static void
test_introduce1_suitable_circuit(void *arg)
{
int ret;
or_circuit_t *circ = NULL;
(void) arg;
/* Valid suitable circuit. */
{
circ = or_circuit_new(0, NULL);
circuit_change_purpose(TO_CIRCUIT(circ), CIRCUIT_PURPOSE_OR);
ret = circuit_is_suitable_for_introduce1(circ);
circuit_free_(TO_CIRCUIT(circ));
tt_int_op(ret, OP_EQ, 1);
}
/* Test if the circuit purpose safeguard works correctly. */
{
circ = or_circuit_new(0, NULL);
circuit_change_purpose(TO_CIRCUIT(circ), CIRCUIT_PURPOSE_INTRO_POINT);
ret = circuit_is_suitable_for_introduce1(circ);
circuit_free_(TO_CIRCUIT(circ));
tt_int_op(ret, OP_EQ, 0);
}
/* Test the non-edge circuit safeguard works correctly. */
{
circ = or_circuit_new(0, NULL);
circuit_change_purpose(TO_CIRCUIT(circ), CIRCUIT_PURPOSE_OR);
/* Bogus pointer, the check is against NULL on n_chan. */
circ->base_.n_chan = (channel_t *) circ;
ret = circuit_is_suitable_for_introduce1(circ);
circuit_free_(TO_CIRCUIT(circ));
tt_int_op(ret, OP_EQ, 0);
}
/* Mangle the circuit a bit more so see if our only one INTRODUCE1 cell
* limit works correctly. */
{
circ = or_circuit_new(0, NULL);
circuit_change_purpose(TO_CIRCUIT(circ), CIRCUIT_PURPOSE_OR);
circ->already_received_introduce1 = 1;
ret = circuit_is_suitable_for_introduce1(circ);
circuit_free_(TO_CIRCUIT(circ));
tt_int_op(ret, OP_EQ, 0);
}
done:
;
}
/* Prepare a circuit for accepting an ESTABLISH_INTRO cell */
static void
helper_prepare_circ_for_intro(or_circuit_t *circ, const char *circ_nonce)
{
/* Prepare the circuit for the incoming ESTABLISH_INTRO */
circuit_change_purpose(TO_CIRCUIT(circ), CIRCUIT_PURPOSE_OR);
memcpy(circ->rend_circ_nonce, circ_nonce, DIGEST_LEN);
}
/* Try sending an ESTABLISH_INTRO cell on a circuit that is already an intro
* point. Should fail. */
static void
test_establish_intro_wrong_purpose(void *arg)
{
int retval;
ssize_t cell_len = 0;
char circ_nonce[DIGEST_LEN] = {0};
uint8_t cell_body[RELAY_PAYLOAD_SIZE];
or_circuit_t *intro_circ = or_circuit_new(0,NULL);
(void)arg;
/* Get the auth key of the intro point */
crypto_rand(circ_nonce, sizeof(circ_nonce));
memcpy(intro_circ->rend_circ_nonce, circ_nonce, DIGEST_LEN);
/* Set a bad circuit purpose!! :) */
circuit_change_purpose(TO_CIRCUIT(intro_circ), CIRCUIT_PURPOSE_INTRO_POINT);
/* Create outgoing ESTABLISH_INTRO cell and extract its payload so that we
attempt to parse it. */
cell_len = new_establish_intro_encoded_cell(circ_nonce, cell_body);
tt_i64_op(cell_len, OP_GT, 0);
/* Receive the cell. Should fail. */
setup_full_capture_of_logs(LOG_INFO);
retval = hs_intro_received_establish_intro(intro_circ, cell_body, cell_len);
expect_log_msg_containing("Rejecting ESTABLISH_INTRO on non-OR circuit.");
teardown_capture_of_logs();
tt_int_op(retval, OP_EQ, -1);
done:
circuit_free_(TO_CIRCUIT(intro_circ));
}
/** Process an ESTABLISH_RENDEZVOUS cell by setting the circuit's purpose and
* rendezvous cookie.
