Part 1 - Hardware

Abstract

The Automotive Grade Linux platform is a Linux distribution with AGL compliant applications and services. The platform includes the following hardware:

• SoC (System-on-Chip).
• Memory (RAM, ROM, storage, etc.).
• Peripherals.

You will find in this first part everything that concerns the hardware security. The goal is to protect system against all attacks that are trying to gain additional privileges by recovering and/or changing cryptographic keys in order to alter the integrity of the boot. We should also prevent hardware modifications in order to achieve this goal. We will expose below some examples of possible configurations.

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Acronyms and Abbreviations

The following table lists the terms utilized within this part of the document.

Acronyms or Abbreviations	Description
HSM	Hardware Security Module
NVM	Non-Volatile Memory
SHE	Secure Hardware Extensions

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Integrity

The board must store hardcoded cryptographic keys in order to verify among others the integrity of the bootloader. Manufacturers can use HSM and SHE to enhance the security of their board.

Domain	Object	Recommendations
Hardware-Integrity-1	Bootloader	Must control bootloader integrity.
Hardware-Integrity-2	Board	Must use a HSM.
Hardware-Integrity-3	RTC	Must not be alterable.

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Certificates

Domain	Object	Recommendations
Hardware-Certificate-1	System	Shall allow storing dedicated certificates.
Hardware-Certificate-2	ECU	The ECU must verify the certification authority hierarchy.
Hardware-Certificate-3	System	Allow the modification of certificates only if the source can be authenticated by a certificate already stored or in the higher levels of the chain of trust.

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Memory

Domain	Object	Recommendations
Hardware-Memory-1	ECU	The ECU shall never expose the unencrypted key in RAM when using cryptographic keys.
Hardware-Memory-2	Bootloader	Internal NVM only
Hardware-Module-3	-	HSM must be used to secure keys.