blob: cd23a16af62809ac95f7682958f40c5111581aa6 [file] [log] [blame]
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +01001/**
2 * \file hmac_drbg.h
3 *
Gilles Peskineeb99c102019-10-02 18:56:17 +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 Szépkúti44bfbe32020-08-19 16:54:51 +020011 * Copyright The Mbed TLS Contributors
Bence Szépkúti4e9f7122020-06-05 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 Szépkúti4e9f7122020-06-05 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 Eldor0559c662018-02-14 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 Eldordf9b93e2017-05-14 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 */
112typedef struct
113{
Antonin Décimo8fd91562019-01-23 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)
131 mbedtls_threading_mutex_t mutex;
132#endif
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200133} mbedtls_hmac_drbg_context;
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100134
135/**
Gilles Peskined8917302019-10-02 19:00:06 +0200136 * \brief HMAC_DRBG context initialization.
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100137 *
Gilles Peskined8917302019-10-02 19:00:06 +0200138 * This function makes the context ready for mbedtls_hmac_drbg_seed(),
139 * mbedtls_hmac_drbg_seed_buf() or mbedtls_hmac_drbg_free().
140 *
Gavin Acquroffceb99902020-03-01 17:06:11 -0800141 * \note The reseed interval is #MBEDTLS_HMAC_DRBG_RESEED_INTERVAL
142 * by default. Override this value by calling
143 * mbedtls_hmac_drbg_set_reseed_interval().
144 *
Gilles Peskined8917302019-10-02 19:00:06 +0200145 * \param ctx HMAC_DRBG context to be initialized.
Manuel Pégourié-Gonnardf9e94812015-04-28 22:07:14 +0200146 */
147void mbedtls_hmac_drbg_init( mbedtls_hmac_drbg_context *ctx );
148
149/**
Gilles Peskined8917302019-10-02 19:00:06 +0200150 * \brief HMAC_DRBG initial seeding.
Manuel Pégourié-Gonnardf9e94812015-04-28 22:07:14 +0200151 *
Gilles Peskined8917302019-10-02 19:00:06 +0200152 * Set the initial seed and set up the entropy source for future reseeds.
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100153 *
Gilles Peskineb9cfe582019-10-02 19:00:57 +0200154 * A typical choice for the \p f_entropy and \p p_entropy parameters is
155 * to use the entropy module:
156 * - \p f_entropy is mbedtls_entropy_func();
157 * - \p p_entropy is an instance of ::mbedtls_entropy_context initialized
158 * with mbedtls_entropy_init() (which registers the platform's default
159 * entropy sources).
160 *
Gilles Peskined8917302019-10-02 19:00:06 +0200161 * You can provide a personalization string in addition to the
162 * entropy source, to make this instantiation as unique as possible.
163 *
164 * \note By default, the security strength as defined by NIST is:
165 * - 128 bits if \p md_info is SHA-1;
166 * - 192 bits if \p md_info is SHA-224;
167 * - 256 bits if \p md_info is SHA-256, SHA-384 or SHA-512.
Manuel Pégourié-Gonnardfe34a5f2014-01-30 15:06:40 +0100168 * Note that SHA-256 is just as efficient as SHA-224.
Gilles Peskined8917302019-10-02 19:00:06 +0200169 * The security strength can be reduced if a smaller
170 * entropy length is set with
Gilles Peskine9c742242019-10-04 11:47:35 +0200171 * mbedtls_hmac_drbg_set_entropy_len().
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100172 *
Gilles Peskine9c742242019-10-04 11:47:35 +0200173 * \note The default entropy length is the security strength
174 * (converted from bits to bytes). You can override
175 * it by calling mbedtls_hmac_drbg_set_entropy_len().
Gilles Peskined8917302019-10-02 19:00:06 +0200176 *
177 * \note During the initial seeding, this function calls
178 * the entropy source to obtain a nonce
179 * whose length is half the entropy length.
180 *
181 * \param ctx HMAC_DRBG context to be seeded.
182 * \param md_info MD algorithm to use for HMAC_DRBG.
183 * \param f_entropy The entropy callback, taking as arguments the
184 * \p p_entropy context, the buffer to fill, and the
185 * length of the buffer.