*/
int
rend_mid_establish_rendezvous(or_circuit_t *circ, const uint8_t *request,
size_t request_len)
{
char hexid[9];
int reason = END_CIRC_REASON_TORPROTOCOL;
log_info(LD_REND, "Received an ESTABLISH_RENDEZVOUS request on circuit %u",
(unsigned)circ->p_circ_id);
if (circ->base_.purpose != CIRCUIT_PURPOSE_OR) {
log_warn(LD_PROTOCOL,
"Tried to establish rendezvous on non-OR circuit with purpose %s",
circuit_purpose_to_string(circ->base_.purpose));
goto err;
}
if (circ->base_.n_chan) {
log_warn(LD_PROTOCOL,
"Tried to establish rendezvous on non-edge circuit");
goto err;
}
if (request_len != REND_COOKIE_LEN) {
log_fn(LOG_PROTOCOL_WARN,
LD_PROTOCOL, "Invalid length on ESTABLISH_RENDEZVOUS.");
goto err;
}
if (circuit_get_rendezvous(request)) {
log_warn(LD_PROTOCOL,
"Duplicate rendezvous cookie in ESTABLISH_RENDEZVOUS.");
goto err;
}
/* Acknowledge the request. */
if (relay_send_command_from_edge(0,TO_CIRCUIT(circ),
RELAY_COMMAND_RENDEZVOUS_ESTABLISHED,
"", 0, NULL)<0) {
log_warn(LD_PROTOCOL, "Couldn't send RENDEZVOUS_ESTABLISHED cell.");
reason = END_CIRC_REASON_INTERNAL;
goto err;
}
circuit_change_purpose(TO_CIRCUIT(circ), CIRCUIT_PURPOSE_REND_POINT_WAITING);
circuit_set_rendezvous_cookie(circ, request);
base16_encode(hexid,9,(char*)request,4);
log_info(LD_REND,
"Established rendezvous point on circuit %u for cookie %s",
(unsigned)circ->p_circ_id, hexid);
return 0;
err:
circuit_mark_for_close(TO_CIRCUIT(circ), reason);
return -1;
}
static or_circuit_t *
helper_create_intro_circuit(void)
{
or_circuit_t *circ = or_circuit_new(0, NULL);
tt_assert(circ);
circuit_change_purpose(TO_CIRCUIT(circ), CIRCUIT_PURPOSE_OR);
done:
return circ;
}
/* Circ has been expecting an INTRO_ESTABLISHED cell that just arrived. Handle
* the INTRO_ESTABLISHED cell payload of length payload_len arriving on the
* given introduction circuit circ. The service is only used for logging
* purposes. Return 0 on success else a negative value. */
int
hs_circ_handle_intro_established(const hs_service_t *service,
const hs_service_intro_point_t *ip,
origin_circuit_t *circ,
const uint8_t *payload, size_t payload_len)
{
int ret = -1;
tor_assert(service);
tor_assert(ip);
tor_assert(circ);
tor_assert(payload);
if (BUG(TO_CIRCUIT(circ)->purpose != CIRCUIT_PURPOSE_S_ESTABLISH_INTRO)) {
goto done;
}
/* Try to parse the payload into a cell making sure we do actually have a
* valid cell. For a legacy node, it's an empty payload so as long as we
* have the cell, we are good. */
if (!ip->base.is_only_legacy &&
hs_cell_parse_intro_established(payload, payload_len) < 0) {
log_warn(LD_REND, "Unable to parse the INTRO_ESTABLISHED cell on "
"circuit %u for service %s",
TO_CIRCUIT(circ)->n_circ_id,
safe_str_client(service->onion_address));
goto done;
}
/* Switch the purpose to a fully working intro point. */
circuit_change_purpose(TO_CIRCUIT(circ), CIRCUIT_PURPOSE_S_INTRO);
/* Getting a valid INTRODUCE_ESTABLISHED means we've successfully used the
* circuit so update our pathbias subsystem. */
pathbias_mark_use_success(circ);
/* Success. */
ret = 0;
done:
return ret;
}
/* Append the final <b>hop</b> to the cpath of the rend <b>circ</b>, and mark
* <b>circ</b> ready for use to transfer HS relay cells. */
static void
finalize_rend_circuit(origin_circuit_t *circ, crypt_path_t *hop,
int is_service_side)
{
tor_assert(circ);
tor_assert(hop);
/* Notify the circuit state machine that we are splicing this circuit */
int new_circ_purpose = is_service_side ?
