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Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +01001/**
2 * \file hmac_drbg.h
3 *
Gilles Peskinedb6f4142019-09-30 15:01:15 +02004 * \brief The HMAC_DRBG pseudorandom generator.
5 *
6 * This module implements the HMAC_DRBG pseudorandom generator described
7 * in <em>NIST SP 800-90A: Recommendation for Random Number Generation Using
8 * Deterministic Random Bit Generators</em>.
Darryl Greena40a1012018-01-05 15:33:17 +00009 */
10/*
Bence Szépkútia2947ac2020-08-19 16:37:36 +020011 * Copyright The Mbed TLS Contributors
Bence Szépkútif744bd72020-06-05 13:02:18 +020012 * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
13 *
14 * This file is provided under the Apache License 2.0, or the
15 * GNU General Public License v2.0 or later.
16 *
17 * **********
18 * Apache License 2.0:
Manuel Pégourié-Gonnard37ff1402015-09-04 14:21:07 +020019 *
20 * Licensed under the Apache License, Version 2.0 (the "License"); you may
21 * not use this file except in compliance with the License.
22 * You may obtain a copy of the License at
23 *
24 * http://www.apache.org/licenses/LICENSE-2.0
25 *
26 * Unless required by applicable law or agreed to in writing, software
27 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
28 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
29 * See the License for the specific language governing permissions and
30 * limitations under the License.
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +010031 *
Bence Szépkútif744bd72020-06-05 13:02:18 +020032 * **********
33 *
34 * **********
35 * GNU General Public License v2.0 or later:
36 *
37 * This program is free software; you can redistribute it and/or modify
38 * it under the terms of the GNU General Public License as published by
39 * the Free Software Foundation; either version 2 of the License, or
40 * (at your option) any later version.
41 *
42 * This program is distributed in the hope that it will be useful,
43 * but WITHOUT ANY WARRANTY; without even the implied warranty of
44 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
45 * GNU General Public License for more details.
46 *
47 * You should have received a copy of the GNU General Public License along
48 * with this program; if not, write to the Free Software Foundation, Inc.,
49 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
50 *
51 * **********
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +010052 */
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +020053#ifndef MBEDTLS_HMAC_DRBG_H
54#define MBEDTLS_HMAC_DRBG_H
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +010055
Ron Eldor8b0cf2e2018-02-14 16:02:41 +020056#if !defined(MBEDTLS_CONFIG_FILE)
57#include "config.h"
58#else
59#include MBEDTLS_CONFIG_FILE
60#endif
61
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +010062#include "md.h"
63
Manuel Pégourié-Gonnard0a4fb092015-05-07 12:50:31 +010064#if defined(MBEDTLS_THREADING_C)
Ron Eldor6fd941f2017-05-14 16:17:33 +030065#include "threading.h"
Manuel Pégourié-Gonnard0a4fb092015-05-07 12:50:31 +010066#endif
67
Manuel Pégourié-Gonnardfe34a5f2014-01-30 15:06:40 +010068/*
Manuel Pégourié-Gonnard9a6e93e2014-03-11 09:34:02 +010069 * Error codes
Manuel Pégourié-Gonnardfe34a5f2014-01-30 15:06:40 +010070 */
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +020071#define MBEDTLS_ERR_HMAC_DRBG_REQUEST_TOO_BIG -0x0003 /**< Too many random requested in single call. */
72#define MBEDTLS_ERR_HMAC_DRBG_INPUT_TOO_BIG -0x0005 /**< Input too large (Entropy + additional). */
73#define MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR -0x0007 /**< Read/write error in file. */
74#define MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED -0x0009 /**< The entropy source failed. */
Manuel Pégourié-Gonnardfe34a5f2014-01-30 15:06:40 +010075
Paul Bakker088c5c52014-04-25 11:11:10 +020076/**
77 * \name SECTION: Module settings
78 *
79 * The configuration options you can set for this module are in this section.
80 * Either change them in config.h or define them on the compiler command line.
