File syn_sha256.c¶

FileList > src > syntropic > util > syn_sha256.c

SHA-256 implementation — FIPS 180-4 compliant, pure C99. More...

#include "syn_assert.h"
#include "syn_pack.h"
#include "syn_sha256.h"
#include <string.h>

Public Static Attributes¶

Type	Name
const uint32_t	H_INIT = `/* multi line expression */`
const uint32_t	K = `/* multi line expression */`

Public Functions¶

Type	Name
void	syn_sha256_final (SYN_SHA256 * ctx, uint8_t hash) Finalize the hash and produce the 32-byte digest.
void	syn_sha256_init (SYN_SHA256 * ctx) Initialize a SHA-256 context.
void	syn_sha256_update (SYN_SHA256 * ctx, const void * data, size_t len) Feed data into the hash.

Public Static Functions¶

Type	Name
uint32_t	ch (uint32_t x, uint32_t y, uint32_t z) Choice function: Ch(x,y,z) = (x ∧ y) ⊕ (¬x ∧ z).
uint32_t	gamma0 (uint32_t x) Small sigma-0: σ₀(x) = ROTR⁷(x) ⊕ ROTR¹⁸(x) ⊕ SHR³(x).
uint32_t	gamma1 (uint32_t x) Small sigma-1: σ₁(x) = ROTR¹⁷(x) ⊕ ROTR¹⁹(x) ⊕ SHR¹⁰(x).
uint32_t	maj (uint32_t x, uint32_t y, uint32_t z) Majority function: Maj(x,y,z) = (x ∧ y) ⊕ (x ∧ z) ⊕ (y ∧ z).
uint32_t	rotr (uint32_t x, unsigned n) Circular right rotate.
void	sha256_transform (uint32_t state, const uint8_t block) Process a single 64-byte block.
uint32_t	sigma0 (uint32_t x) Big Sigma-0: Σ₀(x) = ROTR²(x) ⊕ ROTR¹³(x) ⊕ ROTR²²(x).
uint32_t	sigma1 (uint32_t x) Big Sigma-1: Σ₁(x) = ROTR⁶(x) ⊕ ROTR¹¹(x) ⊕ ROTR²⁵(x).

Detailed Description¶

No heap allocation, no floating point, no external dependencies. Static K[64] round constants table consumes ~256 bytes of ROM.

Public Static Attributes Documentation¶

variable H_INIT¶

const uint32_t H_INIT[8];

FIPS 180-4 initial hash values (H0–H7).

variable K¶

const uint32_t K[64];

FIPS 180-4 round constants (K0–K63).

Public Functions Documentation¶

function syn_sha256_final¶

Finalize the hash and produce the 32-byte digest.

void syn_sha256_final (
    SYN_SHA256 * ctx,
    uint8_t hash
)

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

Parameters:

ctx SHA-256 context.
hash Output buffer (must be at least 32 bytes).

function syn_sha256_init¶

Initialize a SHA-256 context.

void syn_sha256_init (
    SYN_SHA256 * ctx
)

Parameters:

ctx Context to initialize.

function syn_sha256_update¶

Feed data into the hash.

void syn_sha256_update (
    SYN_SHA256 * ctx,
    const void * data,
    size_t len
)

Can be called repeatedly with arbitrary chunk sizes.

Parameters:

ctx SHA-256 context.
data Data to hash.
len Length in bytes.

Public Static Functions Documentation¶

function ch¶

Choice function: Ch(x,y,z) = (x ∧ y) ⊕ (¬x ∧ z).

static inline uint32_t ch (
    uint32_t x,
    uint32_t y,
    uint32_t z
)

Parameters:

x First input.
y Second input.
z Third input.

Returns:

Ch(x, y, z).

function gamma0¶

Small sigma-0: σ₀(x) = ROTR⁷(x) ⊕ ROTR¹⁸(x) ⊕ SHR³(x).

static inline uint32_t gamma0 (
    uint32_t x
)

Parameters:

x Input word.

Returns:

σ₀(x).

function gamma1¶

Small sigma-1: σ₁(x) = ROTR¹⁷(x) ⊕ ROTR¹⁹(x) ⊕ SHR¹⁰(x).

static inline uint32_t gamma1 (
    uint32_t x
)

Parameters:

x Input word.

Returns:

σ₁(x).

function maj¶

Majority function: Maj(x,y,z) = (x ∧ y) ⊕ (x ∧ z) ⊕ (y ∧ z).

static inline uint32_t maj (
    uint32_t x,
    uint32_t y,
    uint32_t z
)

Parameters:

x First input.
y Second input.
z Third input.

Returns:

Maj(x, y, z).

function rotr¶

Circular right rotate.

static inline uint32_t rotr (
    uint32_t x,
    unsigned n
)

Parameters:

x Value to rotate.
n Number of bits to rotate.

Returns:

Rotated value.

function sha256_transform¶

Process a single 64-byte block.

static void sha256_transform (
    uint32_t state,
    const uint8_t block
)

Parameters:

state Running hash state (8 × uint32_t).
block 64-byte input block.

function sigma0¶

Big Sigma-0: Σ₀(x) = ROTR²(x) ⊕ ROTR¹³(x) ⊕ ROTR²²(x).

static inline uint32_t sigma0 (
    uint32_t x
)

Parameters:

x Input word.

Returns:

Σ₀(x).

function sigma1¶

Big Sigma-1: Σ₁(x) = ROTR⁶(x) ⊕ ROTR¹¹(x) ⊕ ROTR²⁵(x).

static inline uint32_t sigma1 (
    uint32_t x
)

Parameters:

x Input word.

Returns:

Σ₁(x).

The documentation for this class was generated from the following file src/syntropic/util/syn_sha256.c