#ifndef ZF_LOG_LEVEL
    #define ZF_LOG_LEVEL ZF_LOG_VERBOSE
#endif
#define ZF_LOG_DEF_SRCLOC ZF_LOG_SRCLOC_LONG
#define ZF_LOG_TAG "ENTROPY"
#include "zf_log/zf_log.h"

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <linux/random.h>
#include <sys/ioctl.h>

#include "entropy.h"


typedef struct {
    int bit_count;               /* number of bits of entropy in data */
    int byte_count;              /* number of bytes of data in array */
    unsigned char buf[1];
} entropy_t;

//=====================================================
int add_entropy(uint8_t byte)
{
    int rand_fid = open("/dev/urandom", O_RDWR);
    if (rand_fid != 0)
    {
        // error opening device
        ZF_LOGE("Opening /dev/urandom device file failed");
        return -1;
    }

    entropy_t ent = 
	{
		.bit_count = 8,
		.byte_count = 1,
		.buf = {byte},
    };

    if (ioctl(rand_fid, RNDADDENTROPY, &ent) != 0)
    {
        ZF_LOGE("IOCTL to /dev/urandom device file failed");
    }

    if (close(rand_fid) !=0 )
    {
        ZF_LOGE("Closing /dev/urandom device file failed");
        return -1;
    }

    return 0;
}