src/random.c


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#include "config.h"

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

#include "logerr.h"
#include "random.h"


int
urandom_bytes(const size_t n, uint8_t (*const addr)[]) {
	int rc = -1;

	FILE *f = NULL;

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

	const size_t read_count = fread(addr, 1, n, f);
	if (ferror(f)) {
		logerr("fread(addr, 1, n, f): %s\n", strerror(errno));
		goto out;
	}
	assert(read_count == n);

	rc = 0;
out:
	if (f != NULL) {
		if (fclose(f)) {
			logerr("fclose(f): %s\n", strerror(errno));
			rc = -1;
		}
	}
	return rc;
}