/*

 * Copyright (C) 2010-2016 Free Software Foundation, Inc.

 * Copyright (C) 2015-2016 Red Hat, Inc.

 * Copyright (C) 2000, 2001, 2008 Niels Möller

 *

 * Author: Nikos Mavrogiannopoulos

 *

 * This file is part of GNUTLS.

 *

 * The GNUTLS library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public License

 * as published by the Free Software Foundation; either version 2.1 of

 * the License, or (at your option) any later version.

 *

 * This library 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

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public License

 * along with this program.  If not, see <https://www.gnu.org/licenses/>

 *

 */

/* Here are the common parts of the random generator layer. 

 * Some of this code was based on the LSH 

 * random generator (the trivia and device source functions for POSIX)

 * and modified to fit gnutls' needs. Relicenced with permission. 

 * Original author Niels Möller.

 */

#include "gnutls_int.h"

#include "errors.h"

#include <locks.h>

#include <num.h>

#include <nettle/yarrow.h>

#include <errno.h>

#include <rnd-common.h>

#include <hash-pjw-bare.h>

#include <sys/types.h>

#include <sys/stat.h>

#include <unistd.h>

/* The windows randomness gatherer.

 */

#include <windows.h>

#include <bcrypt.h>

get_entropy_func _rnd_get_system_entropy = NULL;

static BCRYPT_ALG_HANDLE device_fd = 0;

static

int _rnd_get_system_entropy_win32(void* rnd, size_t size)

{

	NTSTATUS err = BCryptGenRandom(device_fd, rnd, size, 0);

	if (!BCRYPT_SUCCESS(err)) {

		_gnutls_debug_log("Error in BCryptGenRandom: %ld\n", err);

		return GNUTLS_E_RANDOM_DEVICE_ERROR;

	}

	return 0;

}

int _rnd_system_entropy_check(void)

{

	return 0;

}

int _rnd_system_entropy_init(void)

{

	NTSTATUS err = BCryptOpenAlgorithmProvider

	    (&device_fd, BCRYPT_RNG_ALGORITHM, NULL, 0);

	if (!BCRYPT_SUCCESS(err)) {

		_gnutls_debug_log("error in BCryptOpenAlgorithmProvider!\n");

		return GNUTLS_E_RANDOM_DEVICE_ERROR;

	}

	_rnd_get_system_entropy = _rnd_get_system_entropy_win32;

	return 0;

}

void _rnd_system_entropy_deinit(void)

{

	BCryptCloseAlgorithmProvider(device_fd, 0);

}