How to Apply Data-at-Rest Encryption for Downloads via Android's DownloadManager API
Learn to Enforce secure downloads in Android apps, in mobile CI/CD with a Data-Driven DevSecOps™ build system.
Why Data-at-Rest Encryption is Essential for Android's DownloadManager API Downloads
Data-at-Rest Encryption is pivotal for downloads managed by Android’s DownloadManager API because:
- Direct Storage: Downloaded files reside on the device’s storage, exposed to security threats if the device is compromised.
- Limited Default Security: The Android DownloadManager facilitates seamless file downloads but lacks granular security controls.
- Developer Challenges: Applying protective measures to downloaded files can be complex compared to other data handled by apps.
To ensure the integrity and safety of the data, robust security measures are essential. Without them, these files could be vulnerable to potential threats from malicious apps or unauthorized users.
Appdome’s Secure Download ensures that files downloaded by the app are not sent to the Android Download Manager and are executed within the app’s context. In doing so, data encryption is applied to all downloaded files.
How Appdome's Secure Download Enhances Security?
Appdome Secure Download operates by “catching” the download request within an Appdome Built app and executing it directly within the app’s secure environment. This functionality ensures the application of Data at Rest Encryption to files before they are securely stored on the device. When Secure Download is enabled, the app identifies the device’s Download Manager API call to guarantee secure file downloads. This process also ensures that files aren’t directed to the standard Android Download Manager but remain within the app’s context, receiving the added protection of data encryption.
Important Note
Secure Download protects all downloads made by the standard Android Download Manager used in the app. As part of Android Download’s Manager operation, a notification is sent showing the download progress and stating that a file has been downloaded. Due to changes in notification runtime permission starting from Android 13, the download notification will only appear after the application has requested and received notification permissions from the end-user.
For more information, please see Android Developer Documentation on Notification runtime permission.
Prerequisites for Using Data at Rest Encryption > Secure Download:
To use Appdome’s mobile app security build system to Enforce secure downloads , you’ll need:
- Appdome account (create a free Appdome account here)
- A license for Data at Rest Encryption > Secure Download
- Mobile App (.apk or .aab for Android)
- Signing Credentials (see Signing Secure Android apps and Signing Secure iOS apps)
Enforce secure downloads on Android apps using Appdome
On Appdome, follow these 3 simple steps to create self-defending Android Apps that Enforce secure downloads 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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Android Formats: .apk or .aab
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Data at Rest Encryption > Secure Download Compatible With: Java, JS, C++, C#, Kotlin, Flutter, React Native, Unity, Cordova and other Android apps
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Build the feature: Data at Rest Encryption > Secure Download.
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Building Data at Rest Encryption > Secure Download by using Appdome’s DEV-API:
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Create and name the Fusion Set (security template) that will contain the Data at Rest Encryption > Secure Download feature as shown below:
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Follow the steps in Sections 2.2.1-2.2.2 of this article, Building the Data at Rest Encryption > Secure Download feature via Appdome Console, to add the Data at Rest Encryption > Secure Download 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. Copy 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, Circle 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 Data at Rest Encryption > Secure Download 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 Data at Rest Encryption > Secure Download feature via Appdome Console
To build the Data at Rest Encryption > Secure Download protection by using Appdome Console, follow the instructions below.
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Where: Inside the Appdome Console, go to Build > Security Tab > TOTALData™ Encryption section.
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How: Check whether is toggled On (enabled), otherwise enable it . The feature Data at Rest Encryption > Secure Download is enabled by default, as shown below. Toggle (turn ON) Data at Rest Encryption > Secure Download, as shown below.
Figure 3: Enforce secure downloads option
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When you select the Data at Rest Encryption > Secure Download you'll notice that your Fusion Set you created in step 2.1.1 now bears the icon of the protection category that contains Data at Rest Encryption > Secure Download
Figure 4: Fusion Set that displays the newly added Data at Rest Encryption > Secure Download protection
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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 Data at Rest Encryption > Secure Download protection is now added to the mobile app -
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Certify the Data at Rest Encryption > Secure Download feature in Android Apps
After building Data at Rest Encryption > Secure Download, Appdome generates a Certified Secure™ certificate to guarantee that the Data at Rest Encryption > Secure Download protection has been added and is protecting the app. To verify that the Data at Rest Encryption > Secure Download 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 Data at Rest Encryption > Secure Download has been added to each Android app. Certified Secure provides instant and in-line DevSecOps compliance certification that Data at Rest Encryption > Secure Download and other mobile app security features are in each build of the mobile app
Using Threat-Events™ for secure downloads Intelligence and Control in Android Apps
Appdome Threat-Events™ provides consumable in-app mobile app attack intelligence and defense control when secure downloads is detected. To consume and use Threat-Events™ for secure downloads in Android Apps, use registerReceiver in the Application OnCreate, and the code samples for Threat-Events™ for secure downloads shown below.
The specifications and options for Threat-Events™ for secure downloads are:
Threat-Event™ Elements | Enforce secure downloads Method Detail |
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Appdome Feature Name | Data at Rest Encryption > Secure Download |
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 Enforcing secure downloads 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 | |
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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. |
carrierPlmn | PLMN of the device. Only available for Android devices. |
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 |
carrierName | Carrier name of the current device. Only available for Android. |
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 |
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), Android developers can get detailed attack intelligence and granular defense control in Android applications and create amazing user experiences for all mobile end users when secure downloads is detected.
The following is a code sample for native Android apps, which uses all values in the specification above for Data at Rest Encryption > Secure Download:
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.
xxxxxxxxxx
IntentFilter intentFilter = new IntentFilter();
intentFilter.addAction("");
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
// 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...)
}
};
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
registerReceiver(threatEventReceiver, intentFilter, Context.RECEIVER_NOT_EXPORTED);
} else {
registerReceiver(threatEventReceiver, intentFilter);
}
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val intentFilter = IntentFilter()
intentFilter.addAction("")
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
// Current threat event score
var currentThreatEventScore = intent?.getStringExtra("currentThreatEventScore")
// Total threat events score
var threatEventsScore = intent?.getStringExtra("threatEventsScore")
// Replace '<Context Key>' with your specific event context key
// var variable = intent?.getStringExtra("<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)
}
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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(
"",
(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(""));
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)"", // 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("", 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 = "";
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 Android Apps by using Data at Rest Encryption > Secure Download. 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 Data at Rest Encryption > Secure Download
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 Play Encrypted Media with AVPlayer on iOS Devices
- How to Play Encrypted Media With MediaPlayer on Android Devices
- Protect Mobile App Data Using Data Encryption
- How to Encrypt Shared Preferences in Android 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.