/* net_crypto.c * * Functions for the core network crypto. * * NOTE: This code has to be perfect. We don't mess around with encryption. * * Copyright (C) 2013 Tox project All Rights Reserved. * * This file is part of Tox. * * Tox is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * Tox is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with Tox. If not, see . * */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include "net_crypto.h" #include "util.h" #include static uint8_t crypt_connection_id_not_valid(const Net_Crypto *c, int crypt_connection_id) { if ((uint32_t)crypt_connection_id >= c->crypto_connections_length) { return 1; } if (c->crypto_connections == NULL) { return 1; } if (c->crypto_connections[crypt_connection_id].status == CRYPTO_CONN_NO_CONNECTION) { return 1; } return 0; } /* cookie timeout in seconds */ #define COOKIE_TIMEOUT 15 #define COOKIE_DATA_LENGTH (crypto_box_PUBLICKEYBYTES * 2) #define COOKIE_CONTENTS_LENGTH (sizeof(uint64_t) + COOKIE_DATA_LENGTH) #define COOKIE_LENGTH (crypto_box_NONCEBYTES + COOKIE_CONTENTS_LENGTH + crypto_box_MACBYTES) #define COOKIE_REQUEST_PLAIN_LENGTH (COOKIE_DATA_LENGTH + sizeof(uint64_t)) #define COOKIE_REQUEST_LENGTH (1 + crypto_box_PUBLICKEYBYTES + crypto_box_NONCEBYTES + COOKIE_REQUEST_PLAIN_LENGTH + crypto_box_MACBYTES) #define COOKIE_RESPONSE_LENGTH (1 + crypto_box_NONCEBYTES + COOKIE_LENGTH + sizeof(uint64_t) + crypto_box_MACBYTES) /* Create a cookie request packet and put it in packet. * dht_public_key is the dht public key of the other * * packet must be of size COOKIE_REQUEST_LENGTH or bigger. * * return -1 on failure. * return COOKIE_REQUEST_LENGTH on success. */ static int create_cookie_request(const Net_Crypto *c, uint8_t *packet, uint8_t *dht_public_key, uint64_t number, uint8_t *shared_key) { uint8_t plain[COOKIE_REQUEST_PLAIN_LENGTH]; uint8_t padding[crypto_box_PUBLICKEYBYTES] = {0}; memcpy(plain, c->self_public_key, crypto_box_PUBLICKEYBYTES); memcpy(plain + crypto_box_PUBLICKEYBYTES, padding, crypto_box_PUBLICKEYBYTES); memcpy(plain + (crypto_box_PUBLICKEYBYTES * 2), &number, sizeof(uint64_t)); DHT_get_shared_key_sent(c->dht, shared_key, dht_public_key); uint8_t nonce[crypto_box_NONCEBYTES]; new_nonce(nonce); packet[0] = NET_PACKET_COOKIE_REQUEST; memcpy(packet + 1, c->dht->self_public_key, crypto_box_PUBLICKEYBYTES); memcpy(packet + 1 + crypto_box_PUBLICKEYBYTES, nonce, crypto_box_NONCEBYTES); int len = encrypt_data_symmetric(shared_key, nonce, plain, sizeof(plain), packet + 1 + crypto_box_PUBLICKEYBYTES + crypto_box_NONCEBYTES); if (len != COOKIE_REQUEST_PLAIN_LENGTH + crypto_box_MACBYTES) { return -1; } return (1 + crypto_box_PUBLICKEYBYTES + crypto_box_NONCEBYTES + len); } /* Create cookie of length COOKIE_LENGTH from bytes of length COOKIE_DATA_LENGTH using encryption_key * * return -1 on failure. * return 0 on success. */ static int create_cookie(uint8_t *cookie, const uint8_t *bytes, const uint8_t *encryption_key) { uint8_t contents[COOKIE_CONTENTS_LENGTH]; uint64_t temp_time = unix_time(); memcpy(contents, &temp_time, sizeof(temp_time)); memcpy(contents + sizeof(temp_time), bytes, COOKIE_DATA_LENGTH); new_nonce(cookie); int len = encrypt_data_symmetric(encryption_key, cookie, contents, sizeof(contents), cookie + crypto_box_NONCEBYTES); if (len != COOKIE_LENGTH - crypto_box_NONCEBYTES) { return -1; } return 0; } /* Open cookie of length COOKIE_LENGTH to bytes of length COOKIE_DATA_LENGTH