X-Git-Url: http://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/39cc1c879e3d75b3cafd79e4e139a7f6673dd349..700d8687944db0a48535f818b59b6c9859952c61:/common/mbedtls/ctr_drbg.h diff --git a/common/mbedtls/ctr_drbg.h b/common/mbedtls/ctr_drbg.h new file mode 100644 index 00000000..5d62f9be --- /dev/null +++ b/common/mbedtls/ctr_drbg.h @@ -0,0 +1,332 @@ +/** + * \file ctr_drbg.h + * + * \brief This file contains CTR_DRBG definitions and functions. + * + * CTR_DRBG is a standardized way of building a PRNG from a block-cipher + * in counter mode operation, as defined in NIST SP 800-90A: + * Recommendation for Random Number Generation Using Deterministic Random + * Bit Generators. + * + * The Mbed TLS implementation of CTR_DRBG uses AES-256 as the underlying + * block cipher. + */ +/* + * Copyright (C) 2006-2018, Arm Limited (or its affiliates), All Rights Reserved + * SPDX-License-Identifier: GPL-2.0 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + * + * 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 "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 /**< The requested random buffer length is too big. */ +#define MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG -0x0038 /**< The input (entropy + additional data) is too large. */ +#define MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR -0x003A /**< Read or write error in file. */ + +#define MBEDTLS_CTR_DRBG_BLOCKSIZE 16 /**< The block size used by the cipher. */ +#define MBEDTLS_CTR_DRBG_KEYSIZE 32 /**< The key size used by the cipher. */ +#define MBEDTLS_CTR_DRBG_KEYBITS ( MBEDTLS_CTR_DRBG_KEYSIZE * 8 ) /**< The key size for the DRBG operation, in bits. */ +#define MBEDTLS_CTR_DRBG_SEEDLEN ( MBEDTLS_CTR_DRBG_KEYSIZE + MBEDTLS_CTR_DRBG_BLOCKSIZE ) /**< The seed length, calculated as (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 using 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 +/**< The amount of entropy used per seed by default: + * + */ +#else +#define MBEDTLS_CTR_DRBG_ENTROPY_LEN 32 +/**< Amount of entropy used per seed by default: + * + */ +#endif +#endif + +#if !defined(MBEDTLS_CTR_DRBG_RESEED_INTERVAL) +#define MBEDTLS_CTR_DRBG_RESEED_INTERVAL 10000 +/**< The interval before reseed is performed by default. */ +#endif + +#if !defined(MBEDTLS_CTR_DRBG_MAX_INPUT) +#define MBEDTLS_CTR_DRBG_MAX_INPUT 256 +/**< The maximum number of additional input Bytes. */ +#endif + +#if !defined(MBEDTLS_CTR_DRBG_MAX_REQUEST) +#define MBEDTLS_CTR_DRBG_MAX_REQUEST 1024 +/**< The maximum number of requested Bytes per call. */ +#endif + +#if !defined(MBEDTLS_CTR_DRBG_MAX_SEED_INPUT) +#define MBEDTLS_CTR_DRBG_MAX_SEED_INPUT 384 +/**< The maximum size of seed or reseed buffer. */ +#endif + +/* \} name SECTION: Module settings */ + +#define MBEDTLS_CTR_DRBG_PR_OFF 0 +/**< Prediction resistance is disabled. */ +#define MBEDTLS_CTR_DRBG_PR_ON 1 +/**< Prediction resistance is enabled. */ + +#ifdef __cplusplus +extern "C" { +#endif + +/** + * \brief The CTR_DRBG context structure. + */ +typedef struct mbedtls_ctr_drbg_context +{ + unsigned char counter[16]; /*!< The counter (V). */ + int reseed_counter; /*!< The reseed counter. */ + int prediction_resistance; /*!< This determines whether prediction + resistance is enabled, that is + whether to systematically reseed before + each random generation. */ + size_t entropy_len; /*!< The amount of entropy grabbed on each + seed or reseed operation. */ + int reseed_interval; /*!< The reseed interval. */ + + mbedtls_aes_context aes_ctx; /*!< The AES context. */ + + /* + * Callbacks (Entropy) + */ + int (*f_entropy)(void *, unsigned char *, size_t); + /*!< The entropy callback function. */ + + void *p_entropy; /*!< The context for the entropy function. */ + +#if defined(MBEDTLS_THREADING_C) + mbedtls_threading_mutex_t mutex; +#endif +} +mbedtls_ctr_drbg_context; + +/** + * \brief This function initializes the CTR_DRBG context, + * and prepares it for mbedtls_ctr_drbg_seed() + * or mbedtls_ctr_drbg_free(). + * + * \param ctx The CTR_DRBG context to initialize. + */ +void mbedtls_ctr_drbg_init( mbedtls_ctr_drbg_context *ctx ); + +/** + * \brief This function seeds and sets up the CTR_DRBG + * 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 The CTR_DRBG context to seed. + * \param f_entropy The entropy callback, taking as arguments the + * \p p_entropy context, the buffer to fill, and the + length of the buffer. + * \param p_entropy The entropy context. + * \param custom Personalization data, that is device-specific + identifiers. Can be NULL. + * \param len The length of the personalization data. + * + * \return \c 0 on success. + * \return #MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED on failure. + */ +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 This function clears CTR_CRBG context data. + * + * \param ctx The CTR_DRBG context to clear. + */ +void mbedtls_ctr_drbg_free( mbedtls_ctr_drbg_context *ctx ); + +/** + * \brief This function turns prediction resistance on or off. + * The default value is off. + * + * \note If enabled, entropy is gathered at the beginning of + * every call to mbedtls_ctr_drbg_random_with_add(). + * Only use this if your entropy source has sufficient + * throughput. + * + * \param ctx The 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 This function sets the amount of entropy grabbed on each + * seed or reseed. The default value is + * #MBEDTLS_CTR_DRBG_ENTROPY_LEN. + * + * \param ctx The CTR_DRBG context. + * \param len The amount of entropy to grab. + */ +void mbedtls_ctr_drbg_set_entropy_len( mbedtls_ctr_drbg_context *ctx, + size_t len ); + +/** + * \brief This function sets the reseed interval. + * The default value is #MBEDTLS_CTR_DRBG_RESEED_INTERVAL. + * + * \param ctx The CTR_DRBG context. + * \param interval The reseed interval. + */ +void mbedtls_ctr_drbg_set_reseed_interval( mbedtls_ctr_drbg_context *ctx, + int interval ); + +/** + * \brief This function reseeds the CTR_DRBG context, that is + * extracts data from the entropy source. + * + * \param ctx The CTR_DRBG context. + * \param additional Additional data to add to the state. Can be NULL. + * \param len The length of the additional data. + * + * \return \c 0 on success. + * \return #MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED on failure. + */ +int mbedtls_ctr_drbg_reseed( mbedtls_ctr_drbg_context *ctx, + const unsigned char *additional, size_t len ); + +/** + * \brief This function updates the state of the CTR_DRBG context. + * + * \note If \p 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 Bytes are silently discarded. + * + * \param ctx The CTR_DRBG context. + * \param additional The data to update the state with. + * \param add_len Length of \p additional data. + * + */ +void mbedtls_ctr_drbg_update( mbedtls_ctr_drbg_context *ctx, + const unsigned char *additional, size_t add_len ); + +/** + * \brief This function updates a CTR_DRBG instance with additional + * data and uses it to generate random data. + * + * \note The function automatically reseeds if the reseed counter is exceeded. + * + * \param p_rng The CTR_DRBG context. This must be a pointer to a + * #mbedtls_ctr_drbg_context structure. + * \param output The buffer to fill. + * \param output_len The length of the buffer. + * \param additional Additional data to update. Can be NULL. + * \param add_len The length of the additional data. + * + * \return \c 0 on success. + * \return #MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED or + * #MBEDTLS_ERR_CTR_DRBG_REQUEST_TOO_BIG on failure. + */ +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 This function uses CTR_DRBG to generate random data. + * + * \note The function automatically reseeds if the reseed counter is exceeded. + * + * \param p_rng The CTR_DRBG context. This must be a pointer to a + * #mbedtls_ctr_drbg_context structure. + * \param output The buffer to fill. + * \param output_len The length of the buffer. + * + * \return \c 0 on success. + * \return #MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED or + * #MBEDTLS_ERR_CTR_DRBG_REQUEST_TOO_BIG on failure. + */ +int mbedtls_ctr_drbg_random( void *p_rng, + unsigned char *output, size_t output_len ); + +#if defined(MBEDTLS_FS_IO) +/** + * \brief This function writes a seed file. + * + * \param ctx The CTR_DRBG context. + * \param path The name of the file. + * + * \return \c 0 on success. + * \return #MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR on file error. + * \return #MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED on + * failure. + */ +int mbedtls_ctr_drbg_write_seed_file( mbedtls_ctr_drbg_context *ctx, const char *path ); + +/** + * \brief This function reads and updates a seed file. The seed + * is added to this instance. + * + * \param ctx The CTR_DRBG context. + * \param path The name of the file. + * + * \return \c 0 on success. + * \return #MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR on file error. + * \return #MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED or + * #MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG on failure. + */ +int mbedtls_ctr_drbg_update_seed_file( mbedtls_ctr_drbg_context *ctx, const char *path ); +#endif /* MBEDTLS_FS_IO */ + +/** + * \brief The CTR_DRBG checkup routine. + * + * \return \c 0 on success. + * \return \c 1 on failure. + */ +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 */