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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/*
Gilles Peskineeb99c102019-10-02 18:56:17 +020011 * Copyright (C) 2006-2019, ARM Limited, All Rights Reserved
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 * **********
52 *
Manuel Pégourié-Gonnardfe446432015-03-06 13:17:10 +000053 * This file is part of mbed TLS (https://tls.mbed.org)
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +010054 */
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +020055#ifndef MBEDTLS_HMAC_DRBG_H
56#define MBEDTLS_HMAC_DRBG_H
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +010057
Ron Eldor0559c662018-02-14 16:02:41 +020058#if !defined(MBEDTLS_CONFIG_FILE)
59#include "config.h"
60#else
61#include MBEDTLS_CONFIG_FILE
62#endif
63
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +010064#include "md.h"
65
Manuel Pégourié-Gonnard0a4fb092015-05-07 12:50:31 +010066#if defined(MBEDTLS_THREADING_C)
Ron Eldordf9b93e2017-05-14 16:17:33 +030067#include "threading.h"
Manuel Pégourié-Gonnard0a4fb092015-05-07 12:50:31 +010068#endif
69
Manuel Pégourié-Gonnardfe34a5f2014-01-30 15:06:40 +010070/*
Manuel Pégourié-Gonnard9a6e93e2014-03-11 09:34:02 +010071 * Error codes
Manuel Pégourié-Gonnardfe34a5f2014-01-30 15:06:40 +010072 */
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +020073#define MBEDTLS_ERR_HMAC_DRBG_REQUEST_TOO_BIG -0x0003 /**< Too many random requested in single call. */
74#define MBEDTLS_ERR_HMAC_DRBG_INPUT_TOO_BIG -0x0005 /**< Input too large (Entropy + additional). */
75#define MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR -0x0007 /**< Read/write error in file. */
76#define MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED -0x0009 /**< The entropy source failed. */
Manuel Pégourié-Gonnardfe34a5f2014-01-30 15:06:40 +010077
Paul Bakker088c5c52014-04-25 11:11:10 +020078/**
79 * \name SECTION: Module settings
80 *
81 * The configuration options you can set for this module are in this section.
82 * Either change them in config.h or define them on the compiler command line.
83 * \{
84 */
85
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +020086#if !defined(MBEDTLS_HMAC_DRBG_RESEED_INTERVAL)
87#define MBEDTLS_HMAC_DRBG_RESEED_INTERVAL 10000 /**< Interval before reseed is performed by default */
Paul Bakker088c5c52014-04-25 11:11:10 +020088#endif
89
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +020090#if !defined(MBEDTLS_HMAC_DRBG_MAX_INPUT)
91#define MBEDTLS_HMAC_DRBG_MAX_INPUT 256 /**< Maximum number of additional input bytes */
Paul Bakker088c5c52014-04-25 11:11:10 +020092#endif
93
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +020094#if !defined(MBEDTLS_HMAC_DRBG_MAX_REQUEST)
95#define MBEDTLS_HMAC_DRBG_MAX_REQUEST 1024 /**< Maximum number of requested bytes per call */
Paul Bakker088c5c52014-04-25 11:11:10 +020096#endif
97
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +020098#if !defined(MBEDTLS_HMAC_DRBG_MAX_SEED_INPUT)
99#define MBEDTLS_HMAC_DRBG_MAX_SEED_INPUT 384 /**< Maximum size of (re)seed buffer */
Paul Bakker088c5c52014-04-25 11:11:10 +0200100#endif
101
102/* \} name SECTION: Module settings */
Manuel Pégourié-Gonnardfe34a5f2014-01-30 15:06:40 +0100103
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200104#define MBEDTLS_HMAC_DRBG_PR_OFF 0 /**< No prediction resistance */
105#define MBEDTLS_HMAC_DRBG_PR_ON 1 /**< Prediction resistance enabled */
Manuel Pégourié-Gonnardaf786ff2014-01-30 18:44:18 +0100106
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100107#ifdef __cplusplus
108extern "C" {
109#endif
110
Manuel Pégourié-Gonnardfe34a5f2014-01-30 15:06:40 +0100111/**
112 * HMAC_DRBG context.
