| /** |
| * \file entropy.h |
| * |
| * \brief Entropy accumulator implementation |
| */ |
| /* |
| * Copyright The Mbed TLS Contributors |
| * SPDX-License-Identifier: Apache-2.0 |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); you may |
| * not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
| * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| #ifndef MBEDTLS_ENTROPY_H |
| #define MBEDTLS_ENTROPY_H |
| |
| #if !defined(MBEDTLS_CONFIG_FILE) |
| #include "mbedtls/config.h" |
| #else |
| #include MBEDTLS_CONFIG_FILE |
| #endif |
| |
| #include <stddef.h> |
| |
| #if defined(MBEDTLS_SHA512_C) && !defined(MBEDTLS_ENTROPY_FORCE_SHA256) |
| #include "mbedtls/sha512.h" |
| #define MBEDTLS_ENTROPY_SHA512_ACCUMULATOR |
| #else |
| #if defined(MBEDTLS_SHA256_C) |
| #define MBEDTLS_ENTROPY_SHA256_ACCUMULATOR |
| #include "mbedtls/sha256.h" |
| #endif |
| #endif |
| |
| #if defined(MBEDTLS_THREADING_C) |
| #include "mbedtls/threading.h" |
| #endif |
| |
| #if defined(MBEDTLS_HAVEGE_C) |
| #include "mbedtls/havege.h" |
| #endif |
| |
| /** Critical entropy source failure. */ |
| #define MBEDTLS_ERR_ENTROPY_SOURCE_FAILED -0x003C |
| /** No more sources can be added. */ |
| #define MBEDTLS_ERR_ENTROPY_MAX_SOURCES -0x003E |
| /** No sources have been added to poll. */ |
| #define MBEDTLS_ERR_ENTROPY_NO_SOURCES_DEFINED -0x0040 |
| /** No strong sources have been added to poll. */ |
| #define MBEDTLS_ERR_ENTROPY_NO_STRONG_SOURCE -0x003D |
| /** Read/write error in file. */ |
| #define MBEDTLS_ERR_ENTROPY_FILE_IO_ERROR -0x003F |
| |
| /** |
| * \name SECTION: Module settings |
| * |
| * The configuration options you can set for this module are in this section. |
| * Either change them in config.h or define them on the compiler command line. |
| * \{ |
| */ |
| |
| #if !defined(MBEDTLS_ENTROPY_MAX_SOURCES) |
| #define MBEDTLS_ENTROPY_MAX_SOURCES 20 /**< Maximum number of sources supported */ |
| #endif |
| |
| #if !defined(MBEDTLS_ENTROPY_MAX_GATHER) |
| #define MBEDTLS_ENTROPY_MAX_GATHER 128 /**< Maximum amount requested from entropy sources */ |
| #endif |
| |
| /** \} name SECTION: Module settings */ |
| |
| #if defined(MBEDTLS_ENTROPY_SHA512_ACCUMULATOR) |
| #define MBEDTLS_ENTROPY_BLOCK_SIZE 64 /**< Block size of entropy accumulator (SHA-512) */ |
| #else |
| #define MBEDTLS_ENTROPY_BLOCK_SIZE 32 /**< Block size of entropy accumulator (SHA-256) */ |
| #endif |
| |
| #define MBEDTLS_ENTROPY_MAX_SEED_SIZE 1024 /**< Maximum size of seed we read from seed file */ |
| #define MBEDTLS_ENTROPY_SOURCE_MANUAL MBEDTLS_ENTROPY_MAX_SOURCES |
| |
| #define MBEDTLS_ENTROPY_SOURCE_STRONG 1 /**< Entropy source is strong */ |
| #define MBEDTLS_ENTROPY_SOURCE_WEAK 0 /**< Entropy source is weak */ |
| |
| #ifdef __cplusplus |
| extern "C" { |
| #endif |
| |
| /** |
| * \brief Entropy poll callback pointer |
| * |
| * \param data Callback-specific data pointer |
| * \param output Data to fill |
| * \param len Maximum size to provide |
| * \param olen The actual amount of bytes put into the buffer (Can be 0) |
