other app stores. If the original app was signed for Apple’s App Store, Appdome prevents the app from being re-signed with a different application identifier. If the app was originally published to the app store, and the application identifier is different than the originally signed app, Appdome detects the difference and prevents the app from running.
Prerequisites for Using Appdome's App Store Signature Validation Plugins:
To use Appdome’s mobile app security build system to Validate App Store Signature , you’ll need:
- Appdome account (create a free Appdome account here)
- A license for App Store Signature Validation
- Mobile App (.ipa for iOS)
- Signing Credentials (see Signing Secure Android apps and Signing Secure iOS apps)
How to Implement Validate App Store Signature in iOS Apps Using Appdome
On Appdome, follow these 3 simple steps to create self-defending iOS Apps that Validate App Store Signature without an SDK or gateway:
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Designate the Mobile App to be protected.
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Upload an app via the Appdome Mobile Defense platform GUI or via Appdome’s DEV-API or CI/CD Plugins.
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iOS Formats: .ipa
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App Store Signature Validation is compatible with: Obj-C, Java, Swift, Flutter, React Native, Unity, Xamarin, Cordova and other iOS apps.
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Select the defense: App Store Signature Validation.
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Follow the steps in Sections 2.2-2.2.2 of this article to add the App Store Signature Validation feature to your Fusion Set via the Appdome Console.
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When you select the App Store Signature Validation you'll notice that the Fusion Set you created in step 2.1 now bears the icon of the protection category that contains App Store Signature Validation.
Figure 2: Fusion Set that displays the newly added App Store Signature Validation protection
Note: Annotating the Fusion Set to identify the protection(s) selected is optional only (not mandatory). -
Open the Fusion Set Detail Summary by clicking the “...” symbol on the far-right corner of the Fusion Set. Copy the Fusion Set ID from the Fusion Set Detail Summary (as shown below):
Figure 3: Fusion Set Detail Summary
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Follow the instructions below to use the Fusion Set ID inside any standard mobile DevOps or CI/CD toolkit like Bitrise, Jenkins, Travis, Team City, Circle CI or other system:
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Refer to the Appdome API Reference Guide for API building instructions.
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Look for sample APIs in Appdome’s GitHub Repository.
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Create and name the Fusion Set (security template) that will contain the App Store Signature Validation feature as shown below:.Figure 1: Fusion Set that will contain the App Store Signature Validation feature
Note: Naming the Fusion Set to correspond to the protection(s) selected is for illustration purposes only (not required). -
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Add the App Store Signature Validation feature to your security template.
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Navigate to Build > Anti Fraud tab > Social Engineering Prevention section in the Appdome Console.
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Toggle On > App Store Signature Validation.
(a) Choose to monitor this attack vector by checking the Threat Events checkbox associated with App Store Signature Validation as shown below.
(b) To receive mobile Threat Monitoring, check the ThreatScope™ box as shown below. For more details, see our knowledge base article on ThreatScope™ Mobile XDR.Figure 4: Selecting Validate App Store Signature
Note: The Appdome Platform displays the Mobile Operation Systems supported by each defense in real-time. For more details, see our OS Support Policy KB. -
Select the Threat-Event™ in-app mobile Threat Defense and Intelligence policy for App Store Signature Validation:
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Threat-Events™ OFF > In-App Defense
If the Threat-Events™ setting is not selected. Appdome will detect and defend the user and app by enforcing App Store Signature.
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Threat-Events™ ON > In-App Detection
When this setting is used, Appdome detects an attempt to install an app from a non-official App Store. and passes Appdome’s Threat-Event™ attack intelligence to the app’s business logic for processing, enforcement, and user notification. For more information on consuming and using Appdome Threat-Events™ in the app, see section Using Threat-Events™ to App Store Signature ValidationValidate Intelligence and Control in Mobile Apps.
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Threat-Events™ ON > In-App Defense
When this setting is used, Appdome detects and defends against App Store Signature (same as Appdome Enforce) and passes Appdome’s Threat-Event™ attack intelligence to the app’s business logic for processing. For more information on consuming and using Appdome Threat-Events™ in the app, see section Using Threat-Events™ for App Store Signature ValidationValidate Intelligence and Control in Mobile Apps.
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Configure the User Experience Options for App Store Signature Validation:
With Threat-Events™ OFF, Appdome provides several user experience options for mobile brands and developers.- App Compromise Notification: Customize the pop-up or toast Appdome uses to notify the user when a threat is present while using the protected mobile app.
- Short message Option. This is available for mobile devices that allow a banner notification for security events.
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Localized Message Option. Allows Appdome users to support global languages in security notifications.
Figure 5: Default User Experience Options for Appdome’s App Store Signature
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App Store Signature Validation Threat Code™. Appdome uses AI/ML to generate a unique code each time App Store Signature Validation is triggered by an active threat on the mobile device. Use the code in Appdome Threat Resolution Center™ to help end users identify, find and resolve active threats on the personal mobile devices.