81 * \{
82 */
83
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +020084#if !defined(MBEDTLS_HMAC_DRBG_RESEED_INTERVAL)
85#define MBEDTLS_HMAC_DRBG_RESEED_INTERVAL 10000 /**< Interval before reseed is performed by default */
Paul Bakker088c5c52014-04-25 11:11:10 +020086#endif
87
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +020088#if !defined(MBEDTLS_HMAC_DRBG_MAX_INPUT)
89#define MBEDTLS_HMAC_DRBG_MAX_INPUT 256 /**< Maximum number of additional input bytes */
Paul Bakker088c5c52014-04-25 11:11:10 +020090#endif
91
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +020092#if !defined(MBEDTLS_HMAC_DRBG_MAX_REQUEST)
93#define MBEDTLS_HMAC_DRBG_MAX_REQUEST 1024 /**< Maximum number of requested bytes per call */
Paul Bakker088c5c52014-04-25 11:11:10 +020094#endif
95
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +020096#if !defined(MBEDTLS_HMAC_DRBG_MAX_SEED_INPUT)
97#define MBEDTLS_HMAC_DRBG_MAX_SEED_INPUT 384 /**< Maximum size of (re)seed buffer */
Paul Bakker088c5c52014-04-25 11:11:10 +020098#endif
99
100/* \} name SECTION: Module settings */
Manuel Pégourié-Gonnardfe34a5f2014-01-30 15:06:40 +0100101
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200102#define MBEDTLS_HMAC_DRBG_PR_OFF 0 /**< No prediction resistance */
103#define MBEDTLS_HMAC_DRBG_PR_ON 1 /**< Prediction resistance enabled */
Manuel Pégourié-Gonnardaf786ff2014-01-30 18:44:18 +0100104
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100105#ifdef __cplusplus
106extern "C" {
107#endif
108
Manuel Pégourié-Gonnardfe34a5f2014-01-30 15:06:40 +0100109/**
110 * HMAC_DRBG context.
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100111 */
Dawid Drozd428cc522018-07-24 10:02:47 +0200112typedef struct mbedtls_hmac_drbg_context
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100113{
Antonin Décimod5f47592019-01-23 15:24:37 +0100114 /* Working state: the key K is not stored explicitly,
Manuel Pégourié-Gonnardb05db2a2014-02-01 11:38:05 +0100115 * but is implied by the HMAC context */
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200116 mbedtls_md_context_t md_ctx; /*!< HMAC context (inc. K) */
117 unsigned char V[MBEDTLS_MD_MAX_SIZE]; /*!< V in the spec */
Manuel Pégourié-Gonnardb05db2a2014-02-01 11:38:05 +0100118 int reseed_counter; /*!< reseed counter */
Manuel Pégourié-Gonnardfe34a5f2014-01-30 15:06:40 +0100119
Manuel Pégourié-Gonnard658dbed2014-01-30 19:03:45 +0100120 /* Administrative state */
Manuel Pégourié-Gonnardfe34a5f2014-01-30 15:06:40 +0100121 size_t entropy_len; /*!< entropy bytes grabbed on each (re)seed */
Manuel Pégourié-Gonnardaf786ff2014-01-30 18:44:18 +0100122 int prediction_resistance; /*!< enable prediction resistance (Automatic
123 reseed before every random generation) */
Manuel Pégourié-Gonnard658dbed2014-01-30 19:03:45 +0100124 int reseed_interval; /*!< reseed interval */
Manuel Pégourié-Gonnardfe34a5f2014-01-30 15:06:40 +0100125
Manuel Pégourié-Gonnard658dbed2014-01-30 19:03:45 +0100126 /* Callbacks */
Manuel Pégourié-Gonnardaf786ff2014-01-30 18:44:18 +0100127 int (*f_entropy)(void *, unsigned char *, size_t); /*!< entropy function */
128 void *p_entropy; /*!< context for the entropy function */
Manuel Pégourié-Gonnard0a4fb092015-05-07 12:50:31 +0100129
130#if defined(MBEDTLS_THREADING_C)
Gilles Peskineb5e295d2021-02-09 18:43:33 +0100131 /* Invariant: the mutex is initialized if and only if
132 * md_ctx->md_info != NULL. This means that the mutex is initialized
133 * during the initial seeding in mbedtls_hmac_drbg_seed() or
134 * mbedtls_hmac_drbg_seed_buf() and freed in mbedtls_ctr_drbg_free().
