km
d34fed2048
新規ヘッダー：include/se050_x25519_sw.h - WireGuard Ephemeral キー計算用 API 定義 - se050_x25519_sw_generate_keypair() - キーペア生成 - se050_x25519_sw_compute_shared_secret() - 共有秘密計算 - se050_x25519_sw_derive_public_key() - 公開鍵派生 - se050_x25519_sw_clamp() - 秘密鍵クランプ - se050_x25519_sw_zeroize() - キー消去 ソース修正：src/se050_x25519_sw.c - main() 関数をテストスイートに統合 - 独立した API 関数として再構成 - X25519_SW_TEST マクロでテストビルド可能 テスト追加：tests/test_x25519_ecdh.c - テスト 7: ソフトウェアキーペア生成 - テスト 8: ECDH 対称性検証 - テスト 9: 公開鍵派生 - テスト 10: キーゼロ化 Makefile 更新: - test_x25519_sw タスク追加 - make test で全テスト実行 注：RFC 7748 テストベクトル検証中（実装修正必要）
112 lines
2.8 KiB
C
112 lines
2.8 KiB
C
/**
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* @file se050_x25519_sw.h
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* @brief Software X25519 ECDH Implementation Header
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*
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* Pure software implementation for WireGuard ephemeral key generation.
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* Fallback when SE050 hardware is unavailable.
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*
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* License: MIT (Clean-room implementation)
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*/
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#ifndef SE050_X25519_SW_H
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#define SE050_X25519_SW_H
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#include <stdint.h>
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#include <stddef.h>
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#ifdef __cplusplus
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extern "C" {
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#endif
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/* ============================================================================
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* Constants
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* ============================================================================ */
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#define X25519_SECRET_KEY_SIZE 32
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#define X25519_PUBLIC_KEY_SIZE 32
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#define X25519_SHARED_SECRET_SIZE 32
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/* ============================================================================
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* Type Definitions
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* ============================================================================ */
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/**
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* @brief X25519 keypair structure
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*/
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typedef struct {
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uint8_t private_key[X25519_SECRET_KEY_SIZE];
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uint8_t public_key[X25519_PUBLIC_KEY_SIZE];
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} se050_x25519_sw_keypair_t;
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/* ============================================================================
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* API Functions
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* ============================================================================ */
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/**
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* @brief Generate X25519 keypair
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*
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* @param keypair Output keypair structure
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* @param rng_func Random number generator function
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* @param rng_ctx RNG context
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* @return 0 on success, -1 on error
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*/
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typedef int (*x25519_rng_func)(uint8_t *dst, size_t len, void *rng_ctx);
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int se050_x25519_sw_generate_keypair(
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se050_x25519_sw_keypair_t *keypair,
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x25519_rng_func rng_func,
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void *rng_ctx
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);
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/**
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* @brief Compute X25519 shared secret
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*
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* @param shared_secret Output shared secret (32 bytes)
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* @param private_key Private key (32 bytes, will be clamped)
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* @param peer_public Peer's public key (32 bytes)
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* @return 0 on success, -1 on error
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*/
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int se050_x25519_sw_compute_shared_secret(
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uint8_t *shared_secret,
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const uint8_t *private_key,
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const uint8_t *peer_public
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);
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/**
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* @brief Compute X25519 public key from private key
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*
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* @param public_key Output public key (32 bytes)
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* @param private_key Private key (32 bytes, will be clamped)
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* @return 0 on success, -1 on error
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*/
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int se050_x25519_sw_derive_public_key(
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uint8_t *public_key,
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const uint8_t *private_key
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);
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/**
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* @brief Clamp X25519 private key
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*
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* Applies X25519 scalar clamping:
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* - Clear bits 0, 1, 2 of first byte
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* - Clear bit 254 of last byte
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* - Set bit 255 of last byte
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*
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* @param scalar Private key to clamp (modified in place)
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*/
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void se050_x25519_sw_clamp(uint8_t *scalar);
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/**
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* @brief Securely zeroize key material
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*
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* @param key Key material to zeroize
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* @param len Length in bytes
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*/
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void se050_x25519_sw_zeroize(uint8_t *key, size_t len);
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#ifdef __cplusplus
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}
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#endif
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#endif /* SE050_X25519_SW_H */
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