mirror of
https://github.com/irungentoo/toxcore.git
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467 lines
16 KiB
C
467 lines
16 KiB
C
/*
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* onion.c -- Implementation of the onion part of docs/Prevent_Tracking.txt
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*
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* Copyright (C) 2013 Tox project All Rights Reserved.
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*
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* This file is part of Tox.
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*
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* Tox is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* Tox is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with Tox. If not, see <http://www.gnu.org/licenses/>.
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*
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*/
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#ifdef HAVE_CONFIG_H
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#include "config.h"
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#endif
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#include "onion.h"
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#include "util.h"
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#define RETURN_1 ONION_RETURN_1
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#define RETURN_2 ONION_RETURN_2
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#define RETURN_3 ONION_RETURN_3
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#define SEND_BASE ONION_SEND_BASE
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#define SEND_3 ONION_SEND_3
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#define SEND_2 ONION_SEND_2
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#define SEND_1 ONION_SEND_1
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/* Change symmetric keys every hour to make paths expire eventually. */
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#define KEY_REFRESH_INTERVAL (60 * 60)
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static void change_symmetric_key(Onion *onion)
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{
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if (is_timeout(onion->timestamp, KEY_REFRESH_INTERVAL)) {
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new_symmetric_key(onion->secret_symmetric_key);
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onion->timestamp = unix_time();
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}
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}
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/* Create a new onion path.
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*
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* Create a new onion path out of nodes (nodes is a list of 3 nodes)
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*
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* new_path must be an empty memory location of atleast Onion_Path size.
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*
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* return -1 on failure.
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* return 0 on success.
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*/
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int create_onion_path(DHT *dht, Onion_Path *new_path, Node_format *nodes)
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{
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if (!new_path || !nodes)
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return -1;
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encrypt_precompute(nodes[0].client_id, dht->self_secret_key, new_path->shared_key1);
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memcpy(new_path->public_key1, dht->self_public_key, crypto_box_PUBLICKEYBYTES);
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uint8_t random_public_key[crypto_box_PUBLICKEYBYTES];
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uint8_t random_secret_key[crypto_box_SECRETKEYBYTES];
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crypto_box_keypair(random_public_key, random_secret_key);
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encrypt_precompute(nodes[1].client_id, random_secret_key, new_path->shared_key2);
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memcpy(new_path->public_key2, random_public_key, crypto_box_PUBLICKEYBYTES);
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crypto_box_keypair(random_public_key, random_secret_key);
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encrypt_precompute(nodes[2].client_id, random_secret_key, new_path->shared_key3);
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memcpy(new_path->public_key3, random_public_key, crypto_box_PUBLICKEYBYTES);
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new_path->ip_port1 = nodes[0].ip_port;
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new_path->ip_port2 = nodes[1].ip_port;
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new_path->ip_port3 = nodes[2].ip_port;
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/* to_net_family(&new_path->ip_port1.ip); */
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to_net_family(&new_path->ip_port2.ip);
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to_net_family(&new_path->ip_port3.ip);
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return 0;
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}
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/* Create and send a onion packet.
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*
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* Use Onion_Path path to send data of length to dest.
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* Maximum length of data is ONION_MAX_DATA_SIZE.
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*
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* return -1 on failure.
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* return 0 on success.
