| /** |
| * \file ctr_drbg.h |
| * |
| * \brief CTR_DRBG based on AES-256 (NIST SP 800-90) |
| * |
| * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved |
| * 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. |
| * |
| * This file is part of mbed TLS (https://tls.mbed.org) |
| */ |
| #ifndef MBEDTLS_CTR_DRBG_H |
| #define MBEDTLS_CTR_DRBG_H |
| |
| #include "aes.h" |
| |
| #if defined(MBEDTLS_THREADING_C) |
| #include "mbedtls/threading.h" |
| #endif |
| |
| #define MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED -0x0034 /**< The entropy source failed. */ |
| #define MBEDTLS_ERR_CTR_DRBG_REQUEST_TOO_BIG -0x0036 /**< Too many random requested in single call. */ |
| #define MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG -0x0038 /**< Input too large (Entropy + additional). */ |
| #define MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR -0x003A /**< Read/write error in file. */ |
| |
| #define MBEDTLS_CTR_DRBG_BLOCKSIZE 16 /**< Block size used by the cipher */ |
| #define MBEDTLS_CTR_DRBG_KEYSIZE 32 /**< Key size used by the cipher */ |
| #define MBEDTLS_CTR_DRBG_KEYBITS ( MBEDTLS_CTR_DRBG_KEYSIZE * 8 ) |
| #define MBEDTLS_CTR_DRBG_SEEDLEN ( MBEDTLS_CTR_DRBG_KEYSIZE + MBEDTLS_CTR_DRBG_BLOCKSIZE ) |
| /**< The seed length (counter + AES key) */ |
| |
| /** |
| * \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_CTR_DRBG_ENTROPY_LEN) |
| #if defined(MBEDTLS_SHA512_C) && !defined(MBEDTLS_ENTROPY_FORCE_SHA256) |
| #define MBEDTLS_CTR_DRBG_ENTROPY_LEN 48 /**< Amount of entropy used per seed by default (48 with SHA-512, 32 with SHA-256) */ |
| #else |
| #define MBEDTLS_CTR_DRBG_ENTROPY_LEN 32 /**< Amount of entropy used per seed by default (48 with SHA-512, 32 with SHA-256) */ |
| #endif |
| #endif |
| |
| #if !defined(MBEDTLS_CTR_DRBG_RESEED_INTERVAL) |
| #define MBEDTLS_CTR_DRBG_RESEED_INTERVAL 10000 /**< Interval before reseed is performed by default */ |
| #endif |
| |
| #if !defined(MBEDTLS_CTR_DRBG_MAX_INPUT) |
| #define MBEDTLS_CTR_DRBG_MAX_INPUT 256 /**< Maximum number of additional input bytes */ |
| #endif |
| |
| #if !defined(MBEDTLS_CTR_DRBG_MAX_REQUEST) |
| #define MBEDTLS_CTR_DRBG_MAX_REQUEST 1024 /**< Maximum number of requested bytes per call */ |
| #endif |
| |
| #if !defined(MBEDTLS_CTR_DRBG_MAX_SEED_INPUT) |
| #define MBEDTLS_CTR_DRBG_MAX_SEED_INPUT 384 /**< Maximum size of (re)seed buffer */ |
| #endif |
| |
| /* \} name SECTION: Module settings */ |
| |
| #define MBEDTLS_CTR_DRBG_PR_OFF 0 /**< No prediction resistance */ |
| #define MBEDTLS_CTR_DRBG_PR_ON 1 /**< Prediction resistance enabled */ |
| |
| #ifdef __cplusplus |
| extern "C" { |
| #endif |
| |
| /** |
| * \brief CTR_DRBG context structure |
| */ |
| typedef struct |
| { |
| unsigned char counter[16]; /*!< counter (V) */ |
| int reseed_counter; /*!< reseed counter */ |
| int prediction_resistance; /*!< enable prediction resistance (Automatic |
| reseed before every random generation) */ |
| size_t entropy_len; /*!< amount of entropy grabbed on each |
| (re)seed */ |
| int reseed_interval; /*!< reseed interval */ |
| |
| mbedtls_aes_context aes_ctx; /*!< AES context */ |
| |
| /* |
| * Callbacks (Entropy) |
| */ |
| int (*f_entropy)(void *, unsigned char *, size_t); |
| |
| void *p_entropy; /*!< context for the entropy function */ |
| |
| #if defined(MBEDTLS_THREADING_C) |
| mbedtls_threading_mutex_t mutex; |
| #endif |
| } |
| mbedtls_ctr_drbg_context; |
| |
| /** |
| * \brief CTR_DRBG context initialization |
| * Makes the context ready for mbedtls_ctr_drbg_seed() or |
| * mbedtls_ctr_drbg_free(). |
| * |
| * \param ctx CTR_DRBG context to be initialized |
| */ |
| void mbedtls_ctr_drbg_init( mbedtls_ctr_drbg_context *ctx ); |
| |
| /** |
| * \brief CTR_DRBG initial seeding |
| * Seed and setup entropy source for future reseeds. |
| * |
| * Note: Personalization data can be provided in addition to the more generic |
| * entropy source to make this instantiation as unique as possible. |
| * |
| * \param ctx CTR_DRBG context to be seeded |
| * \param f_entropy Entropy callback (p_entropy, buffer to fill, buffer |
| * length) |
| * \param p_entropy Entropy context |
| * \param custom Personalization data (Device specific identifiers) |
| * (Can be NULL) |
| * \param len Length of personalization data |
| * |
| * \return 0 if successful, or |
| * MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED |
| */ |
| 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 ); |
| |
| /** |
| * \brief Clear CTR_CRBG context data |
| * |
| * \param ctx CTR_DRBG context to clear |
| */ |
