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Paul Bakker37ca75d2011-01-06 12:28:03 +00001/**
2 * @file
3 * Random number generator (RNG) module documentation file.
Manuel Pégourié-Gonnard8119dad2015-08-06 10:59:26 +02004 *
5 * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
Manuel Pégourié-Gonnard37ff1402015-09-04 14:21:07 +02006 * SPDX-License-Identifier: Apache-2.0
7 *
8 * Licensed under the Apache License, Version 2.0 (the "License"); you may
9 * not use this file except in compliance with the License.
10 * You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing, software
15 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
16 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17 * See the License for the specific language governing permissions and
18 * limitations under the License.
Manuel Pégourié-Gonnard8119dad2015-08-06 10:59:26 +020019 *
20 * This file is part of mbed TLS (https://tls.mbed.org)
Paul Bakker37ca75d2011-01-06 12:28:03 +000021 */
22
23/**
24 * @addtogroup rng_module Random number generator (RNG) module
Paul Bakker6083fd22011-12-03 21:45:14 +000025 *
Paul Bakkerdcbfdcc2013-09-10 16:16:50 +020026 * The Random number generator (RNG) module provides random number
Simon Butcher6e7d3d52016-01-04 16:09:23 +000027 * generation, see \c mbedtls_ctr_drbg_random().
Paul Bakkerdcbfdcc2013-09-10 16:16:50 +020028 *
29 * The block-cipher counter-mode based deterministic random
Paul Bakker6083fd22011-12-03 21:45:14 +000030 * bit generator (CTR_DBRG) as specified in NIST SP800-90. It needs an external
Simon Butcher6e7d3d52016-01-04 16:09:23 +000031 * source of entropy. For these purposes \c mbedtls_entropy_func() can be used.
32 * This is an implementation based on a simple entropy accumulator design.
Paul Bakker6083fd22011-12-03 21:45:14 +000033 *
Simon Butcher6e7d3d52016-01-04 16:09:23 +000034 * The other number generator that is included is less strong and uses the
35 * HAVEGE (HArdware Volatile Entropy Gathering and Expansion) software heuristic
Paul Bakkerdcbfdcc2013-09-10 16:16:50 +020036 * which considered unsafe for primary usage, but provides additional random
37 * to the entropy pool if enables.
Paul Bakker37ca75d2011-01-06 12:28:03 +000038 *
Simon Butcher6e7d3d52016-01-04 16:09:23 +000039 * Meaning that there seems to be no practical algorithm that can guess
Paul Bakker37ca75d2011-01-06 12:28:03 +000040 * the next bit with a probability larger than 1/2 in an output sequence.
41 *
42 * This module can be used to generate random numbers.
43 */