Does the X-CUBE-CRYPTOLIB use crypto hardware of the STM32F7 MCU?

[M Spiessens]

Posted on August 22, 2017 at 10:11

More specifically we are interested in the AES256-GCM algorithm on STM32F777.

Looking at the User Manual (

http://www.st.com/content/ccc/resource/technical/document/user_manual/group0/f9/6e/f2/a2/b4/ec/49/c0/DM00215061/files/DM00215061.pdf/jcr:content/translations/en.DM00215061.pdf

 ) I conclude that for the STM32F756 the crypto hardware is used when using the STM32AccHwCryptoV3.1.0_Xy_C_O.a library.

However, if I look at the actual software (library and headers) I get confused:

The STM32_Crypto library (not HW accelerated) has a Inc/AES/GCM/aes_gcm.h header.

The STM32_Crypto_AccHw variant does not include any header for GCM but Inc/AES/AccHw_aes.h contains the following:

&sharpifdef INCLUDE_AccHw_GCM

&sharpinclude 'GCM/AccHw_aes_gcm.h'

&sharpendif

A header with this filename does not ship with the libraries.

Does anyone have experience with AES-GCM on a STM32 with crypto accelerator?

Best regards,

M

#aes-256 #crypto #stm32-crypto-lib #stm32f7 #aes

[After Forever]

Posted on August 22, 2017 at 11:47

I can confirm that the AccHw_AES_GCM_xxx family of functions are missing from the F7 library. I can't guarantee that it'll work but the F4 library has the AccHw_AES_GCM_xxx functions, and it just might work for F7 too.

[M Spiessens]

Posted on August 24, 2017 at 13:01

Thank you for the suggestion! I've just tested this and can confirm that it works (confirmed for AES128-GCM) using the library for STM32F4 on our STM32F777.