Gilles Peskine55e120b2019-10-04 11:52:22 +0200186 * \p f_entropy is always called with a length that is
187 * less than or equal to the entropy length.
Gilles Peskined8917302019-10-02 19:00:06 +0200188 * \param p_entropy The entropy context to pass to \p f_entropy.
189 * \param custom The personalization string.
190 * This can be \c NULL, in which case the personalization
191 * string is empty regardless of the value of \p len.
192 * \param len The length of the personalization string.
193 * This must be at most #MBEDTLS_HMAC_DRBG_MAX_INPUT
194 * and also at most
195 * #MBEDTLS_HMAC_DRBG_MAX_SEED_INPUT - \p entropy_len * 3 / 2
196 * where \p entropy_len is the entropy length
197 * described above.
198 *
199 * \return \c 0 if successful.
200 * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA if \p md_info is
201 * invalid.
202 * \return #MBEDTLS_ERR_MD_ALLOC_FAILED if there was not enough
203 * memory to allocate context data.
204 * \return #MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED
205 * if the call to \p f_entropy failed.
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100206 */
Manuel Pégourié-Gonnardf9e94812015-04-28 22:07:14 +0200207int mbedtls_hmac_drbg_seed( mbedtls_hmac_drbg_context *ctx,
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200208 const mbedtls_md_info_t * md_info,
Manuel Pégourié-Gonnardfe34a5f2014-01-30 15:06:40 +0100209 int (*f_entropy)(void *, unsigned char *, size_t),
210 void *p_entropy,
211 const unsigned char *custom,
212 size_t len );
213
214/**
Manuel Pégourié-Gonnard4e669c62014-01-30 18:06:08 +0100215 * \brief Initilisation of simpified HMAC_DRBG (never reseeds).
Manuel Pégourié-Gonnardfe34a5f2014-01-30 15:06:40 +0100216 *
Gilles Peskined8917302019-10-02 19:00:06 +0200217 * This function is meant for use in algorithms that need a pseudorandom
218 * input such as deterministic ECDSA.
Manuel Pégourié-Gonnardfe34a5f2014-01-30 15:06:40 +0100219 *
Gilles Peskined8917302019-10-02 19:00:06 +0200220 * \param ctx HMAC_DRBG context to be initialised.
221 * \param md_info MD algorithm to use for HMAC_DRBG.
222 * \param data Concatenation of the initial entropy string and
223 * the additional data.
224 * \param data_len Length of \p data in bytes.
225 *
226 * \return \c 0 if successful. or
227 * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA if \p md_info is
228 * invalid.
229 * \return #MBEDTLS_ERR_MD_ALLOC_FAILED if there was not enough
230 * memory to allocate context data.
Manuel Pégourié-Gonnardfe34a5f2014-01-30 15:06:40 +0100231 */
Manuel Pégourié-Gonnardf9e94812015-04-28 22:07:14 +0200232int mbedtls_hmac_drbg_seed_buf( mbedtls_hmac_drbg_context *ctx,
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200233 const mbedtls_md_info_t * md_info,
Manuel Pégourié-Gonnardfe34a5f2014-01-30 15:06:40 +0100234 const unsigned char *data, size_t data_len );
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100235
236/**
Gilles Peskined8917302019-10-02 19:00:06 +0200237 * \brief This function turns prediction resistance on or off.
238 * The default value is off.
Manuel Pégourié-Gonnardaf786ff2014-01-30 18:44:18 +0100239 *
Gilles Peskined8917302019-10-02 19:00:06 +0200240 * \note If enabled, entropy is gathered at the beginning of
241 * every call to mbedtls_hmac_drbg_random_with_add()
242 * or mbedtls_hmac_drbg_random().
243 * Only use this if your entropy source has sufficient
244 * throughput.
Manuel Pégourié-Gonnardaf786ff2014-01-30 18:44:18 +0100245 *
Gilles Peskined8917302019-10-02 19:00:06 +0200246 * \param ctx The HMAC_DRBG context.
247 * \param resistance #MBEDTLS_HMAC_DRBG_PR_ON or #MBEDTLS_HMAC_DRBG_PR_OFF.
