hmac_drbg.h

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#ifndef MBEDTLS_HMAC_DRBG_H
#define MBEDTLS_HMAC_DRBG_H

#include "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
{
    /* Working state: the key K is not stored explicitely,
     * but is implied by the HMAC context */
    mbedtls_md_context_t md_ctx;                    
    unsigned char V[MBEDTLS_MD_MAX_SIZE];  
    int reseed_counter;                     
    /* Administrative state */
    size_t entropy_len;         
    int prediction_resistance;  
    int reseed_interval;        
    /* Callbacks */
    int (*f_entropy)(void *, unsigned char *, size_t); 
    void *p_entropy;            
#if defined(MBEDTLS_THREADING_C)
    mbedtls_threading_mutex_t mutex;
#endif
} mbedtls_hmac_drbg_context;

void mbedtls_hmac_drbg_init( mbedtls_hmac_drbg_context *ctx );

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 );

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 );

void 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 );

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 */