135 *
136 * Note that this invariant may change without notice. Do not rely on it
137 * and do not access the mutex directly in application code.
138 */
Manuel Pégourié-Gonnard0a4fb092015-05-07 12:50:31 +0100139 mbedtls_threading_mutex_t mutex;
140#endif
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200141} mbedtls_hmac_drbg_context;
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100142
143/**
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200144 * \brief HMAC_DRBG context initialization.
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100145 *
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200146 * This function makes the context ready for mbedtls_hmac_drbg_seed(),
147 * mbedtls_hmac_drbg_seed_buf() or mbedtls_hmac_drbg_free().
148 *
Gavin Acquroff77cb30c2020-03-01 17:06:11 -0800149 * \note The reseed interval is #MBEDTLS_HMAC_DRBG_RESEED_INTERVAL
150 * by default. Override this value by calling
151 * mbedtls_hmac_drbg_set_reseed_interval().
152 *
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200153 * \param ctx HMAC_DRBG context to be initialized.
Manuel Pégourié-Gonnardf9e94812015-04-28 22:07:14 +0200154 */
155void mbedtls_hmac_drbg_init( mbedtls_hmac_drbg_context *ctx );
156
157/**
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200158 * \brief HMAC_DRBG initial seeding.
Manuel Pégourié-Gonnardf9e94812015-04-28 22:07:14 +0200159 *
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200160 * Set the initial seed and set up the entropy source for future reseeds.
161 *
Gilles Peskine0b5e8042019-09-30 15:20:52 +0200162 * A typical choice for the \p f_entropy and \p p_entropy parameters is
163 * to use the entropy module:
164 * - \p f_entropy is mbedtls_entropy_func();
165 * - \p p_entropy is an instance of ::mbedtls_entropy_context initialized
166 * with mbedtls_entropy_init() (which registers the platform's default
167 * entropy sources).
168 *
Gilles Peskine9fb45182019-10-01 18:39:45 +0200169 * You can provide a personalization string in addition to the
170 * entropy source, to make this instantiation as unique as possible.
171 *
Gilles Peskine0b5e8042019-09-30 15:20:52 +0200172 * \note By default, the security strength as defined by NIST is:
173 * - 128 bits if \p md_info is SHA-1;
174 * - 192 bits if \p md_info is SHA-224;
175 * - 256 bits if \p md_info is SHA-256, SHA-384 or SHA-512.
176 * Note that SHA-256 is just as efficient as SHA-224.
177 * The security strength can be reduced if a smaller
178 * entropy length is set with
Gilles Peskinec68b70c2019-10-04 11:47:35 +0200179 * mbedtls_hmac_drbg_set_entropy_len().
Gilles Peskine0b5e8042019-09-30 15:20:52 +0200180 *
Gilles Peskinec68b70c2019-10-04 11:47:35 +0200181 * \note The default entropy length is the security strength
182 * (converted from bits to bytes). You can override
183 * it by calling mbedtls_hmac_drbg_set_entropy_len().
Gilles Peskine0b5e8042019-09-30 15:20:52 +0200184 *
185 * \note During the initial seeding, this function calls
186 * the entropy source to obtain a nonce
187 * whose length is half the entropy length.
188 *
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200189 * \param ctx HMAC_DRBG context to be seeded.
190 * \param md_info MD algorithm to use for HMAC_DRBG.
191 * \param f_entropy The entropy callback, taking as arguments the
192 * \p p_entropy context, the buffer to fill, and the
193 * length of the buffer.
Gilles Peskine8b424392019-10-04 11:52:22 +0200194 * \p f_entropy is always called with a length that is
195 * less than or equal to the entropy length.
