7 ms·
A Gap in the TrustZone preset settings for the LPC55S69
- demondemidi 3y agoThis requires the attacker to sign an image with a private key which is owned by NXP or the Oem. A much larger hack! Now if they glitched the startup code before programming the vtor and setting up tz, wouldn’t that fault with the debugger AP active?
- zitterbewegung 3y agoIt’s a good advertisement or due diligence that they respect security and take it seriously.
- demondemidi 3y agoAny MCU manufacturer that wants to sell in the EU needs to adhere to RED/CRA, which outlines some pretty strict requirements. The implementaiton varies (e.g. PSA). It's consumer protection laws and not due-diligence that force this. Sure, some companies were using security to differentiate, but OEMs/ODMs didn't give a f__k until regulations made them. And this benefits us all.
- charcircuit 3y ago>In the absence of a fix for this errata, we will not be using the TrustZone preset data. I don't understand the reason behind doing this as the non security errata doesn't make it insecure to use.
- steveklabnik 3y ago> as the non security errata doesn't make it insecure to use. I am a little bit unclear as to exactly what you're asking, to be honest. Could you maybe rephrase this?
- charcircuit 3y agoI didn't understand what the downsides were in using the TrustZone preset data. From my reading it sounds like it provides extra security until the secure signing key is compromised.
- steveklabnik 3y agoIn my understanding, the preset data only makes implementing this easier, but has this issue where if you use it wrong, bad things can happen. We prefer to use tools that make using them incorrectly difficult, especially in such a sensitive context.