CIRCUIT_PURPOSE_S_REND_JOINED : CIRCUIT_PURPOSE_C_REND_JOINED;
circuit_change_purpose(TO_CIRCUIT(circ), new_circ_purpose);
/* All is well. Extend the circuit. */
hop->state = CPATH_STATE_OPEN;
/* Set the windows to default. */
hop->package_window = circuit_initial_package_window();
hop->deliver_window = CIRCWINDOW_START;
/* Now that this circuit has finished connecting to its destination,
* make sure circuit_get_open_circ_or_launch is willing to return it
* so we can actually use it. */
circ->hs_circ_has_timed_out = 0;
/* Append the hop to the cpath of this circuit */
onion_append_to_cpath(&circ->cpath, hop);
/* In legacy code, 'pending_final_cpath' points to the final hop we just
* appended to the cpath. We set the original pointer to NULL so that we
* don't double free it. */
if (circ->build_state) {
circ->build_state->pending_final_cpath = NULL;
}
/* Finally, mark circuit as ready to be used for client streams */
if (!is_service_side) {
circuit_try_attaching_streams(circ);
}
}
/** Process a RENDEZVOUS1 cell by looking up the correct rendezvous
* circuit by its relaying the cell's body in a RENDEZVOUS2 cell, and
* connecting the two circuits.
*/
int
rend_mid_rendezvous(or_circuit_t *circ, const uint8_t *request,
size_t request_len)
{
or_circuit_t *rend_circ;
char hexid[9];
int reason = END_CIRC_REASON_INTERNAL;
if (circ->base_.purpose != CIRCUIT_PURPOSE_OR || circ->base_.n_chan) {
log_info(LD_REND,
"Tried to complete rendezvous on non-OR or non-edge circuit %u.",
(unsigned)circ->p_circ_id);
reason = END_CIRC_REASON_TORPROTOCOL;
goto err;
}
if (request_len != REND_COOKIE_LEN+DH_KEY_LEN+DIGEST_LEN) {
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Rejecting RENDEZVOUS1 cell with bad length (%d) on circuit %u.",
(int)request_len, (unsigned)circ->p_circ_id);
reason = END_CIRC_REASON_TORPROTOCOL;
goto err;
}
base16_encode(hexid, sizeof(hexid), (const char*)request, 4);
log_info(LD_REND,
"Got request for rendezvous from circuit %u to cookie %s.",
(unsigned)circ->p_circ_id, hexid);
rend_circ = circuit_get_rendezvous(request);
if (!rend_circ) {
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Rejecting RENDEZVOUS1 cell with unrecognized rendezvous cookie %s.",
hexid);
reason = END_CIRC_REASON_TORPROTOCOL;
goto err;
}
/* Send the RENDEZVOUS2 cell to Alice. */
if (relay_send_command_from_edge(0, TO_CIRCUIT(rend_circ),
RELAY_COMMAND_RENDEZVOUS2,
(char*)(request+REND_COOKIE_LEN),
request_len-REND_COOKIE_LEN, NULL)) {
log_warn(LD_GENERAL,
"Unable to send RENDEZVOUS2 cell to client on circuit %u.",
(unsigned)rend_circ->p_circ_id);
goto err;
}
/* Join the circuits. */
log_info(LD_REND,
"Completing rendezvous: circuit %u joins circuit %u (cookie %s)",
(unsigned)circ->p_circ_id, (unsigned)rend_circ->p_circ_id, hexid);
circuit_change_purpose(TO_CIRCUIT(circ), CIRCUIT_PURPOSE_REND_ESTABLISHED);
circuit_change_purpose(TO_CIRCUIT(rend_circ),
CIRCUIT_PURPOSE_REND_ESTABLISHED);
circuit_set_rendezvous_cookie(circ, NULL);
rend_circ->rend_splice = circ;
circ->rend_splice = rend_circ;
return 0;
err:
circuit_mark_for_close(TO_CIRCUIT(circ), reason);
return -1;
}
/** Respond to an ESTABLISH_INTRO cell by checking the signed data and
* setting the circuit's purpose and service pk digest.