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100113 */
114typedef struct
115{
Antonin Décimo8fd91562019-01-23 15:24:37 +0100116 /* Working state: the key K is not stored explicitly,
Manuel Pégourié-Gonnardb05db2a2014-02-01 11:38:05 +0100117 * but is implied by the HMAC context */
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200118 mbedtls_md_context_t md_ctx; /*!< HMAC context (inc. K) */
119 unsigned char V[MBEDTLS_MD_MAX_SIZE]; /*!< V in the spec */
Manuel Pégourié-Gonnardb05db2a2014-02-01 11:38:05 +0100120 int reseed_counter; /*!< reseed counter */
Manuel Pégourié-Gonnardfe34a5f2014-01-30 15:06:40 +0100121
Manuel Pégourié-Gonnard658dbed2014-01-30 19:03:45 +0100122 /* Administrative state */
Manuel Pégourié-Gonnardfe34a5f2014-01-30 15:06:40 +0100123 size_t entropy_len; /*!< entropy bytes grabbed on each (re)seed */
Manuel Pégourié-Gonnardaf786ff2014-01-30 18:44:18 +0100124 int prediction_resistance; /*!< enable prediction resistance (Automatic
125 reseed before every random generation) */
Manuel Pégourié-Gonnard658dbed2014-01-30 19:03:45 +0100126 int reseed_interval; /*!< reseed interval */
Manuel Pégourié-Gonnardfe34a5f2014-01-30 15:06:40 +0100127
Manuel Pégourié-Gonnard658dbed2014-01-30 19:03:45 +0100128 /* Callbacks */
Manuel Pégourié-Gonnardaf786ff2014-01-30 18:44:18 +0100129 int (*f_entropy)(void *, unsigned char *, size_t); /*!< entropy function */
130 void *p_entropy; /*!< context for the entropy function */
Manuel Pégourié-Gonnard0a4fb092015-05-07 12:50:31 +0100131
132#if defined(MBEDTLS_THREADING_C)
133 mbedtls_threading_mutex_t mutex;
134#endif
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200135} mbedtls_hmac_drbg_context;
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100136
137/**
Gilles Peskined8917302019-10-02 19:00:06 +0200138 * \brief HMAC_DRBG context initialization.
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100139 *
Gilles Peskined8917302019-10-02 19:00:06 +0200140 * This function makes the context ready for mbedtls_hmac_drbg_seed(),
141 * mbedtls_hmac_drbg_seed_buf() or mbedtls_hmac_drbg_free().
142 *
143 * \param ctx HMAC_DRBG context to be initialized.
Manuel Pégourié-Gonnardf9e94812015-04-28 22:07:14 +0200144 */
145void mbedtls_hmac_drbg_init( mbedtls_hmac_drbg_context *ctx );
146
147/**
Gilles Peskined8917302019-10-02 19:00:06 +0200148 * \brief HMAC_DRBG initial seeding.
Manuel Pégourié-Gonnardf9e94812015-04-28 22:07:14 +0200149 *
Gilles Peskined8917302019-10-02 19:00:06 +0200150 * Set the initial seed and set up the entropy source for future reseeds.
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100151 *
Gilles Peskineb9cfe582019-10-02 19:00:57 +0200152 * A typical choice for the \p f_entropy and \p p_entropy parameters is
153 * to use the entropy module:
154 * - \p f_entropy is mbedtls_entropy_func();
155 * - \p p_entropy is an instance of ::mbedtls_entropy_context initialized
156 * with mbedtls_entropy_init() (which registers the platform's default
157 * entropy sources).
158 *
Gilles Peskined8917302019-10-02 19:00:06 +0200159 * You can provide a personalization string in addition to the
160 * entropy source, to make this instantiation as unique as possible.
161 *
162 * \note By default, the security strength as defined by NIST is:
163 * - 128 bits if \p md_info is SHA-1;
164 * - 192 bits if \p md_info is SHA-224;
165 * - 256 bits if \p md_info is SHA-256, SHA-384 or SHA-512.
Manuel Pégourié-Gonnardfe34a5f2014-01-30 15:06:40 +0100166 * Note that SHA-256 is just as efficient as SHA-224.
Gilles Peskined8917302019-10-02 19:00:06 +0200167 * The security strength can be reduced if a smaller
168 * entropy length is set with
Gilles Peskine9c742242019-10-04 11:47:35 +0200169 * mbedtls_hmac_drbg_set_entropy_len().
