How to Connect to Trusted Mobile Hosts with URL Whitelisting on Android & iOS Apps
Learn to Add a list of approved, trusted website in Mobile apps, in mobile CI/CD with a Data-Driven DevSecOps™ build system.
What is URL Whitelisting?
URL Whitelisting in mobile apps includes a list of approved, trusted websites that the app is permitted to communicate with. All other URLs are blocked. URL Whitelisting provides a method to identify sites that an app can access. The goal of whitelisting is to provide a safe space for users accessing services via an app.
Why Should Developers Add URL Whitelisting?
URL Whitelisting ensures that a mobile app connects only to specified, trusted server URLs. This measure protects apps from attacks such as XcodeGhost, which can insert malware and adware into the app, potentially causing the app to send user data to undesired locations. Once installed on a user’s device, these infected apps can engage in various malicious activities, such as collecting unauthorized data or receiving commands from a malicious server. Implementing URL whitelisting provides an additional layer of protection against such threats. Moreover, URL whitelisting restricts malware-infected apps from communicating with unauthorized or malicious servers, further safeguarding user data and blocking the execution of harmful commands.
Note: When adding URL whitelisting to your app’s secure communication protection layer, it’s crucial to include both a list of pre-approved website URLs and specify the DNS server for accurate IP address resolution. By incorporating both elements, app developers ensure not only that the app interacts with the intended websites but also that the pathway to these sites is secure and uncompromised.
Add a list of approved, trusted website on Mobile apps using Appdome
On Appdome, follow these 3 simple steps to create self-defending Mobile Apps that Add a list of approved, trusted website without an SDK or gateway:
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Upload the Mobile App to Appdome.
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Upload an app to Appdome’s Mobile App Security Build System
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Upload Method: Appdome Console or DEV-API
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Mobile App Formats: .ipa For iOS device or .apk or .aab
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URL Whitelisting Compatible With: Obj-C, C+, Java, JS, C#, C++, Swift, Kotlin, Flutter, React Native, Unity, Xamarin, and more
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Build the feature: URL Whitelisting.
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Building URL Whitelisting by using Appdome’s DEV-API:
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Create and name the Fusion Set (security template) that will contain the URL Whitelisting feature as shown below:
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Follow the steps in Sections 2.2.1-2.2.2 of this article, Building the URL Whitelisting feature via Appdome Console, to add the URL Whitelisting feature to this Fusion Set.
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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). -
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:
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Build an API for the app – for instructions, see the tasks under Appdome API Reference Guide
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Look for sample APIs in Appdome’s GitHub Repository
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Figure 1: Fusion Set that will contain the URL Whitelisting feature
Note: Naming the Fusion Set to correspond to the protection(s) selected is for illustration purposes only (not required). -
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Building the URL Whitelisting feature via Appdome Console
To build the URL Whitelisting protection by using Appdome Console, follow the instructions below.
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Where: Inside the Appdome Console, go to Build > Security Tab > Secure Communication section
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How: Toggle (turn ON) URL Whitelisting, 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 Adds a list of approved, trusted website.Figure 3: Add a list of approved, trusted website 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. -
When you select the URL Whitelisting you'll notice that your Fusion Set you created in step 2.1.1 now bears the icon of the protection category that contains URL Whitelisting
Figure 4: Fusion Set that displays the newly added URL Whitelisting protection
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Select the Threat-Event™ in-app mobile Threat Defense and Intelligence policy for URL Whitelisting:
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Threat-Events™ OFF > In-App Defense
If the Threat-Events™ setting is cleared (not selected). Appdome will detect and defend the user and app by enforcing Add a list of approved, trusted website.
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Threat-Events™ ON > In-App Detection
When this setting is used, Appdome detects a Server URL that is not included in the whitelist 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™ for URL Whitelisting 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 a list of approved, trusted website (same as Appdome Enforce) and passes Appdome’s Threat-Event™ attack intelligence 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 URL Whitelisting Intelligence and Control in Mobile Apps.
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Click Build My App at the bottom of the Build Workflow (shown in Figure 3).
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Congratulations! The URL Whitelisting protection is now added to the mobile app -
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Certify the URL Whitelisting feature in Mobile Apps.
