Overview

The increasing popularity of connected devices in recent years has led manufacturers to put a greater emphasis on security, finding themselves in need of robust designs that would protect their users. From these requirements emerged the ARM TrustZone, a system-wide hardware isolation technology. It introduces a trusted Secure World that can process code and data while ensuring their integrity and confidentiality. This Secure World can also watch over the user-controlled (and therefore untrusted) Normal World to verify its integrity, similarly to the mechanism implemented in Samsung's TIMA. It can also access hardware peripherals, such as keyboards, screens or cryptoprocessors, in a secure and isolated manner to create trusted UIs, implement DRMs, etc. All the sensitive data and the critical interruptions are directly handled by the Secure World without ever passing through the Normal World.

During this practical two-day training, attendees will be introduced to the ARM TrustZone technology, the related problematics and how they can be answered using both hardware and software components using Samsung's TrustZone to illustrate the course. Once the OS running in the Trusted Execution Environment, or TEE-OS for short, has been extracted by the trainees on Samsung’s Exynos based Android platforms, they will be reverse-engineered to list the entry points, the differences with other TEE-OSs, the communication mechanisms, etc. The course will then focus on how to extract, reverse-engineer and communicate with trusted applications. Ultimately, the main objective of the training is for the attendees to get arbitrary code execution in trusted application and in a secure driver on Exynos by exploiting, now-fixed, vulnerabilities. The course ends by providing different tips to go further and presents the attack surface offered once code execution is reached in trusted applications and in secure drivers.

Who Should Attend?

The training is optimally suited for:

• Individuals interested by the ARM TrustZone technology, how it works, how it’s implemented and how to break it.
• Security researchers who wish to assess the security of ARM TrustZone implementations and its components.
• Software engineers developing on ARM TrustZone who would like to understand how an attacker could compromise the system.