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100170 *
Gilles Peskine9c742242019-10-04 11:47:35 +0200171 * \note The default entropy length is the security strength
172 * (converted from bits to bytes). You can override
173 * it by calling mbedtls_hmac_drbg_set_entropy_len().
Gilles Peskined8917302019-10-02 19:00:06 +0200174 *
175 * \note During the initial seeding, this function calls
176 * the entropy source to obtain a nonce
177 * whose length is half the entropy length.
178 *
179 * \param ctx HMAC_DRBG context to be seeded.
180 * \param md_info MD algorithm to use for HMAC_DRBG.
181 * \param f_entropy The entropy callback, taking as arguments the
182 * \p p_entropy context, the buffer to fill, and the
183 * length of the buffer.
Gilles Peskine55e120b2019-10-04 11:52:22 +0200184 * \p f_entropy is always called with a length that is
185 * less than or equal to the entropy length.
Gilles Peskined8917302019-10-02 19:00:06 +0200186 * \param p_entropy The entropy context to pass to \p f_entropy.
187 * \param custom The personalization string.
188 * This can be \c NULL, in which case the personalization
189 * string is empty regardless of the value of \p len.
190 * \param len The length of the personalization string.
191 * This must be at most #MBEDTLS_HMAC_DRBG_MAX_INPUT
192 * and also at most
193 * #MBEDTLS_HMAC_DRBG_MAX_SEED_INPUT - \p entropy_len * 3 / 2
194 * where \p entropy_len is the entropy length
195 * described above.
196 *
197 * \return \c 0 if successful.
198 * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA if \p md_info is
199 * invalid.
200 * \return #MBEDTLS_ERR_MD_ALLOC_FAILED if there was not enough
201 * memory to allocate context data.
202 * \return #MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED
203 * if the call to \p f_entropy failed.
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100204 */
Manuel Pégourié-Gonnardf9e94812015-04-28 22:07:14 +0200205int mbedtls_hmac_drbg_seed( mbedtls_hmac_drbg_context *ctx,
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200206 const mbedtls_md_info_t * md_info,
Manuel Pégourié-Gonnardfe34a5f2014-01-30 15:06:40 +0100207 int (*f_entropy)(void *, unsigned char *, size_t),
208 void *p_entropy,
209 const unsigned char *custom,
210 size_t len );
211
212/**
Manuel Pégourié-Gonnard4e669c62014-01-30 18:06:08 +0100213 * \brief Initilisation of simpified HMAC_DRBG (never reseeds).
Manuel Pégourié-Gonnardfe34a5f2014-01-30 15:06:40 +0100214 *
Gilles Peskined8917302019-10-02 19:00:06 +0200215 * This function is meant for use in algorithms that need a pseudorandom
216 * input such as deterministic ECDSA.
Manuel Pégourié-Gonnardfe34a5f2014-01-30 15:06:40 +0100217 *
Gilles Peskined8917302019-10-02 19:00:06 +0200218 * \param ctx HMAC_DRBG context to be initialised.
219 * \param md_info MD algorithm to use for HMAC_DRBG.
220 * \param data Concatenation of the initial entropy string and
221 * the additional data.
222 * \param data_len Length of \p data in bytes.
223 *
224 * \return \c 0 if successful. or
225 * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA if \p md_info is
226 * invalid.
227 * \return #MBEDTLS_ERR_MD_ALLOC_FAILED if there was not enough
228 * memory to allocate context data.
Manuel Pégourié-Gonnardfe34a5f2014-01-30 15:06:40 +0100229 */
Manuel Pégourié-Gonnardf9e94812015-04-28 22:07:14 +0200230int mbedtls_hmac_drbg_seed_buf( mbedtls_hmac_drbg_context *ctx,
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200231 const mbedtls_md_info_t * md_info,
Manuel Pégourié-Gonnardfe34a5f2014-01-30 15:06:40 +0100232 const unsigned char *data, size_t data_len );
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100233
234/**
Gilles Peskined8917302019-10-02 19:00:06 +0200235 * \brief This function turns prediction resistance on or off.
236 * The default value is off.
Manuel Pégourié-Gonnardaf786ff2014-01-30 18:44:18 +0100237 *
Gilles Peskined8917302019-10-02 19:00:06 +0200238 * \note If enabled, entropy is gathered at the beginning of
239 * every call to mbedtls_hmac_drbg_random_with_add()
240 * or mbedtls_hmac_drbg_random().
