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Diffstat (limited to 'src/or/hs_cell.h')
| -rw-r--r-- | src/or/hs_cell.h | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/src/or/hs_cell.h b/src/or/hs_cell.h new file mode 100644 index 0000000000..958dde4ffc --- /dev/null +++ b/src/or/hs_cell.h @@ -0,0 +1,122 @@ +/* Copyright (c) 2017, 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 + +#include "or.h" +#include "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) */ + |