hmac_drbg.h

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/*
 *  Copyright The Mbed TLS Contributors
 *  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.
 */
#ifndef MBEDTLS_HMAC_DRBG_H
#define MBEDTLS_HMAC_DRBG_H
#include "mbedtls/private_access.h"

#include "mbedtls/build_info.h"

#include "mbedtls/md.h"

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

/*
 * Error codes
 */
#define MBEDTLS_ERR_HMAC_DRBG_REQUEST_TOO_BIG              -0x0003

#define MBEDTLS_ERR_HMAC_DRBG_INPUT_TOO_BIG                -0x0005

#define MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR                -0x0007

#define MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED        -0x0009

#if !defined(MBEDTLS_HMAC_DRBG_RESEED_INTERVAL)
#define MBEDTLS_HMAC_DRBG_RESEED_INTERVAL   10000   
#endif

#if !defined(MBEDTLS_HMAC_DRBG_MAX_INPUT)
#define MBEDTLS_HMAC_DRBG_MAX_INPUT         256     
#endif

#if !defined(MBEDTLS_HMAC_DRBG_MAX_REQUEST)
#define MBEDTLS_HMAC_DRBG_MAX_REQUEST       1024    
#endif

#if !defined(MBEDTLS_HMAC_DRBG_MAX_SEED_INPUT)
#define MBEDTLS_HMAC_DRBG_MAX_SEED_INPUT    384     
#endif

/* \} name SECTION: Module settings */

#define MBEDTLS_HMAC_DRBG_PR_OFF   0   
#define MBEDTLS_HMAC_DRBG_PR_ON    1   
#ifdef __cplusplus
extern "C" {
#endif

typedef struct mbedtls_hmac_drbg_context
{
    /* Working state: the key K is not stored explicitly,
     * but is implied by the HMAC context */
    mbedtls_md_context_t MBEDTLS_PRIVATE(md_ctx);                    
    unsigned char MBEDTLS_PRIVATE(V)[MBEDTLS_MD_MAX_SIZE];  
    int MBEDTLS_PRIVATE(reseed_counter);                     
    /* Administrative state */
    size_t MBEDTLS_PRIVATE(entropy_len);         
    int MBEDTLS_PRIVATE(prediction_resistance);  
    int MBEDTLS_PRIVATE(reseed_interval);        
    /* Callbacks */
    int (*MBEDTLS_PRIVATE(f_entropy))(void *, unsigned char *, size_t); 
    void *MBEDTLS_PRIVATE(p_entropy);            
#if defined(MBEDTLS_THREADING_C)
    /* Invariant: the mutex is initialized if and only if
     * md_ctx->md_info != NULL. This means that the mutex is initialized
     * during the initial seeding in mbedtls_hmac_drbg_seed() or
     * mbedtls_hmac_drbg_seed_buf() and freed in mbedtls_ctr_drbg_free().
     *
     * Note that this invariant may change without notice. Do not rely on it
     * and do not access the mutex directly in application code.
     */
    mbedtls_threading_mutex_t MBEDTLS_PRIVATE(mutex);
#endif
} mbedtls_hmac_drbg_context;

void mbedtls_hmac_drbg_init( mbedtls_hmac_drbg_context *ctx );

#if defined(MBEDTLS_THREADING_C)

#endif /* MBEDTLS_THREADING_C */

int mbedtls_hmac_drbg_seed( mbedtls_hmac_drbg_context *ctx,
                    const mbedtls_md_info_t * md_info,
                    int (*f_entropy)(void *, unsigned char *, size_t),
                    void *p_entropy,
                    const unsigned char *custom,
                    size_t len );

#if defined(MBEDTLS_THREADING_C)

#endif /* MBEDTLS_THREADING_C */

int mbedtls_hmac_drbg_seed_buf( mbedtls_hmac_drbg_context *ctx,
                        const mbedtls_md_info_t * md_info,
                        const unsigned char *data, size_t data_len );

void mbedtls_hmac_drbg_set_prediction_resistance( mbedtls_hmac_drbg_context *ctx,
                                          int resistance );

void mbedtls_hmac_drbg_set_entropy_len( mbedtls_hmac_drbg_context *ctx,
                                size_t len );

void mbedtls_hmac_drbg_set_reseed_interval( mbedtls_hmac_drbg_context *ctx,
                                    int interval );

int mbedtls_hmac_drbg_update( mbedtls_hmac_drbg_context *ctx,
                              const unsigned char *additional, size_t add_len );

int mbedtls_hmac_drbg_reseed( mbedtls_hmac_drbg_context *ctx,
                      const unsigned char *additional, size_t len );

int mbedtls_hmac_drbg_random_with_add( void *p_rng,
                               unsigned char *output, size_t output_len,
                               const unsigned char *additional,
                               size_t add_len );

#if defined(MBEDTLS_THREADING_C)

#endif /* MBEDTLS_THREADING_C */

int mbedtls_hmac_drbg_random( void *p_rng, unsigned char *output, size_t out_len );

void mbedtls_hmac_drbg_free( mbedtls_hmac_drbg_context *ctx );

#if defined(MBEDTLS_FS_IO)

int mbedtls_hmac_drbg_write_seed_file( mbedtls_hmac_drbg_context *ctx, const char *path );

int mbedtls_hmac_drbg_update_seed_file( mbedtls_hmac_drbg_context *ctx, const char *path );
#endif /* MBEDTLS_FS_IO */


#if defined(MBEDTLS_SELF_TEST)

int mbedtls_hmac_drbg_self_test( int verbose );
#endif

#ifdef __cplusplus
}
#endif

#endif /* hmac_drbg.h */