diff options
Diffstat (limited to 'src/or/rendmid.c')
| -rw-r--r-- | src/or/rendmid.c | 370 |
1 files changed, 0 insertions, 370 deletions
diff --git a/src/or/rendmid.c b/src/or/rendmid.c deleted file mode 100644 index 38c1c52e43..0000000000 --- a/src/or/rendmid.c +++ /dev/null @@ -1,370 +0,0 @@ -/* Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2018, The Tor Project, Inc. */ -/* See LICENSE for licensing information */ - -/** - * \file rendmid.c - * \brief Implement introductions points and rendezvous points. - **/ - -#include "or/or.h" -#include "or/channel.h" -#include "or/circuitlist.h" -#include "or/circuituse.h" -#include "or/config.h" -#include "lib/crypt_ops/crypto.h" -#include "or/dos.h" -#include "or/relay.h" -#include "or/rendmid.h" -#include "or/rephist.h" -#include "or/hs_circuitmap.h" -#include "or/hs_intropoint.h" - -#include "or/or_circuit_st.h" - -/** 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_legacy(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 a legacy ESTABLISH_INTRO request on circuit %u", - (unsigned) circ->p_circ_id); - - if (!hs_intro_circuit_is_suitable_for_establish_intro(circ)) { - 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 */ - 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 the service'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 = hs_circuitmap_get_intro_circ_v2_relay_side( - (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 (hs_intro_send_intro_established_cell(circ) < 0) { - log_info(LD_GENERAL, "Couldn't send INTRO_ESTABLISHED cell."); - goto err_no_close; - } - - /* Now, set up this circuit. */ - circuit_change_purpose(TO_CIRCUIT(circ), CIRCUIT_PURPOSE_INTRO_POINT); - hs_circuitmap_register_intro_circ_v2_relay_side(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: - circuit_mark_for_close(TO_CIRCUIT(circ), reason); - err_no_close: - if (pk) crypto_pk_free(pk); - return -1; -} - -/** Process an INTRODUCE1 cell by finding the corresponding introduction - * circuit, and relaying the body of the INTRODUCE1 cell inside an - * INTRODUCE2 cell. - */ -int -rend_mid_introduce_legacy(or_circuit_t *circ, const uint8_t *request, - size_t request_len) -{ - or_circuit_t *intro_circ; - char serviceid[REND_SERVICE_ID_LEN_BASE32+1]; - char nak_body[1]; - - log_info(LD_REND, "Received an INTRODUCE1 request on circuit %u", - (unsigned)circ->p_circ_id); - - /* At this point, we know that the circuit is valid for an INTRODUCE1 - * because the validation has been made before calling this function. */ - tor_assert(circ->base_.purpose == CIRCUIT_PURPOSE_OR); - tor_assert(!circ->base_.n_chan); - - /* We could change this to MAX_HEX_NICKNAME_LEN now that 0.0.9.x is - * obsolete; however, there isn't much reason to do so, and we're going - * to revise this protocol anyway. - */ - if (request_len < (DIGEST_LEN+(MAX_NICKNAME_LEN+1)+REND_COOKIE_LEN+ - DH1024_KEY_LEN+CIPHER_KEY_LEN+ - PKCS1_OAEP_PADDING_OVERHEAD)) { - log_warn(LD_PROTOCOL, "Impossibly short INTRODUCE1 cell on circuit %u; " - "responding with nack.", - (unsigned)circ->p_circ_id); - goto err; - } - - base32_encode(serviceid, REND_SERVICE_ID_LEN_BASE32+1, - (char*)request, REND_SERVICE_ID_LEN); - - /* The first 20 bytes are all we look at: they have a hash of the service's - * PK. */ - intro_circ = hs_circuitmap_get_intro_circ_v2_relay_side( - (const uint8_t*)request); - if (!intro_circ) { - log_info(LD_REND, - "No intro circ found for INTRODUCE1 cell (%s) from circuit %u; " - "responding with nack.", - safe_str(serviceid), (unsigned)circ->p_circ_id); - goto err; - } - - log_info(LD_REND, - "Sending introduction request for service %s " - "from circ %u to circ %u", - safe_str(serviceid), (unsigned)circ->p_circ_id, - (unsigned)intro_circ->p_circ_id); - - /* Great. Now we just relay the cell down the circuit. */ - if (relay_send_command_from_edge(0, TO_CIRCUIT(intro_circ), - RELAY_COMMAND_INTRODUCE2, - (char*)request, request_len, NULL)) { - log_warn(LD_GENERAL, - "Unable to send INTRODUCE2 cell to Tor client."); - /* Stop right now, the circuit has been closed. */ - return -1; - } - /* And send an ack down the client's circuit. Empty body means succeeded. */ - if (relay_send_command_from_edge(0,TO_CIRCUIT(circ), - RELAY_COMMAND_INTRODUCE_ACK, - NULL,0,NULL)) { - log_warn(LD_GENERAL, "Unable to send INTRODUCE_ACK cell to Tor client."); - /* Stop right now, the circuit has been closed. */ - return -1; - } - - return 0; - err: - /* Send the client a NACK */ - nak_body[0] = 1; - if (relay_send_command_from_edge(0,TO_CIRCUIT(circ), - RELAY_COMMAND_INTRODUCE_ACK, - nak_body, 1, NULL)) { - log_warn(LD_GENERAL, "Unable to send NAK to Tor client."); - } - return -1; -} - -/** 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; - } - - /* Check if we are configured to accept established rendezvous cells from - * client or in other words tor2web clients. */ - if (channel_is_client(circ->p_chan) && - dos_should_refuse_single_hop_client()) { - /* Note it down for the heartbeat log purposes. */ - dos_note_refuse_single_hop_client(); - /* Silent drop so the client has to time out before moving on. */ - return 0; - } - - 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 (hs_circuitmap_get_rend_circ_relay_side(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."); - /* Stop right now, the circuit has been closed. */ - return -1; - } - - circuit_change_purpose(TO_CIRCUIT(circ), CIRCUIT_PURPOSE_REND_POINT_WAITING); - hs_circuitmap_register_rend_circ_relay_side(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; -} - -/** 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) -{ - const or_options_t *options = get_options(); - 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) { - 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 = hs_circuitmap_get_rend_circ_relay_side(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; - } - - /* Statistics: Mark this circuit as an RP circuit so that we collect - stats from it. */ - if (options->HiddenServiceStatistics) { - circ->circuit_carries_hs_traffic_stats = 1; - } - - /* Send the RENDEZVOUS2 cell to the client. */ - 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); - /* Stop right now, the circuit has been closed. */ - return -1; - } - - /* 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); - hs_circuitmap_remove_circuit(TO_CIRCUIT(circ)); - - rend_circ->rend_splice = circ; - circ->rend_splice = rend_circ; - - return 0; - err: - circuit_mark_for_close(TO_CIRCUIT(circ), reason); - return -1; -} |