241 * Only use this if your entropy source has sufficient
242 * throughput.
Manuel Pégourié-Gonnardaf786ff2014-01-30 18:44:18 +0100243 *
Gilles Peskined8917302019-10-02 19:00:06 +0200244 * \param ctx The HMAC_DRBG context.
245 * \param resistance #MBEDTLS_HMAC_DRBG_PR_ON or #MBEDTLS_HMAC_DRBG_PR_OFF.
Manuel Pégourié-Gonnardaf786ff2014-01-30 18:44:18 +0100246 */
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200247void mbedtls_hmac_drbg_set_prediction_resistance( mbedtls_hmac_drbg_context *ctx,
Manuel Pégourié-Gonnardaf786ff2014-01-30 18:44:18 +0100248 int resistance );
249
250/**
Gilles Peskined8917302019-10-02 19:00:06 +0200251 * \brief This function sets the amount of entropy grabbed on each
Gilles Peskine9c742242019-10-04 11:47:35 +0200252 * seed or reseed.
Manuel Pégourié-Gonnard4e669c62014-01-30 18:06:08 +0100253 *
Gilles Peskine9c742242019-10-04 11:47:35 +0200254 * See the documentation of mbedtls_hmac_drbg_seed() for the default value.
Gilles Peskined8917302019-10-02 19:00:06 +0200255 *
256 * \param ctx The HMAC_DRBG context.
257 * \param len The amount of entropy to grab, in bytes.
Manuel Pégourié-Gonnard4e669c62014-01-30 18:06:08 +0100258 */
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200259void mbedtls_hmac_drbg_set_entropy_len( mbedtls_hmac_drbg_context *ctx,
Manuel Pégourié-Gonnard4e669c62014-01-30 18:06:08 +0100260 size_t len );
261
262/**
Gilles Peskined8917302019-10-02 19:00:06 +0200263 * \brief Set the reseed interval.
Manuel Pégourié-Gonnard658dbed2014-01-30 19:03:45 +0100264 *
Gilles Peskined8917302019-10-02 19:00:06 +0200265 * The reseed interval is the number of calls to mbedtls_hmac_drbg_random()
266 * or mbedtls_hmac_drbg_random_with_add() after which the entropy function
267 * is called again.
268 *
269 * The default value is #MBEDTLS_HMAC_DRBG_RESEED_INTERVAL.
270 *
271 * \param ctx The HMAC_DRBG context.
272 * \param interval The reseed interval.
Manuel Pégourié-Gonnard658dbed2014-01-30 19:03:45 +0100273 */
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200274void mbedtls_hmac_drbg_set_reseed_interval( mbedtls_hmac_drbg_context *ctx,
Manuel Pégourié-Gonnard658dbed2014-01-30 19:03:45 +0100275 int interval );
276
277/**
Gilles Peskined8917302019-10-02 19:00:06 +0200278 * \brief This function updates the state of the HMAC_DRBG context.
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100279 *
Gilles Peskined8917302019-10-02 19:00:06 +0200280 * \param ctx The HMAC_DRBG context.
281 * \param additional The data to update the state with.
282 * If this is \c NULL, there is no additional data.
283 * \param add_len Length of \p additional in bytes.
284 * Unused if \p additional is \c NULL.
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100285 *
Gilles Peskine4d237572018-09-13 22:19:57 +0200286 * \return \c 0 on success, or an error from the underlying
287 * hash calculation.
Gilles Peskine4d237572018-09-13 22:19:57 +0200288 */
289int mbedtls_hmac_drbg_update_ret( mbedtls_hmac_drbg_context *ctx,
290 const unsigned char *additional, size_t add_len );
291
292/**
293 * \brief HMAC_DRBG update state
294 *
295 * \warning This function cannot report errors. You should use
296 * mbedtls_hmac_drbg_update_ret() instead.
297 *
298 * \param ctx HMAC_DRBG context
299 * \param additional Additional data to update state with, or NULL
300 * \param add_len Length of additional data, or 0
301 *
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100302 * \note Additional data is optional, pass NULL and 0 as second
303 * third argument if no additional data is being used.
