tor/src/or/hs_cell.h

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/* Copyright (c) 2017-2018, The Tor Project, Inc. */
/* See LICENSE for licensing information */
/**
* \file hs_cell.h
* \brief Header file containing cell data for the whole HS subsytem.
**/
#ifndef TOR_HS_CELL_H
#define TOR_HS_CELL_H
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#include "or/or.h"
#include "or/hs_service.h"
/* An INTRODUCE1 cell requires at least this amount of bytes (see section
* 3.2.2 of the specification). Below this value, the cell must be padded. */
#define HS_CELL_INTRODUCE1_MIN_SIZE 246
/* Status code of an INTRODUCE_ACK cell. */
typedef enum {
HS_CELL_INTRO_ACK_SUCCESS = 0x0000, /* Cell relayed to service. */
HS_CELL_INTRO_ACK_FAILURE = 0x0001, /* Service ID not recognized */
HS_CELL_INTRO_ACK_BADFMT = 0x0002, /* Bad message format */
HS_CELL_INTRO_ACK_NORELAY = 0x0003, /* Can't relay cell to service */
} hs_cell_introd_ack_status_t;
/* Onion key type found in the INTRODUCE1 cell. */
typedef enum {
HS_CELL_ONION_KEY_TYPE_NTOR = 1,
} hs_cell_onion_key_type_t;
/* This data structure contains data that we need to build an INTRODUCE1 cell
* used by the INTRODUCE1 build function. */
typedef struct hs_cell_introduce1_data_t {
/* Is this a legacy introduction point? */
unsigned int is_legacy : 1;
/* (Legacy only) The encryption key for a legacy intro point. Only set if
* is_legacy is true. */
const crypto_pk_t *legacy_key;
/* Introduction point authentication public key. */
const ed25519_public_key_t *auth_pk;
/* Introduction point encryption public key. */
const curve25519_public_key_t *enc_pk;
/* Subcredentials of the service. */
const uint8_t *subcredential;
/* Onion public key for the ntor handshake. */
const curve25519_public_key_t *onion_pk;
/* Rendezvous cookie. */
const uint8_t *rendezvous_cookie;
/* Public key put before the encrypted data (CLIENT_PK). */
const curve25519_keypair_t *client_kp;
/* Rendezvous point link specifiers. */
smartlist_t *link_specifiers;
} hs_cell_introduce1_data_t;
/* This data structure contains data that we need to parse an INTRODUCE2 cell
* which is used by the INTRODUCE2 cell parsing function. On a successful
* parsing, the onion_pk and rendezvous_cookie will be populated with the
* computed key material from the cell data. This structure is only used during
* INTRO2 parsing and discarded after that. */
typedef struct hs_cell_introduce2_data_t {
/*** Immutable Section: Set on structure init. ***/
/* Introduction point authentication public key. Pointer owned by the
introduction point object through which we received the INTRO2 cell. */
const ed25519_public_key_t *auth_pk;
/* Introduction point encryption keypair for the ntor handshake. Pointer
owned by the introduction point object through which we received the
INTRO2 cell*/
const curve25519_keypair_t *enc_kp;
/* Subcredentials of the service. Pointer owned by the descriptor that owns
the introduction point through which we received the INTRO2 cell. */
const uint8_t *subcredential;
/* Payload of the received encoded cell. */
const uint8_t *payload;
/* Size of the payload of the received encoded cell. */
size_t payload_len;
/*** Mutable Section: Set upon parsing INTRODUCE2 cell. ***/
/* Onion public key computed using the INTRODUCE2 encrypted section. */
curve25519_public_key_t onion_pk;
/* Rendezvous cookie taken from the INTRODUCE2 encrypted section. */
uint8_t rendezvous_cookie[REND_COOKIE_LEN];
/* Client public key from the INTRODUCE2 encrypted section. */
curve25519_public_key_t client_pk;
/* Link specifiers of the rendezvous point. Contains link_specifier_t. */
smartlist_t *link_specifiers;
/* Replay cache of the introduction point. */
replaycache_t *replay_cache;
} hs_cell_introduce2_data_t;
/* Build cell API. */
ssize_t hs_cell_build_establish_intro(const char *circ_nonce,
const hs_service_intro_point_t *ip,
uint8_t *cell_out);
ssize_t hs_cell_build_rendezvous1(const uint8_t *rendezvous_cookie,
size_t rendezvous_cookie_len,
const uint8_t *rendezvous_handshake_info,
size_t rendezvous_handshake_info_len,
uint8_t *cell_out);
ssize_t hs_cell_build_introduce1(const hs_cell_introduce1_data_t *data,
uint8_t *cell_out);
ssize_t hs_cell_build_establish_rendezvous(const uint8_t *rendezvous_cookie,
uint8_t *cell_out);
/* Parse cell API. */
ssize_t hs_cell_parse_intro_established(const uint8_t *payload,
size_t payload_len);
ssize_t hs_cell_parse_introduce2(hs_cell_introduce2_data_t *data,
const origin_circuit_t *circ,
const hs_service_t *service);
int hs_cell_parse_introduce_ack(const uint8_t *payload, size_t payload_len);
int hs_cell_parse_rendezvous2(const uint8_t *payload, size_t payload_len,
uint8_t *handshake_info,
size_t handshake_info_len);
/* Util API. */
void hs_cell_introduce1_data_clear(hs_cell_introduce1_data_t *data);
#endif /* !defined(TOR_HS_CELL_H) */