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200196 * \param p_entropy The entropy context to pass to \p f_entropy.
Gilles Peskine9fb45182019-10-01 18:39:45 +0200197 * \param custom The personalization string.
198 * This can be \c NULL, in which case the personalization
199 * string is empty regardless of the value of \p len.
200 * \param len The length of the personalization string.
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200201 * This must be at most #MBEDTLS_HMAC_DRBG_MAX_INPUT
202 * and also at most
203 * #MBEDTLS_HMAC_DRBG_MAX_SEED_INPUT - \p entropy_len * 3 / 2
204 * where \p entropy_len is the entropy length
Gilles Peskine0b5e8042019-09-30 15:20:52 +0200205 * described above.
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100206 *
Gilles Peskine759c91d2019-10-01 18:30:02 +0200207 * \return \c 0 if successful.
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200208 * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA if \p md_info is
209 * invalid.
210 * \return #MBEDTLS_ERR_MD_ALLOC_FAILED if there was not enough
211 * memory to allocate context data.
212 * \return #MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED
213 * if the call to \p f_entropy failed.
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100214 */
Manuel Pégourié-Gonnardf9e94812015-04-28 22:07:14 +0200215int mbedtls_hmac_drbg_seed( mbedtls_hmac_drbg_context *ctx,
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200216 const mbedtls_md_info_t * md_info,
Manuel Pégourié-Gonnardfe34a5f2014-01-30 15:06:40 +0100217 int (*f_entropy)(void *, unsigned char *, size_t),
218 void *p_entropy,
219 const unsigned char *custom,
220 size_t len );
221
222/**
Manuel Pégourié-Gonnard4e669c62014-01-30 18:06:08 +0100223 * \brief Initilisation of simpified HMAC_DRBG (never reseeds).
Manuel Pégourié-Gonnardfe34a5f2014-01-30 15:06:40 +0100224 *
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200225 * This function is meant for use in algorithms that need a pseudorandom
226 * input such as deterministic ECDSA.
Manuel Pégourié-Gonnardfe34a5f2014-01-30 15:06:40 +0100227 *
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200228 * \param ctx HMAC_DRBG context to be initialised.
229 * \param md_info MD algorithm to use for HMAC_DRBG.
230 * \param data Concatenation of the initial entropy string and
231 * the additional data.
232 * \param data_len Length of \p data in bytes.
233 *
Gilles Peskine759c91d2019-10-01 18:30:02 +0200234 * \return \c 0 if successful. or
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200235 * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA if \p md_info is
236 * invalid.
237 * \return #MBEDTLS_ERR_MD_ALLOC_FAILED if there was not enough
238 * memory to allocate context data.
Manuel Pégourié-Gonnardfe34a5f2014-01-30 15:06:40 +0100239 */
Manuel Pégourié-Gonnardf9e94812015-04-28 22:07:14 +0200240int mbedtls_hmac_drbg_seed_buf( mbedtls_hmac_drbg_context *ctx,
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200241 const mbedtls_md_info_t * md_info,
Manuel Pégourié-Gonnardfe34a5f2014-01-30 15:06:40 +0100242 const unsigned char *data, size_t data_len );
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100243
244/**
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200245 * \brief This function turns prediction resistance on or off.
246 * The default value is off.
Manuel Pégourié-Gonnardaf786ff2014-01-30 18:44:18 +0100247 *
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200248 * \note If enabled, entropy is gathered at the beginning of
249 * every call to mbedtls_hmac_drbg_random_with_add()
250 * or mbedtls_hmac_drbg_random().
251 * Only use this if your entropy source has sufficient
252 * throughput.
Manuel Pégourié-Gonnardaf786ff2014-01-30 18:44:18 +0100253 *
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200254 * \param ctx The HMAC_DRBG context.
255 * \param resistance #MBEDTLS_HMAC_DRBG_PR_ON or #MBEDTLS_HMAC_DRBG_PR_OFF.