| void mbedtls_ctr_drbg_free( mbedtls_ctr_drbg_context *ctx ); |
| |
| /** |
| * \brief Enable / disable prediction resistance (Default: Off) |
| * |
| * Note: If enabled, entropy is used for ctx->entropy_len before each call! |
| * Only use this if you have ample supply of good entropy! |
| * |
| * \param ctx CTR_DRBG context |
| * \param resistance MBEDTLS_CTR_DRBG_PR_ON or MBEDTLS_CTR_DRBG_PR_OFF |
| */ |
| void mbedtls_ctr_drbg_set_prediction_resistance( mbedtls_ctr_drbg_context *ctx, |
| int resistance ); |
| |
| /** |
| * \brief Set the amount of entropy grabbed on each (re)seed |
| * (Default: MBEDTLS_CTR_DRBG_ENTROPY_LEN) |
| * |
| * \param ctx CTR_DRBG context |
| * \param len Amount of entropy to grab |
| */ |
| void mbedtls_ctr_drbg_set_entropy_len( mbedtls_ctr_drbg_context *ctx, |
| size_t len ); |
| |
| /** |
| * \brief Set the reseed interval |
| * (Default: MBEDTLS_CTR_DRBG_RESEED_INTERVAL) |
| * |
| * \param ctx CTR_DRBG context |
| * \param interval Reseed interval |
| */ |
| void mbedtls_ctr_drbg_set_reseed_interval( mbedtls_ctr_drbg_context *ctx, |
| int interval ); |
| |
| /** |
| * \brief CTR_DRBG reseeding (extracts data from entropy source) |
| * |
| * \param ctx CTR_DRBG context |
| * \param additional Additional data to add to state (Can be NULL) |
| * \param len Length of additional data |
| * |
| * \return 0 if successful, or |
| * MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED |
| */ |
| int mbedtls_ctr_drbg_reseed( mbedtls_ctr_drbg_context *ctx, |
| const unsigned char *additional, size_t len ); |
| |
| /** |
| * \brief CTR_DRBG update state |
| * |
| * \param ctx CTR_DRBG context |
| * \param additional Additional data to update state with |
| * \param add_len Length of additional data |
| * |
| * \note If add_len is greater than MBEDTLS_CTR_DRBG_MAX_SEED_INPUT, |
| * only the first MBEDTLS_CTR_DRBG_MAX_SEED_INPUT bytes are used, |
| * the remaining ones are silently discarded. |
| */ |
| void mbedtls_ctr_drbg_update( mbedtls_ctr_drbg_context *ctx, |
| const unsigned char *additional, size_t add_len ); |
| |
| /** |
| * \brief CTR_DRBG generate random with additional update input |
| * |
| * Note: Automatically reseeds if reseed_counter is reached. |
| * |
| * \param p_rng CTR_DRBG context |
| * \param output Buffer to fill |
| * \param output_len Length of the buffer |
| * \param additional Additional data to update with (Can be NULL) |
| * \param add_len Length of additional data |
| * |
| * \return 0 if successful, or |
| * MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED, or |
| * MBEDTLS_ERR_CTR_DRBG_REQUEST_TOO_BIG |
| */ |
| 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 ); |
| |
| /** |
| * \brief CTR_DRBG generate random |
| * |
| * Note: Automatically reseeds if reseed_counter is reached. |
| * |
| * \param p_rng CTR_DRBG context |
| * \param output Buffer to fill |
| * \param output_len Length of the buffer |
| * |
| * \return 0 if successful, or |
| * MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED, or |
| * MBEDTLS_ERR_CTR_DRBG_REQUEST_TOO_BIG |
| */ |
| int mbedtls_ctr_drbg_random( void *p_rng, |
| unsigned char *output, size_t output_len ); |
| |
| #if defined(MBEDTLS_FS_IO) |
| /** |
| * \brief Write a seed file |
| * |
| * \param ctx CTR_DRBG context |
| * \param path Name of the file |
| * |
| * \return 0 if successful, |
| * MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR on file error, or |
| * MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED |
| */ |
| int mbedtls_ctr_drbg_write_seed_file( mbedtls_ctr_drbg_context *ctx, const char *path ); |
| |
| /** |
| * \brief Read and update a seed file. Seed is added to this |
| * instance |
| * |
| * \param ctx CTR_DRBG context |
| * \param path Name of the file |
| * |
| * \return 0 if successful, |
| * MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR on file error, |
| * MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED or |
| * MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG |
| */ |
| int mbedtls_ctr_drbg_update_seed_file( mbedtls_ctr_drbg_context *ctx, const char *path ); |
| #endif /* MBEDTLS_FS_IO */ |
| |
| /** |
| * \brief Checkup routine |
| * |
| * \return 0 if successful, or 1 if the test failed |
| */ |
| int mbedtls_ctr_drbg_self_test( int verbose ); |
| |
| /* Internal functions (do not call directly) */ |
| int mbedtls_ctr_drbg_seed_entropy_len( mbedtls_ctr_drbg_context *, |
| int (*)(void *, unsigned char *, size_t), void *, |
| const unsigned char *, size_t, size_t ); |
| |
| #ifdef __cplusplus |
| } |
| #endif |
| |
| #endif /* ctr_drbg.h */ |