Manuel Pégourié-Gonnardaf786ff2014-01-30 18:44:18 +0100248 */
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200249void mbedtls_hmac_drbg_set_prediction_resistance( mbedtls_hmac_drbg_context *ctx,
Manuel Pégourié-Gonnardaf786ff2014-01-30 18:44:18 +0100250 int resistance );
251
252/**
Gilles Peskined8917302019-10-02 19:00:06 +0200253 * \brief This function sets the amount of entropy grabbed on each
Gilles Peskine9c742242019-10-04 11:47:35 +0200254 * seed or reseed.
Manuel Pégourié-Gonnard4e669c62014-01-30 18:06:08 +0100255 *
Gilles Peskine9c742242019-10-04 11:47:35 +0200256 * See the documentation of mbedtls_hmac_drbg_seed() for the default value.
Gilles Peskined8917302019-10-02 19:00:06 +0200257 *
258 * \param ctx The HMAC_DRBG context.
259 * \param len The amount of entropy to grab, in bytes.
Manuel Pégourié-Gonnard4e669c62014-01-30 18:06:08 +0100260 */
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200261void mbedtls_hmac_drbg_set_entropy_len( mbedtls_hmac_drbg_context *ctx,
Manuel Pégourié-Gonnard4e669c62014-01-30 18:06:08 +0100262 size_t len );
263
264/**
Gilles Peskined8917302019-10-02 19:00:06 +0200265 * \brief Set the reseed interval.
Manuel Pégourié-Gonnard658dbed2014-01-30 19:03:45 +0100266 *
Gilles Peskined8917302019-10-02 19:00:06 +0200267 * The reseed interval is the number of calls to mbedtls_hmac_drbg_random()
268 * or mbedtls_hmac_drbg_random_with_add() after which the entropy function
269 * is called again.
270 *
271 * The default value is #MBEDTLS_HMAC_DRBG_RESEED_INTERVAL.
272 *
273 * \param ctx The HMAC_DRBG context.
274 * \param interval The reseed interval.
Manuel Pégourié-Gonnard658dbed2014-01-30 19:03:45 +0100275 */
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200276void mbedtls_hmac_drbg_set_reseed_interval( mbedtls_hmac_drbg_context *ctx,
Manuel Pégourié-Gonnard658dbed2014-01-30 19:03:45 +0100277 int interval );
278
279/**
Gilles Peskined8917302019-10-02 19:00:06 +0200280 * \brief This function updates the state of the HMAC_DRBG context.
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100281 *
Gilles Peskined8917302019-10-02 19:00:06 +0200282 * \param ctx The HMAC_DRBG context.
283 * \param additional The data to update the state with.
284 * If this is \c NULL, there is no additional data.
285 * \param add_len Length of \p additional in bytes.
286 * Unused if \p additional is \c NULL.
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100287 *
Gilles Peskine4d237572018-09-13 22:19:57 +0200288 * \return \c 0 on success, or an error from the underlying
289 * hash calculation.
Gilles Peskine4d237572018-09-13 22:19:57 +0200290 */
291int mbedtls_hmac_drbg_update_ret( mbedtls_hmac_drbg_context *ctx,
292 const unsigned char *additional, size_t add_len );
293
294/**
295 * \brief HMAC_DRBG update state
296 *
297 * \warning This function cannot report errors. You should use
298 * mbedtls_hmac_drbg_update_ret() instead.
299 *
300 * \param ctx HMAC_DRBG context
301 * \param additional Additional data to update state with, or NULL
302 * \param add_len Length of additional data, or 0
303 *
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100304 * \note Additional data is optional, pass NULL and 0 as second
305 * third argument if no additional data is being used.
306 */
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200307void mbedtls_hmac_drbg_update( mbedtls_hmac_drbg_context *ctx,
Gilles Peskine4d237572018-09-13 22:19:57 +0200308 const unsigned char *additional,
309 size_t add_len );
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100310
311/**
Gilles Peskined8917302019-10-02 19:00:06 +0200312 * \brief This function reseeds the HMAC_DRBG context, that is
313 * extracts data from the entropy source.
