This application note provides an overview of the STM32 secure firmware upgrade (SFU), including a description of the secure upgrade process, the secure download and upgrade solutions, and the roles of the involved parties.
The document describes a flexible method for remotely upgrading STM32 microcontroller Flash memory with new firmware versions while ensuring security against malicious copying. The process involves three main actors: STMicroelectronics (device manufacturer), the Original Equipment Manufacturer (OEM), and an OEM subcontractor (OEM-CM) operating in a non-secure environment.
The process allows the microcontroller to be reprogrammed remotely with new firmware versions, adding features and correcting issues.
The device must decrypt the binary and check the version number and code authenticity or integrity.
STMicroelectronics is responsible for programming the solution provided as binary by the OEM.