How to Block Mobile Bots with Client Certificates, Authenticate Legitimate Mobile Apps

Learn to Prevent non-validated apps from connecting to the Server in Mobile apps, in mobile CI/CD with a Data-Driven DevSecOps™ build system.

What Threat do Non-validated Mobile Apps Pose?

Mobile apps connect to all sorts of external services. They connect to their host server to perform, tasks such as authenticating users, downloading content, and connecting to other mobile resources. Mobile apps also connect to 3rd-party services embedded in the app, such as payment providers, analytics vendors, location services, and more. As a mobile app connects with the outside world, hackers and malicious parties exploit weaknesses in the communications or transport layer to conduct network-based attacks that target the mobile application backend. For example, attackers often use techniques like session hijacking, fake or forged digital certificates, or automated malicious bots or scripts. These techniques are designed to attack infrastructure by using click fraud, credential stuffing or other large-scale automated attacks.

How do Mobile Client Certificates Work?

Using Appdome’s no-code mobile app security platform you can embed the trusted, approved client certificates (client P12/PKCS) inside the application, where it is securely stored (encrypted using AES-256). For every connection, the application presents its unique certificate along with a unique password/secret to the server for inspection and validation as part of the SSL/TLS handshake. The server then inspects the certificate using its private key to ensure that it matches, in which case the server knows it can trust the client/app and establish the secure session. This protects the backend servers and infrastructure against connections originating from compromised endpoints or malicious bots. In order to use Appdome’s Mobile Client Certificates feature, the server must be configured to validate incoming connections based on client certificates.

Prerequisites to Using Mobile Client Certificates:

To use Appdome’s mobile app security build system to Prevent non-validated apps from connecting to the Server , you’ll need:

• Appdome account (create a free Appdome account here)
• A license for Mobile Client Certificates
• 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 non-validated apps from connecting to the Server on Mobile apps using Appdome

On Appdome, follow these 3 simple steps to create self-defending Mobile Apps that Prevent non-validated apps from connecting to the Server 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. Mobile Client Certificates Compatible With: Obj-C, C+, Java, JS, C#, C++, Swift, Kotlin, Flutter, React Native, Unity, Xamarin, and more

2. Build the feature: Mobile Client Certificates.

   1. Building Mobile Client Certificates by using Appdome’s DEV-API:

      1. Create and name the Fusion Set (security template) that will contain the Mobile Client Certificates feature as shown below:
      

      Figure 1: Fusion Set that will contain the Mobile Client Certificates 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 Mobile Client Certificates feature via Appdome Console, to add the Mobile Client Certificates 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 Mobile Client Certificates feature via Appdome Console

      To build the Mobile Client Certificates protection by using Appdome Console, follow the instructions below.

      1. Where: Inside the Appdome Console, go to Build > Security Tab > Secure Communication section
      2. How: Toggle (turn ON) Mobile Client Certificates, as shown below.

         Figure 3: Prevent non-validated apps from connecting to the Server option

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

         

         Figure 4: Fusion Set that displays the newly added Mobile Client Certificates protection

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

   Congratulations!  The Mobile Client Certificates protection is now added to the mobile app

3. Certify the Mobile Client Certificates feature in Mobile Apps.

   After building Mobile Client Certificates, Appdome generates a Certified Secure™ certificate to guarantee that the Mobile Client Certificates protection has been added and is protecting the app. To verify that the Mobile Client Certificates 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 Mobile Client Certificates has been added to each Mobile app. Certified Secure provides instant and in-line DevSecOps compliance certification that Mobile Client Certificates and other mobile app security features are in each build of the mobile app