commit 80955be6ecae7095d267981b39d10237aabc38a6 Author: Nick Mathewson <nickm@torproject.org> Date: Sat Mar 17 10:21:57 2018 -0400 Move relay-crypto functions from relay.[ch] to relay_crypto.[ch] This should help us improve modularity, and should also make it easier for people to experiment with other relay crypto strategies down the road. This commit is pure function movement. --- src/or/include.am | 2 + src/or/relay.c | 192 +---------------------------------------------- src/or/relay.h | 7 -- src/or/relay_crypto.c | 202 ++++++++++++++++++++++++++++++++++++++++++++++++++ src/or/relay_crypto.h | 23 ++++++ src/test/bench.c | 2 +- 6 files changed, 229 insertions(+), 199 deletions(-) diff --git a/src/or/include.am b/src/or/include.am index e0366a0ca..77a9dcc0b 100644 --- a/src/or/include.am +++ b/src/or/include.am @@ -91,6 +91,7 @@ LIBTOR_A_SOURCES = \ src/or/policies.c \ src/or/reasons.c \ src/or/relay.c \ + src/or/relay_crypto.c \ src/or/rendcache.c \ src/or/rendclient.c \ src/or/rendcommon.c \ @@ -237,6 +238,7 @@ ORHEADERS = \ src/or/proto_socks.h \ src/or/reasons.h \ src/or/relay.h \ + src/or/relay_crypto.h \ src/or/rendcache.h \ src/or/rendclient.h \ src/or/rendcommon.h \ diff --git a/src/or/relay.c b/src/or/relay.c index 9431c93be..5f241423a 100644 --- a/src/or/relay.c +++ b/src/or/relay.c @@ -70,6 +70,7 @@ #include "policies.h" #include "reasons.h" #include "relay.h" +#include "relay_crypto.h" #include "rendcache.h" #include "rendcommon.h" #include "router.h" @@ -122,79 +123,6 @@ uint64_t stats_n_relay_cells_delivered = 0; /** Used to tell which stream to read from first on a circuit. */ static tor_weak_rng_t stream_choice_rng = TOR_WEAK_RNG_INIT; -/** Update digest from the payload of cell. Assign integrity part to - * cell. - */ -static void -relay_set_digest(crypto_digest_t *digest, cell_t *cell) -{ - char integrity[4]; - relay_header_t rh; - - crypto_digest_add_bytes(digest, (char*)cell->payload, CELL_PAYLOAD_SIZE); - crypto_digest_get_digest(digest, integrity, 4); -// log_fn(LOG_DEBUG,"Putting digest of %u %u %u %u into relay cell.", -// integrity[0], integrity[1], integrity[2], integrity[3]); - relay_header_unpack(&rh, cell->payload); - memcpy(rh.integrity, integrity, 4); - relay_header_pack(cell->payload, &rh); -} - -/** Does the digest for this circuit indicate that this cell is for us? - * - * Update digest from the payload of cell (with the integrity part set - * to 0). If the integrity part is valid, return 1, else restore digest - * and cell to their original state and return 0. - */ -static int -relay_digest_matches(crypto_digest_t *digest, cell_t *cell) -{ - uint32_t received_integrity, calculated_integrity; - relay_header_t rh; - crypto_digest_checkpoint_t backup_digest; - - crypto_digest_checkpoint(&backup_digest, digest); - - relay_header_unpack(&rh, cell->payload); - memcpy(&received_integrity, rh.integrity, 4); - memset(rh.integrity, 0, 4); - relay_header_pack(cell->payload, &rh); - -// log_fn(LOG_DEBUG,"Reading digest of %u %u %u %u from relay cell.", -// received_integrity[0], received_integrity[1], -// received_integrity[2], received_integrity[3]); - - crypto_digest_add_bytes(digest, (char*) cell->payload, CELL_PAYLOAD_SIZE); - crypto_digest_get_digest(digest, (char*) &calculated_integrity, 4); - - int rv = 1; - - if (calculated_integrity != received_integrity) { -// log_fn(LOG_INFO,"Recognized=0 but bad digest. Not recognizing."); -// (%d vs %d).", received_integrity, calculated_integrity); - /* restore digest to its old form */ - crypto_digest_restore(digest, &backup_digest); - /* restore the relay header */ - memcpy(rh.integrity, &received_integrity, 4); - relay_header_pack(cell->payload, &rh); - rv = 0; - } - - memwipe(&backup_digest, 0, sizeof(backup_digest)); - return rv; -} - -/** Apply <b>cipher</b> to CELL_PAYLOAD_SIZE bytes of <b>in</b> - * (in place). - * - * Note that we use the same operation for encrypting and for decrypting. - */ -static void -relay_crypt_one_payload(crypto_cipher_t *cipher, uint8_t *in) -{ - crypto_cipher_crypt_inplace(cipher, (char*) in, CELL_PAYLOAD_SIZE); -} - /** * Update