using encryption_key * * return -1 on failure. * return 0 on success. */ static int open_cookie(uint8_t *bytes, const uint8_t *cookie, const uint8_t *encryption_key) { uint8_t contents[COOKIE_CONTENTS_LENGTH]; int len = decrypt_data_symmetric(encryption_key, cookie, cookie + crypto_box_NONCEBYTES, COOKIE_LENGTH - crypto_box_NONCEBYTES, contents); if (len != sizeof(contents)) { return -1; } uint64_t cookie_time; memcpy(&cookie_time, contents, sizeof(cookie_time)); uint64_t temp_time = unix_time(); if (cookie_time + COOKIE_TIMEOUT < temp_time || temp_time < cookie_time) { return -1; } memcpy(bytes, contents + sizeof(cookie_time), COOKIE_DATA_LENGTH); return 0; } /* Create a cookie response packet and put it in packet. * request_plain must be COOKIE_REQUEST_PLAIN_LENGTH bytes. * packet must be of size COOKIE_RESPONSE_LENGTH or bigger. * * return -1 on failure. * return COOKIE_RESPONSE_LENGTH on success. */ static int create_cookie_response(const Net_Crypto *c, uint8_t *packet, const uint8_t *request_plain, const uint8_t *shared_key, const uint8_t *dht_public_key) { uint8_t cookie_plain[COOKIE_DATA_LENGTH]; memcpy(cookie_plain, request_plain, crypto_box_PUBLICKEYBYTES); memcpy(cookie_plain + crypto_box_PUBLICKEYBYTES, dht_public_key, crypto_box_PUBLICKEYBYTES); uint8_t plain[COOKIE_LENGTH + sizeof(uint64_t)]; if (create_cookie(plain, cookie_plain, c->secret_symmetric_key) != 0) { return -1; } memcpy(plain + COOKIE_LENGTH, request_plain + COOKIE_DATA_LENGTH, sizeof(uint64_t)); packet[0] = NET_PACKET_COOKIE_RESPONSE; new_nonce(packet + 1); int len = encrypt_data_symmetric(shared_key, packet + 1, plain, sizeof(plain), packet + 1 + crypto_box_NONCEBYTES); if (len != COOKIE_RESPONSE_LENGTH - (1 + crypto_box_NONCEBYTES)) { return -1; } return COOKIE_RESPONSE_LENGTH; } /* Handle the cookie request packet of length length. * Put what was in the request in request_plain (must be of size COOKIE_REQUEST_PLAIN_LENGTH) * Put the key used to decrypt the request into shared_key (of size crypto_box_BEFORENMBYTES) for use in the response. * * return -1 on failure. * return 0 on success. */ static int handle_cookie_request(const Net_Crypto *c, uint8_t *request_plain, uint8_t *shared_key, uint8_t *dht_public_key, const uint8_t *packet, uint16_t length) { if (length != COOKIE_REQUEST_LENGTH) { return -1; } memcpy(dht_public_key, packet + 1, crypto_box_PUBLICKEYBYTES); DHT_get_shared_key_sent(c->dht, shared_key, dht_public_key); int len = decrypt_data_symmetric(shared_key, packet + 1 + crypto_box_PUBLICKEYBYTES, packet + 1 + crypto_box_PUBLICKEYBYTES + crypto_box_NONCEBYTES, COOKIE_REQUEST_PLAIN_LENGTH + crypto_box_MACBYTES, request_plain); if (len != COOKIE_REQUEST_PLAIN_LENGTH) { return -1; } return 0; } /* Handle the cookie request packet (for raw UDP) */ static int udp_handle_cookie_request(void *object, IP_Port source, const uint8_t *packet, uint16_t length, void *userdata) { Net_Crypto *c = (Net_Crypto *)object; uint8_t request_plain[COOKIE_REQUEST_PLAIN_LENGTH]; uint8_t shared_key[crypto_box_BEFORENMBYTES]; uint8_t dht_public_key[crypto_box_PUBLICKEYBYTES]; if (handle_cookie_request(c, request_plain, shared_key, dht_public_key, packet, length) != 0) { return 1; } uint8_t data[COOKIE_RESPONSE_LENGTH]; if (create_cookie_response(c, data, request_plain, shared_key, dht_public_key) != sizeof(data)) { return 1; } if ((uint32_t)sendpacket(c->dht->net, source, data, sizeof(data)) != sizeof(data)) { return 