About antfarmer

antfarmer · 2024-05-20

I can't get ECDH working for CURVE25519 using the STM32 HAL / crypto lib. This may be an issue with the somewhat confusing constants for this library. I can get the NIST curves working with ECDH. The trouble I have is it seems there are two cmox_ecc_...

antfarmer · 2024-05-20

I'm trying to create ECDSA keys on a STM32WL55 using the X-Cube/HAL Crypto library. I can generate NIST keys no problem, however when I try using the Brainpool curves, it mostly returns the following error: CMOX_ECC_ERR_WRONG_RANDOM ((cmox_ecc_retval...

antfarmer · 2024-03-22

This is probably a *** question, but I was wondering if there is a difference in performance between the following C statements given b is a standard boolean:bool b = false; //... if (b == false) //... if (!b) //...Will gcc in STM32 Cube IDE translat...

antfarmer · 2024-02-13

I have a timer (TIM15) setup in trigger slave mode which uses CH1 for edge detect, and output compare on CH2. I have it working nicely to have the output low during the initial delay until the CNT reaches autoreload ARR. Then the output goes high as ...

antfarmer · 2023-12-21

If you put an MCU in sleep mode with WFI, such as the STM32L452, you are supposed to suspend the SysTick and resume it after. Usually this is done in the main thread context. However, when you have an interrupt, I believe the next instruction will be...

antfarmer · 2024-06-03

I have confirmed the constants used are in the documentation of the functions. For key generation: CMOX_ECC_ED25519_HIGHMEM and for ECDH: CMOX_ECC_CURVE25519. By cutting down the key size to 32 bytes for both public and private the cmox_ecdh function...

antfarmer · 2024-05-21

I missed this section. Wow, got it working. At first I tried running a HKDF routine on the random buffer with extra random salt, but only after multiple retries does it work. Interesting. Any point to running HKDF on the random to improve the "qualit...

antfarmer · 2024-03-25

Ya it works. Exactly the same. Good to know.

antfarmer · 2024-02-15

In case anyone is looking for clocking a timer with the LSE, I found how to route the LSE clock internally. It's just on the next step up MCU: STM32G071 using TIM2, which not available on the G070. Looks like that will simplify the software a bit.

antfarmer · 2024-02-15

So I was able to get this working finally using regular slave trigger mode. I freeze the OC CH2 output after the initial delay, then after long, delay flip the oc mode to inactive on match and the rest works as it should. I'm not sure but in my testi...

User statistics

User Activity

ECDH fails for CURVE25519 using X-CUBE-CRYPTOLIB

Can't generate ECDSA key for Brainpool curves using X-CUBE-CRYPTOLIB

Difference between using logical not operator and comparison to (boolean) constants

How to retrigger an externally triggered timer without changing the output channel state

What is the best way to re-enable SysTick after resuming from sleep, specifically for interrupts?

Re: ECDH fails for CURVE25519 using X-CUBE-CRYPTOLIB

Re: Can't generate ECDSA key for Brainpool curves using X-CUBE-CRYPTOLIB

Re: Difference between using logical not operator and comparison to (boolean) constants

Re: How to retrigger an externally triggered timer without changing the output channel state

Re: How to retrigger an externally triggered timer without changing the output channel state