channel usage state based on the type of relay cell and * circuit properties. @@ -405,124 +333,6 @@ circuit_receive_relay_cell(cell_t *cell, circuit_t *circ, return 0; } -/** Do the appropriate en/decryptions for <b>cell</b> arriving on - * <b>circ</b> in direction <b>cell_direction</b>. - * - * If cell_direction == CELL_DIRECTION_IN: - * - If we're at the origin (we're the OP), for hops 1..N, - * decrypt cell. If recognized, stop. - * - Else (we're not the OP), encrypt one hop. Cell is not recognized. - * - * If cell_direction == CELL_DIRECTION_OUT: - * - decrypt one hop. Check if recognized. - * - * If cell is recognized, set *recognized to 1, and set - * *layer_hint to the hop that recognized it. - * - * Return -1 to indicate that we should mark the circuit for close, - * else return 0. - */ -int -relay_decrypt_cell(circuit_t *circ, cell_t *cell, - cell_direction_t cell_direction, - crypt_path_t **layer_hint, char *recognized) -{ - relay_header_t rh; - - tor_assert(circ); - tor_assert(cell); - tor_assert(recognized); - tor_assert(cell_direction == CELL_DIRECTION_IN || - cell_direction == CELL_DIRECTION_OUT); - - if (cell_direction == CELL_DIRECTION_IN) { - if (CIRCUIT_IS_ORIGIN(circ)) { /* We're at the beginning of the circuit. - * We'll want to do layered decrypts. */ - crypt_path_t *thishop, *cpath = TO_ORIGIN_CIRCUIT(circ)->cpath; - thishop = cpath; - if (thishop->state != CPATH_STATE_OPEN) { - log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL, - "Relay cell before first created cell? Closing."); - return -1; - } - do { /* Remember: cpath is in forward order, that is, first hop first. */ - tor_assert(thishop); - - /* decrypt one layer */ - relay_crypt_one_payload(thishop->b_crypto, cell->payload); - - relay_header_unpack(&rh, cell->payload); - if (rh.recognized == 0) { - /* it's possibly recognized. have to check digest to be sure. */ - if (relay_digest_matches(thishop->b_digest, cell)) { - *recognized = 1; - *layer_hint = thishop; - return 0; - } - } - - thishop = thishop->next; - } while (thishop != cpath && thishop->state == CPATH_STATE_OPEN); - log_fn(LOG_PROTOCOL_WARN, LD_OR, - "Incoming cell at client not recognized. Closing."); - return -1; - } else { - /* We're in the middle. Encrypt one layer. */ - relay_crypt_one_payload(TO_OR_CIRCUIT(circ)->p_crypto, cell->payload); - } - } else /* cell_direction == CELL_DIRECTION_OUT */ { - /* We're in the middle. Decrypt one layer. */ - - relay_crypt_one_payload(TO_OR_CIRCUIT(circ)->n_crypto, cell->payload); - - relay_header_unpack(&rh, cell->payload); - if (rh.recognized == 0) { - /* it's possibly recognized. have to check digest to be sure. */ - if (relay_digest_matches(TO_OR_CIRCUIT(circ)->n_digest, cell)) { - *recognized = 1; - return 0; - } - } - } - return 0; -} - -/** - * Encrypt a cell <b>cell</b> that we are creating, and sending outbound on - * <b>circ</b> until the hop corresponding to <b>layer_hint</b>. - */ -void -relay_encrypt_cell_outbound(cell_t *cell, - origin_circuit_t *circ, - crypt_path_t *layer_hint) -{ - crypt_path_t *thishop; /* counter for repeated crypts */ - relay_set_digest(layer_hint->f_digest, cell); - - thishop = layer_hint; - /* moving from farthest to nearest hop */ - do { - tor_assert(thishop); - log_debug(LD_OR,"encrypting a layer of the relay cell."); - relay_crypt_one_payload(thishop->f_crypto, cell->payload); - - thishop = thishop->prev; - } while (thishop != circ->cpath->prev); -} - -/** - * Encrypt a cell <b>cell</b> that we are creating, and sending on - * <b>circuit</b> to the origin. - */ -void -relay_encrypt_cell_inbound(cell_t *cell, - or_circuit_t *or_circ) -{ - relay_set_digest(or_circ->p_digest, cell); - /* encrypt one layer */ - relay_crypt_one_payload(or_circ->p_crypto, cell->payload); -} - /** Package a relay cell from an edge: * - Encrypt it to the right layer * - Append it to the appropriate cell_queue on <b>circ</b>. diff --git a/src/or/relay.h b/src/or/relay.h index ff4d011f7..4bc3cb288 100644 --- a/src/or/relay.h +++ b/src/or/relay.h @@ -90,13 +90,6 @@ void circuit_clear_cell_queue(circuit_t *circ, channel_t *chan); void stream_choice_seed_weak_rng(void); -int relay_decrypt_cell(circuit_t *circ, cell_t *cell, - cell_direction_t cell_direction, - crypt_path_t **layer_hint, char *recognized); -void relay_encrypt_cell_outbound(cell_t *cell, origin_circuit_t *or_circ, - crypt_path_t *layer_hint); -void relay_encrypt_cell_inbound(cell_t *cell, or_circuit_t *or_circ); - circid_t packed_cell_get_circid(const packed_cell_t *cell, int wide_circ_ids); #ifdef RELAY_PRIVATE diff --git a/src/or/relay_crypto.c b/src/or/relay_crypto.c new file mode 100644 index 000000000..e0992a301 --- /dev/null +++ b/src/or/relay_crypto.c @@ -0,0 +1,202 @@ +/* Copyright (c) 2001 Matej Pfajfar. + * Copyright (c) 2001-2004, Roger Dingledine. + * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. + * Copyright (c) 2007-2018, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +#include "or.h" +#include "config.h" +#include "relay_crypto.h" +#include "relay.h" + +/** Update digest from the payload of cell. Assign integrity part to + * cell. + */ +static void +relay_set_digest(crypto_digest_t *digest, cell_t *cell) +{ + char integrity[4]; + relay_header_t rh; + + crypto_digest_add_bytes(digest, (char*)cell->payload, CELL_PAYLOAD_SIZE); + crypto_digest_get_digest(digest, integrity, 4); +// log_fn(LOG_DEBUG,"Putting digest of %u %u %u %u into relay cell.", +// integrity[0], integrity[1], integrity[2], integrity[3]); + relay_header_unpack(&rh, cell->payload); + memcpy(rh.integrity, integrity, 4); + relay_header_pack(cell->payload, &rh); +} + +/** Does the digest for this circuit indicate that this cell is for us? + * + * Update digest from the payload of cell (with the integrity part set + * to 0). If the integrity part is valid, return 1, else restore digest + * and cell to their original state and return 0. + */ +static int +relay_digest_matches(crypto_digest_t *digest, cell_t *cell) +{ + uint32_t received_integrity, calculated_integrity; + relay_header_t rh; + crypto_digest_checkpoint_t backup_digest; + + crypto_digest_checkpoint(&backup_digest, digest); + + relay_header_unpack(&rh, cell->payload); + memcpy(&received_integrity, rh.integrity, 4); + memset(rh.integrity, 0, 4); + relay_header_pack(cell->payload, &rh); + +// log_fn(LOG_DEBUG,"Reading digest of %u %u %u %u from relay cell.", +// received_integrity[0], received_integrity[1], +// received_integrity[2], received_integrity[3]); + + crypto_digest_add_bytes(digest, (char*) cell->payload, CELL_PAYLOAD_SIZE); + crypto_digest_get_digest(digest, (char*) &calculated_integrity, 4); + + int rv = 1; + + if (calculated_integrity != received_integrity) { +// log_fn(LOG_INFO,"Recognized=0 but bad digest. Not recognizing."); +// (%d vs %d).", received_integrity, calculated_integrity); + /* restore digest to its old form */ + crypto_digest_restore(digest, &backup_digest); + /* restore the relay header */ + memcpy(rh.integrity, &received_integrity, 4); + relay_header_pack(cell->payload, &rh); + rv = 0; + } + + memwipe(&backup_digest, 0, sizeof(backup_digest)); + return rv; +} + +/** Apply <b>cipher</b> to CELL_PAYLOAD_SIZE bytes of <b>in</b> + * (in place). + * + * Note that we use the same operation for encrypting and for decrypting. + */ +static void +relay_crypt_one_payload(crypto_cipher_t *cipher, uint8_t *in) +{ + crypto_cipher_crypt_inplace(cipher, (char*) in, CELL_PAYLOAD_SIZE); +} + +/** Do the appropriate en/decryptions for <b>cell</b> arriving on + * <b>circ</b> in direction <b>cell_direction</b>. + * + * If cell_direction == CELL_DIRECTION_IN: + * - If we're at the origin (we're the OP), for hops 1..N, + * decrypt cell. If recognized, stop. + * - Else (we're not the OP), encrypt one hop. Cell is not recognized. + * + * If cell_direction == CELL_DIRECTION_OUT: + * - decrypt one hop. Check if recognized. + * + * If cell is recognized, set *recognized to 1, and set + * *layer_hint to the hop that recognized it. + * + * Return -1 to indicate that we should mark the circuit for close, + * else return 0. + */ +int +relay_decrypt_cell(circuit_t *circ, cell_t *cell, + cell_direction_t cell_direction, + crypt_path_t **layer_hint, char *recognized) +{ + relay_header_t rh; + + tor_assert(circ); + tor_assert(cell); + tor_assert(recognized); + tor_assert(cell_direction == CELL_DIRECTION_IN || + cell_direction == CELL_DIRECTION_OUT); + + if (cell_direction == CELL_DIRECTION_IN) { + if (CIRCUIT_IS_ORIGIN(circ)) { /* We're at the beginning of the circuit. + * We'll want to do layered decrypts. */ + crypt_path_t *thishop, *cpath = TO_ORIGIN_CIRCUIT(circ)->cpath; + thishop = cpath; + if (thishop->state != CPATH_STATE_OPEN) { + log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL, + "Relay cell before first created cell? Closing."); + return -1; + } + do { /* Remember: cpath is in forward order, that is, first hop first. */ + tor_assert(thishop); + + /* decrypt one layer */ + relay_crypt_one_payload(thishop->b_crypto, cell->payload); + + relay_header_unpack(&rh, cell->payload); + if (rh.recognized == 0) { + /* it's possibly recognized. have to check digest to be sure. */ + if (relay_digest_matches(thishop->b_digest, cell)) { + *recognized = 1; + *layer_hint = thishop; + return 0; + } + } + + thishop = thishop->next; + } while (thishop != cpath && thishop->state == CPATH_STATE_OPEN); + log_fn(LOG_PROTOCOL_WARN, LD_OR, + "Incoming cell at client not recognized. Closing."); + return -1; + } else { + /* We're in the middle. Encrypt one layer. */ + relay_crypt_one_payload(TO_OR_CIRCUIT(circ)->p_crypto, cell->payload); + } + } else /* cell_direction == CELL_DIRECTION_OUT */ { + /* We're in the middle. Decrypt one layer. */ + + relay_crypt_one_payload(TO_OR_CIRCUIT(circ)->n_crypto, cell->payload); + + relay_header_unpack(&rh, cell->payload); + if (rh.recognized == 0) { + /* it's possibly recognized. have to check digest to be sure. */ + if (relay_digest_matches(TO_OR_CIRCUIT(circ)->n_digest, cell)) { + *recognized = 1; + return 0; + } + } + } + return 0; +} + +/** + * Encrypt a cell <b>cell</b> that we are creating, and sending outbound on + * <b>circ</b> until the hop corresponding to <b>layer_hint</b>. + */ +void +relay_encrypt_cell_outbound(cell_t *cell, + origin_circuit_t *circ, + crypt_path_t *layer_hint) +{ + crypt_path_t *thishop; /* counter for repeated crypts */ + relay_set_digest(layer_hint->f_digest, cell); + + thishop = layer_hint; + /* moving from farthest to nearest hop */ + do { + tor_assert(thishop); + log_debug(LD_OR,"encrypting a layer of the relay cell."); + relay_crypt_one_payload(thishop->f_crypto, cell->payload); + + thishop = thishop->prev; + } while (thishop != circ->cpath->prev); +} + +/** + * Encrypt a cell <b>cell</b> that we are creating, and sending on + * <b>circuit</b> to the origin. + */ +void +relay_encrypt_cell_inbound(cell_t *cell, + or_circuit_t *or_circ) +{ + relay_set_digest(or_circ->p_digest, cell); + /* encrypt one layer */ + relay_crypt_one_payload(or_circ->p_crypto, cell->payload); +} + diff --git a/src/or/relay_crypto.h b/src/or/relay_crypto.h new file mode 100644 index 000000000..8d0917941 --- /dev/null +++ b/src/or/relay_crypto.h @@ -0,0 +1,23 @@ +/* Copyright (c) 2001 Matej Pfajfar. + * Copyright (c) 2001-2004, Roger Dingledine. + * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. + * Copyright (c) 2007-2017, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +/** + * \file relay.h + * \brief Header file for relay.c. + **/ + +#ifndef TOR_RELAY_CRYPTO_H +#define TOR_RELAY_CRYPTO_H + +int relay_decrypt_cell(circuit_t *circ, cell_t *cell, + cell_direction_t cell_direction, + crypt_path_t **layer_hint, char *recognized); +void relay_encrypt_cell_outbound(cell_t *cell, origin_circuit_t *or_circ, + crypt_path_t *layer_hint); +void relay_encrypt_cell_inbound(cell_t *cell, or_circuit_t *or_circ); + +#endif /* !defined(TOR_RELAY_CRYPTO_H) */ + diff --git a/src/test/bench.c b/src/test/bench.c index ad3732568..67e127311 100644 --- a/src/test/bench.c +++ b/src/test/bench.c @@ -12,7 +12,7 @@ #include "or.h" #include "onion_tap.h" -#include "relay.h" +#include "relay_crypto.h" #include <openssl/opensslv.h> #include <openssl/evp.h> #include <openssl/ec.h>