304 */
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200305void mbedtls_hmac_drbg_update( mbedtls_hmac_drbg_context *ctx,
Gilles Peskine4d237572018-09-13 22:19:57 +0200306 const unsigned char *additional,
307 size_t add_len );
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100308
309/**
Gilles Peskined8917302019-10-02 19:00:06 +0200310 * \brief This function reseeds the HMAC_DRBG context, that is
311 * extracts data from the entropy source.
Manuel Pégourié-Gonnard8fc484d2014-01-30 18:28:09 +0100312 *
Gilles Peskined8917302019-10-02 19:00:06 +0200313 * \param ctx The HMAC_DRBG context.
314 * \param additional Additional data to add to the state.
315 * If this is \c NULL, there is no additional data
316 * and \p len should be \c 0.
317 * \param len The length of the additional data.
318 * This must be at most #MBEDTLS_HMAC_DRBG_MAX_INPUT
319 * and also at most
320 * #MBEDTLS_HMAC_DRBG_MAX_SEED_INPUT - \p entropy_len
321 * where \p entropy_len is the entropy length
322 * (see mbedtls_hmac_drbg_set_entropy_len()).
Manuel Pégourié-Gonnard8fc484d2014-01-30 18:28:09 +0100323 *
Gilles Peskined8917302019-10-02 19:00:06 +0200324 * \return \c 0 if successful.
325 * \return #MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED
326 * if a call to the entropy function failed.
Manuel Pégourié-Gonnard8fc484d2014-01-30 18:28:09 +0100327 */
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200328int mbedtls_hmac_drbg_reseed( mbedtls_hmac_drbg_context *ctx,
Manuel Pégourié-Gonnard8fc484d2014-01-30 18:28:09 +0100329 const unsigned char *additional, size_t len );
330
331/**
Gilles Peskined8917302019-10-02 19:00:06 +0200332 * \brief This function updates an HMAC_DRBG instance with additional
333 * data and uses it to generate random data.
Manuel Pégourié-Gonnard8208d162014-01-30 12:19:26 +0100334 *
Gilles Peskined8917302019-10-02 19:00:06 +0200335 * This function automatically reseeds if the reseed counter is exceeded
336 * or prediction resistance is enabled.
Manuel Pégourié-Gonnard8208d162014-01-30 12:19:26 +0100337 *
Gilles Peskined8917302019-10-02 19:00:06 +0200338 * \param p_rng The HMAC_DRBG context. This must be a pointer to a
339 * #mbedtls_hmac_drbg_context structure.
340 * \param output The buffer to fill.
341 * \param output_len The length of the buffer in bytes.
342 * This must be at most #MBEDTLS_HMAC_DRBG_MAX_REQUEST.
343 * \param additional Additional data to update with.
344 * If this is \c NULL, there is no additional data
345 * and \p add_len should be \c 0.
346 * \param add_len The length of the additional data.
347 * This must be at most #MBEDTLS_HMAC_DRBG_MAX_INPUT.
Manuel Pégourié-Gonnard8208d162014-01-30 12:19:26 +0100348 *
Gilles Peskined8917302019-10-02 19:00:06 +0200349 * \return \c 0 if successful.
350 * \return #MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED
351 * if a call to the entropy source failed.
352 * \return #MBEDTLS_ERR_HMAC_DRBG_REQUEST_TOO_BIG if
353 * \p output_len > #MBEDTLS_HMAC_DRBG_MAX_REQUEST.
354 * \return #MBEDTLS_ERR_HMAC_DRBG_INPUT_TOO_BIG if
355 * \p add_len > #MBEDTLS_HMAC_DRBG_MAX_INPUT.
Manuel Pégourié-Gonnard8208d162014-01-30 12:19:26 +0100356 */
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200357int mbedtls_hmac_drbg_random_with_add( void *p_rng,
Manuel Pégourié-Gonnard8208d162014-01-30 12:19:26 +0100358 unsigned char *output, size_t output_len,
359 const unsigned char *additional,
360 size_t add_len );
361
362/**
Gilles Peskined8917302019-10-02 19:00:06 +0200363 * \brief This function uses HMAC_DRBG to generate random data.
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100364 *
Gilles Peskined8917302019-10-02 19:00:06 +0200365 * This function automatically reseeds if the reseed counter is exceeded
366 * or prediction resistance is enabled.
