auditing-secure-boot-and-firmware-signinglisted

# Auditing secure boot and firmware signing: does a verified signature gate every path to flash and boot Firmware is the most durable place an attacker can land, and the whole defense is one property: an image is verified for authenticity before any code writes it to a boot slot or jumps to it. Auditing that property is a domination question, not a checklist. Trace the received image to every place it is committed, to flash or to the program counter, and ask whether a correct, enforced signature check stands on every path, over the exact bytes that reach the commit, against a key the attacker cannot influence. The common failures are all ways that check is absent, thrown away, checking the wrong thing, or checking the wrong bytes. You find them by reading the receipt-to-commit path, not by trusting that a function named verify verifies. ## When to use - Code receives a firmware image over an update channel and writes it to flash or activates a boot slot. - A bootloader decides whether to execute an image at startup. - You want to know whether an unsigned, tampered, or downgraded image can be flashed or booted. ## Scope check Audit firmware trust boundaries only on devices and code you own or are authorized to assess, and flash crafted images only to hardware in scope. A confirmed secure-boot bypass is persistent code execution, so treat it accordingly and coordinate. If you can't name the authorization, stop. ## The loop 1. **Map the receipt-to-commit paths.** Find whe