RSA / AES Key generation

[BSunw.1]

Hello,

I am working with the STM32U585 and am looking for a HAL function to generate RSA key pairs? And AES keys if possible? I see that wolfssl has these functions available but they do not support the STM32U575 / 585 yet. I've seen other posts suggesting to use OpenSSL but I'm worried about how large the library is.

I would like to generate a new set of keys upon every power on to ensure better security as apposed to just using OpenSSL to external generate keys and then input them into the system. Is there any build it functions using the AES or PKA that can generate keys?

Thanks

[Tesla DeLorean]

STM32Cube_FW_U5_V1.1.1\Projects\B-U585I-IOT02A\Applications\SBSFU\SBSFU_Boot\Src\rsa_alt.c

#if defined(MBEDTLS_GENPRIME)
 
/*
 * Generate an RSA key pair
 *
 * This generation method follows the RSA key pair generation procedure of
 * FIPS 186-4 if 2^16 < exponent < 2^256 and nbits = 2048 or nbits = 3072.
 */
int mbedtls_rsa_gen_key( mbedtls_rsa_context *ctx,
                 int (*f_rng)(void *, unsigned char *, size_t),
                 void *p_rng,
                 unsigned int nbits, int exponent )
{
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
    mbedtls_mpi H, G, L;
    int prime_quality = 0;
...

[BSunw.1]

Thanks for the reply! Do you know if there are any tutorials on how to set up mbedtls with STM32CubeIDE? It seems like the F4 devices have this package already added in the .ioc view under Middleware but the U585 does not.

I tried adding an external software package "ARM.mbedTLS.3.1.0.pack" downloaded from https://www.keil.com/dd2/pack/#!#eula-container but there are missing dependencies. Not sure if there is a better way do add the mbedtls package?

[Tesla DeLorean]

That's a bit outside the scope of what I'm doing, using SECP192R1 in directly coded projects.

I'm not sure they are using any of the PKA native functionality of the U5, but there are other things that do. You could at least built the MBEDTLS examples that ST provides to get a feeling for the overall weight of the library. And there's related code on the interwebs using it to better understand the mechanics

[Rajan Soma]

have you got the answer from ST commiunity?