unleashed-firmware/lib/one_wire/maxim_crc.c

#include "maxim_crc.h"
#include <furi.h>

uint8_t maxim_crc8(const uint8_t* data, const uint8_t data_size, const uint8_t crc_init) {
    furi_check(data);

    uint8_t crc = crc_init;

    for(uint8_t index = 0; index < data_size; ++index) {
        uint8_t input_byte = data[index];
        for(uint8_t bit_position = 0; bit_position < 8; ++bit_position) {
            const uint8_t mix = (crc ^ input_byte) & (uint8_t)(0x01);
            crc >>= 1;
            if(mix != 0) crc ^= 0x8C;
            input_byte >>= 1;
        }
    }
    return crc;
}