Mbed TLS v3.5.0
entropy.h
Go to the documentation of this file.
1 
6 /*
7  * Copyright The Mbed TLS Contributors
8  * SPDX-License-Identifier: Apache-2.0
9  *
10  * Licensed under the Apache License, Version 2.0 (the "License"); you may
11  * not use this file except in compliance with the License.
12  * You may obtain a copy of the License at
13  *
14  * http://www.apache.org/licenses/LICENSE-2.0
15  *
16  * Unless required by applicable law or agreed to in writing, software
17  * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
18  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
19  * See the License for the specific language governing permissions and
20  * limitations under the License.
21  */
22 #ifndef MBEDTLS_ENTROPY_H
23 #define MBEDTLS_ENTROPY_H
24 #include "mbedtls/private_access.h"
25 
26 #include "mbedtls/build_info.h"
27 
28 #include <stddef.h>
29 
30 #include "md.h"
31 
32 #if defined(MBEDTLS_MD_CAN_SHA512) && !defined(MBEDTLS_ENTROPY_FORCE_SHA256)
33 #define MBEDTLS_ENTROPY_SHA512_ACCUMULATOR
34 #define MBEDTLS_ENTROPY_MD MBEDTLS_MD_SHA512
35 #define MBEDTLS_ENTROPY_BLOCK_SIZE 64
36 #else
37 #if defined(MBEDTLS_MD_CAN_SHA256)
38 #define MBEDTLS_ENTROPY_SHA256_ACCUMULATOR
39 #define MBEDTLS_ENTROPY_MD MBEDTLS_MD_SHA256
40 #define MBEDTLS_ENTROPY_BLOCK_SIZE 32
41 #endif
42 #endif
43 
44 #if defined(MBEDTLS_THREADING_C)
45 #include "mbedtls/threading.h"
46 #endif
47 
48 
50 #define MBEDTLS_ERR_ENTROPY_SOURCE_FAILED -0x003C
52 #define MBEDTLS_ERR_ENTROPY_MAX_SOURCES -0x003E
54 #define MBEDTLS_ERR_ENTROPY_NO_SOURCES_DEFINED -0x0040
56 #define MBEDTLS_ERR_ENTROPY_NO_STRONG_SOURCE -0x003D
58 #define MBEDTLS_ERR_ENTROPY_FILE_IO_ERROR -0x003F
59 
68 #if !defined(MBEDTLS_ENTROPY_MAX_SOURCES)
69 #define MBEDTLS_ENTROPY_MAX_SOURCES 20
70 #endif
71 
72 #if !defined(MBEDTLS_ENTROPY_MAX_GATHER)
73 #define MBEDTLS_ENTROPY_MAX_GATHER 128
74 #endif
75 
78 #define MBEDTLS_ENTROPY_MAX_SEED_SIZE 1024
79 #define MBEDTLS_ENTROPY_SOURCE_MANUAL MBEDTLS_ENTROPY_MAX_SOURCES
80 
81 #define MBEDTLS_ENTROPY_SOURCE_STRONG 1
82 #define MBEDTLS_ENTROPY_SOURCE_WEAK 0
84 #ifdef __cplusplus
85 extern "C" {
86 #endif
87 
99 typedef int (*mbedtls_entropy_f_source_ptr)(void *data, unsigned char *output, size_t len,
100  size_t *olen);
101 
107  void *MBEDTLS_PRIVATE(p_source);
108  size_t MBEDTLS_PRIVATE(size);
109  size_t MBEDTLS_PRIVATE(threshold);
110  int MBEDTLS_PRIVATE(strong);
111 }
113 
117 typedef struct mbedtls_entropy_context {
119  int MBEDTLS_PRIVATE(accumulator_started); /* 0 after init.
120  * 1 after the first update.
