Secure Firmware Updates for Automotive Nodes
Carlos I. Ávila-Gutiérrez, Jorge A. González-Rodríguez, Tomas I. Páez-Rodríguez · ITESO Institutional Repository (ReI) (Western Institute of Technology and Higher Education) · 2018
With the fast-growing smart applications in the automotive market, the need to provide a robust, secure, and standardized mechanism to solve firmware defects or improve the features within the node, has become a key factor for the Electronic Control Units (ECUs) in the car. Some research has aimed to solve this mechanism; however, a standardized and secure solution has not been addressed. The objective of this thesis is to provide a robust, secure, and standardized firmware update mechanism for any given ECU. The update process consisted in implementing a bootloader application in charge of the reprogramming process while the new firmware was received through the use of Unified Diagnostic Services (UDS) over the Controller Area Network (CAN) protocol. A secure communication channel was required since an unauthorized access might cause a security risk for car users. This security requirement was fulfilled by implementing a “Seed & Key” mechanism using encryption and decryption algorithms implemented in the hardware. The process described in this thesis does not cover the mechanisms used to transmit the new firmware version (wired or wirelessly), as the application targets the ECU / edge node considerations to achieve a secure and sophisticated firmware update process. The implementation was based on an ARM Cortex® M4 device manufactured by NXP Semiconductors showing satisfactory results as the device was able to update its firmware by connecting a UDS client in charge of sending the new image over the CAN protocol. This update process can be used in further research to address other electronic features, such as the implementation on reduced-memory devices, the use of different encryption/decryption algorithms not implemented in hardware or even extend the functionality to other fast-speed interfaces.