sha256_config.h

#ifndef Sha256_config_h
#define Sha256_config_h

#include <string.h>

#if (defined(__linux) || defined(linux)) && !defined(__ARDUINO_x86__)
        #define SHA256_LINUX
        #include <stdint.h>
        #include <stdio.h>
        #include <stdlib.h>
        #include <sys/time.h>
        #include <unistd.h>
#else
        #include "arduino.h"
#endif

#if  (defined(__linux) || defined(linux)) || defined(__ARDUINO_X86__)
    #define memcpy_P memcpy
    #undef PROGMEM
    #define PROGMEM __attribute__(( section(".progmem.data") ))
    #define pgm_read_dword(p) (*(p))
    #if defined(__ARDUINO_X86__)
        #include "Print.h"
    #endif  
#else
    #include <avr/io.h>
    #include <avr/pgmspace.h>
    #include "Print.h"
#endif

#include <inttypes.h>

#define HASH_LENGTH 32
#define BLOCK_LENGTH 64

#endif