commit ca04e9b8edd1752c802b053be12594c948405d36 Author: David Goulet dgoulet@torproject.org Date: Tue Feb 16 09:27:45 2021 -0500

hs: Remove introduction point v2 support

Related to #40266

Signed-off-by: David Goulet dgoulet@torproject.org --- src/feature/hs/hs_intropoint.c | 40 +------- src/feature/hs/hs_intropoint.h | 1 - src/feature/rend/rendmid.c | 205 ----------------------------------------- 3 files changed, 5 insertions(+), 241 deletions(-)

diff --git a/src/feature/hs/hs_intropoint.c b/src/feature/hs/hs_intropoint.c index 69d60f21c3..7ae6deffa2 100644 --- a/src/feature/hs/hs_intropoint.c +++ b/src/feature/hs/hs_intropoint.c @@ -494,8 +494,8 @@ hs_intro_circuit_is_suitable_for_establish_intro(const or_circuit_t *circ) return circuit_is_suitable_intro_point(circ, "ESTABLISH_INTRO"); }

-/** We just received an ESTABLISH_INTRO cell in <b>circ</b>. Figure out of it's - * a legacy or a next gen cell, and pass it to the appropriate handler. */ +/** We just received an ESTABLISH_INTRO cell in <b>circ</b>. Pass it to the + * appropriate handler. */ int hs_intro_received_establish_intro(or_circuit_t *circ, const uint8_t *request, size_t request_len) @@ -512,9 +512,6 @@ hs_intro_received_establish_intro(or_circuit_t *circ, const uint8_t *request, * ESTABLISH_INTRO and pass it to the appropriate cell handler */ const uint8_t first_byte = request[0]; switch (first_byte) { - case TRUNNEL_HS_INTRO_AUTH_KEY_TYPE_LEGACY0: - case TRUNNEL_HS_INTRO_AUTH_KEY_TYPE_LEGACY1: - return rend_mid_establish_intro_legacy(circ, request, request_len); case TRUNNEL_HS_INTRO_AUTH_KEY_TYPE_ED25519: return handle_establish_intro(circ, request, request_len); default: @@ -717,23 +714,6 @@ handle_introduce1(or_circuit_t *client_circ, const uint8_t *request, return ret; }

-/** Identify if the encoded cell we just received is a legacy one or not. The - * <b>request</b> should be at least DIGEST_LEN bytes long. */ -STATIC int -introduce1_cell_is_legacy(const uint8_t *request) -{ - tor_assert(request); - - /* If the first 20 bytes of the cell (DIGEST_LEN) are NOT zeroes, it - * indicates a legacy cell (v2). */ - if (!fast_mem_is_zero((const char *) request, DIGEST_LEN)) { - /* Legacy cell. */ - return 1; - } - /* Not a legacy cell. */ - return 0; -} - /** Return true iff the circuit <b>circ</b> is suitable for receiving an * INTRODUCE1 cell. */ STATIC int @@ -772,13 +752,10 @@ int hs_intro_received_introduce1(or_circuit_t *circ, const uint8_t *request, size_t request_len) { - int ret; - tor_assert(circ); tor_assert(request);

- /* A cell that can't hold a DIGEST_LEN is invalid as we need to check if - * it's a legacy cell or not using the first DIGEST_LEN bytes. */ + /* A cell that can't hold a DIGEST_LEN is invalid. */ if (request_len < DIGEST_LEN) { log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL, "Invalid INTRODUCE1 cell length."); goto err; @@ -794,15 +771,8 @@ hs_intro_received_introduce1(or_circuit_t *circ, const uint8_t *request, * DoS mitigation since one circuit with one client can hammer a service. */ circ->already_received_introduce1 = 1;

- /* We are sure here to have at least DIGEST_LEN bytes. */ - if (introduce1_cell_is_legacy(request)) { - /* Handle a legacy cell. */ - ret = rend_mid_introduce_legacy(circ, request, request_len); - } else { - /* Handle a non legacy cell. */ - ret = handle_introduce1(circ, request, request_len); - } - return ret; + /* Handle the cell. */ + return handle_introduce1(circ, request, request_len);

err: circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_TORPROTOCOL); diff --git a/src/feature/hs/hs_intropoint.h b/src/feature/hs/hs_intropoint.h index 8b2b9892b3..f08cef9afe 100644 --- a/src/feature/hs/hs_intropoint.h +++ b/src/feature/hs/hs_intropoint.h @@ -52,7 +52,6 @@ STATIC void get_auth_key_from_cell(ed25519_public_key_t *auth_key_out, unsigned int cell_type, const void *cell);

-STATIC int introduce1_cell_is_legacy(const uint8_t *request); STATIC int handle_introduce1(or_circuit_t *client_circ, const uint8_t *request, size_t request_len); STATIC int validate_introduce1_parsed_cell(const trn_cell_introduce1_t *cell); diff --git a/src/feature/rend/rendmid.c b/src/feature/rend/rendmid.c index b497362857..fdd5202a95 100644 --- a/src/feature/rend/rendmid.c +++ b/src/feature/rend/rendmid.c @@ -16,217 +16,12 @@ #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_dos.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_fn(LOG_PROTOCOL_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_fn(LOG_PROTOCOL_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_fn(LOG_PROTOCOL_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); - hs_dos_setup_default_intro2_defenses(circ); - - 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_fn(LOG_PROTOCOL_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; - } - - /* Before sending, lets make sure this cell can be sent on the service - * circuit asking the DoS defenses. */ - if (!hs_dos_can_send_intro2(intro_circ)) { - log_info(LD_PROTOCOL, "Can't relay INTRODUCE1 v2 cell due to DoS " - "limitations. Sending NACK to client."); - 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. */