A novel open-source HSM Firmware compatible with AUTOSAR specifications for Secure Hardware Extensions

Automotive control systems face security as the biggest challenge in the next few years. The race towards Vehicle-to-Everything technology, while improving vehicle capabilities and enabling driverless cars, is also dangerously exposing them. As cars become increasingly interconnected, it is easier for malicious users to attack them by leveraging the improved communication capabilities of the vehicle. However, attacks may be conducted at any level, from the network to the physical layer. One of the potential targets of a cyberattack consists of critical information to decode confidential data; such an attack could allow a malicious user to access information that should be kept secret, potentially making the attacker capable of controlling the vehicle itself. For this purpose, key management systems such as Hardware Security Modules (HSM) address this issue by defining a secure area where these secrets are safe. However, most HSMs are deployed on specific boards with highly specific hardware requirements and features, making any software developed for such systems not portable; moreover, given the peculiarity of the target system, such software is neither available to reuse. The present work describes a novel open-source HSM Firmware, which is compatible with AUTOSAR specifications for Secure Hardware Extensions. By examining these requirements together with the prerequisites to achieve an acceptable degree of security when using an HSM, the current work delves into the details of designing and developing firmware to deploy on a specific category of boards that can support HSM by hardware design. Besides, the Thesis encompasses the issue of the intrinsic dependency of such a kind of firmware from the underlying hardware by considering portability as an essential project requirement. Without this additional effort, trying to make the HSM firmware open-source would prove useless because it would suffer from low applicability. Particular attention has been posed to the interaction between the HSM, its underlying hardware and the external domain with which it communicates by implementing a suitable driver that acts as the sole interlocutor with software and hardware access to this module. For validation, functional tests are performed in emulation and then by porting the project on a target board, thus proving the portability of the firmware. Starting from the results of this Thesis, it would be possible for future developers to enhance the driver's capabilities and increase the set of supported boards by porting the current project to them, too.