1; } return 0; } /* Handle the cookie request packet (for TCP) */ static int tcp_handle_cookie_request(Net_Crypto *c, int connections_number, const uint8_t *packet, uint16_t length) { uint8_t request_plain[COOKIE_REQUEST_PLAIN_LENGTH]; uint8_t shared_key[crypto_box_BEFORENMBYTES]; uint8_t dht_public_key[crypto_box_PUBLICKEYBYTES]; if (handle_cookie_request(c, request_plain, shared_key, dht_public_key, packet, length) != 0) { return -1; } uint8_t data[COOKIE_RESPONSE_LENGTH]; if (create_cookie_response(c, data, request_plain, shared_key, dht_public_key) != sizeof(data)) { return -1; } int ret = send_packet_tcp_connection(c->tcp_c, connections_number, data, sizeof(data)); return ret; } /* Handle the cookie request packet (for TCP oob packets) */ static int tcp_oob_handle_cookie_request(const Net_Crypto *c, unsigned int tcp_connections_number, const uint8_t *dht_public_key, const uint8_t *packet, uint16_t length) { uint8_t request_plain[COOKIE_REQUEST_PLAIN_LENGTH]; uint8_t shared_key[crypto_box_BEFORENMBYTES]; uint8_t dht_public_key_temp[crypto_box_PUBLICKEYBYTES]; if (handle_cookie_request(c, request_plain, shared_key, dht_public_key_temp, packet, length) != 0) { return -1; } if (public_key_cmp(dht_public_key, dht_public_key_temp) != 0) { return -1; } uint8_t data[COOKIE_RESPONSE_LENGTH]; if (create_cookie_response(c, data, request_plain, shared_key, dht_public_key) != sizeof(data)) { return -1; } int ret = tcp_send_oob_packet(c->tcp_c, tcp_connections_number, dht_public_key, data, sizeof(data)); return ret; } /* Handle a cookie response packet of length encrypted with shared_key. * put the cookie in the response in cookie * * cookie must be of length COOKIE_LENGTH. * * return -1 on failure. * return COOKIE_LENGTH on success. */ static int handle_cookie_response(uint8_t *cookie, uint64_t *number, const uint8_t *packet, uint16_t length, const uint8_t *shared_key) { if (length != COOKIE_RESPONSE_LENGTH) { return -1; } uint8_t plain[COOKIE_LENGTH + sizeof(uint64_t)]; int len = decrypt_data_symmetric(shared_key, packet + 1, packet + 1 + crypto_box_NONCEBYTES, length - (1 + crypto_box_NONCEBYTES), plain); if (len != sizeof(plain)) { return -1; } memcpy(cookie, plain, COOKIE_LENGTH); memcpy(number, plain + COOKIE_LENGTH, sizeof(uint64_t)); return COOKIE_LENGTH; } #define HANDSHAKE_PACKET_LENGTH (1 + COOKIE_LENGTH + crypto_box_NONCEBYTES + crypto_box_NONCEBYTES + crypto_box_PUBLICKEYBYTES + crypto_hash_sha512_BYTES + COOKIE_LENGTH + crypto_box_MACBYTES) /* Create a handshake packet and put it in packet. * cookie must be COOKIE_LENGTH bytes. * packet must be of size HANDSHAKE_PACKET_LENGTH or bigger. * * return -1 on failure. * return HANDSHAKE_PACKET_LENGTH on success. */ static int create_crypto_handshake(const Net_Crypto *c, uint8_t *packet, const uint8_t *cookie, const uint8_t *nonce, const uint8_t *session_pk, const uint8_t *peer_real_pk, const uint8_t *peer_dht_pubkey) { uint8_t plain[crypto_box_NONCEBYTES + crypto_box_PUBLICKEYBYTES + crypto_hash_sha512_BYTES + COOKIE_LENGTH]; memcpy(plain, nonce, crypto_box_NONCEBYTES); memcpy(plain + crypto_box_NONCEBYTES, session_pk, crypto_box_PUBLICKEYBYTES); crypto_hash_sha512(plain + crypto_box_NONCEBYTES + crypto_box_PUBLICKEYBYTES, cookie, COOKIE_LENGTH); uint8_t cookie_plain[COOKIE_DATA_LENGTH]; memcpy(cookie_plain, peer_real_pk, crypto_box_PUBLICKEYBYTES); memcpy(cookie_plain + crypto_box_PUBLICKEYBYTES, peer_dht_pubkey, crypto_box_PUBLICKEYBYTES); if (create_cookie(plain + crypto_box_NONCEBYTES + crypto_box_PUBLICKEYBYTES + crypto_hash_sha512_BYTES, cookie_plain, c->secret_symmetric_key) != 0) { return -1; } new_nonce(packet + 1 + COOKIE_LENGTH); int len = encrypt_data(peer_real_pk, c->self_secret_key, packet + 1 + COOKIE_LENGTH, plain, sizeof(plain), packet + 1 + COOKIE_LENGTH + crypto_box_NONCEBYTES); if (len != HANDSHAKE_PACKET_LENGTH - (1 + COOKIE_LENGTH + crypto_box_NONCEBYTES)) { return -1; } packet[0] = NET_PACKET_CRYPTO_HS; memcpy(packet + 1, cookie, COOKIE_LENGTH); return HANDSHAKE_PACKET_LENGTH; } /* Handle a crypto handshake packet of length. * put the nonce contained in the packet in nonce, * the session public key in session_pk * the real public key of the peer in peer_real_pk * the dht public key of the peer in dht_public_key and * the cookie inside the encrypted part of the packet in cookie. * * if expected_real_pk isn't NULL it denotes the real public key * the packet should be from. * * nonce must be at least crypto_box_NONCEBYTES * session_pk must be at least crypto_box_PUBLICKEYBYTES * peer_real_pk must be at least crypto_box_PUBLICKEYBYTES * cookie must be at least COOKIE_LENGTH * * return -1 on failure. * return 0 on success. */ static int handle_crypto_handshake(const Net_Crypto *c, uint8_t *nonce, uint8_t *session_pk, uint8_t *peer_real_pk, uint8_t *dht_public_key, uint8_t *cookie, const uint8_t *packet, uint16_t length, const uint8_t *expected_real_pk) { if (length != HANDSHAKE_PACKET_LENGTH) { return -1; } uint8_t cookie_plain[COOKIE_DATA_LENGTH]; if (open_cookie(cookie_plain, packet + 1, c->secret_symmetric_key) != 0) { return -1; } if (expected_real_pk) { if (public_key_cmp(cookie_plain, expected_real_pk) != 0) { return -1; } } uint8_t cookie_hash[crypto_hash_sha512_BYTES]; crypto_hash_sha512(cookie_hash, packet + 1, COOKIE_LENGTH); uint8_t plain[crypto_box_NONCEBYTES + crypto_box_PUBLICKEYBYTES + crypto_hash_sha512_BYTES + COOKIE_LENGTH]; int len = decrypt_data(cookie_plain, c->self_secret_key, packet + 1 + COOKIE_LENGTH, packet + 1 + COOKIE_LENGTH + crypto_box_NONCEBYTES, HANDSHAKE_PACKET_LENGTH - (1 + COOKIE_LENGTH + crypto_box_NONCEBYTES), plain); if (len != sizeof(plain)) { return -1; } if (sodium_memcmp(cookie_hash, plain + crypto_box_NONCEBYTES + crypto_box_PUBLICKEYBYTES, crypto_hash_sha512_BYTES) != 0) { return -1; } memcpy(nonce, plain, crypto_box_NONCEBYTES); memcpy(session_pk, plain + crypto_box_NONCEBYTES, crypto_box_PUBLICKEYBYTES); memcpy(cookie, plain + crypto_box_NONCEBYTES + crypto_box_PUBLICKEYBYTES + crypto_hash_sha512_BYTES, COOKIE_LENGTH); memcpy(peer_real_pk, cookie_plain, crypto_box_PUBLICKEYBYTES); memcpy(dht_public_key, cookie_plain + crypto_box_PUBLICKEYBYTES, crypto_box_PUBLICKEYBYTES); return 0; } static Crypto_Connection *get_crypto_connection(const Net_Crypto *c, int crypt_connection_id) { if (crypt_connection_id_not_valid(c, crypt_connection_id)) { return 0; } return &c->crypto_connections[crypt_connection_id]; } /* Associate an ip_port to a connection. * * return -1 on failure. * return 0 on success. */ static int add_ip_port_connection(Net_Crypto *c, int crypt_connection_id, IP_Port ip_port) { Crypto_Connection *conn = get_crypto_connection(c, crypt_connection_id); if (conn == 0) { return -1; } if (ip_port.ip.family == AF_INET) { if (!ipport_equal(&ip_port, &conn->ip_portv4) && LAN_ip(conn->ip_portv4.ip) != 