ctr_drbg.h

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/*
 *  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

#if !defined(MBEDTLS_CONFIG_FILE)
#include "mbedtls/config.h"
#else
#include MBEDTLS_CONFIG_FILE
#endif

#include "mbedtls/aes.h"

#if defined(MBEDTLS_THREADING_C)
#include "mbedtls/threading.h"
#endif

#define MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED        -0x0034  
#define MBEDTLS_ERR_CTR_DRBG_REQUEST_TOO_BIG              -0x0036  
#define MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG                -0x0038  
#define MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR                -0x003A  
#define MBEDTLS_CTR_DRBG_BLOCKSIZE          16 
#if defined(MBEDTLS_CTR_DRBG_USE_128_BIT_KEY)
#define MBEDTLS_CTR_DRBG_KEYSIZE            16 
#else
#define MBEDTLS_CTR_DRBG_KEYSIZE            32 
#endif

#define MBEDTLS_CTR_DRBG_KEYBITS            ( MBEDTLS_CTR_DRBG_KEYSIZE * 8 ) 
#define MBEDTLS_CTR_DRBG_SEEDLEN            ( MBEDTLS_CTR_DRBG_KEYSIZE + MBEDTLS_CTR_DRBG_BLOCKSIZE ) 
#if !defined(MBEDTLS_CTR_DRBG_ENTROPY_LEN)
#if defined(MBEDTLS_SHA512_C) && !defined(MBEDTLS_ENTROPY_FORCE_SHA256)
#define MBEDTLS_CTR_DRBG_ENTROPY_LEN        48

#else
#define MBEDTLS_CTR_DRBG_ENTROPY_LEN        32

#endif
#endif

#if !defined(MBEDTLS_CTR_DRBG_RESEED_INTERVAL)
#define MBEDTLS_CTR_DRBG_RESEED_INTERVAL    10000

#endif

#if !defined(MBEDTLS_CTR_DRBG_MAX_INPUT)
#define MBEDTLS_CTR_DRBG_MAX_INPUT          256

#endif

#if !defined(MBEDTLS_CTR_DRBG_MAX_REQUEST)
#define MBEDTLS_CTR_DRBG_MAX_REQUEST        1024

#endif

#if !defined(MBEDTLS_CTR_DRBG_MAX_SEED_INPUT)
#define MBEDTLS_CTR_DRBG_MAX_SEED_INPUT     384

#endif

#define MBEDTLS_CTR_DRBG_PR_OFF             0

#define MBEDTLS_CTR_DRBG_PR_ON              1

#ifdef __cplusplus
extern "C" {
#endif

typedef struct mbedtls_ctr_drbg_context
{
    unsigned char counter[16];  
    int reseed_counter;         
    int prediction_resistance;  
    size_t entropy_len;         
    int reseed_interval;        
    mbedtls_aes_context aes_ctx;        
    /*
     * Callbacks (Entropy)
     */
    int (*f_entropy)(void *, unsigned char *, size_t);
    void *p_entropy;            
#if defined(MBEDTLS_THREADING_C)
    mbedtls_threading_mutex_t mutex;
#endif
}
mbedtls_ctr_drbg_context;

void mbedtls_ctr_drbg_init( mbedtls_ctr_drbg_context *ctx );

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 );

void mbedtls_ctr_drbg_free( mbedtls_ctr_drbg_context *ctx );

void mbedtls_ctr_drbg_set_prediction_resistance( mbedtls_ctr_drbg_context *ctx,
                                         int resistance );

void mbedtls_ctr_drbg_set_entropy_len( mbedtls_ctr_drbg_context *ctx,
                               size_t len );

void mbedtls_ctr_drbg_set_reseed_interval( mbedtls_ctr_drbg_context *ctx,
                                   int interval );

int mbedtls_ctr_drbg_reseed( mbedtls_ctr_drbg_context *ctx,
                     const unsigned char *additional, size_t len );

int mbedtls_ctr_drbg_update_ret( mbedtls_ctr_drbg_context *ctx,
                                 const unsigned char *additional,
                                 size_t add_len );

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 );

int mbedtls_ctr_drbg_random( void *p_rng,
                     unsigned char *output, size_t output_len );


#if ! defined(MBEDTLS_DEPRECATED_REMOVED)
#if defined(MBEDTLS_DEPRECATED_WARNING)
#define MBEDTLS_DEPRECATED    __attribute__((deprecated))
#else
#define MBEDTLS_DEPRECATED
#endif

MBEDTLS_DEPRECATED void mbedtls_ctr_drbg_update(
    mbedtls_ctr_drbg_context *ctx,
    const unsigned char *additional,
    size_t add_len );
#undef MBEDTLS_DEPRECATED
#endif /* !MBEDTLS_DEPRECATED_REMOVED */

#if defined(MBEDTLS_FS_IO)

int mbedtls_ctr_drbg_write_seed_file( mbedtls_ctr_drbg_context *ctx, const char *path );

int mbedtls_ctr_drbg_update_seed_file( mbedtls_ctr_drbg_context *ctx, const char *path );
#endif /* MBEDTLS_FS_IO */

#if defined(MBEDTLS_SELF_TEST)

int mbedtls_ctr_drbg_self_test( int verbose );

#endif /* MBEDTLS_SELF_TEST */

/* 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 */