Manuel Pégourié-Gonnard8fc484d2014-01-30 18:28:09 +0100314 *
Gilles Peskined8917302019-10-02 19:00:06 +0200315 * \param ctx The HMAC_DRBG context.
316 * \param additional Additional data to add to the state.
317 * If this is \c NULL, there is no additional data
318 * and \p len should be \c 0.
319 * \param len The length of the additional data.
320 * This must be at most #MBEDTLS_HMAC_DRBG_MAX_INPUT
321 * and also at most
322 * #MBEDTLS_HMAC_DRBG_MAX_SEED_INPUT - \p entropy_len
323 * where \p entropy_len is the entropy length
324 * (see mbedtls_hmac_drbg_set_entropy_len()).
Manuel Pégourié-Gonnard8fc484d2014-01-30 18:28:09 +0100325 *
Gilles Peskined8917302019-10-02 19:00:06 +0200326 * \return \c 0 if successful.
327 * \return #MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED
328 * if a call to the entropy function failed.
Manuel Pégourié-Gonnard8fc484d2014-01-30 18:28:09 +0100329 */
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200330int mbedtls_hmac_drbg_reseed( mbedtls_hmac_drbg_context *ctx,
Manuel Pégourié-Gonnard8fc484d2014-01-30 18:28:09 +0100331 const unsigned char *additional, size_t len );
332
333/**
Gilles Peskined8917302019-10-02 19:00:06 +0200334 * \brief This function updates an HMAC_DRBG instance with additional
335 * data and uses it to generate random data.
Manuel Pégourié-Gonnard8208d162014-01-30 12:19:26 +0100336 *
Gilles Peskined8917302019-10-02 19:00:06 +0200337 * This function automatically reseeds if the reseed counter is exceeded
338 * or prediction resistance is enabled.
Manuel Pégourié-Gonnard8208d162014-01-30 12:19:26 +0100339 *
Gilles Peskined8917302019-10-02 19:00:06 +0200340 * \param p_rng The HMAC_DRBG context. This must be a pointer to a
341 * #mbedtls_hmac_drbg_context structure.
342 * \param output The buffer to fill.
343 * \param output_len The length of the buffer in bytes.
344 * This must be at most #MBEDTLS_HMAC_DRBG_MAX_REQUEST.
345 * \param additional Additional data to update with.
346 * If this is \c NULL, there is no additional data
347 * and \p add_len should be \c 0.
348 * \param add_len The length of the additional data.
349 * This must be at most #MBEDTLS_HMAC_DRBG_MAX_INPUT.
Manuel Pégourié-Gonnard8208d162014-01-30 12:19:26 +0100350 *
Gilles Peskined8917302019-10-02 19:00:06 +0200351 * \return \c 0 if successful.
352 * \return #MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED
353 * if a call to the entropy source failed.
354 * \return #MBEDTLS_ERR_HMAC_DRBG_REQUEST_TOO_BIG if
355 * \p output_len > #MBEDTLS_HMAC_DRBG_MAX_REQUEST.
356 * \return #MBEDTLS_ERR_HMAC_DRBG_INPUT_TOO_BIG if
357 * \p add_len > #MBEDTLS_HMAC_DRBG_MAX_INPUT.
Manuel Pégourié-Gonnard8208d162014-01-30 12:19:26 +0100358 */
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200359int mbedtls_hmac_drbg_random_with_add( void *p_rng,
Manuel Pégourié-Gonnard8208d162014-01-30 12:19:26 +0100360 unsigned char *output, size_t output_len,
361 const unsigned char *additional,
362 size_t add_len );
363
364/**
Gilles Peskined8917302019-10-02 19:00:06 +0200365 * \brief This function uses HMAC_DRBG to generate random data.
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100366 *
Gilles Peskined8917302019-10-02 19:00:06 +0200367 * This function automatically reseeds if the reseed counter is exceeded
368 * or prediction resistance is enabled.
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100369 *
Gilles Peskined8917302019-10-02 19:00:06 +0200370 * \param p_rng The HMAC_DRBG context. This must be a pointer to a
371 * #mbedtls_hmac_drbg_context structure.