Manuel Pégourié-Gonnardaf786ff2014-01-30 18:44:18 +0100256 */
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200257void mbedtls_hmac_drbg_set_prediction_resistance( mbedtls_hmac_drbg_context *ctx,
Manuel Pégourié-Gonnardaf786ff2014-01-30 18:44:18 +0100258 int resistance );
259
260/**
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200261 * \brief This function sets the amount of entropy grabbed on each
Gilles Peskinec68b70c2019-10-04 11:47:35 +0200262 * seed or reseed.
Manuel Pégourié-Gonnard4e669c62014-01-30 18:06:08 +0100263 *
Gilles Peskinec68b70c2019-10-04 11:47:35 +0200264 * See the documentation of mbedtls_hmac_drbg_seed() for the default value.
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200265 *
266 * \param ctx The HMAC_DRBG context.
267 * \param len The amount of entropy to grab, in bytes.
Manuel Pégourié-Gonnard4e669c62014-01-30 18:06:08 +0100268 */
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200269void mbedtls_hmac_drbg_set_entropy_len( mbedtls_hmac_drbg_context *ctx,
Manuel Pégourié-Gonnard4e669c62014-01-30 18:06:08 +0100270 size_t len );
271
272/**
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200273 * \brief Set the reseed interval.
Manuel Pégourié-Gonnard658dbed2014-01-30 19:03:45 +0100274 *
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200275 * The reseed interval is the number of calls to mbedtls_hmac_drbg_random()
276 * or mbedtls_hmac_drbg_random_with_add() after which the entropy function
277 * is called again.
278 *
279 * The default value is #MBEDTLS_HMAC_DRBG_RESEED_INTERVAL.
280 *
281 * \param ctx The HMAC_DRBG context.
282 * \param interval The reseed interval.
Manuel Pégourié-Gonnard658dbed2014-01-30 19:03:45 +0100283 */
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200284void mbedtls_hmac_drbg_set_reseed_interval( mbedtls_hmac_drbg_context *ctx,
Manuel Pégourié-Gonnard658dbed2014-01-30 19:03:45 +0100285 int interval );
286
287/**
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200288 * \brief This function updates the state of the HMAC_DRBG context.
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100289 *
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200290 * \param ctx The HMAC_DRBG context.
291 * \param additional The data to update the state with.
Gilles Peskine759c91d2019-10-01 18:30:02 +0200292 * If this is \c NULL, there is no additional data.
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200293 * \param add_len Length of \p additional in bytes.
Gilles Peskine759c91d2019-10-01 18:30:02 +0200294 * Unused if \p additional is \c NULL.
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100295 *
Gilles Peskinee0e9c572018-09-11 16:47:16 +0200296 * \return \c 0 on success, or an error from the underlying
297 * hash calculation.
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100298 */
Gilles Peskinee0e9c572018-09-11 16:47:16 +0200299int mbedtls_hmac_drbg_update_ret( mbedtls_hmac_drbg_context *ctx,
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100300 const unsigned char *additional, size_t add_len );
301
302/**
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200303 * \brief This function reseeds the HMAC_DRBG context, that is
304 * extracts data from the entropy source.
Manuel Pégourié-Gonnard8fc484d2014-01-30 18:28:09 +0100305 *
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200306 * \param ctx The HMAC_DRBG context.
307 * \param additional Additional data to add to the state.
308 * If this is \c NULL, there is no additional data
309 * and \p len should be \c 0.
310 * \param len The length of the additional data.
311 * This must be at most #MBEDTLS_HMAC_DRBG_MAX_INPUT
312 * and also at most
313 * #MBEDTLS_HMAC_DRBG_MAX_SEED_INPUT - \p entropy_len
314 * where \p entropy_len is the entropy length
315 * (see mbedtls_hmac_drbg_set_entropy_len()).
Manuel Pégourié-Gonnard8fc484d2014-01-30 18:28:09 +0100316 *
Gilles Peskine759c91d2019-10-01 18:30:02 +0200317 * \return \c 0 if successful.
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200318 * \return #MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED
319 * if a call to the entropy function failed.
