Enforce Certificate Roles in Android and iOS apps

What are certificate roles, why are they important?

Let’s get back to basics: How does your application know that the resource it’s accessing is truly www.your-company-domain.com?

Well, during the connection’s negotiation, the remote service presents its certificate which roughly has two interesting parameters:

1. Domain: This is how we verify that the domain we intended to connect is the same domain we got connected to.
   This, however, raises a question: Can’t a malicious domain just present a certificate with your domain?
   What solves this is the second property – the next certificate in the chain of trust
2. Issuer: This is the identity of a “higher” certificate that “signed” the “lower” certificate.
   Signing is a cryptographically safe method that helps test whether a “lower” certificate was modified.

But how do we trust the issuer? Well, the issuer also has an issuer of its own, and this goes all the way up to an issuer that’s trusted by the platform on which your application runs.

The certificate presented by the server is called a “leaf” certificate, while each issuer is called a CA (Certificate Authority). These are, in essence, the roles of these certificates.

For example, the “chain-of-trust” in a normal connection might be:

• *.your-company-domain.com signed by “Go Daddy Secure Certificate Authority – G2”
• “Go DaddySecure Certificate Authority – G2” signed by “Go Daddy Root Certificate Authority – G2”
• “Go Daddy Root Certificate Authority – G2” trusted by your browser/Android/iPhone.

However, there no functional difference between certificates, regardless of their roles. So while leaf certificates are not meant to be used as certificate-authorities, each certificate can be used to sign another certificate. This makes the following chain also 100% correct:

• *.your-company-domain.com signed by *.malicious-domain.com
• *.malicious-domain.com signed by “Go Daddy Secure Certificate Authority – G2”
  The attacker can obtain this certificate legitimately as it’s not different from buying a certificate for your own domain.
• “Go DaddySecure Certificate Authority – G2” signed by “Go Daddy Root Certificate Authority – G2”
• “Go Daddy Root Certificate Authority – G2” trusted by your browser/Android/iPhone.

So your application could blindly trust a connection to www.malicious-domain.com, thinking it iswww.your-comany-domain.com.

So how can this be enforced? Very simple, just include in each certificate information about its role. This is a common extension called “Basic-Constraints”.

The catch is that if a certificate does not have this extension, an SSL(TLS) implementation won’t enforce it.

This is why it’s important to enforce the presence of the Basic-Constraints extension and the roles of the certificates in the chain.

Enforcing the Certificate Roles 

Implementing and especially maintaining such measures is a difficult task. Sometimes the source code is not available, and more often the services are on uncontrolled endpoints.

Appdome is a mobile integration platform as a service (iPaaS) that allows users to add a wide variety of features, SDKs, and APIs to Android and iOS apps. Using a simple ‘click to add’ user interface, Appdome allows anyone to easily implement Trusted Session Inspection to any mobile app – instantly, no code or coding required.

Using Appdome, there are no development or coding prerequisites. For example, there is no Appdome SDK, libraries, or plug-ins to implement Certificate Roles Enforcement. Certificate Roles Enforcement can be added to any iOS or Android app in seconds, with no code or coding.

Prerequisites for using Enforce Certificate Roles

How to Add Enforce Certificate Roles to Any Mobile App on Appdome 

Follow these step-by-step instructions to add Certificate Roles Enforcement:

Upload a Mobile App to Your Account

Please follow these steps to add a mobile app to your Appdome account.
If you don’t have an Appdome account, click here to create an account.

From the “Build” tab, go to the Security menu.

1. Click  Secure Communications to expand the bundle.
2. Click on the toggle to enable Trusted Session.
3. Expand the sub-bundle Session Management.
4. Toggle the Enforce Certificate Roles switch
5. Enable Threat Events to configure this security alert on your app
6. Click Build My App

The technology behind Build My App has two major elements – (1) a micro-service architecture filled with 1000s of code sets needed for mobile integrations, and (2) an adaptive code generation engine that can recognize the development environment, frameworks and methods in each app and match the app to the relevant code-sets needed to add the requested service to the mobile app in seconds.

Congratulations! When your integration is complete, you will see the notice below. You now have a mobile app fully integrated with Enforce Certificate Roles.

Dany Zatuchna