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*/
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int send_onion_packet(Networking_Core *net, Onion_Path *path, IP_Port dest, uint8_t *data, uint32_t length)
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{
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if (1 + length + SEND_1 > ONION_MAX_PACKET_SIZE || length == 0)
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return -1;
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to_net_family(&dest.ip);
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uint8_t step1[SIZE_IPPORT + length];
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ipport_pack(step1, &dest);
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memcpy(step1 + SIZE_IPPORT, data, length);
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uint8_t nonce[crypto_box_NONCEBYTES];
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random_nonce(nonce);
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uint8_t step2[SIZE_IPPORT + SEND_BASE + length];
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ipport_pack(step2, &path->ip_port3);
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memcpy(step2 + SIZE_IPPORT, path->public_key3, crypto_box_PUBLICKEYBYTES);
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int len = encrypt_data_symmetric(path->shared_key3, nonce, step1, sizeof(step1),
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step2 + SIZE_IPPORT + crypto_box_PUBLICKEYBYTES);
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if ((uint32_t)len != SIZE_IPPORT + length + crypto_box_MACBYTES)
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return -1;
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uint8_t step3[SIZE_IPPORT + SEND_BASE * 2 + length];
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ipport_pack(step3, &path->ip_port2);
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memcpy(step3 + SIZE_IPPORT, path->public_key2, crypto_box_PUBLICKEYBYTES);
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len = encrypt_data_symmetric(path->shared_key2, nonce, step2, sizeof(step2),
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step3 + SIZE_IPPORT + crypto_box_PUBLICKEYBYTES);
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if ((uint32_t)len != SIZE_IPPORT + SEND_BASE + length + crypto_box_MACBYTES)
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return -1;
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uint8_t packet[1 + length + SEND_1];
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packet[0] = NET_PACKET_ONION_SEND_INITIAL;
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memcpy(packet + 1, nonce, crypto_box_NONCEBYTES);
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memcpy(packet + 1 + crypto_box_NONCEBYTES, path->public_key1, crypto_box_PUBLICKEYBYTES);
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len = encrypt_data_symmetric(path->shared_key1, nonce, step3, sizeof(step3),
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packet + 1 + crypto_box_NONCEBYTES + crypto_box_PUBLICKEYBYTES);
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if ((uint32_t)len != SIZE_IPPORT + SEND_BASE * 2 + length + crypto_box_MACBYTES)
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return -1;
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if ((uint32_t)sendpacket(net, path->ip_port1, packet, sizeof(packet)) != sizeof(packet))
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return -1;
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return 0;
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}
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/* Create and send a onion response sent initially to dest with.
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* Maximum length of data is ONION_RESPONSE_MAX_DATA_SIZE.
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*
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* return -1 on failure.
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* return 0 on success.
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*/
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int send_onion_response(Networking_Core *net, IP_Port dest, uint8_t *data, uint32_t length, uint8_t *ret)
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{
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if (length > ONION_RESPONSE_MAX_DATA_SIZE || length == 0)
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return -1;
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uint8_t packet[1 + RETURN_3 + length];
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packet[0] = NET_PACKET_ONION_RECV_3;
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memcpy(packet + 1, ret, RETURN_3);
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memcpy(packet + 1 + RETURN_3, data, length);
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if ((uint32_t)sendpacket(net, dest, packet, sizeof(packet)) != sizeof(packet))
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return -1;
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return 0;
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}
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static int handle_send_initial(void *object, IP_Port source, uint8_t *packet, uint32_t length)
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{
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Onion *onion = object;
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if (length > ONION_MAX_PACKET_SIZE)
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return 1;
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if (length <= 1 + SEND_1)
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return 1;
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change_symmetric_key(onion);
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uint8_t plain[ONION_MAX_PACKET_SIZE];
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uint8_t shared_key[crypto_box_BEFORENMBYTES];
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get_shared_key(&onion->shared_keys_1, shared_key, onion->dht->self_secret_key, packet + 1 + crypto_box_NONCEBYTES);
