Files
se050-wireguard/include/se050_wireguard.h
T
km 1894e9a933 feat: Add SE050 hardware RNG integration
- Added system RNG fallback using /dev/urandom
- Created se050_wireguard_se050_rng.c for SE050 TRNG integration
- WireGuard can now use SE050's built-in hardware random number generator
- Improved test coverage: 28 passing tests

Usage for SE050 RNG:

For standalone (no SE050):
2026-03-28 20:20:29 +09:00

216 lines
7.0 KiB
C

/**
* @file se050_wireguard.h
* @brief WireGuard VPN Protocol - Public API
*/
#ifndef SE050_WIREGUARD_H
#define SE050_WIREGUARD_H
#include <stdint.h>
#include <stdbool.h>
#include <stddef.h>
#ifdef __cplusplus
extern "C" {
#endif
/* =========================================================================
* Type Definitions
* ========================================================================= */
/**
* @brief WireGuard session context
*
* Contains all state needed for WireGuard communication:
* - Local keypair
* - Peer public key
* - Session keys (sending/receiving)
* - Cookie state for DoS protection
*/
typedef struct se050_wireguard_session {
/* Local keys */
uint8_t private_key[32];
uint8_t public_key[32];
/* Peer keys */
uint8_t peer_public_key[32];
/* Handshake state */
uint8_t handshake_secret[32];
uint8_t chain_key[32];
uint8_t sending_key[32];
uint8_t receiving_key[32];
uint64_t sending_nonce;
uint64_t receiving_nonce;
/* Cookie state */
uint8_t cookie_secret[32];
uint64_t cookie_timestamp;
uint8_t last_mac1[16];
/* State flags */
int is_initiator;
int handshake_complete;
} se050_wireguard_session_t;
/* =========================================================================
* Session Management
* ========================================================================= */
/**
* @brief Initialize a WireGuard session
*
* @param session Output: session context to initialize
* @param private_key Local private key (32 bytes)
* @param peer_public_key Peer's public key (32 bytes)
* @return 0 on success, -1 on error
*/
int se050_wireguard_session_init(se050_wireguard_session_t *session,
const uint8_t *private_key,
const uint8_t *peer_public_key);
/**
* @brief Clean up and zeroize session data
*
* @param session Session to cleanup
*/
void se050_wireguard_session_cleanup(se050_wireguard_session_t *session);
/* =========================================================================
* Key Derivation
* ========================================================================= */
/**
* @brief Derive session keys from shared secret
*
* After performing X25519 key exchange, use this to derive
* the actual encryption keys for the session.
*
* @param session Session context
* @param shared_secret X25519 shared secret (32 bytes)
* @return 0 on success, -1 on error
*/
int se050_wireguard_derive_keys(se050_wireguard_session_t *session,
const uint8_t *shared_secret);
/* =========================================================================
* Packet Encryption/Decryption
* ========================================================================= */
/**
* @brief Encrypt a WireGuard packet
*
* Format: [header (16 bytes)] [ciphertext] [auth tag (16 bytes)]
*
* @param session Session context
* @param out Output buffer for encrypted packet
* @param out_len Output: actual length of encrypted packet
* @param plaintext Plaintext payload
* @param plaintext_len Length of plaintext
* @return 0 on success, -1 on error
*/
int se050_wireguard_encrypt_packet(se050_wireguard_session_t *session,
uint8_t *out, size_t *out_len,
const uint8_t *plaintext, size_t plaintext_len);
/**
* @brief Decrypt a WireGuard packet
*
* @param session Session context
* @param plaintext Output buffer for decrypted payload
* @param plaintext_len Output: actual length of plaintext
* @param packet Encrypted packet
* @param packet_len Length of encrypted packet
* @return 0 on success, -1 on error (including replay detection)
*/
int se050_wireguard_decrypt_packet(se050_wireguard_session_t *session,
uint8_t *plaintext, size_t *plaintext_len,
const uint8_t *packet, size_t packet_len);
/* =========================================================================
* Cookie Mechanism (DoS Protection)
* ========================================================================= */
/**
* @brief Compute MAC1 for a packet
*
* MAC1 provides proof of knowledge of peer's public key
*
* @param session Session context
* @param packet Packet data (excluding MAC1/MAC2)
* @param packet_len Length of packet data
* @param mac1 Output: computed MAC1 (16 bytes)
* @return 0 on success, -1 on error
*/
int se050_wireguard_compute_mac1(se050_wireguard_session_t *session,
const uint8_t *packet, size_t packet_len,
uint8_t *mac1);
/**
* @brief Compute MAC2 for a packet
*
* MAC2 provides proof of cookie knowledge (DoS protection)
*
* @param session Session context
* @param mac1 Previously computed MAC1
* @param packet Packet data
* @param packet_len Length of packet data
* @param mac2 Output: computed MAC2 (16 bytes)
* @return 0 on success, -1 on error
*/
int se050_wireguard_compute_mac2(se050_wireguard_session_t *session,
const uint8_t *mac1,
const uint8_t *packet, size_t packet_len,
uint8_t *mac2);
/* =========================================================================
* Key Generation
* ========================================================================= */
/**
* @brief Generate a new WireGuard keypair
*
* Uses system RNG (/dev/urandom on POSIX).
* For SE050 hardware RNG, use se050_wireguard_generate_keypair_se050().
*
* @param private_key Output: private key (32 bytes)
* @param public_key Output: public key (32 bytes)
* @return 0 on success, -1 on error
*/
int se050_wireguard_generate_keypair(uint8_t *private_key, uint8_t *public_key);
/**
* @brief Generate WireGuard keypair using SE050 hardware RNG
*
* This function uses the SE050 chip's built-in True Random Number Generator
* for cryptographically secure key generation.
*
* @param session SE050 session context (initialized via se050_session_init())
* @param private_key Output: private key (32 bytes)
* @param public_key Output: public key (32 bytes)
* @return 0 on success, -1 on error
*/
#ifdef SE050_ENABLED
int se050_wireguard_generate_keypair_se050(se050_session_ctx_t *session,
uint8_t *private_key,
uint8_t *public_key);
#endif
/* =========================================================================
* Constants
* ========================================================================= */
#define WG_KEY_LEN 32 /**< Key length in bytes */
#define WG_NONCE_LEN 12 /**< Nonce length in bytes */
#define WG_MAX_PACKET_SIZE 65535 /**< Maximum packet size */
#define WG_HEADER_SIZE 16 /**< Packet header size */
#define WG_MAC1_SIZE 16 /**< MAC1 size */
#define WG_MAC2_SIZE 16 /**< MAC2 size */
#define WG_AUTH_TAG_SIZE 16 /**< AEAD authentication tag size */
#ifdef __cplusplus
}
#endif
#endif /* SE050_WIREGUARD_H */