mirror of
https://github.com/yuzu-emu/mbedtls.git
synced 2024-12-30 23:25:35 +00:00
331 lines
12 KiB
C
331 lines
12 KiB
C
/**
|
|
* \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 <em>NIST SP 800-90A:
|
|
* Recommendation for Random Number Generation Using Deterministic Random
|
|
* Bit Generators</em>.
|
|
*
|
|
* 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: 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 /**< 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:
|
|
* <ul><li>48 with SHA-512.</li>
|
|
* <li>32 with SHA-256.</li></ul>
|
|
*/
|
|
#else
|
|
#define MBEDTLS_CTR_DRBG_ENTROPY_LEN 32
|
|
/**< Amount of entropy used per seed by default:
|
|
* <ul><li>48 with SHA-512.</li>
|
|
* <li>32 with SHA-256.</li></ul>
|
|
*/
|
|
#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
|
|
{
|
|
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 */
|