`whoami`

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2024-10-07 13:30:05

Before you can write an exploit, you need a bug. When there are no bugs, we have to get creative—that's where Fault Injection comes in. Fault injection can take many forms, including software-controlled data corruption, power glitching, clock glitching, electromagnetic pulses, lasers, and more.

Hardware fault injection is something that typically requires specialized (and expensive) equipment. The costs stem from requiring a high degree of precision in terms of both when and where the fault is injected. There are many valiant attempts at bringing down the costs, with notable projects ranging from the RP2040-based PicoEMP, all the way to "Laser Fault Injection for The Masses". (The RP2040 crops up a lot due to its low cost combined with the "PIO" peripheral, which can do I/O with tight timings and latency)

A while back I read about using a piezo-electric BBQ Igniter coupled to an inductor as a low-budget tool for electro-magnetic fault injection (EMFI), and I was captivated. I wondered, how far can you take such a primitive tool? At the time, the best thing I could come up with was exploiting a software implementation of AES running on an Arduino, using DFA—it worked!