File syn_blake2s.h¶

FileList > crypto > syn_blake2s.h

BLAKE2s cryptographic hash — RFC 7693, pure C99. More...

#include <stddef.h>
#include <stdint.h>
#include <string.h>

Classes¶

Type	Name
struct	SYN_BLAKE2s BLAKE2s hash context — caller-owned.
struct	SYN_HMAC_BLAKE2s HMAC-BLAKE2s context — caller-owned.

Public Functions¶

Type	Name
void	syn_blake2s_final (SYN_BLAKE2s * ctx, uint8_t * out) Finalize and produce the digest.
void	syn_blake2s_init (SYN_BLAKE2s * ctx, size_t outlen) Initialize BLAKE2s for unkeyed hashing.
void	syn_blake2s_init_keyed (SYN_BLAKE2s * ctx, const void * key, size_t keylen, size_t outlen) Initialize BLAKE2s for keyed hashing (MAC mode).
void	syn_blake2s_update (SYN_BLAKE2s * ctx, const void * data, size_t len) Feed data into the hash.

Public Static Functions¶

Type	Name
void	syn_blake2s (const void * data, size_t len, uint8_t * out, size_t outlen) One-shot unkeyed BLAKE2s hash.
void	syn_blake2s_mac (const void * key, size_t keylen, const void * data, size_t len, uint8_t * out, size_t outlen) One-shot keyed BLAKE2s MAC.
void	syn_hmac_blake2s (const void * key, size_t keylen, const void * data, size_t datalen, uint8_t mac) One-shot HMAC-BLAKE2s.
void	syn_hmac_blake2s_final (SYN_HMAC_BLAKE2s * ctx, uint8_t mac) Finalize HMAC-BLAKE2s and produce 32-byte MAC.
void	syn_hmac_blake2s_init (SYN_HMAC_BLAKE2s * ctx, const void * key, size_t keylen) Initialize HMAC-BLAKE2s with a key.
void	syn_hmac_blake2s_update (SYN_HMAC_BLAKE2s * ctx, const void * data, size_t len) Feed message data into the HMAC.

Macros¶

Type	Name
define	SYN_BLAKE2S_BLOCK_SIZE `64`
define	SYN_BLAKE2S_MAX_DIGEST `32`
define	SYN_BLAKE2S_MAX_KEY `32`

Detailed Description¶

Supports both unkeyed hashing and keyed MAC mode. WireGuard uses both: unkeyed BLAKE2s-256 for chaining hash, keyed BLAKE2s for MAC.

Context is caller-owned (~120 bytes on 32-bit targets). No heap.

Also provides HMAC-BLAKE2s as static inline functions — used internally by the WireGuard module for HKDF key derivation.

** **

// Unkeyed hash:
uint8_t hash[32];
syn_blake2s(data, len, hash, 32);

// Keyed MAC (16-byte tag):
uint8_t mac[16];
syn_blake2s_mac(key, 32, data, len, mac, 16);

// Streaming:
SYN_BLAKE2s ctx;
syn_blake2s_init(&ctx, 32);
syn_blake2s_update(&ctx, chunk1, len1);
syn_blake2s_update(&ctx, chunk2, len2);
syn_blake2s_final(&ctx, hash);

Public Functions Documentation¶

function syn_blake2s_final¶

Finalize and produce the digest.

void syn_blake2s_final (
    SYN_BLAKE2s * ctx,
    uint8_t * out
)

After calling this, the context must be re-initialized before reuse.

Parameters:

ctx BLAKE2s context.
out Output buffer (must be at least ctx->outlen bytes).

function syn_blake2s_init¶

Initialize BLAKE2s for unkeyed hashing.

void syn_blake2s_init (
    SYN_BLAKE2s * ctx,
    size_t outlen
)

Parameters:

ctx Context to initialize.
outlen Desired digest length (1–32).

function syn_blake2s_init_keyed¶

Initialize BLAKE2s for keyed hashing (MAC mode).

void syn_blake2s_init_keyed (
    SYN_BLAKE2s * ctx,
    const void * key,
    size_t keylen,
    size_t outlen
)

Parameters:

ctx Context to initialize.
key Secret key.
keylen Key length (1–32).
outlen Desired digest length (1–32).

function syn_blake2s_update¶

Feed data into the hash.

void syn_blake2s_update (
    SYN_BLAKE2s * ctx,
    const void * data,
    size_t len
)

Parameters:

ctx BLAKE2s context.
data Data to hash.
len Length in bytes.

Public Static Functions Documentation¶

function syn_blake2s¶

One-shot unkeyed BLAKE2s hash.

static inline void syn_blake2s (
    const void * data,
    size_t len,
    uint8_t * out,
    size_t outlen
)

Parameters:

data Data to hash.
len Length in bytes.
out Output buffer.
outlen Desired digest length (1–32).

function syn_blake2s_mac¶

One-shot keyed BLAKE2s MAC.

static inline void syn_blake2s_mac (
    const void * key,
    size_t keylen,
    const void * data,
    size_t len,
    uint8_t * out,
    size_t outlen
)

Parameters:

key Secret key.
keylen Key length (1–32).
data Data to authenticate.
len Data length in bytes.
out Output buffer.
outlen Desired MAC length (1–32).

function syn_hmac_blake2s¶

One-shot HMAC-BLAKE2s.

static inline void syn_hmac_blake2s (
    const void * key,
    size_t keylen,
    const void * data,
    size_t datalen,
    uint8_t mac
)

Parameters:

key Secret key.
keylen Key length in bytes.
data Message data.
datalen Message length in bytes.
mac Output buffer for the 32-byte MAC.

function syn_hmac_blake2s_final¶

Finalize HMAC-BLAKE2s and produce 32-byte MAC.

static inline void syn_hmac_blake2s_final (
    SYN_HMAC_BLAKE2s * ctx,
    uint8_t mac
)

Parameters:

ctx HMAC context.
mac Output buffer for the 32-byte MAC.

function syn_hmac_blake2s_init¶

Initialize HMAC-BLAKE2s with a key.

static inline void syn_hmac_blake2s_init (
    SYN_HMAC_BLAKE2s * ctx,
    const void * key,
    size_t keylen
)

Parameters:

ctx HMAC context.
key Secret key.
keylen Key length in bytes.

function syn_hmac_blake2s_update¶

Feed message data into the HMAC.

static inline void syn_hmac_blake2s_update (
    SYN_HMAC_BLAKE2s * ctx,
    const void * data,
    size_t len
)

Parameters:

ctx HMAC context.
data Message data.
len Data length in bytes.

Macro Definition Documentation¶

define SYN_BLAKE2S_BLOCK_SIZE¶

#define SYN_BLAKE2S_BLOCK_SIZE `64`

Input block size (bytes)

define SYN_BLAKE2S_MAX_DIGEST¶

#define SYN_BLAKE2S_MAX_DIGEST `32`

Maximum digest size (bytes)

define SYN_BLAKE2S_MAX_KEY¶

#define SYN_BLAKE2S_MAX_KEY `32`

Maximum key size (bytes)

The documentation for this class was generated from the following file src/syntropic/crypto/syn_blake2s.h