Mbed TLS v3.5.0
ctr_drbg.h
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1 
24 /*
25  * Copyright The Mbed TLS Contributors
26  * SPDX-License-Identifier: Apache-2.0
27  *
28  * Licensed under the Apache License, Version 2.0 (the "License"); you may
29  * not use this file except in compliance with the License.
30  * You may obtain a copy of the License at
31  *
32  * http://www.apache.org/licenses/LICENSE-2.0
33  *
34  * Unless required by applicable law or agreed to in writing, software
35  * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
36  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
37  * See the License for the specific language governing permissions and
38  * limitations under the License.
39  */
40 
41 #ifndef MBEDTLS_CTR_DRBG_H
42 #define MBEDTLS_CTR_DRBG_H
43 #include "mbedtls/private_access.h"
44 
45 #include "mbedtls/build_info.h"
46 
47 #include "mbedtls/aes.h"
48 #include "entropy.h"
49 
50 #if defined(MBEDTLS_THREADING_C)
51 #include "mbedtls/threading.h"
52 #endif
53 
55 #define MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED -0x0034
57 #define MBEDTLS_ERR_CTR_DRBG_REQUEST_TOO_BIG -0x0036
59 #define MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG -0x0038
61 #define MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR -0x003A
62 
63 #define MBEDTLS_CTR_DRBG_BLOCKSIZE 16
65 #if defined(MBEDTLS_CTR_DRBG_USE_128_BIT_KEY)
66 #define MBEDTLS_CTR_DRBG_KEYSIZE 16
72 #else
73 #define MBEDTLS_CTR_DRBG_KEYSIZE 32
79 #endif
80 
81 #define MBEDTLS_CTR_DRBG_KEYBITS (MBEDTLS_CTR_DRBG_KEYSIZE * 8)
82 #define MBEDTLS_CTR_DRBG_SEEDLEN (MBEDTLS_CTR_DRBG_KEYSIZE + MBEDTLS_CTR_DRBG_BLOCKSIZE)
97 #if !defined(MBEDTLS_CTR_DRBG_ENTROPY_LEN)
98 #if defined(MBEDTLS_ENTROPY_SHA512_ACCUMULATOR)
101 #define MBEDTLS_CTR_DRBG_ENTROPY_LEN 48
102 
103 #else /* MBEDTLS_ENTROPY_SHA512_ACCUMULATOR */
104 
107 #if !defined(MBEDTLS_CTR_DRBG_USE_128_BIT_KEY)
111 #endif /* !defined(MBEDTLS_CTR_DRBG_USE_128_BIT_KEY) */
112 #define MBEDTLS_CTR_DRBG_ENTROPY_LEN 32
113 #endif /* MBEDTLS_ENTROPY_SHA512_ACCUMULATOR */
114 #endif /* !defined(MBEDTLS_CTR_DRBG_ENTROPY_LEN) */
115 
116 #if !defined(MBEDTLS_CTR_DRBG_RESEED_INTERVAL)
117 #define MBEDTLS_CTR_DRBG_RESEED_INTERVAL 10000
119 #endif
120 
121 #if !defined(MBEDTLS_CTR_DRBG_MAX_INPUT)
122 #define MBEDTLS_CTR_DRBG_MAX_INPUT 256
124 #endif
125 
126 #if !defined(MBEDTLS_CTR_DRBG_MAX_REQUEST)
127 #define MBEDTLS_CTR_DRBG_MAX_REQUEST 1024
129 #endif
130 
131 #if !defined(MBEDTLS_CTR_DRBG_MAX_SEED_INPUT)
132 #define MBEDTLS_CTR_DRBG_MAX_SEED_INPUT 384
134 #endif
135 
138 #define MBEDTLS_CTR_DRBG_PR_OFF 0
140 #define MBEDTLS_CTR_DRBG_PR_ON 1
143 #ifdef __cplusplus
144 extern "C" {
145 #endif
146 
147 #if MBEDTLS_CTR_DRBG_ENTROPY_LEN >= MBEDTLS_CTR_DRBG_KEYSIZE * 3 / 2
154 #define MBEDTLS_CTR_DRBG_ENTROPY_NONCE_LEN 0
155 #else
162 #define MBEDTLS_CTR_DRBG_ENTROPY_NONCE_LEN (MBEDTLS_CTR_DRBG_ENTROPY_LEN + 1) / 2
163 #endif
164 
168 typedef struct mbedtls_ctr_drbg_context {
169  unsigned char MBEDTLS_PRIVATE(counter)[16];
170  int MBEDTLS_PRIVATE(reseed_counter);
180  int MBEDTLS_PRIVATE(prediction_resistance);
184  size_t MBEDTLS_PRIVATE(entropy_len);
186  int MBEDTLS_PRIVATE(reseed_interval);
192  /*
193  * Callbacks (Entropy)
194  */
195  int(*MBEDTLS_PRIVATE(f_entropy))(void *, unsigned char *, size_t);
198  void *MBEDTLS_PRIVATE(p_entropy);
200 #if defined(MBEDTLS_THREADING_C)
201  /* Invariant: the mutex is initialized if and only if f_entropy != NULL.
