commit 358ce9a19d522d1e1cf9a119850e924ca106fec5 Author: Nick Mathewson <nickm@torproject.org> Date: Tue Sep 14 14:19:22 2021 -0400 Add a size argument for the buffer on onion handshake functions --- src/core/crypto/onion_crypto.c | 19 ++++++++++++++++--- src/core/crypto/onion_crypto.h | 4 +++- src/core/mainloop/cpuworker.c | 1 + src/core/or/circuitbuild.c | 6 ++++-- src/core/or/command.c | 1 + 5 files changed, 25 insertions(+), 6 deletions(-) diff --git a/src/core/crypto/onion_crypto.c b/src/core/crypto/onion_crypto.c index f85ee2c82b..66c21bf655 100644 --- a/src/core/crypto/onion_crypto.c +++ b/src/core/crypto/onion_crypto.c @@ -103,19 +103,23 @@ onion_handshake_state_release(onion_handshake_state_t *state) /** Perform the first step of a circuit-creation handshake of type <b>type</b> * (one of ONION_HANDSHAKE_TYPE_*): generate the initial "onion skin" in - * <b>onion_skin_out</b>, and store any state information in <b>state_out</b>. + * <b>onion_skin_out</b> with length of up to <b>onion_skin_out_maxlen</b>, + * and store any state information in <b>state_out</b>. * Return -1 on failure, and the length of the onionskin on acceptance. */ int onion_skin_create(int type, const extend_info_t *node, onion_handshake_state_t *state_out, - uint8_t *onion_skin_out) + uint8_t *onion_skin_out, + size_t onion_skin_out_maxlen) { int r = -1; switch (type) { case ONION_HANDSHAKE_TYPE_TAP: + if (onion_skin_out_maxlen < TAP_ONIONSKIN_CHALLENGE_LEN) + return -1; if (!node->onion_key) return -1; @@ -133,7 +137,9 @@ onion_skin_create(int type, r = CREATE_FAST_LEN; break; case ONION_HANDSHAKE_TYPE_NTOR: - if (!extend_info_supports_ntor(node)) + if (onion_skin_out_maxlen < NTOR_ONIONSKIN_LEN) + return -1; + if (!extend_info_supports_ntor(node)) return -1; if (onion_skin_ntor_create((const uint8_t*)node->identity_digest, &node->curve25519_onion_key, @@ -175,6 +181,7 @@ onion_skin_server_handshake(int type, const uint8_t *onion_skin, size_t onionskin_len, const server_onion_keys_t *keys, uint8_t *reply_out, + size_t reply_out_maxlen, uint8_t *keys_out, size_t keys_out_len, uint8_t *rend_nonce_out) { @@ -182,6 +189,8 @@ onion_skin_server_handshake(int type, switch (type) { case ONION_HANDSHAKE_TYPE_TAP: + if (reply_out_maxlen < TAP_ONIONSKIN_REPLY_LEN) + return -1; if (onionskin_len != TAP_ONIONSKIN_CHALLENGE_LEN) return -1; if (onion_skin_TAP_server_handshake((const char*)onion_skin, @@ -193,6 +202,8 @@ onion_skin_server_handshake(int type, memcpy(rend_nonce_out, reply_out+DH1024_KEY_LEN, DIGEST_LEN); break; case ONION_HANDSHAKE_TYPE_FAST: + if (reply_out_maxlen < CREATED_FAST_LEN) + return -1; if (onionskin_len != CREATE_FAST_LEN) return -1; if (fast_server_handshake(onion_skin, reply_out, keys_out, keys_out_len)<0) @@ -201,6 +212,8 @@ onion_skin_server_handshake(int type, memcpy(rend_nonce_out, reply_out+DIGEST_LEN, DIGEST_LEN); break; case ONION_HANDSHAKE_TYPE_NTOR: + if (reply_out_maxlen < NTOR_REPLY_LEN) + return -1; if (onionskin_len < NTOR_ONIONSKIN_LEN) return -1; { diff --git a/src/core/crypto/onion_crypto.h b/src/core/crypto/onion_crypto.h index 68cd465cf7..bf25552b83 100644 --- a/src/core/crypto/onion_crypto.h +++ b/src/core/crypto/onion_crypto.h @@ -25,11 +25,13 @@ void onion_handshake_state_release(onion_handshake_state_t *state); int onion_skin_create(int type, const extend_info_t *node, onion_handshake_state_t *state_out, - uint8_t *onion_skin_out); + uint8_t *onion_skin_out, + size_t onion_skin_out_maxlen); int onion_skin_server_handshake(int type, const uint8_t *onion_skin, size_t onionskin_len, const server_onion_keys_t *keys, uint8_t *reply_out, + size_t reply_out_maxlen, uint8_t *keys_out, size_t key_out_len, uint8_t *rend_nonce_out); int onion_skin_client_handshake(int type, diff --git a/src/core/mainloop/cpuworker.c b/src/core/mainloop/cpuworker.c index 17855b8567..b7b09784fa 100644 --- a/src/core/mainloop/cpuworker.c +++ b/src/core/mainloop/cpuworker.c @@ -426,6 +426,7 @@ cpuworker_onion_handshake_threadfn(void *state_, void *work_) cc->onionskin, cc->handshake_len, onion_keys, cell_out->reply, + sizeof(cell_out->reply), rpl.keys, CPATH_KEY_MATERIAL_LEN, rpl.rend_auth_material); if (n < 0) { diff --git a/src/core/or/circuitbuild.c b/src/core/or/circuitbuild.c index 31e3868b65..dc8d888c97 100644 --- a/src/core/or/circuitbuild.c +++ b/src/core/or/circuitbuild.c @@ -995,7 +995,8 @@ circuit_send_first_onion_skin(origin_circuit_t *circ) len = onion_skin_create(cc.handshake_type, circ->cpath->extend_info, &circ->cpath->handshake_state, - cc.onionskin); + cc.onionskin, + sizeof(cc.onionskin)); if (len < 0) { log_warn(LD_CIRC,"onion_skin_create (first hop) failed."); return - END_CIRC_REASON_INTERNAL; @@ -1142,7 +1143,8 @@ circuit_send_intermediate_onion_skin(origin_circuit_t *circ, len = onion_skin_create(ec.create_cell.handshake_type, hop->extend_info, &hop->handshake_state, - ec.create_cell.onionskin); + ec.create_cell.onionskin, + sizeof(ec.create_cell.onionskin)); if (len < 0) { log_warn(LD_CIRC,"onion_skin_create failed."); return - END_CIRC_REASON_INTERNAL; diff --git a/src/core/or/command.c b/src/core/or/command.c index 40eb1554c0..5fdd8dd135 100644 --- a/src/core/or/command.c +++ b/src/core/or/command.c @@ -367,6 +367,7 @@ command_process_create_cell(cell_t *cell, channel_t *chan) create_cell->handshake_len, NULL, created_cell.reply, + sizeof(created_cell.reply), keys, CPATH_KEY_MATERIAL_LEN, rend_circ_nonce); tor_free(create_cell);