After building URL Whitelisting, Appdome generates a Certified Secure™ certificate to guarantee that the URL Whitelisting protection has been added and is protecting the app. To verify that the URL Whitelisting 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 URL Whitelisting has been added to each Mobile app. Certified Secure provides instant and in-line DevSecOps compliance certification that URL Whitelisting and other mobile app security features are in each build of the mobile app
Using Threat-Events™ for a list of approved, trusted website Intelligence and Control in Mobile Apps
Appdome Threat-Events™ provides consumable in-app mobile app attack intelligence and defense control when a list of approved, trusted website is detected. To consume and use Threat-Events™ for a list of approved, trusted website in Mobile Apps, use AddObserverForName in Notification Center, and the code samples for Threat-Events™ for a list of approved, trusted website shown below.
The specifications and options for Threat-Events™ for a list of approved, trusted website are:
Threat-Event™ Elements | Add a list of approved, trusted website Method Detail |
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Appdome Feature Name | URL Whitelisting |
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 Adding a list of approved, trusted website Threat-Event™ | |
Threat-Event NAME | UrlWhitelistFailed |
Threat-Event DATA | reasonData |
Threat-Event CODE | reasonCode |
Threat-Event REF | 6600 |
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 |
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 long |
locationLat | Location lat |
locationState | Location state |
wifiSsid | Wifi SSID |
wifiSsidPermissionStatus | Wifi SSID permission status |
host | Blocked host |
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 a list of approved, trusted website is detected.
The following is a code sample for native Mobile apps, which uses all values in the specification above for URL Whitelisting:
x
IntentFilter intentFilter = new IntentFilter();
intentFilter.addAction("UrlWhitelistFailed");
BroadcastReceiver threatEventReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
String message = intent.getStringExtra("message"); // Message shown to the user
String reasonData = intent.getStringExtra("reasonData"); // Threat detection cause
String reasonCode = intent.getStringExtra("reasonCode"); // Event reason code
String currentThreatEventScore = intent.getStringExtra("currentThreatEventScore"); // Current threat event score
String threatEventsScore = intent.getStringExtra("threatEventsScore"); // Total threat events score
String variable = intent.getStringExtra("<Context Key>"); // Any other event specific context key
​
// Your logic goes here (Send data to Splunk/Dynatrace/Show Popup...)
}
};
​
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
registerReceiver(threatEventReceiver, intentFilter, Context.RECEIVER_NOT_EXPORTED);
} else {
registerReceiver(threatEventReceiver, intentFilter);
}
x
val intentFilter = IntentFilter()
intentFilter.addAction("UrlWhitelistFailed")
val threatEventReceiver = object : BroadcastReceiver() {
override fun onReceive(context: Context?, intent: Intent?) {
var message = intent?.getStringExtra("message") // Message shown to the user
var reasonData = intent?.getStringExtra("reasonData") // Threat detection cause
var reasonCode = intent?.getStringExtra("reasonCode") // Event reason code
var currentThreatEventScore = intent?.getStringExtra("currentThreatEventScore") // Current threat event score
var threatEventsScore = intent?.getStringExtra("threatEventsScore") // Total threat events score
var variable = intent?.getStringExtra("<Context Key>") // Any other event specific context key
​
// Your logic goes here (Send data to Splunk/Dynatrace/Show Popup...)
}
}
​
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
registerReceiver(threatEventReceiver, intentFilter, Context.RECEIVER_NOT_EXPORTED)
} else {
registerReceiver(threatEventReceiver, intentFilter)
}
let center = NotificationCenter.default
center.addObserver(forName: Notification.Name("UrlWhitelistFailed"), 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
let currentThreatEventScore = usrInf["currentThreatEventScore"]; // Current threat event score
let threatEventsScore = usrInf["threatEventsScore"]; // Total threat events score
let variable = usrInf["<Context Key>"]; // Any other event specific context key
// Your logic goes here (Send data to Splunk/Dynatrace/Show Popup...)