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int len = decrypt_data_symmetric(shared_key, packet + 1, packet + 1 + crypto_box_NONCEBYTES + crypto_box_PUBLICKEYBYTES,
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length - (1 + crypto_box_NONCEBYTES + crypto_box_PUBLICKEYBYTES), plain);
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if ((uint32_t)len != length - (1 + crypto_box_NONCEBYTES + crypto_box_PUBLICKEYBYTES + crypto_box_MACBYTES))
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return 1;
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return onion_send_1(onion, plain, len, source, packet + 1);
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}
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int onion_send_1(Onion *onion, uint8_t *plain, uint32_t len, IP_Port source, uint8_t *nonce)
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{
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IP_Port send_to;
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ipport_unpack(&send_to, plain);
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to_host_family(&send_to.ip);
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uint8_t ip_port[SIZE_IPPORT];
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ipport_pack(ip_port, &source);
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uint8_t data[ONION_MAX_PACKET_SIZE];
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data[0] = NET_PACKET_ONION_SEND_1;
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memcpy(data + 1, nonce, crypto_box_NONCEBYTES);
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memcpy(data + 1 + crypto_box_NONCEBYTES, plain + SIZE_IPPORT, len - SIZE_IPPORT);
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uint32_t data_len = 1 + crypto_box_NONCEBYTES + (len - SIZE_IPPORT);
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uint8_t *ret_part = data + data_len;
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new_nonce(ret_part);
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len = encrypt_data_symmetric(onion->secret_symmetric_key, ret_part, ip_port, SIZE_IPPORT,
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ret_part + crypto_box_NONCEBYTES);
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if (len != SIZE_IPPORT + crypto_box_MACBYTES)
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return 1;
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data_len += crypto_box_NONCEBYTES + len;
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if ((uint32_t)sendpacket(onion->net, send_to, data, data_len) != data_len)
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return 1;
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return 0;
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}
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static int handle_send_1(void *object, IP_Port source, uint8_t *packet, uint32_t length)
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{
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Onion *onion = object;
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if (length > ONION_MAX_PACKET_SIZE)
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return 1;
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if (length <= 1 + SEND_2)
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return 1;
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change_symmetric_key(onion);
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uint8_t plain[ONION_MAX_PACKET_SIZE];
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uint8_t shared_key[crypto_box_BEFORENMBYTES];
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get_shared_key(&onion->shared_keys_2, shared_key, onion->dht->self_secret_key, packet + 1 + crypto_box_NONCEBYTES);
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int len = decrypt_data_symmetric(shared_key, packet + 1, packet + 1 + crypto_box_NONCEBYTES + crypto_box_PUBLICKEYBYTES,
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length - (1 + crypto_box_NONCEBYTES + crypto_box_PUBLICKEYBYTES + RETURN_1), plain);
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if ((uint32_t)len != length - (1 + crypto_box_NONCEBYTES + crypto_box_PUBLICKEYBYTES + RETURN_1 + crypto_box_MACBYTES))
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return 1;
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IP_Port send_to;
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ipport_unpack(&send_to, plain);
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to_host_family(&send_to.ip);
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uint8_t data[ONION_MAX_PACKET_SIZE];
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data[0] = NET_PACKET_ONION_SEND_2;
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memcpy(data + 1, packet + 1, crypto_box_NONCEBYTES);
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memcpy(data + 1 + crypto_box_NONCEBYTES, plain + SIZE_IPPORT, len - SIZE_IPPORT);
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uint32_t data_len = 1 + crypto_box_NONCEBYTES + (len - SIZE_IPPORT);
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uint8_t *ret_part = data + data_len;
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new_nonce(ret_part);
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uint8_t ret_data[RETURN_1 + SIZE_IPPORT];
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ipport_pack(ret_data, &source);
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memcpy(ret_data + SIZE_IPPORT, packet + (length - RETURN_1), RETURN_1);
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len = encrypt_data_symmetric(onion->secret_symmetric_key, ret_part, ret_data, sizeof(ret_data),
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ret_part + crypto_box_NONCEBYTES);
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if (len != RETURN_2 - crypto_box_NONCEBYTES)
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return 1;
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data_len += crypto_box_NONCEBYTES + len;
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if ((uint32_t)sendpacket(onion->net, send_to, data, data_len) != data_len)
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return 1;
