Computing ECDH shared secret on STM32U585 using HAL_PKA_ECCMul

[Madhu_Kurimeti]

I'm trying to compute the ECDH shared secret by multiplying local private key and other party public key using HAL_PKA_ECCMul. For some reason it is not working. I'm using curve secp256r1. But I'm able to use HAL_PKA_ECCMul to generate public key by multiplying a private key with the secp256r1 generator x and y.

[Tesla DeLorean]

@Jocelyn RICARD 

https://community.st.com/t5/security-mcu/computing-ecdh-shared-secret-on-stm32l562-using-hal-pka-eccmul/td-p/236690

[Madhu_Kurimeti]

@Tesla DeLorean I checked the thread you mentioned, but no one replied with solution in that.

[Tesla DeLorean]

Yes, not sure who has responsibility for supporting this code / library here, so flagging to staff, and linking to a thread of similar issue that this might have been better posting against.

Not sure I'm seeing any code attachment that quickly demonstrates / confirms the issue in either thread, which might go a way to explaining the lack of responses.

[Madhu_Kurimeti · Accepted solution]

I found out that I was initializing the crypto accelerator twice. That's why the issue was happening. Closing this ticket.