Paul Bakker | 37ca75d | 2011-01-06 12:28:03 +0000 | [diff] [blame] | 1 | /** |
| 2 | * @file |
| 3 | * Random number generator (RNG) module documentation file. |
Manuel Pégourié-Gonnard | 8119dad | 2015-08-06 10:59:26 +0200 | [diff] [blame] | 4 | * |
| 5 | * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved |
Manuel Pégourié-Gonnard | 37ff140 | 2015-09-04 14:21:07 +0200 | [diff] [blame] | 6 | * 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-Gonnard | 8119dad | 2015-08-06 10:59:26 +0200 | [diff] [blame] | 19 | * |
| 20 | * This file is part of mbed TLS (https://tls.mbed.org) |
Paul Bakker | 37ca75d | 2011-01-06 12:28:03 +0000 | [diff] [blame] | 21 | */ |
| 22 | |
| 23 | /** |
| 24 | * @addtogroup rng_module Random number generator (RNG) module |
Paul Bakker | 6083fd2 | 2011-12-03 21:45:14 +0000 | [diff] [blame] | 25 | * |
Paul Bakker | dcbfdcc | 2013-09-10 16:16:50 +0200 | [diff] [blame] | 26 | * The Random number generator (RNG) module provides random number |
Simon Butcher | 6e7d3d5 | 2016-01-04 16:09:23 +0000 | [diff] [blame] | 27 | * generation, see \c mbedtls_ctr_drbg_random(). |
Paul Bakker | dcbfdcc | 2013-09-10 16:16:50 +0200 | [diff] [blame] | 28 | * |
| 29 | * The block-cipher counter-mode based deterministic random |
Paul Bakker | 6083fd2 | 2011-12-03 21:45:14 +0000 | [diff] [blame] | 30 | * bit generator (CTR_DBRG) as specified in NIST SP800-90. It needs an external |
Simon Butcher | 6e7d3d5 | 2016-01-04 16:09:23 +0000 | [diff] [blame] | 31 | * 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 Bakker | 6083fd2 | 2011-12-03 21:45:14 +0000 | [diff] [blame] | 33 | * |
Simon Butcher | 6e7d3d5 | 2016-01-04 16:09:23 +0000 | [diff] [blame] | 34 | * The other number generator that is included is less strong and uses the |
| 35 | * HAVEGE (HArdware Volatile Entropy Gathering and Expansion) software heuristic |
Paul Bakker | dcbfdcc | 2013-09-10 16:16:50 +0200 | [diff] [blame] | 36 | * which considered unsafe for primary usage, but provides additional random |
| 37 | * to the entropy pool if enables. |
Paul Bakker | 37ca75d | 2011-01-06 12:28:03 +0000 | [diff] [blame] | 38 | * |
Simon Butcher | 6e7d3d5 | 2016-01-04 16:09:23 +0000 | [diff] [blame] | 39 | * Meaning that there seems to be no practical algorithm that can guess |
Paul Bakker | 37ca75d | 2011-01-06 12:28:03 +0000 | [diff] [blame] | 40 | * 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 | */ |