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return 0;
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}
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static int handle_send_2(void *object, IP_Port source, uint8_t *packet, uint32_t length)
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{
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Onion *onion = object;
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if (length > ONION_MAX_PACKET_SIZE)
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return 1;
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if (length <= 1 + SEND_3)
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return 1;
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change_symmetric_key(onion);
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uint8_t plain[ONION_MAX_PACKET_SIZE];
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uint8_t shared_key[crypto_box_BEFORENMBYTES];
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get_shared_key(&onion->shared_keys_3, shared_key, onion->dht->self_secret_key, packet + 1 + crypto_box_NONCEBYTES);
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int len = decrypt_data_symmetric(shared_key, packet + 1, packet + 1 + crypto_box_NONCEBYTES + crypto_box_PUBLICKEYBYTES,
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length - (1 + crypto_box_NONCEBYTES + crypto_box_PUBLICKEYBYTES + RETURN_2), plain);
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if ((uint32_t)len != length - (1 + crypto_box_NONCEBYTES + crypto_box_PUBLICKEYBYTES + RETURN_2 + crypto_box_MACBYTES))
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return 1;
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IP_Port send_to;
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ipport_unpack(&send_to, plain);
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to_host_family(&send_to.ip);
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uint8_t data[ONION_MAX_PACKET_SIZE];
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memcpy(data, plain + SIZE_IPPORT, len - SIZE_IPPORT);
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uint32_t data_len = (len - SIZE_IPPORT);
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uint8_t *ret_part = data + (len - SIZE_IPPORT);
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new_nonce(ret_part);
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uint8_t ret_data[RETURN_2 + SIZE_IPPORT];
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ipport_pack(ret_data, &source);
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memcpy(ret_data + SIZE_IPPORT, packet + (length - RETURN_2), RETURN_2);
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len = encrypt_data_symmetric(onion->secret_symmetric_key, ret_part, ret_data, sizeof(ret_data),
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ret_part + crypto_box_NONCEBYTES);
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if (len != RETURN_3 - crypto_box_NONCEBYTES)
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return 1;
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data_len += RETURN_3;
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if ((uint32_t)sendpacket(onion->net, send_to, data, data_len) != data_len)
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return 1;
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return 0;
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}
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static int handle_recv_3(void *object, IP_Port source, uint8_t *packet, uint32_t length)
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{
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Onion *onion = object;
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if (length > ONION_MAX_PACKET_SIZE)
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return 1;
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if (length <= 1 + RETURN_3)
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return 1;
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change_symmetric_key(onion);
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uint8_t plain[SIZE_IPPORT + RETURN_2];
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int len = decrypt_data_symmetric(onion->secret_symmetric_key, packet + 1, packet + 1 + crypto_box_NONCEBYTES,
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SIZE_IPPORT + RETURN_2 + crypto_box_MACBYTES, plain);
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if ((uint32_t)len != sizeof(plain))
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return 1;
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IP_Port send_to;
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ipport_unpack(&send_to, plain);
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uint8_t data[ONION_MAX_PACKET_SIZE];
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data[0] = NET_PACKET_ONION_RECV_2;
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memcpy(data + 1, plain + SIZE_IPPORT, RETURN_2);
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memcpy(data + 1 + RETURN_2, packet + 1 + RETURN_3, length - (1 + RETURN_3));
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uint32_t data_len = 1 + RETURN_2 + (length - (1 + RETURN_3));
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if ((uint32_t)sendpacket(onion->net, send_to, data, data_len) != data_len)
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return 1;
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return 0;
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}
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static int handle_recv_2(void *object, IP_Port source, uint8_t *packet, uint32_t length)
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{
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Onion *onion = object;
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if (length > ONION_MAX_PACKET_SIZE)
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return 1;
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if (length <= 1 + RETURN_2)
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return 1;
