How to generate random numbers (T)RNG

Mbed OS
2

HI @withthegrid

trng is a True Random Number Generator, and is used to seed the DRBG. It is not recommended to use directly the trng, as it may be biased.

I would suggest you use Mbed Crypto DRBG API, as shown in the example:

static void generate_a_random_value(void)
{
    psa_status_t status;
    uint8_t random[10] = { 0 };

    printf("Generate random...\t");
    fflush(stdout);

    /* Initialize PSA Crypto */
    status = psa_crypto_init();
    if (status != PSA_SUCCESS) {
        printf("Failed to initialize PSA Crypto\n");
        return;
    }

    status = psa_generate_random(random, sizeof(random));
    if (status != PSA_SUCCESS) {
        printf("Failed to generate a random value\n");
        return;
    }

    printf("Generated random data\n");

    /* Clean up */
    mbedtls_psa_crypto_free();
}

Regards,
Mbed Support
Ron