202  * This means that the mutex is initialized during the initial seeding
203  * in mbedtls_ctr_drbg_seed() and freed in mbedtls_ctr_drbg_free().
204  *
205  * Note that this invariant may change without notice. Do not rely on it
206  * and do not access the mutex directly in application code.
207  */
209 #endif
210 }
212 
226 
260 #if MBEDTLS_CTR_DRBG_ENTROPY_NONCE_LEN == 0
265 #else
271 #endif
272 #if defined(MBEDTLS_THREADING_C)
280 #endif /* MBEDTLS_THREADING_C */
327  int (*f_entropy)(void *, unsigned char *, size_t),
328  void *p_entropy,
329  const unsigned char *custom,
330  size_t len);
331 
339 
354  int resistance);
355 
381  size_t len);
382 
403  size_t len);
404 
418  int interval);
419 
441  const unsigned char *additional, size_t len);
442 
464  const unsigned char *additional,
465  size_t add_len);
466 
499  unsigned char *output, size_t output_len,
500  const unsigned char *additional, size_t add_len);
501 
508 #if defined(MBEDTLS_THREADING_C)
515 #endif /* MBEDTLS_THREADING_C */
526 int mbedtls_ctr_drbg_random(void *p_rng,
527  unsigned char *output, size_t output_len);
528 
529 #if defined(MBEDTLS_FS_IO)
542 
558 #endif /* MBEDTLS_FS_IO */
559 
560 #if defined(MBEDTLS_SELF_TEST)
561 
568 int mbedtls_ctr_drbg_self_test(int verbose);
569 
570 #endif /* MBEDTLS_SELF_TEST */
571 
572 #ifdef __cplusplus
573 }
574 #endif
575 
576 #endif /* ctr_drbg.h */
This file contains AES definitions and functions.
int mbedtls_ctr_drbg_set_nonce_len(mbedtls_ctr_drbg_context *ctx, size_t len)
This function sets the amount of entropy grabbed as a nonce for the initial seeding.
int mbedtls_ctr_drbg_random_with_add(void *p_rng, unsigned char *output, size_t output_len, const unsigned char *additional, size_t add_len)
This function updates a CTR_DRBG instance with additional data and uses it to generate random data.
void mbedtls_ctr_drbg_free(mbedtls_ctr_drbg_context *ctx)
This function resets CTR_DRBG context to the state immediately after initial call of mbedtls_ctr_drbg...
int mbedtls_ctr_drbg_update_seed_file(mbedtls_ctr_drbg_context *ctx, const char *path)
This function reads and updates a seed file. The seed is added to this instance.
int mbedtls_ctr_drbg_reseed(mbedtls_ctr_drbg_context *ctx, const unsigned char *additional, size_t len)
This function reseeds the CTR_DRBG context, that is extracts data from the entropy source.
struct mbedtls_ctr_drbg_context mbedtls_ctr_drbg_context
The CTR_DRBG context structure.
int mbedtls_ctr_drbg_self_test(int verbose)
The CTR_DRBG checkup routine.
void mbedtls_ctr_drbg_init(mbedtls_ctr_drbg_context *ctx)
This function initializes the CTR_DRBG context, and prepares it for mbedtls_ctr_drbg_seed() or mbedtl...
int mbedtls_ctr_drbg_update(mbedtls_ctr_drbg_context *ctx, const unsigned char *additional, size_t add_len)
This function updates the state of the CTR_DRBG context.
int mbedtls_ctr_drbg_seed(mbedtls_ctr_drbg_context *ctx, int(*f_entropy)(void *, unsigned char *, size_t), void *p_entropy, const unsigned char *custom, size_t len)
This function seeds and sets up the CTR_DRBG entropy source for future reseeds.
void mbedtls_ctr_drbg_set_prediction_resistance(mbedtls_ctr_drbg_context *ctx, int resistance)
This function turns prediction resistance on or off. The default value is off.
void mbedtls_ctr_drbg_set_reseed_interval(mbedtls_ctr_drbg_context *ctx, int interval)
This function sets the reseed interval.
void mbedtls_ctr_drbg_set_entropy_len(mbedtls_ctr_drbg_context *ctx, size_t len)
This function sets the amount of entropy grabbed on each seed or reseed.
int mbedtls_ctr_drbg_random(void *p_rng, unsigned char *output, size_t output_len)
This function uses CTR_DRBG to generate random data.
int mbedtls_ctr_drbg_write_seed_file(mbedtls_ctr_drbg_context *ctx, const char *path)
This function writes a seed file.
Entropy accumulator implementation.
Build-time configuration info.
Macro wrapper for struct's members.
#define MBEDTLS_PRIVATE(member)
The AES context-type definition.
Definition: aes.h:75
The CTR_DRBG context structure.
Definition: ctr_drbg.h:168
Threading abstraction layer.