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change_symmetric_key(onion);
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uint8_t plain[SIZE_IPPORT + RETURN_1];
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int len = decrypt_data_symmetric(onion->secret_symmetric_key, packet + 1, packet + 1 + crypto_box_NONCEBYTES,
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SIZE_IPPORT + RETURN_1 + crypto_box_MACBYTES, plain);
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if ((uint32_t)len != sizeof(plain))
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return 1;
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IP_Port send_to;
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ipport_unpack(&send_to, plain);
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uint8_t data[ONION_MAX_PACKET_SIZE];
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data[0] = NET_PACKET_ONION_RECV_1;
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memcpy(data + 1, plain + SIZE_IPPORT, RETURN_1);
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memcpy(data + 1 + RETURN_1, packet + 1 + RETURN_2, length - (1 + RETURN_2));
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uint32_t data_len = 1 + RETURN_1 + (length - (1 + RETURN_2));
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if ((uint32_t)sendpacket(onion->net, send_to, data, data_len) != data_len)
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return 1;
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return 0;
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}
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static int handle_recv_1(void *object, IP_Port source, uint8_t *packet, uint32_t length)
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{
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Onion *onion = object;
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if (length > ONION_MAX_PACKET_SIZE)
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return 1;
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if (length <= 1 + RETURN_1)
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return 1;
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change_symmetric_key(onion);
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uint8_t plain[SIZE_IPPORT];
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int len = decrypt_data_symmetric(onion->secret_symmetric_key, packet + 1, packet + 1 + crypto_box_NONCEBYTES,
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SIZE_IPPORT + crypto_box_MACBYTES, plain);
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if ((uint32_t)len != SIZE_IPPORT)
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return 1;
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IP_Port send_to;
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ipport_unpack(&send_to, plain);
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uint32_t data_len = length - (1 + RETURN_1);
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if (onion->recv_1_function && send_to.ip.family != AF_INET && send_to.ip.family != AF_INET6)
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return onion->recv_1_function(onion->callback_object, send_to, packet + (1 + RETURN_1), data_len);
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if ((uint32_t)sendpacket(onion->net, send_to, packet + (1 + RETURN_1), data_len) != data_len)
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return 1;
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return 0;
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}
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void set_callback_handle_recv_1(Onion *onion, int (*function)(void *, IP_Port, uint8_t *, uint16_t), void *object)
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{
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onion->recv_1_function = function;
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onion->callback_object = object;
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}
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Onion *new_onion(DHT *dht)
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{
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if (dht == NULL)
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return NULL;
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Onion *onion = calloc(1, sizeof(Onion));
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if (onion == NULL)
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return NULL;
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onion->dht = dht;
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onion->net = dht->net;
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new_symmetric_key(onion->secret_symmetric_key);
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onion->timestamp = unix_time();
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networking_registerhandler(onion->net, NET_PACKET_ONION_SEND_INITIAL, &handle_send_initial, onion);
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networking_registerhandler(onion->net, NET_PACKET_ONION_SEND_1, &handle_send_1, onion);
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networking_registerhandler(onion->net, NET_PACKET_ONION_SEND_2, &handle_send_2, onion);
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networking_registerhandler(onion->net, NET_PACKET_ONION_RECV_3, &handle_recv_3, onion);
|
|
networking_registerhandler(onion->net, NET_PACKET_ONION_RECV_2, &handle_recv_2, onion);
|
|
networking_registerhandler(onion->net, NET_PACKET_ONION_RECV_1, &handle_recv_1, onion);
|
|
|
|
return onion;
|
|
}
|
|
|
|
void kill_onion(Onion *onion)
|
|
{
|
|
if (onion == NULL)
|
|
return;
|
|
|
|
networking_registerhandler(onion->net, NET_PACKET_ONION_SEND_INITIAL, NULL, NULL);
|
|
networking_registerhandler(onion->net, NET_PACKET_ONION_SEND_1, NULL, NULL);
|
|
networking_registerhandler(onion->net, NET_PACKET_ONION_SEND_2, NULL, NULL);
|
|
|
|
networking_registerhandler(onion->net, NET_PACKET_ONION_RECV_3, NULL, NULL);
|
|
networking_registerhandler(onion->net, NET_PACKET_ONION_RECV_2, NULL, NULL);
|
|
networking_registerhandler(onion->net, NET_PACKET_ONION_RECV_1, NULL, NULL);
|
|
|
|
free(onion);
|
|
}
|