372 * \param output The buffer to fill.
373 * \param out_len The length of the buffer in bytes.
374 * This must be at most #MBEDTLS_HMAC_DRBG_MAX_REQUEST.
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100375 *
Gilles Peskined8917302019-10-02 19:00:06 +0200376 * \return \c 0 if successful.
377 * \return #MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED
378 * if a call to the entropy source failed.
379 * \return #MBEDTLS_ERR_HMAC_DRBG_REQUEST_TOO_BIG if
380 * \p out_len > #MBEDTLS_HMAC_DRBG_MAX_REQUEST.
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100381 */
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200382int mbedtls_hmac_drbg_random( void *p_rng, unsigned char *output, size_t out_len );
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100383
384/**
Gavin Acquroffceb99902020-03-01 17:06:11 -0800385 * \brief This function resets HMAC_DRBG context to the state immediately
386 * after initial call of mbedtls_hmac_drbg_init().
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100387 *
Gilles Peskined8917302019-10-02 19:00:06 +0200388 * \param ctx The HMAC_DRBG context to free.
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100389 */
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200390void mbedtls_hmac_drbg_free( mbedtls_hmac_drbg_context *ctx );
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100391
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200392#if defined(MBEDTLS_FS_IO)
Manuel Pégourié-Gonnard48bc3e82014-01-30 21:11:16 +0100393/**
Gilles Peskined8917302019-10-02 19:00:06 +0200394 * \brief This function writes a seed file.
Manuel Pégourié-Gonnard48bc3e82014-01-30 21:11:16 +0100395 *
Gilles Peskined8917302019-10-02 19:00:06 +0200396 * \param ctx The HMAC_DRBG context.
397 * \param path The name of the file.
Manuel Pégourié-Gonnard48bc3e82014-01-30 21:11:16 +0100398 *
Gilles Peskined8917302019-10-02 19:00:06 +0200399 * \return \c 0 on success.
400 * \return #MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR on file error.
401 * \return #MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED on reseed
402 * failure.
Manuel Pégourié-Gonnard48bc3e82014-01-30 21:11:16 +0100403 */
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200404int mbedtls_hmac_drbg_write_seed_file( mbedtls_hmac_drbg_context *ctx, const char *path );
Manuel Pégourié-Gonnard48bc3e82014-01-30 21:11:16 +0100405
406/**
Gilles Peskined8917302019-10-02 19:00:06 +0200407 * \brief This function reads and updates a seed file. The seed
408 * is added to this instance.
Manuel Pégourié-Gonnard48bc3e82014-01-30 21:11:16 +0100409 *
Gilles Peskined8917302019-10-02 19:00:06 +0200410 * \param ctx The HMAC_DRBG context.
411 * \param path The name of the file.
Manuel Pégourié-Gonnard48bc3e82014-01-30 21:11:16 +0100412 *
Gilles Peskined8917302019-10-02 19:00:06 +0200413 * \return \c 0 on success.
414 * \return #MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR on file error.
415 * \return #MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED on
416 * reseed failure.
417 * \return #MBEDTLS_ERR_HMAC_DRBG_INPUT_TOO_BIG if the existing
418 * seed file is too large.
Manuel Pégourié-Gonnard48bc3e82014-01-30 21:11:16 +0100419 */
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200420int mbedtls_hmac_drbg_update_seed_file( mbedtls_hmac_drbg_context *ctx, const char *path );
421#endif /* MBEDTLS_FS_IO */
Manuel Pégourié-Gonnard48bc3e82014-01-30 21:11:16 +0100422
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100423
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200424#if defined(MBEDTLS_SELF_TEST)
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100425/**
Gilles Peskined8917302019-10-02 19:00:06 +0200426 * \brief The HMAC_DRBG Checkup routine.
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100427 *
Gilles Peskined8917302019-10-02 19:00:06 +0200428 * \return \c 0 if successful.
429 * \return \c 1 if the test failed.
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100430 */
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200431int mbedtls_hmac_drbg_self_test( int verbose );
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100432#endif
433
434#ifdef __cplusplus
435}
436#endif
437
438#endif /* hmac_drbg.h */