SDK • Cryptographically Secure Pseudorandom Number Generator

Code:

uint8_t rosc_random_u8(size_t cycles) {    static uint8_t r;    for (size_t i = 0; i < cycles; ++i) {        r = ((r << 1) | rosc_hw->randombit) ^ (r & 0x80 ? POLY : 0);        mp_hal_delay_us_fast(1);    }    return r;}uint32_t rosc_random_u32(void) {    uint32_t value = 0;    for (size_t i = 0; i < 4; ++i) {        value = value << 8 | rosc_random_u8(32);    }    return value;}

Code:

                // we won the race (if any) for the bit, so we collect it locally                samples <<= 1;                samples |= rosc_hw->randombit & 1u;                // use of relative time to now, rather than offset from before makes things                // a bit less predictable at the cost of some speed.                next_sample_time = make_timeout_time_us(PICO_RAND_MIN_ROSC_BIT_SAMPLE_TIME_US);