*/
int
rend_mid_establish_intro(or_circuit_t *circ, const uint8_t *request,
size_t request_len)
{
crypto_pk_t *pk = NULL;
char buf[DIGEST_LEN+9];
char expected_digest[DIGEST_LEN];
char pk_digest[DIGEST_LEN];
size_t asn1len;
or_circuit_t *c;
char serviceid[REND_SERVICE_ID_LEN_BASE32+1];
int reason = END_CIRC_REASON_INTERNAL;
log_info(LD_REND,
"Received an ESTABLISH_INTRO request on circuit %u",
(unsigned) circ->p_circ_id);
if (circ->base_.purpose != CIRCUIT_PURPOSE_OR || circ->base_.n_chan) {
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Rejecting ESTABLISH_INTRO on non-OR or non-edge circuit.");
reason = END_CIRC_REASON_TORPROTOCOL;
goto err;
}
if (request_len < 2+DIGEST_LEN)
goto truncated;
/* First 2 bytes: length of asn1-encoded key. */
asn1len = ntohs(get_uint16(request));
/* Next asn1len bytes: asn1-encoded key. */
if (request_len < 2+DIGEST_LEN+asn1len)
goto truncated;
pk = crypto_pk_asn1_decode((char*)(request+2), asn1len);
if (!pk) {
reason = END_CIRC_REASON_TORPROTOCOL;
log_warn(LD_PROTOCOL, "Couldn't decode public key.");
goto err;
}
/* Next 20 bytes: Hash of rend_circ_nonce | "INTRODUCE" */
memcpy(buf, circ->rend_circ_nonce, DIGEST_LEN);
memcpy(buf+DIGEST_LEN, "INTRODUCE", 9);
if (crypto_digest(expected_digest, buf, DIGEST_LEN+9) < 0) {
log_warn(LD_BUG, "Internal error computing digest.");
goto err;
}
if (tor_memneq(expected_digest, request+2+asn1len, DIGEST_LEN)) {
log_warn(LD_PROTOCOL, "Hash of session info was not as expected.");
reason = END_CIRC_REASON_TORPROTOCOL;
goto err;
}
/* Rest of body: signature of previous data */
note_crypto_pk_op(REND_MID);
if (crypto_pk_public_checksig_digest(pk,
(char*)request, 2+asn1len+DIGEST_LEN,
(char*)(request+2+DIGEST_LEN+asn1len),
request_len-(2+DIGEST_LEN+asn1len))<0) {
log_warn(LD_PROTOCOL,
"Incorrect signature on ESTABLISH_INTRO cell; rejecting.");
reason = END_CIRC_REASON_TORPROTOCOL;
goto err;
}
/* The request is valid. First, compute the hash of Bob's PK.*/
if (crypto_pk_get_digest(pk, pk_digest)<0) {
log_warn(LD_BUG, "Internal error: couldn't hash public key.");
goto err;
}
crypto_pk_free(pk); /* don't need it anymore */
pk = NULL; /* so we don't free it again if err */
base32_encode(serviceid, REND_SERVICE_ID_LEN_BASE32+1,
pk_digest, REND_SERVICE_ID_LEN);
/* Close any other intro circuits with the same pk. */
c = NULL;
while ((c = circuit_get_intro_point((const uint8_t *)pk_digest))) {
log_info(LD_REND, "Replacing old circuit for service %s",
safe_str(serviceid));
circuit_mark_for_close(TO_CIRCUIT(c), END_CIRC_REASON_FINISHED);
/* Now it's marked, and it won't be returned next time. */
}
/* Acknowledge the request. */
if (relay_send_command_from_edge(0, TO_CIRCUIT(circ),
RELAY_COMMAND_INTRO_ESTABLISHED,
"", 0, NULL)<0) {
log_info(LD_GENERAL, "Couldn't send INTRO_ESTABLISHED cell.");
goto err;
}
/* Now, set up this circuit. */
circuit_change_purpose(TO_CIRCUIT(circ), CIRCUIT_PURPOSE_INTRO_POINT);
circuit_set_intro_point_digest(circ, (uint8_t *)pk_digest);
log_info(LD_REND,
"Established introduction point on circuit %u for service %s",