| * |
| * \return 0 if no critical failures occurred, |
| * MBEDTLS_ERR_ENTROPY_SOURCE_FAILED otherwise |
| */ |
| typedef int (*mbedtls_entropy_f_source_ptr)(void *data, unsigned char *output, size_t len, |
| size_t *olen); |
| |
| /** |
| * \brief Entropy source state |
| */ |
| typedef struct mbedtls_entropy_source_state { |
| mbedtls_entropy_f_source_ptr f_source; /**< The entropy source callback */ |
| void *p_source; /**< The callback data pointer */ |
| size_t size; /**< Amount received in bytes */ |
| size_t threshold; /**< Minimum bytes required before release */ |
| int strong; /**< Is the source strong? */ |
| } |
| mbedtls_entropy_source_state; |
| |
| /** |
| * \brief Entropy context structure |
| */ |
| typedef struct mbedtls_entropy_context { |
| int accumulator_started; /* 0 after init. |
| * 1 after the first update. |
| * -1 after free. */ |
| #if defined(MBEDTLS_ENTROPY_SHA512_ACCUMULATOR) |
| mbedtls_sha512_context accumulator; |
| #elif defined(MBEDTLS_ENTROPY_SHA256_ACCUMULATOR) |
| mbedtls_sha256_context accumulator; |
| #endif |
| int source_count; /* Number of entries used in source. */ |
| mbedtls_entropy_source_state source[MBEDTLS_ENTROPY_MAX_SOURCES]; |
| #if defined(MBEDTLS_HAVEGE_C) |
| mbedtls_havege_state havege_data; |
| #endif |
| #if defined(MBEDTLS_THREADING_C) |
| mbedtls_threading_mutex_t mutex; /*!< mutex */ |
| #endif |
| #if defined(MBEDTLS_ENTROPY_NV_SEED) |
| int initial_entropy_run; |
| #endif |
| } |
| mbedtls_entropy_context; |
| |
| /** |
| * \brief Initialize the context |
| * |
| * \param ctx Entropy context to initialize |
| */ |
| void mbedtls_entropy_init(mbedtls_entropy_context *ctx); |
| |
| /** |
| * \brief Free the data in the context |
| * |
| * \param ctx Entropy context to free |
| */ |
| void mbedtls_entropy_free(mbedtls_entropy_context *ctx); |
| |
| /** |
| * \brief Adds an entropy source to poll |
| * (Thread-safe if MBEDTLS_THREADING_C is enabled) |
| * |
| * \param ctx Entropy context |
| * \param f_source Entropy function |
| * \param p_source Function data |
| * \param threshold Minimum required from source before entropy is released |
| * ( with mbedtls_entropy_func() ) (in bytes) |
| * \param strong MBEDTLS_ENTROPY_SOURCE_STRONG or |
| * MBEDTLS_ENTROPY_SOURCE_WEAK. |
| * At least one strong source needs to be added. |
| * Weaker sources (such as the cycle counter) can be used as |
| * a complement. |
| * |
| * \return 0 if successful or MBEDTLS_ERR_ENTROPY_MAX_SOURCES |
| */ |
| int mbedtls_entropy_add_source(mbedtls_entropy_context *ctx, |
| mbedtls_entropy_f_source_ptr f_source, void *p_source, |
| size_t threshold, int strong); |
| |
| /** |
| * \brief Trigger an extra gather poll for the accumulator |
| * (Thread-safe if MBEDTLS_THREADING_C is enabled) |
| * |
| * \param ctx Entropy context |
| * |
| * \return 0 if successful, or MBEDTLS_ERR_ENTROPY_SOURCE_FAILED |
| */ |
| int mbedtls_entropy_gather(mbedtls_entropy_context *ctx); |
| |
| /** |
| * \brief Retrieve entropy from the accumulator |
