diff options
Diffstat (limited to 'src/or/hs_circuit.c')
| -rw-r--r-- | src/or/hs_circuit.c | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/src/or/hs_circuit.c b/src/or/hs_circuit.c index 7704fd0bad..95100e9b3a 100644 --- a/src/or/hs_circuit.c +++ b/src/or/hs_circuit.c @@ -530,6 +530,83 @@ retry_service_rendezvous_point(const origin_circuit_t *circ) return; } +/* Using an extend info object ei, set all possible link specifiers in lspecs. + * IPv4, legacy ID and ed25519 ID are mandatory thus MUST be present in ei. */ +static void +get_lspecs_from_extend_info(const extend_info_t *ei, smartlist_t *lspecs) +{ + link_specifier_t *ls; + + tor_assert(ei); + tor_assert(lspecs); + + /* IPv4 is mandatory. */ + ls = link_specifier_new(); + link_specifier_set_ls_type(ls, LS_IPV4); + link_specifier_set_un_ipv4_addr(ls, tor_addr_to_ipv4h(&ei->addr)); + link_specifier_set_un_ipv4_port(ls, ei->port); + /* Four bytes IPv4 and two bytes port. */ + link_specifier_set_ls_len(ls, sizeof(ei->addr.addr.in_addr) + + sizeof(ei->port)); + smartlist_add(lspecs, ls); + + /* Legacy ID is mandatory. */ + ls = link_specifier_new(); + link_specifier_set_ls_type(ls, LS_LEGACY_ID); + memcpy(link_specifier_getarray_un_legacy_id(ls), ei->identity_digest, + link_specifier_getlen_un_legacy_id(ls)); + link_specifier_set_ls_len(ls, link_specifier_getlen_un_legacy_id(ls)); + smartlist_add(lspecs, ls); + + /* ed25519 ID is mandatory. */ + ls = link_specifier_new(); + link_specifier_set_ls_type(ls, LS_ED25519_ID); + memcpy(link_specifier_getarray_un_ed25519_id(ls), &ei->ed_identity, + link_specifier_getlen_un_ed25519_id(ls)); + link_specifier_set_ls_len(ls, link_specifier_getlen_un_ed25519_id(ls)); + smartlist_add(lspecs, ls); + + /* XXX: IPv6 is not clearly a thing in extend_info_t? */ +} + +/* Using the given descriptor intro point ip, the extend information of the + * rendezvous point rp_ei and the service's subcredential, populate the + * already allocated intro1_data object with the needed key material and link + * specifiers. + * + * This can't fail but the ip MUST be a valid object containing the needed + * keys and authentication method. */ +static void +setup_introduce1_data(const hs_desc_intro_point_t *ip, + const extend_info_t *rp_ei, + const uint8_t *subcredential, + hs_cell_introduce1_data_t *intro1_data) +{ + smartlist_t *rp_lspecs; + + tor_assert(ip); + tor_assert(rp_ei); + tor_assert(subcredential); + tor_assert(intro1_data); + + /* Build the link specifiers from the extend information of the rendezvous + * circuit that we've picked previously. */ + rp_lspecs = smartlist_new(); + get_lspecs_from_extend_info(rp_ei, rp_lspecs); + + /* Populate the introduce1 data object. */ + memset(intro1_data, 0, sizeof(hs_cell_introduce1_data_t)); + if (ip->legacy.key != NULL) { + intro1_data->is_legacy = 1; + intro1_data->legacy_key = ip->legacy.key; + } + intro1_data->auth_pk = &ip->auth_key_cert->signed_key; + intro1_data->enc_pk = &ip->enc_key; + intro1_data->subcredential = subcredential; + intro1_data->onion_pk = &rp_ei->curve25519_onion_key; + intro1_data->link_specifiers = rp_lspecs; +} + /* ========== */ /* Public API */ /* ========== */ @@ -937,3 +1014,73 @@ hs_circuit_setup_e2e_rend_circ_legacy_client(origin_circuit_t *circ, return 0; } +/* Given the introduction circuit intro_circ, the rendezvous circuit + * rend_circ, a descriptor intro point object ip and the service's + * subcredential, send an INTRODUCE1 cell on intro_circ. + * + * This will also setup the circuit identifier on rend_circ containing the key + * material for the handshake and e2e encryption. Return 0 on success else + * negative value. Because relay_send_command_from_edge() closes the circuit + * on error, it is possible that intro_circ is closed on error. */ +int +hs_circ_send_introduce1(origin_circuit_t *intro_circ, + origin_circuit_t *rend_circ, + const hs_desc_intro_point_t *ip, + const uint8_t *subcredential) +{ + int ret = -1; + ssize_t payload_len; + uint8_t payload[RELAY_PAYLOAD_SIZE] = {0}; + hs_cell_introduce1_data_t intro1_data; + + tor_assert(intro_circ); + tor_assert(rend_circ); + tor_assert(ip); + tor_assert(subcredential); + + /* This takes various objects in order to populate the introduce1 data + * object which is used to build the content of the cell. */ + setup_introduce1_data(ip, rend_circ->build_state->chosen_exit, + subcredential, &intro1_data); + + /* Final step before we encode a cell, we setup the circuit identifier which + * will generate both the rendezvous cookie and client keypair for this + * connection. Those are put in the ident. */ + intro1_data.rendezvous_cookie = rend_circ->hs_ident->rendezvous_cookie; + intro1_data.client_kp = &rend_circ->hs_ident->rendezvous_client_kp; + + memcpy(intro_circ->hs_ident->rendezvous_cookie, + rend_circ->hs_ident->rendezvous_cookie, + sizeof(intro_circ->hs_ident->rendezvous_cookie)); + + /* From the introduce1 data object, this will encode the INTRODUCE1 cell + * into payload which is then ready to be sent as is. */ + payload_len = hs_cell_build_introduce1(&intro1_data, payload); + if (BUG(payload_len < 0)) { + goto done; + } + + if (relay_send_command_from_edge(CONTROL_CELL_ID, TO_CIRCUIT(intro_circ), + RELAY_COMMAND_INTRODUCE1, + (const char *) payload, payload_len, + intro_circ->cpath->prev) < 0) { + /* On error, circuit is closed. */ + log_warn(LD_REND, "Unable to send INTRODUCE1 cell on circuit %u.", + TO_CIRCUIT(intro_circ)->n_circ_id); + goto done; + } + + /* Success. */ + ret = 0; + goto done; + + done: + /* Object in this list have been moved to the cell object when building it + * so they've been freed earlier. We do that in order to avoid duplicating + * them leading to more memory and CPU time being used for nothing. */ + smartlist_free(intro1_data.link_specifiers); + memwipe(&intro1_data, 0, sizeof(intro1_data)); + memwipe(payload, 0, sizeof(payload)); + return ret; +} + |