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[tor-commits] [tor/maint-0.3.5] Merge branch 'maint-0.3.4' into maint-0.3.5
commit a8580a683696eb76f5f24fe36e7ea61f9c49db0a
Merge: f0408b844 761f1bf71
Author: Nick Mathewson <nickm@xxxxxxxxxxxxxx>
Date: Fri Jan 18 12:25:08 2019 -0500
Merge branch 'maint-0.3.4' into maint-0.3.5
changes/bug29029 | 5 +++++
src/feature/rend/rendmid.c | 6 +++---
2 files changed, 8 insertions(+), 3 deletions(-)
diff --cc src/feature/rend/rendmid.c
index 151604ada,000000000..fcfa5052c
mode 100644,000000..100644
--- a/src/feature/rend/rendmid.c
+++ b/src/feature/rend/rendmid.c
@@@ -1,370 -1,0 +1,370 @@@
+/* Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2019, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * \file rendmid.c
+ * \brief Implement introductions points and rendezvous points.
+ **/
+
+#include "core/or/or.h"
+#include "core/or/channel.h"
+#include "core/or/circuitlist.h"
+#include "core/or/circuituse.h"
+#include "app/config/config.h"
+#include "lib/crypt_ops/crypto_cipher.h"
+#include "core/or/dos.h"
+#include "core/or/relay.h"
+#include "feature/rend/rendmid.h"
+#include "feature/stats/rephist.h"
+#include "feature/hs/hs_circuitmap.h"
+#include "feature/hs/hs_intropoint.h"
+
+#include "core/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));
++ log_fn(LOG_PROTOCOL_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;
+}
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