aliro_crypto.h

Cstruct aliro_secchan

---- Secure channel (AES-256-GCM, directional per-message counters) ------ Nonce = 8-byte big-endian direction (0 outbound/seal, 1 inbound/open) followed by a 4-byte big-endian per-direction counter. Separate seal/open counters, start at 0, no wrap. SessionCrypto sends no AAD; the BLE channel authenticates a 4-byte AAD (caller-supplied here).

##define ALIRO_URSK_LEN 32u

##define ALIRO_KEY_BLOCK_LEN 160u

##define ALIRO_URSK_OFFSET 128u

##define ALIRO_SESSION_KEY_LEN 32u

##define ALIRO_SHARED_SECRET_LEN 32u

##define ALIRO_TXID_LEN 16u

##define ALIRO_EC_PUBX_LEN 32u

##define ALIRO_GCM_NONCE_LEN 12u

##define ALIRO_GCM_TAG_LEN 16u

##define ALIRO_IFACE_NFC 0x5Eu

##define ALIRO_IFACE_BLE 0xC3u

Fint aliro_crypto_init(void)

Fvoid aliro_crypto_ursk_from_block(const uint8_t block[ALIRO_KEY_BLOCK_LEN], uint8_t ursk[ALIRO_URSK_LEN])

Fvoid aliro_crypto_derive_z(const uint8_t shared_secret[ALIRO_SHARED_SECRET_LEN], const uint8_t txid[ALIRO_TXID_LEN], uint8_t z[32])

Fint aliro_crypto_derive_block(const uint8_t z[32], const uint8_t *salt, size_t salt_len, const uint8_t device_pub_x[ALIRO_EC_PUBX_LEN], uint8_t block[ALIRO_KEY_BLOCK_LEN])

Fint aliro_crypto_derive_key32(const uint8_t z[32], const uint8_t *salt, size_t salt_len, const uint8_t device_pub_x[ALIRO_EC_PUBX_LEN], uint8_t out[32])

Fvoid aliro_crypto_split(const uint8_t block[ALIRO_KEY_BLOCK_LEN], int with_c, uint8_t enc_key[ALIRO_SESSION_KEY_LEN], uint8_t dec_key[ALIRO_SESSION_KEY_LEN], uint8_t ursk[ALIRO_URSK_LEN])

##define ALIRO_CRYPTOGRAM_SK_OFFSET 0u

##define ALIRO_CRYPTOGRAM_LEN 64u

Fint aliro_crypto_verify_cryptogram(const uint8_t cryptogram_sk[ALIRO_SESSION_KEY_LEN], const uint8_t *cryptogram, size_t cryptogram_len, uint8_t *plain_payload)

Fvoid aliro_secchan_init(struct aliro_secchan *sc, const uint8_t enc_key[ALIRO_SESSION_KEY_LEN], const uint8_t dec_key[ALIRO_SESSION_KEY_LEN])

Fvoid aliro_crypto_gcm_nonce(uint64_t direction, uint32_t counter, uint8_t nonce[ALIRO_GCM_NONCE_LEN])

Fint aliro_secchan_seal(struct aliro_secchan *sc, const uint8_t *aad, size_t aad_len, const uint8_t *pt, size_t pt_len, uint8_t *ct, uint8_t tag[ALIRO_GCM_TAG_LEN])

Fint aliro_secchan_open(struct aliro_secchan *sc, const uint8_t *aad, size_t aad_len, const uint8_t *ct, size_t ct_len, const uint8_t tag[ALIRO_GCM_TAG_LEN], uint8_t *pt)

##define ALIRO_BLESK_OFFSET 96u

Fint aliro_crypto_derive_ble_keys(const uint8_t block[ALIRO_KEY_BLOCK_LEN], const uint8_t *salt, size_t salt_len, uint8_t ble_reader[ALIRO_SESSION_KEY_LEN], uint8_t ble_device[ALIRO_SESSION_KEY_LEN])

Fint aliro_msg_seal(struct aliro_secchan *sc, const uint8_t *plain, size_t plain_len, uint8_t *wire, size_t wire_cap, size_t *wire_len)

Fint aliro_msg_open(struct aliro_secchan *sc, const uint8_t *wire, size_t wire_len, uint8_t *plain, size_t plain_cap, size_t *plain_len)

Cenum aliro_salt_type

##define ALIRO_SALT_MAX 256u

Fint aliro_salt_build(enum aliro_salt_type type, const uint8_t txid[ALIRO_TXID_LEN], const uint8_t span_s1[ALIRO_EC_PUBX_LEN], const uint8_t reader_value[ALIRO_EC_PUBX_LEN], const uint8_t reader_id[32], uint8_t interface_byte, uint16_t proto_version, uint8_t exp_phase_type, uint8_t user_auth_policy, const uint8_t s3opt[ALIRO_EC_PUBX_LEN] , const uint8_t *a5_tlv, size_t a5_tlv_len, uint8_t *out, size_t *out_len)