121  * -1 after free. */
122  int MBEDTLS_PRIVATE(source_count); /* Number of entries used in source. */
124 #if defined(MBEDTLS_THREADING_C)
126 #endif
127 #if defined(MBEDTLS_ENTROPY_NV_SEED)
128  int MBEDTLS_PRIVATE(initial_entropy_run);
129 #endif
130 }
132 
133 #if !defined(MBEDTLS_NO_PLATFORM_ENTROPY)
138  unsigned char *output, size_t len, size_t *olen);
139 #endif
140 
147 
154 
173  mbedtls_entropy_f_source_ptr f_source, void *p_source,
174  size_t threshold, int strong);
175 
185 
197 int mbedtls_entropy_func(void *data, unsigned char *output, size_t len);
198 
210  const unsigned char *data, size_t len);
211 
212 #if defined(MBEDTLS_ENTROPY_NV_SEED)
221 int mbedtls_entropy_update_nv_seed(mbedtls_entropy_context *ctx);
222 #endif /* MBEDTLS_ENTROPY_NV_SEED */
223 
224 #if defined(MBEDTLS_FS_IO)
236 
250 #endif /* MBEDTLS_FS_IO */
251 
252 #if defined(MBEDTLS_SELF_TEST)
261 int mbedtls_entropy_self_test(int verbose);
262 
263 #if defined(MBEDTLS_ENTROPY_HARDWARE_ALT)
277 int mbedtls_entropy_source_self_test(int verbose);
278 #endif /* MBEDTLS_ENTROPY_HARDWARE_ALT */
279 #endif /* MBEDTLS_SELF_TEST */
280 
281 #ifdef __cplusplus
282 }
283 #endif
284 
285 #endif /* entropy.h */
void mbedtls_entropy_free(mbedtls_entropy_context *ctx)
Free the data in the context.
int(* mbedtls_entropy_f_source_ptr)(void *data, unsigned char *output, size_t len, size_t *olen)
Entropy poll callback pointer.
Definition: entropy.h:99
int mbedtls_entropy_update_seed_file(mbedtls_entropy_context *ctx, const char *path)
Read and update a seed file. Seed is added to this instance. No more than MBEDTLS_ENTROPY_MAX_SEED_SI...
int mbedtls_entropy_func(void *data, unsigned char *output, size_t len)
Retrieve entropy from the accumulator (Maximum length: MBEDTLS_ENTROPY_BLOCK_SIZE) (Thread-safe if MB...
#define MBEDTLS_ENTROPY_MAX_SOURCES
Definition: entropy.h:69
struct mbedtls_entropy_source_state mbedtls_entropy_source_state
Entropy source state.
struct mbedtls_entropy_context mbedtls_entropy_context
Entropy context structure.
int mbedtls_entropy_update_manual(mbedtls_entropy_context *ctx, const unsigned char *data, size_t len)
Add data to the accumulator manually (Thread-safe if MBEDTLS_THREADING_C is enabled)
void mbedtls_entropy_init(mbedtls_entropy_context *ctx)
Initialize the context.
int mbedtls_entropy_write_seed_file(mbedtls_entropy_context *ctx, const char *path)
Write a seed file.
int mbedtls_entropy_gather(mbedtls_entropy_context *ctx)
Trigger an extra gather poll for the accumulator (Thread-safe if MBEDTLS_THREADING_C is enabled)
int mbedtls_entropy_add_source(mbedtls_entropy_context *ctx, mbedtls_entropy_f_source_ptr f_source, void *p_source, size_t threshold, int strong)
Adds an entropy source to poll (Thread-safe if MBEDTLS_THREADING_C is enabled)
int mbedtls_entropy_self_test(int verbose)
Checkup routine.
int mbedtls_platform_entropy_poll(void *data, unsigned char *output, size_t len, size_t *olen)
Platform-specific entropy poll callback.
Build-time configuration info.
This file contains the generic functions for message-digest (hashing) and HMAC.
Macro wrapper for struct's members.
#define MBEDTLS_PRIVATE(member)
Entropy context structure.
Definition: entropy.h:117
Entropy source state.
Definition: entropy.h:105
Threading abstraction layer.