| * (Maximum length: MBEDTLS_ENTROPY_BLOCK_SIZE) |
| * (Thread-safe if MBEDTLS_THREADING_C is enabled) |
| * |
| * \param data Entropy context |
| * \param output Buffer to fill |
| * \param len Number of bytes desired, must be at most MBEDTLS_ENTROPY_BLOCK_SIZE |
| * |
| * \return 0 if successful, or MBEDTLS_ERR_ENTROPY_SOURCE_FAILED |
| */ |
| int mbedtls_entropy_func(void *data, unsigned char *output, size_t len); |
| |
| /** |
| * \brief Add data to the accumulator manually |
| * (Thread-safe if MBEDTLS_THREADING_C is enabled) |
| * |
| * \param ctx Entropy context |
| * \param data Data to add |
| * \param len Length of data |
| * |
| * \return 0 if successful |
| */ |
| int mbedtls_entropy_update_manual(mbedtls_entropy_context *ctx, |
| const unsigned char *data, size_t len); |
| |
| #if defined(MBEDTLS_ENTROPY_NV_SEED) |
| /** |
| * \brief Trigger an update of the seed file in NV by using the |
| * current entropy pool. |
| * |
| * \param ctx Entropy context |
| * |
| * \return 0 if successful |
| */ |
| int mbedtls_entropy_update_nv_seed(mbedtls_entropy_context *ctx); |
| #endif /* MBEDTLS_ENTROPY_NV_SEED */ |
| |
| #if defined(MBEDTLS_FS_IO) |
| /** |
| * \brief Write a seed file |
| * |
| * \param ctx Entropy context |
| * \param path Name of the file |
| * |
| * \return 0 if successful, |
| * MBEDTLS_ERR_ENTROPY_FILE_IO_ERROR on file error, or |
| * MBEDTLS_ERR_ENTROPY_SOURCE_FAILED |
| */ |
| int mbedtls_entropy_write_seed_file(mbedtls_entropy_context *ctx, const char *path); |
| |
| /** |
| * \brief Read and update a seed file. Seed is added to this |
| * instance. No more than MBEDTLS_ENTROPY_MAX_SEED_SIZE bytes are |
| * read from the seed file. The rest is ignored. |
| * |
| * \param ctx Entropy context |
| * \param path Name of the file |
| * |
| * \return 0 if successful, |
| * MBEDTLS_ERR_ENTROPY_FILE_IO_ERROR on file error, |
| * MBEDTLS_ERR_ENTROPY_SOURCE_FAILED |
| */ |
| int mbedtls_entropy_update_seed_file(mbedtls_entropy_context *ctx, const char *path); |
| #endif /* MBEDTLS_FS_IO */ |
| |
| #if defined(MBEDTLS_SELF_TEST) |
| /** |
| * \brief Checkup routine |
| * |
| * This module self-test also calls the entropy self-test, |
| * mbedtls_entropy_source_self_test(); |
| * |
| * \return 0 if successful, or 1 if a test failed |
| */ |
| int mbedtls_entropy_self_test(int verbose); |
| |
| #if defined(MBEDTLS_ENTROPY_HARDWARE_ALT) |
| /** |
| * \brief Checkup routine |
| * |
| * Verifies the integrity of the hardware entropy source |
| * provided by the function 'mbedtls_hardware_poll()'. |
| * |
| * Note this is the only hardware entropy source that is known |
| * at link time, and other entropy sources configured |
| * dynamically at runtime by the function |
| * mbedtls_entropy_add_source() will not be tested. |
| * |
| * \return 0 if successful, or 1 if a test failed |
| */ |
| int mbedtls_entropy_source_self_test(int verbose); |
| #endif /* MBEDTLS_ENTROPY_HARDWARE_ALT */ |
| #endif /* MBEDTLS_SELF_TEST */ |
| |
| #ifdef __cplusplus |
| } |
| #endif |
| |
| #endif /* entropy.h */ |