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Congratulations! The App Store Signature Validation protection is now added to the mobile app -
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Certify the App Store Signature Validation feature in iOS Apps
After building App Store Signature Validation, Appdome generates a Certified Secure™ certificate to guarantee that the App Store Signature Validation protection has been added and is protecting the app. To verify that the App Store Signature Validation protection has been added to the mobile app, locate the protection in the Certified Secure™ certificate as shown below:
Figure 6: 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 App Store Signature Validation has been added to each iOS app. Certified Secure provides instant and in-line DevSecOps compliance certification that App Store Signature Validation and other mobile app security features are in each build of the mobile app.
Using Threat-Events™ for App Store Signature Intelligence and Control in iOS Apps
Appdome Threat-Events™ provides consumable in-app mobile app attack intelligence and defense control when App Store Signature is detected. To consume and use Threat-Events™ for App Store Signature in iOS Apps, use AddObserverForName in Notification Center, and the code samples for Threat-Events™ for App Store Signature shown below.
The specifications and options for Threat-Events™ for App Store Signature are:
Threat-Event™ Elements | Validate App Store Signature Method Detail |
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Appdome Feature Name | App Store Signature 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 | |
Visible in ThreatScope™ | |
Developer Parameters for Validating App Store Signature Threat-Event™ | |
Threat-Event NAME | NotInstalledFromOfficialStore |
Threat-Event DATA | reasonData |
Threat-Event CODE | reasonCode |
Threat-Event REF | 6902 |
Threat-Event SCORE | |
currentThreatEventScore | Current Threat-Event score |
threatEventsScore | Total Threat-events score |
Threat-Event Context Keys | |
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message | Message displayed for the user on event |
failSafeEnforce | Timed enforcement against the identified threat |
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. |
deviceID | Current device ID |
reasonCode | Reason code of the occurred event |
buildDate | Appdome fusion date of the current application |
devicePlatform | OS name of the current device |
updatedOSVersion | Is the OS version up to date |
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 |
threatCode | The last six characters of the threat code specify the OS, allowing the Threat Resolution Center to address the attack on the affected device. |
With Threat-Events™ enabled (turned ON), iOS developers can get detailed attack intelligence and granular defense control in iOS applications and create amazing user experiences for all mobile end users when App Store Signature is detected.
The following is a code sample for native iOS apps, which uses all values in the specification above for App Store Signature Validation:
Important! Replace all placeholder instances of <Context Key> with the specific name of your threat event context key across all language examples. This is crucial to ensure your code functions correctly with the intended event data. For example, The <Context Key> could be the message, externalID, OS Version, reason code, etc.
x
let center = NotificationCenter.default
center.addObserver(forName: Notification.Name("NotInstalledFromOfficialStore"), object: nil, queue: nil) { (note) in
guard let usrInf = note.userInfo else {
return
}
let message = usrInf["message"]; // Message shown to the user
let reasonData = usrInf["reasonData"]; // Threat detection cause
let reasonCode = usrInf["reasonCode"]; // Event reason code
// Current threat event score
let currentThreatEventScore = usrInf["currentThreatEventScore"];
// Total threat events score
let threatEventsScore = usrInf["threatEventsScore"];
// Replace '<Context Key>' with your specific event context key
// let variable = usrInf["<Context Key>"];
// Your logic goes here (Send data to Splunk/Dynatrace/Show Popup...)
}
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[[NSNotificationCenter defaultCenter] addObserverForName: @"NotInstalledFromOfficialStore" object:nil queue:nil usingBlock:^(NSNotification *org_note) {
__block NSNotification *note = org_note;
dispatch_async(dispatch_get_main_queue(), ^(void) {
// Message shown to the user
NSString *message = [[note userInfo] objectForKey:@"message"];
// Threat detection cause
NSString *reasonData = [[note userInfo] objectForKey:@"reasonData"];
// Event reason code
NSString *reasonCode = [[note userInfo] objectForKey:@"reasonCode"];
// Current threat event score
NSString *currentThreatEventScore = [[note userInfo] objectForKey:@"currentThreatEventScore"];
// Total threat events score
NSString *threatEventsScore = [[note userInfo] objectForKey:@"threatEventsScore"];
// Replace '<Context Key>' with your specific event context key
// NSString *variable = [[note userInfo] objectForKey:@"<Context Key>"];
// Your logic goes here (Send data to Splunk/Dynatrace/Show Popup...)