Manuel Pégourié-Gonnard8fc484d2014-01-30 18:28:09 +0100320 */
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200321int mbedtls_hmac_drbg_reseed( mbedtls_hmac_drbg_context *ctx,
Manuel Pégourié-Gonnard8fc484d2014-01-30 18:28:09 +0100322 const unsigned char *additional, size_t len );
323
324/**
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200325 * \brief This function updates an HMAC_DRBG instance with additional
326 * data and uses it to generate random data.
Manuel Pégourié-Gonnard8208d162014-01-30 12:19:26 +0100327 *
Gilles Peskine3f9c9732019-10-01 18:31:28 +0200328 * This function automatically reseeds if the reseed counter is exceeded
329 * or prediction resistance is enabled.
Manuel Pégourié-Gonnard8208d162014-01-30 12:19:26 +0100330 *
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200331 * \param p_rng The HMAC_DRBG context. This must be a pointer to a
332 * #mbedtls_hmac_drbg_context structure.
333 * \param output The buffer to fill.
334 * \param output_len The length of the buffer in bytes.
335 * This must be at most #MBEDTLS_HMAC_DRBG_MAX_REQUEST.
336 * \param additional Additional data to update with.
Gilles Peskine759c91d2019-10-01 18:30:02 +0200337 * If this is \c NULL, there is no additional data
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200338 * and \p add_len should be \c 0.
339 * \param add_len The length of the additional data.
340 * This must be at most #MBEDTLS_HMAC_DRBG_MAX_INPUT.
Manuel Pégourié-Gonnard8208d162014-01-30 12:19:26 +0100341 *
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200342 * \return \c 0 if successful.
343 * \return #MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED
344 * if a call to the entropy source failed.
345 * \return #MBEDTLS_ERR_HMAC_DRBG_REQUEST_TOO_BIG if
346 * \p output_len > #MBEDTLS_HMAC_DRBG_MAX_REQUEST.
347 * \return #MBEDTLS_ERR_HMAC_DRBG_INPUT_TOO_BIG if
348 * \p add_len > #MBEDTLS_HMAC_DRBG_MAX_INPUT.
Manuel Pégourié-Gonnard8208d162014-01-30 12:19:26 +0100349 */
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200350int mbedtls_hmac_drbg_random_with_add( void *p_rng,
Manuel Pégourié-Gonnard8208d162014-01-30 12:19:26 +0100351 unsigned char *output, size_t output_len,
352 const unsigned char *additional,
353 size_t add_len );
354
355/**
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200356 * \brief This function uses HMAC_DRBG to generate random data.
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100357 *
Gilles Peskine3f9c9732019-10-01 18:31:28 +0200358 * This function automatically reseeds if the reseed counter is exceeded
359 * or prediction resistance is enabled.
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100360 *
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200361 * \param p_rng The HMAC_DRBG context. This must be a pointer to a
362 * #mbedtls_hmac_drbg_context structure.
363 * \param output The buffer to fill.
364 * \param out_len The length of the buffer in bytes.
365 * This must be at most #MBEDTLS_HMAC_DRBG_MAX_REQUEST.
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100366 *
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200367 * \return \c 0 if successful.
368 * \return #MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED
369 * if a call to the entropy source failed.
370 * \return #MBEDTLS_ERR_HMAC_DRBG_REQUEST_TOO_BIG if
371 * \p out_len > #MBEDTLS_HMAC_DRBG_MAX_REQUEST.
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100372 */
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200373int mbedtls_hmac_drbg_random( void *p_rng, unsigned char *output, size_t out_len );
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100374
375/**
Gavin Acquroff77cb30c2020-03-01 17:06:11 -0800376 * \brief This function resets HMAC_DRBG context to the state immediately
377 * after initial call of mbedtls_hmac_drbg_init().
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100378 *
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200379 * \param ctx The HMAC_DRBG context to free.