(unsigned) circ->p_circ_id, safe_str(serviceid));
return 0;
truncated:
log_warn(LD_PROTOCOL, "Rejecting truncated ESTABLISH_INTRO cell.");
reason = END_CIRC_REASON_TORPROTOCOL;
err:
if (pk) crypto_pk_free(pk);
circuit_mark_for_close(TO_CIRCUIT(circ), reason);
return -1;
}
/* Called when a service introduction point circuit is done building. Given
* the service and intro point object, this function will send the
* ESTABLISH_INTRO cell on the circuit. Return 0 on success. Return 1 if the
* circuit has been repurposed to General because we already have too many
* opened. */
int
hs_circ_service_intro_has_opened(hs_service_t *service,
hs_service_intro_point_t *ip,
const hs_service_descriptor_t *desc,
origin_circuit_t *circ)
{
int ret = 0;
unsigned int num_intro_circ, num_needed_circ;
tor_assert(service);
tor_assert(ip);
tor_assert(desc);
tor_assert(circ);
/* Cound opened circuits that have sent ESTABLISH_INTRO cells or are already
* established introduction circuits */
num_intro_circ = count_opened_desc_intro_point_circuits(service, desc);
num_needed_circ = service->config.num_intro_points;
if (num_intro_circ > num_needed_circ) {
/* There are too many opened valid intro circuit for what the service
* needs so repurpose this one. */
/* XXX: Legacy code checks options->ExcludeNodes and if not NULL it just
* closes the circuit. I have NO idea why it does that so it hasn't been
* added here. I can only assume in case our ExcludeNodes list changes but
* in that case, all circuit are flagged unusable (config.c). --dgoulet */
log_info(LD_CIRC | LD_REND, "Introduction circuit just opened but we "
"have enough for service %s. Repurposing "
"it to general and leaving internal.",
safe_str_client(service->onion_address));
tor_assert(circ->build_state->is_internal);
/* Remove it from the circuitmap. */
hs_circuitmap_remove_circuit(TO_CIRCUIT(circ));
/* Cleaning up the hidden service identifier and repurpose. */
hs_ident_circuit_free(circ->hs_ident);
circ->hs_ident = NULL;
if (circuit_should_use_vanguards(TO_CIRCUIT(circ)->purpose))
circuit_change_purpose(TO_CIRCUIT(circ), CIRCUIT_PURPOSE_HS_VANGUARDS);
else
circuit_change_purpose(TO_CIRCUIT(circ), CIRCUIT_PURPOSE_C_GENERAL);
/* Inform that this circuit just opened for this new purpose. */
circuit_has_opened(circ);
/* This return value indicate to the caller that the IP object should be
* removed from the service because it's corresponding circuit has just
* been repurposed. */
ret = 1;
goto done;
}
log_info(LD_REND, "Introduction circuit %u established for service %s.",
TO_CIRCUIT(circ)->n_circ_id,
safe_str_client(service->onion_address));
circuit_log_path(LOG_INFO, LD_REND, circ);
/* Time to send an ESTABLISH_INTRO cell on this circuit. On error, this call
* makes sure the circuit gets closed. */
send_establish_intro(service, ip, circ);
done:
return ret;
}
static void
test_received_introduce1_handling(void *arg)
{
int ret;
uint8_t *request = NULL, buf[128];
trn_cell_introduce1_t *cell = NULL;
or_circuit_t *circ = NULL;
