/** * \file doc_rng.h * * \brief Random number generator (RNG) module documentation file. */ /* * * Copyright The Mbed TLS Contributors * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later * * This file is provided under the Apache License 2.0, or the * GNU General Public License v2.0 or later. * * ********** * Apache License 2.0: * * Licensed under the Apache License, Version 2.0 (the "License"); you may * not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * * ********** * * ********** * GNU General Public License v2.0 or later: * * This program 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. * * This program 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 this program; if not, write to the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. * * ********** */ /** * @addtogroup rng_module Random number generator (RNG) module * * The Random number generator (RNG) module provides random number * generation, see \c mbedtls_ctr_drbg_random(). * * The block-cipher counter-mode based deterministic random * bit generator (CTR_DBRG) as specified in NIST SP800-90. It needs an external * source of entropy. For these purposes \c mbedtls_entropy_func() can be used. * This is an implementation based on a simple entropy accumulator design. * * The other number generator that is included is less strong and uses the * HAVEGE (HArdware Volatile Entropy Gathering and Expansion) software heuristic * which considered unsafe for primary usage, but provides additional random * to the entropy pool if enables. * * Meaning that there seems to be no practical algorithm that can guess * the next bit with a probability larger than 1/2 in an output sequence. * * This module can be used to generate random numbers. */