});
}];
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const { ADDevEvents } = NativeModules;
const aDDevEvents = new NativeEventEmitter(ADDevEvents);
function registerToDevEvent(action, callback) {
NativeModules.ADDevEvents.registerForDevEvent(action);
aDDevEvents.addListener(action, callback);
}
export function registerToAllEvents() {
registerToDevEvent(
"NotInstalledFromOfficialStore",
(userinfo) => Alert.alert(JSON.stringify(userinfo))
var message = userinfo["message"] // Message shown to the user
var reasonData = userinfo["reasonData"] // Threat detection cause
var reasonCode = userinfo["reasonCode"] // Event reason code
// Current threat event score
var currentThreatEventScore = userinfo["currentThreatEventScore"]
// Total threat events score
var threatEventsScore = userinfo["threatEventsScore"]
// Replace '<Context Key>' with your specific event context key
// var variable = userinfo["<Context Key>"]
// Your logic goes here (Send data to Splunk/Dynatrace/Show Popup...)
);
}
x
RegisterReceiver(new ThreatEventReceiver(), new IntentFilter("NotInstalledFromOfficialStore"));
class ThreatEventReceiver : BroadcastReceiver
{
public override void OnReceive(Context context, Intent intent)
{
// Message shown to the user
String message = intent.GetStringExtra("message");
// Threat detection cause
String reasonData = intent.GetStringExtra("reasonData");
// Event reason code
String reasonCode = intent.GetStringExtra("reasonCode");
// Current threat event score
String currentThreatEventScore = intent.GetStringExtra("currentThreatEventScore");
// Total threat events score
String threatEventsScore = intent.GetStringExtra("threatEventsScore");
// Replace '<Context Key>' with your specific event context key
// String variable = intent.GetStringExtra("<Context Key>");
// Your logic goes here (Send data to Splunk/Dynatrace/Show Popup...)
}
}
x
NSNotificationCenter.DefaultCenter.AddObserver(
(NSString)"NotInstalledFromOfficialStore", // Threat-Event Identifier
delegate (NSNotification notification)
{
// Message shown to the user
var message = notification.UserInfo.ObjectForKey("message");
// Threat detection cause
var reasonData = notification.UserInfo.ObjectForKey("reasonData");
// Event reason code
var reasonCode = notification.UserInfo.ObjectForKey("reasonCode");
// Current threat event score
var currentThreatEventScore = notification.UserInfo.ObjectForKey("currentThreatEventScore");
// Total threat events score
var threatEventsScore = notification.UserInfo.ObjectForKey("threatEventsScore");
// Replace '<Context Key>' with your specific event context key
// var variable = notification.UserInfo.ObjectForKey("<Context Keys>");
// Your logic goes here (Send data to Splunk/Dynatrace/Show Popup...)
}
);
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window.broadcaster.addEventListener("NotInstalledFromOfficialStore", function(userInfo) {
var message = userInfo.message // Message shown to the user
var reasonData = userInfo.reasonData // Threat detection cause
var reasonCode = userInfo.reasonCode // Event reason code
// Current threat event score
var currentThreatEventScore = userInfo.currentThreatEventScore
// Total threat events score
var threatEventsScore = userInfo.threatEventsScore
// Replace '<Context Key>' with your specific event context key
// var variable = userInfo.<Context Keys>
// Your logic goes here (Send data to Splunk/Dynatrace/Show Popup...)
});
x
import 'dart:async';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
class PlatformChannel extends StatefulWidget {
const PlatformChannel({super.key});
State<PlatformChannel> createState() => _PlatformChannelState();
}
class _PlatformChannelState extends State<PlatformChannel> {
// Replace with your EventChannel name
static const String _eventChannelName = "NotInstalledFromOfficialStore";
static const EventChannel _eventChannel = EventChannel(_eventChannelName);
void initState() {
super.initState();
_eventChannel.receiveBroadcastStream().listen(_onEvent, onError: _onError);
}
void _onEvent(Object? event) {
setState(() {
// Adapt this section based on your specific event data structure
var eventData = event as Map;
// Example: Accessing 'externalID' field from the event
var externalID = eventData['externalID'];
// Customize the rest of the fields based on your event structure
String message = eventData['message']; // Message shown to the user
String reasonData = eventData['reasonData']; // Threat detection cause
String reasonCode = eventData['reasonCode']; // Event reason code
// Current threat event score
String currentThreatEventScore = eventData['currentThreatEventScore'];
// Total threat events score
String threatEventsScore = eventData['threatEventsScore'];
// Replace '<Context Key>' with your specific event context key
// String variable = eventData['<Context Keys>'];
});
}
// Your logic goes here (Send data to Splunk/Dynatrace/Show Popup...)
}
Using Appdome, there are no development or coding prerequisites to build secured iOS Apps by using App Store Signature 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 App Store Signature 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:
- Customizing, Configuring & Branding Secure Mobile Apps.
- Deploying/Publishing Secure mobile apps to Public or Private app stores.
- Releasing Secured Android & iOS Apps built on Appdome.
Related Articles:
- How to Troubleshoot App Signing in Secured Android & iOS Apps
- Binary Code Obfuscation, Anti-Reversing for Android & iOS Apps
- How to Prevent Code Tampering in Android & iOS Apps
- How to Prevent Code Injection & Process Injection Attacks in Mobile Apps
How Do I Learn More?
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.