File syn_hmac_drbg.c¶

FileList > crypto > syn_hmac_drbg.c

NIST SP 800-90A HMAC-DRBG (Deterministic Random Bit Generator) implementation.

#include "../util/syn_assert.h"
#include "syn_hmac_drbg.h"
#include <string.h>

Public Functions¶

Type	Name
SYN_Status	syn_hmac_drbg_generate (SYN_HMAC_DRBG * ctx, uint8_t * out, size_t out_len, const uint8_t * add_input, size_t add_len) Generate pseudorandom bytes from the HMAC-DRBG.
SYN_Status	syn_hmac_drbg_generate_pr (SYN_HMAC_DRBG * ctx, uint8_t * out, size_t out_len, const uint8_t * entropy, size_t ent_len, const uint8_t * add_input, size_t add_len) Generate pseudorandom bytes with Prediction Resistance (PR).
SYN_Status	syn_hmac_drbg_init (SYN_HMAC_DRBG * ctx, const uint8_t * entropy, size_t ent_len, const uint8_t * nonce, size_t nonce_len, const uint8_t * pers_str, size_t pers_len) Instantiate the HMAC-DRBG state with initial entropy, nonce, and optional personalization.
SYN_Status	syn_hmac_drbg_reseed (SYN_HMAC_DRBG * ctx, const uint8_t * entropy, size_t ent_len, const uint8_t * add_input, size_t add_len) Reseed the HMAC-DRBG with fresh entropy and optional additional input.
void	syn_hmac_drbg_set_reseed_interval (SYN_HMAC_DRBG * ctx, uint32_t interval) Set the maximum reseed interval for the DRBG instance.
void	syn_hmac_drbg_wipe (SYN_HMAC_DRBG * ctx) Securely wipe internal working key, state vector, and counters.

Public Static Functions¶

Type	Name
void	drbg_update (SYN_HMAC_DRBG * ctx, const uint8_t * c1, size_t l1, const uint8_t * c2, size_t l2, const uint8_t * c3, size_t l3) Internal HMAC-DRBG state update function per NIST SP 800-90A Rev 1 Section 10.1.2.2.

Public Functions Documentation¶

function syn_hmac_drbg_generate¶

Generate pseudorandom bytes from the HMAC-DRBG.

SYN_Status syn_hmac_drbg_generate (
    SYN_HMAC_DRBG * ctx,
    uint8_t * out,
    size_t out_len,
    const uint8_t * add_input,
    size_t add_len
)

Implements NIST SP 800-90A Rev 1 Section 10.1.2.5 without prediction resistance.

Parameters:

ctx Pointer to initialized DRBG context.
out [out] Destination buffer for generated random bytes.
out_len Number of random bytes to generate (<= 65536).
add_input Optional additional input buffer (can be NULL).
add_len Length of additional input in bytes.

Returns:

SYN_OK on success, SYN_ERROR if reseed interval is exceeded (reseed required), SYN_INVALID_PARAM if parameters or state are invalid.

function syn_hmac_drbg_generate_pr¶

Generate pseudorandom bytes with Prediction Resistance (PR).

SYN_Status syn_hmac_drbg_generate_pr (
    SYN_HMAC_DRBG * ctx,
    uint8_t * out,
    size_t out_len,
    const uint8_t * entropy,
    size_t ent_len,
    const uint8_t * add_input,
    size_t add_len
)

Reseeds the DRBG with fresh entropy before generating pseudorandom bytes.

Parameters:

ctx Pointer to initialized DRBG context.
out [out] Destination buffer for generated random bytes.
out_len Number of random bytes to generate (<= 65536).
entropy Fresh entropy for prediction resistance (must be >= 32 bytes).
ent_len Length of entropy in bytes (must be >= 32).
add_input Optional additional input buffer (can be NULL).
add_len Length of additional input in bytes.

Returns:

SYN_OK on success, SYN_INVALID_PARAM on invalid inputs.

function syn_hmac_drbg_init¶

Instantiate the HMAC-DRBG state with initial entropy, nonce, and optional personalization.

SYN_Status syn_hmac_drbg_init (
    SYN_HMAC_DRBG * ctx,
    const uint8_t * entropy,
    size_t ent_len,
    const uint8_t * nonce,
    size_t nonce_len,
    const uint8_t * pers_str,
    size_t pers_len
)

Implements NIST SP 800-90A Rev 1 Section 10.1.2.3.

Parameters:

ctx Pointer to caller-allocated DRBG context.
entropy Initial entropy input buffer (must be at least 32 bytes).
ent_len Length of entropy in bytes (must be >= 32).
nonce Nonce buffer (can be NULL if ent_len includes extra entropy).
nonce_len Length of nonce in bytes.
pers_str Optional personalization string (can be NULL).
pers_len Length of personalization string in bytes.

Returns:

SYN_OK on success, SYN_INVALID_PARAM if inputs are invalid.

function syn_hmac_drbg_reseed¶

Reseed the HMAC-DRBG with fresh entropy and optional additional input.

SYN_Status syn_hmac_drbg_reseed (
    SYN_HMAC_DRBG * ctx,
    const uint8_t * entropy,
    size_t ent_len,
    const uint8_t * add_input,
    size_t add_len
)

Implements NIST SP 800-90A Rev 1 Section 10.1.2.4.

Parameters:

ctx Pointer to initialized DRBG context.
entropy Fresh entropy input buffer (must be at least 32 bytes).
ent_len Length of entropy in bytes (must be >= 32).
add_input Optional additional input buffer (can be NULL).
add_len Length of additional input in bytes.

Returns:

SYN_OK on success, SYN_INVALID_PARAM if inputs or state are invalid.

function syn_hmac_drbg_set_reseed_interval¶

Set the maximum reseed interval for the DRBG instance.

void syn_hmac_drbg_set_reseed_interval (
    SYN_HMAC_DRBG * ctx,
    uint32_t interval
)

Parameters:

ctx Pointer to DRBG context.
interval Maximum number of generate calls before reseed is required (default: 10000).

function syn_hmac_drbg_wipe¶

Securely wipe internal working key, state vector, and counters.

void syn_hmac_drbg_wipe (
    SYN_HMAC_DRBG * ctx
)

Parameters:

ctx Pointer to DRBG context.

Public Static Functions Documentation¶

function drbg_update¶

Internal HMAC-DRBG state update function per NIST SP 800-90A Rev 1 Section 10.1.2.2.

static void drbg_update (
    SYN_HMAC_DRBG * ctx,
    const uint8_t * c1,
    size_t l1,
    const uint8_t * c2,
    size_t l2,
    const uint8_t * c3,
    size_t l3
)

Parameters:

ctx Pointer to DRBG context.
c1 First chunk of provided data (or NULL).
l1 Length of first chunk.
c2 Second chunk of provided data (or NULL).
l2 Length of second chunk.
c3 Third chunk of provided data (or NULL).
l3 Length of third chunk.

The documentation for this class was generated from the following file src/syntropic/crypto/syn_hmac_drbg.c