}
[[NSNotificationCenter defaultCenter] addObserverForName: @"UrlWhitelistFailed" object:nil queue:nil usingBlock:^(NSNotification *org_note) {
__block NSNotification *note = org_note;
dispatch_async(dispatch_get_main_queue(), ^(void) {
var threatEventsScore = intent.getStringExtra("threatEventsScore")
NSString *message = [[note userInfo] objectForKey:@"message"]; // Message shown to the user
NSString *reasonData = [[note userInfo] objectForKey:@"reasonData"]; // Threat detection cause
NSString *reasonCode = [[note userInfo] objectForKey:@"reasonCode"]; // Event reason code
NSString *currentThreatEventScore = [[note userInfo] objectForKey:@"currentThreatEventScore"]; // Current threat event score
NSString *threatEventsScore = [[note userInfo] objectForKey:@"threatEventsScore"]; // Total threat events score
NSString *variable = [[note userInfo] objectForKey:@"<Context Key>"]; // Any other event specific context key
// Your logic goes here (Send data to Splunk/Dynatrace/Show Popup...)
});
}];
const { ADDevEvents } = NativeModules;
const aDDevEvents = new NativeEventEmitter(ADDevEvents);
function registerToDevEvent(action, callback) {
NativeModules.ADDevEvents.registerForDevEvent(action);
aDDevEvents.addListener(action, callback);
}
export function registerToAllEvents() {
registerToDevEvent(
"UrlWhitelistFailed",
(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
var currentThreatEventScore = userinfo["currentThreatEventScore"] // Current threat event score
var threatEventsScore = userinfo["threatEventsScore"] // Total threat events score
var variable = userinfo["<Context Key>"] // Any other event specific context key
// Your logic goes here (Send data to Splunk/Dynatrace/Show Popup...)
);
}
RegisterReceiver(new ThreatEventReceiver(), new IntentFilter("UrlWhitelistFailed"));
class ThreatEventReceiver : BroadcastReceiver
{
public override void OnReceive(Context context, Intent intent)
{
String message = intent.getStringExtra("message"); // Message shown to the user
String reasonData = intent.getStringExtra("reasonData"); // Threat detection cause
String reasonCode = intent.getStringExtra("reasonCode"); // Event reason code
String currentThreatEventScore = intent.getStringExtra("currentThreatEventScore"); // Current threat event score
String threatEventsScore = intent.getStringExtra("threatEventsScore"); // Total threat events score
String variable = intent.getStringExtra("<Context Key>"); // Any other event specific context key
// Your logic goes here (Send data to Splunk/Dynatrace/Show Popup...)
}
}
NSNotificationCenter.DefaultCenter.AddObserver(
(NSString)"UrlWhitelistFailed", // Threat-Event Identifier
delegate (NSNotification notification)
{
var message = notification.UserInfo.ObjectForKey("message"); // Message shown to the user
var reasonData = notification.UserInfo.ObjectForKey("reasonData"); // Threat detection cause
var reasonCode = notification.UserInfo.ObjectForKey("reasonCode"); // Event reason code
var currentThreatEventScore = notification.UserInfo.ObjectForKey("currentThreatEventScore"); // Current threat event score
var threatEventsScore = notification.UserInfo.ObjectForKey("threatEventsScore"); // Total threat events score
var variable = notification.UserInfo.ObjectForKey("<Context Keys>"); // Any other event specific context key
// Your logic goes here (Send data to Splunk/Dynatrace/Show Popup...)
});
window.broadcaster.addEventListener("UrlWhitelistFailed", 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
var currentThreatEventScore = userInfo.currentThreatEventScore // Current threat event score
var threatEventsScore = userInfo.threatEventsScore // Total threat events score
var variable = userInfo.<Context Key> // Any other event specific context key
// Your logic goes here (Send data to Splunk/Dynatrace/Show Popup...)
});
Prerequisites to Using URL Whitelisting:
To use Appdome’s mobile app security build system to Add a list of approved, trusted website , you’ll need:
- Appdome account (create a free Appdome account here)
- A license for URL Whitelisting
- Mobile App (.ipa For iOS device or .apk or .aab For Mobile)
- Signing Credentials (see Signing Secure Android apps and Signing Secure iOS apps)
Using Appdome, there are no development or coding prerequisites to build secured Mobile Apps by using URL Whitelisting. 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 URL Whitelisting
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.
All apps protected by Appdome are fully compatible with any public app store, including Apple App Store, Google Play, Huawei App Gallery and more.
Related Articles:
- MOBILEBot™ Defense
- How to Block Mobile Bots with Client Certificates, Authenticate Legitimate Mobile Apps
- How to Block Mobile Bots Using Session & Header Secrets
If you have any questions, please send them our way at support.appdome.com or via the chat window on the Appdome platform.
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