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100367 *
Gilles Peskined8917302019-10-02 19:00:06 +0200368 * \param p_rng The HMAC_DRBG context. This must be a pointer to a
369 * #mbedtls_hmac_drbg_context structure.
370 * \param output The buffer to fill.
371 * \param out_len The length of the buffer in bytes.
372 * This must be at most #MBEDTLS_HMAC_DRBG_MAX_REQUEST.
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100373 *
Gilles Peskined8917302019-10-02 19:00:06 +0200374 * \return \c 0 if successful.
375 * \return #MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED
376 * if a call to the entropy source failed.
377 * \return #MBEDTLS_ERR_HMAC_DRBG_REQUEST_TOO_BIG if
378 * \p out_len > #MBEDTLS_HMAC_DRBG_MAX_REQUEST.
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100379 */
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200380int mbedtls_hmac_drbg_random( void *p_rng, unsigned char *output, size_t out_len );
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100381
382/**
383 * \brief Free an HMAC_DRBG context
384 *
Gilles Peskined8917302019-10-02 19:00:06 +0200385 * \param ctx The HMAC_DRBG context to free.
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100386 */
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200387void mbedtls_hmac_drbg_free( mbedtls_hmac_drbg_context *ctx );
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100388
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200389#if defined(MBEDTLS_FS_IO)
Manuel Pégourié-Gonnard48bc3e82014-01-30 21:11:16 +0100390/**
Gilles Peskined8917302019-10-02 19:00:06 +0200391 * \brief This function writes a seed file.
Manuel Pégourié-Gonnard48bc3e82014-01-30 21:11:16 +0100392 *
Gilles Peskined8917302019-10-02 19:00:06 +0200393 * \param ctx The HMAC_DRBG context.
394 * \param path The name of the file.
Manuel Pégourié-Gonnard48bc3e82014-01-30 21:11:16 +0100395 *
Gilles Peskined8917302019-10-02 19:00:06 +0200396 * \return \c 0 on success.
397 * \return #MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR on file error.
398 * \return #MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED on reseed
399 * failure.
Manuel Pégourié-Gonnard48bc3e82014-01-30 21:11:16 +0100400 */
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200401int mbedtls_hmac_drbg_write_seed_file( mbedtls_hmac_drbg_context *ctx, const char *path );
Manuel Pégourié-Gonnard48bc3e82014-01-30 21:11:16 +0100402
403/**
Gilles Peskined8917302019-10-02 19:00:06 +0200404 * \brief This function reads and updates a seed file. The seed
405 * is added to this instance.
Manuel Pégourié-Gonnard48bc3e82014-01-30 21:11:16 +0100406 *
Gilles Peskined8917302019-10-02 19:00:06 +0200407 * \param ctx The HMAC_DRBG context.
408 * \param path The name of the file.
Manuel Pégourié-Gonnard48bc3e82014-01-30 21:11:16 +0100409 *
Gilles Peskined8917302019-10-02 19:00:06 +0200410 * \return \c 0 on success.
411 * \return #MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR on file error.
412 * \return #MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED on
413 * reseed failure.
414 * \return #MBEDTLS_ERR_HMAC_DRBG_INPUT_TOO_BIG if the existing
415 * seed file is too large.
Manuel Pégourié-Gonnard48bc3e82014-01-30 21:11:16 +0100416 */
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200417int mbedtls_hmac_drbg_update_seed_file( mbedtls_hmac_drbg_context *ctx, const char *path );
418#endif /* MBEDTLS_FS_IO */
Manuel Pégourié-Gonnard48bc3e82014-01-30 21:11:16 +0100419
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100420
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200421#if defined(MBEDTLS_SELF_TEST)
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100422/**
Gilles Peskined8917302019-10-02 19:00:06 +0200423 * \brief The HMAC_DRBG Checkup routine.
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100424 *
Gilles Peskined8917302019-10-02 19:00:06 +0200425 * \return \c 0 if successful.
426 * \return \c 1 if the test failed.
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100427 */
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200428int mbedtls_hmac_drbg_self_test( int verbose );
Manuel Pégourié-Gonnard490bdf32014-01-27 14:03:10 +0100429#endif
430
431#ifdef __cplusplus
432}
433#endif
434
435#endif /* hmac_drbg.h */