crypto.h

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// Copyright (c) 2024-2026 Lux Industries Inc.
// SPDX-License-Identifier: BSD-3-Clause-Eco
//
// Lux GPU crypto types
//
// Shared types for cryptographic kernels (MSM, KZG, Poseidon2, Shamir, ...).
// The curve enum lives in <lux/gpu.h> as LuxCurve and is the single source of
// truth — int curve_type fields in the vtbl ABI are LuxCurve values cast to int.
 
#ifndef LUX_GPU_CRYPTO_H
#define LUX_GPU_CRYPTO_H
 
#include <stdint.h>
#include <stddef.h>
 
#ifdef __cplusplus
extern "C" {
#endif
 
// =============================================================================
// Field Types
// =============================================================================
 
// 256-bit scalar (BN254 base/scalar, BLS12-381 scalar, secp256k1, ed25519)
typedef struct {
    uint64_t limbs[4];
} LuxScalar256;
 
// 384-bit base field element (BLS12-381)
typedef struct {
    uint64_t limbs[6];
} LuxFp384;
 
// 64-bit Goldilocks field element (2^64 - 2^32 + 1)
typedef uint64_t LuxGoldilocks;
 
// =============================================================================
// Point Types
// =============================================================================
 
// G1 affine point (BN254) — Fp254 is encoded as 4×u64 to match shader layout
typedef struct {
    LuxScalar256 x;
    LuxScalar256 y;
    uint32_t infinity;
    uint32_t _pad;
} LuxG1Affine254;
 
// G1 projective (Jacobian) point (BN254)
typedef struct {
    LuxScalar256 x;
    LuxScalar256 y;
    LuxScalar256 z;
} LuxG1Projective254;
 
// G1 affine point (BLS12-381) — Fp384 is 6×u64
typedef struct {
    LuxFp384 x;
    LuxFp384 y;
    uint32_t infinity;
    uint32_t _pad;
} LuxG1Affine381;
 
// G1 projective (Jacobian) point (BLS12-381)
typedef struct {
    LuxFp384 x;
    LuxFp384 y;
    LuxFp384 z;
} LuxG1Projective381;
 
// 768-bit quadratic-extension element Fp2 = Fp[u]/(u² + 1). Layout matches
// blst's `blst_fp2 { blst_fp fp[2]; }` byte-for-byte: c0 first, then c1.
// All limbs are in Montgomery form (R = 2^384 mod p), same convention as
// LuxFp384.
typedef struct {
    LuxFp384 c0;
    LuxFp384 c1;
} LuxFp2_381;
 
// G2 affine point on the BLS12-381 sextic twist E'(Fp2): y² = x³ + 4(1+u).
// Layout matches blst's `blst_p2_affine { blst_fp2 x, y; }` and adds the
// infinity flag word for ABI symmetry with LuxG1Affine381.
typedef struct {
    LuxFp2_381 x;
    LuxFp2_381 y;
    uint32_t infinity;
    uint32_t _pad;
} LuxG2Affine381;
 
// G2 projective (Jacobian) point. Layout matches blst's
// `blst_p2 { blst_fp2 x, y, z; }`.
typedef struct {
    LuxFp2_381 x;
    LuxFp2_381 y;
    LuxFp2_381 z;
} LuxG2Projective381;
 
// Fp12 element — the pairing target group GT lives here. Layout matches
// blst byte-for-byte: 12 Fp limbs grouped as c0 ‖ c1 with c_i = Fp6 =
// (Fp2)³. Total size = 576 bytes (12 × 6 × u64).
typedef struct {
    LuxFp2_381 fp2[6];
} LuxFp12_381;
 
// =============================================================================
// Error Codes
// =============================================================================
 
typedef enum {
    LUX_CRYPTO_OK                  = 0,
    LUX_CRYPTO_ERROR_INVALID_ARG   = 1,
    LUX_CRYPTO_ERROR_OUT_OF_MEMORY = 2,
    LUX_CRYPTO_ERROR_NOT_SUPPORTED = 3,
    LUX_CRYPTO_ERROR_INVALID_CURVE = 4,
    LUX_CRYPTO_ERROR_INVALID_POINT = 5,
    LUX_CRYPTO_ERROR_DEVICE_ERROR  = 6,
} LuxCryptoError;
 
#ifdef __cplusplus
}
#endif
 
#endif // LUX_GPU_CRYPTO_H