#include <s.h>

#include <assert.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>

#include "logerr.h"

#include "random.h"



static FILE *
FRANDOM = NULL;



int
random_init(void) {
	int rc = -1;

	FRANDOM = fopen("/dev/urandom", "r");
	if (FRANDOM == NULL) {
		logerr("fopen(): %s", strerror(errno));
		goto out;
	}

	rc = 0;
out:
	return rc;
}

int
random_end(void) {
	int rc = -1;

	if (fclose(FRANDOM)) {
		logerr("fclose(): %s", strerror(errno));
		goto out;
	}

	rc = 0;
out:
	FRANDOM = NULL;
	return rc;
}

int
random_bytes(const size_t length, u8 (*const out)[]) {
	int rc = -1;

	assert(FRANDOM != NULL);
	const size_t read_count = fread(out, 1U, length, FRANDOM);
	if (ferror(FRANDOM)) {
		logerr("fread(): %s", strerror(errno));
		goto out;
	}
	assert(read_count == length);

	rc = 0;
out:
	return rc;
}