mbed TLS Build
Diff: include/mbedtls/ctr_drbg.h
- Revision:
- 0:cdf462088d13
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/include/mbedtls/ctr_drbg.h Thu Jan 05 00:18:44 2017 +0000 @@ -0,0 +1,290 @@ +/** + * \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 */