(void) arg;
MOCK(relay_send_command_from_edge_, mock_relay_send_command_from_edge);
hs_circuitmap_init();
/* Too small request length. An INTRODUCE1 expect at the very least a
* DIGEST_LEN size. */
{
memset(buf, 0, sizeof(buf));
circ = helper_create_intro_circuit();
ret = hs_intro_received_introduce1(circ, buf, DIGEST_LEN - 1);
tt_int_op(ret, OP_EQ, -1);
circuit_free_(TO_CIRCUIT(circ));
}
/* We have a unit test only for the suitability of a circuit to receive an
* INTRODUCE1 cell so from now on we'll only test the handling of a cell. */
/* Bad request. */
{
circ = helper_create_intro_circuit();
uint8_t test[2]; /* Too small request. */
memset(test, 0, sizeof(test));
ret = handle_introduce1(circ, test, sizeof(test));
tor_free(circ->p_chan);
circuit_free_(TO_CIRCUIT(circ));
tt_int_op(ret, OP_EQ, -1);
}
/* Valid case. */
{
cell = helper_create_introduce1_cell();
ssize_t request_len = trn_cell_introduce1_encoded_len(cell);
tt_int_op((int)request_len, OP_GT, 0);
request = tor_malloc_zero(request_len);
ssize_t encoded_len =
trn_cell_introduce1_encode(request, request_len, cell);
tt_int_op((int)encoded_len, OP_GT, 0);
circ = helper_create_intro_circuit();
or_circuit_t *service_circ = helper_create_intro_circuit();
circuit_change_purpose(TO_CIRCUIT(service_circ),
CIRCUIT_PURPOSE_INTRO_POINT);
/* Register the circuit in the map for the auth key of the cell. */
ed25519_public_key_t auth_key;
const uint8_t *cell_auth_key =
trn_cell_introduce1_getconstarray_auth_key(cell);
memcpy(auth_key.pubkey, cell_auth_key, ED25519_PUBKEY_LEN);
hs_circuitmap_register_intro_circ_v3_relay_side(service_circ, &auth_key);
ret = hs_intro_received_introduce1(circ, request, request_len);
circuit_free_(TO_CIRCUIT(circ));
circuit_free_(TO_CIRCUIT(service_circ));
tt_int_op(ret, OP_EQ, 0);
}
/* Valid legacy cell. */
{
tor_free(request);
trn_cell_introduce1_free(cell);
cell = helper_create_introduce1_cell();
uint8_t *legacy_key_id = trn_cell_introduce1_getarray_legacy_key_id(cell);
memset(legacy_key_id, 'a', DIGEST_LEN);
/* Add an arbitrary amount of data for the payload of a v2 cell. */
size_t request_len = trn_cell_introduce1_encoded_len(cell) + 256;
tt_size_op(request_len, OP_GT, 0);
request = tor_malloc_zero(request_len + 256);
ssize_t encoded_len =
trn_cell_introduce1_encode(request, request_len, cell);
tt_int_op((int)encoded_len, OP_GT, 0);
circ = helper_create_intro_circuit();
or_circuit_t *service_circ = helper_create_intro_circuit();
circuit_change_purpose(TO_CIRCUIT(service_circ),
CIRCUIT_PURPOSE_INTRO_POINT);
/* Register the circuit in the map for the auth key of the cell. */
uint8_t token[REND_TOKEN_LEN];
memcpy(token, legacy_key_id, sizeof(token));
hs_circuitmap_register_intro_circ_v2_relay_side(service_circ, token);
ret = hs_intro_received_introduce1(circ, request, request_len);
circuit_free_(TO_CIRCUIT(circ));
circuit_free_(TO_CIRCUIT(service_circ));
tt_int_op(ret, OP_EQ, 0);
}
done:
trn_cell_introduce1_free(cell);
tor_free(request);
hs_circuitmap_free_all();
UNMOCK(relay_send_command_from_edge_);
}
