How to Enforce TLS Certificate Roles, Android & iOS Apps

Learn how to to Enforce SSL TLS Certificate Roles in Android & iOS Apps to protect mobile app data-in-transit and ensure safe connections.

TLS Certificate Role Enforcement – Why it’s Important to Secure Android & iOS App Sessions 

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 is 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.

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 no-code mobile app security platform designed to add security features, like Certificate Role Enforcement to Android & iOS apps without coding. This KB shows mobile developers, DevSec and security professionals how to use Appdome’s simple ‘click to build’ user interface to quickly and easily protect mobile data in transit. 

3 Easy Steps to Enforce TLS Certificate Roles in Android & iOS Apps

Please follow these 3 easy steps to Enforce TLS Certificate Roles in Android & iOS Apps

1. Upload an Android or iOS App to Appdome’s no code security platform (.apk, .aab, or .ipa)
2. Under Build, Click Security, then Secure Communications,  switch ON Trusted Session, Expand Session Management, switch ON Enforce Certificate Roles– (optional) Enable Threat Events to configure a Threat Alert
3. Click Build My App

Appdome’s no-code mobile app security platform offers mobile developers, DevSec and security professionals a convenient and reliable way to protect Android and iOS apps with Enforce Certificate Roles. When an Appdome user clicks “Build My App,” Appdome leverages a microservice architecture filled with 1000s of security plugins, and an adaptive code generation engine that matches the correct required plugins to the development environment, frameworks, and methods in each app.

Prerequisites for Enforce TLS Certificate Roles

Here’s what you need to build secured apps with Enforce TLS Certificate Roles

• Appdome account (If you don’t have an Appdome account, create a free Appdome account here)
• Mobile App (.ipa for iOS, or .apk or .aab for Android)
• Signing Credentials (e.g., signing certificates and provisioning profile)

No Coding Dependency

Alan Bavosa