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100380 */
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200381void mbedtls_hmac_drbg_free( mbedtls_hmac_drbg_context *ctx );
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100382
Gilles Peskinee0e9c572018-09-11 16:47:16 +0200383#if ! defined(MBEDTLS_DEPRECATED_REMOVED)
384#if defined(MBEDTLS_DEPRECATED_WARNING)
385#define MBEDTLS_DEPRECATED __attribute__((deprecated))
386#else
387#define MBEDTLS_DEPRECATED
388#endif
389/**
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200390 * \brief This function updates the state of the HMAC_DRBG context.
Gilles Peskinee0e9c572018-09-11 16:47:16 +0200391 *
392 * \deprecated Superseded by mbedtls_hmac_drbg_update_ret()
393 * in 2.16.0.
394 *
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200395 * \param ctx The HMAC_DRBG context.
396 * \param additional The data to update the state with.
Gilles Peskine759c91d2019-10-01 18:30:02 +0200397 * If this is \c NULL, there is no additional data.
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200398 * \param add_len Length of \p additional in bytes.
Gilles Peskine759c91d2019-10-01 18:30:02 +0200399 * Unused if \p additional is \c NULL.
Gilles Peskinee0e9c572018-09-11 16:47:16 +0200400 */
401MBEDTLS_DEPRECATED void mbedtls_hmac_drbg_update(
402 mbedtls_hmac_drbg_context *ctx,
403 const unsigned char *additional, size_t add_len );
404#undef MBEDTLS_DEPRECATED
405#endif /* !MBEDTLS_DEPRECATED_REMOVED */
406
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200407#if defined(MBEDTLS_FS_IO)
Manuel Pégourié-Gonnard48bc3e82014-01-30 21:11:16 +0100408/**
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200409 * \brief This function writes a seed file.
Manuel Pégourié-Gonnard48bc3e82014-01-30 21:11:16 +0100410 *
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200411 * \param ctx The HMAC_DRBG context.
412 * \param path The name of the file.
Manuel Pégourié-Gonnard48bc3e82014-01-30 21:11:16 +0100413 *
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200414 * \return \c 0 on success.
415 * \return #MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR on file error.
416 * \return #MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED on reseed
417 * failure.
Manuel Pégourié-Gonnard48bc3e82014-01-30 21:11:16 +0100418 */
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200419int mbedtls_hmac_drbg_write_seed_file( mbedtls_hmac_drbg_context *ctx, const char *path );
Manuel Pégourié-Gonnard48bc3e82014-01-30 21:11:16 +0100420
421/**
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200422 * \brief This function reads and updates a seed file. The seed
423 * is added to this instance.
Manuel Pégourié-Gonnard48bc3e82014-01-30 21:11:16 +0100424 *
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200425 * \param ctx The HMAC_DRBG context.
426 * \param path The name of the file.
Manuel Pégourié-Gonnard48bc3e82014-01-30 21:11:16 +0100427 *
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200428 * \return \c 0 on success.
429 * \return #MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR on file error.
430 * \return #MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED on
431 * reseed failure.
432 * \return #MBEDTLS_ERR_HMAC_DRBG_INPUT_TOO_BIG if the existing
433 * seed file is too large.
Manuel Pégourié-Gonnard48bc3e82014-01-30 21:11:16 +0100434 */
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200435int mbedtls_hmac_drbg_update_seed_file( mbedtls_hmac_drbg_context *ctx, const char *path );
436#endif /* MBEDTLS_FS_IO */
Manuel Pégourié-Gonnard48bc3e82014-01-30 21:11:16 +0100437
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100438
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200439#if defined(MBEDTLS_SELF_TEST)
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100440/**
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200441 * \brief The HMAC_DRBG Checkup routine.
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100442 *
Gilles Peskinedb6f4142019-09-30 15:01:15 +0200443 * \return \c 0 if successful.
444 * \return \c 1 if the test failed.
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100445 */
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200446int mbedtls_hmac_drbg_self_test( int verbose );
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100447#endif
448
449#ifdef __cplusplus
450}
451#endif
452
453#endif /* hmac_drbg.h */