/*
 * Copyright (C) 2008-2012 Free Software Foundation, Inc.
 *
 * Author: Nikos Mavrogiannopoulos
 *
 * This file is part of GnuTLS.
 *
 * The GnuTLS 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 <http://www.gnu.org/licenses/>
 *
 */

/* This file handles all the internal functions that cope with random data.
 */

#include "gnutls_int.h"
#include "errors.h"
#include <random.h>
#include <fips.h>

void *gnutls_rnd_ctx;

int _gnutls_rnd_init(void)
{
#ifdef ENABLE_FIPS140
	/* The FIPS140 random generator is only enabled when we are compiled
	 * with FIPS support, _and_ the system requires FIPS140.
	 */
	if (_gnutls_fips_mode_enabled() == 1) {
		int ret;

		ret = gnutls_crypto_rnd_register(100, &_gnutls_fips_rnd_ops);
		if (ret < 0)
			return ret;
	}
#endif

	if (_gnutls_rnd_ops.init != NULL) {
		if (_gnutls_rnd_ops.init(&gnutls_rnd_ctx) < 0) {
			gnutls_assert();
			return GNUTLS_E_RANDOM_FAILED;
		}
	}

	return 0;
}

void _gnutls_rnd_deinit(void)
{
	if (_gnutls_rnd_ops.deinit != NULL) {
		_gnutls_rnd_ops.deinit(gnutls_rnd_ctx);
	}

	return;
}

/**
 * gnutls_rnd:
 * @level: a security level
 * @data: place to store random bytes
 * @len: The requested size
 *
 * This function will generate random data and store it to output
 * buffer.
 *
 * This function is thread-safe and also fork-safe.
 *
 * Returns: Zero on success, or a negative error code on error.
 *
 * Since: 2.12.0
 **/
int gnutls_rnd(gnutls_rnd_level_t level, void *data, size_t len)
{
	FAIL_IF_LIB_ERROR;
	return _gnutls_rnd(level, data, len);
}

/**
 * gnutls_rnd_refresh:
 *
 * This function refreshes the random generator state.
 * That is the current precise time, CPU usage, and
 * other values are input into its state.
 *
 * On a slower rate input from /dev/urandom is mixed too.
 *
 * Since: 3.1.7
 **/
void gnutls_rnd_refresh(void)
{
	_gnutls_rnd_refresh();
}