/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set et sw=2 ts=2: */
/***************************************************************************
 *            salt.cc
 *
 *  Sun Jul  5 14:34:25 CEST 2020
 *  Copyright 2020 Bent Bisballe Nyeng
 *  deva@aasimon.org
 ****************************************************************************/

/*
 *  This file is part of Munia.
 *
 *  Munia is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  Munia is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with Munia; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.
 */
#include "salt.h"

#define _GNU_SOURCE 1
#include <linux/random.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <unistd.h>
//#include <errno.h>

Salt getSalt()
{
	Salt salt(16, '\0');

	auto ret = syscall(SYS_getrandom, salt.data(), salt.size(), 1);
	if(ret == -1)
	{
		throw "Could not get random bytes for salt"; // strerror(errno));
	}

	if(ret != (int)salt.size())
	{
		throw "Not enough entropy.";
	}

	return salt;
}