0) { if (!bs_list_add(&c->ip_port_list, (uint8_t *)&ip_port, crypt_connection_id)) { return -1; } bs_list_remove(&c->ip_port_list, (uint8_t *)&conn->ip_portv4, crypt_connection_id); conn->ip_portv4 = ip_port; return 0; } } else if (ip_port.ip.family == AF_INET6) { if (!ipport_equal(&ip_port, &conn->ip_portv6)) { if (!bs_list_add(&c->ip_port_list, (uint8_t *)&ip_port, crypt_connection_id)) { return -1; } bs_list_remove(&c->ip_port_list, (uint8_t *)&conn->ip_portv6, crypt_connection_id); conn->ip_portv6 = ip_port; return 0; } } return -1; } /* Return the IP_Port that should be used to send packets to the other peer. * * return IP_Port with family 0 on failure. * return IP_Port on success. */ static IP_Port return_ip_port_connection(Net_Crypto *c, int crypt_connection_id) { IP_Port empty; empty.ip.family = 0; Crypto_Connection *conn = get_crypto_connection(c, crypt_connection_id); if (conn == 0) { return empty; } uint64_t current_time = unix_time(); bool v6 = 0, v4 = 0; if ((UDP_DIRECT_TIMEOUT + conn->direct_lastrecv_timev4) > current_time) { v4 = 1; } if ((UDP_DIRECT_TIMEOUT + conn->direct_lastrecv_timev6) > current_time) { v6 = 1; } if (v4 && LAN_ip(conn->ip_portv4.ip) == 0) { return conn->ip_portv4; } if (v6 && conn->ip_portv6.ip.family == AF_INET6) { return conn->ip_portv6; } if (conn->ip_portv4.ip.family == AF_INET) { return conn->ip_portv4; } return empty; } /* Sends a packet to the peer using the fastest route. * * return -1 on failure. * return 0 on success. */ static int send_packet_to(Net_Crypto *c, int crypt_connection_id, const uint8_t *data, uint16_t length) { // TODO(irungentoo): TCP, etc... Crypto_Connection *conn = get_crypto_connection(c, crypt_connection_id); if (conn == 0) { return -1; } int direct_send_attempt = 0; pthread_mutex_lock(&conn->mutex); IP_Port ip_port = return_ip_port_connection(c, crypt_connection_id); // TODO(irungentoo): on bad networks, direct connections might not last indefinitely. if (ip_port.ip.family != 0) { bool direct_connected = 0; crypto_connection_status(c, crypt_connection_id, &direct_connected, NULL); if (direct_connected) { if ((uint32_t)sendpacket(c->dht->net, ip_port, data, length) == length) { pthread_mutex_unlock(&conn->mutex); return 0; } pthread_mutex_unlock(&conn->mutex); return -1; } // TODO(irungentoo): a better way of sending packets directly to confirm the others ip. uint64_t current_time = unix_time(); if ((((UDP_DIRECT_TIMEOUT / 2) + conn->direct_send_attempt_time) > current_time && length < 96) || data[0] == NET_PACKET_COOKIE_REQUEST || data[0] == NET_PACKET_CRYPTO_HS) { if ((uint32_t)sendpacket(c->dht->net, ip_port, data, length) == length) { direct_send_attempt = 1; conn->direct_send_attempt_time = unix_time(); } } } pthread_mutex_unlock(&conn->mutex); pthread_mutex_lock(&c->tcp_mutex); int ret = send_packet_tcp_connection(c->tcp_c, conn->connection_number_tcp, data, length); pthread_mutex_unlock(&c->tcp_mutex); pthread_mutex_lock(&conn->mutex); if (ret == 0) { conn->last_tcp_sent = current_time_monotonic(); } pthread_mutex_unlock(&conn->mutex); if (ret == 0 || direct_send_attempt) { return 0; } return -1; } /** START: Array Related functions **/ /* Return number of packets in array * Note that holes are counted too. */ static uint32_t num_packets_array(const Packets_Array *array) { return array->buffer_end - array->buffer_start; } /* Add data with packet number to array. * * return -1 on failure. * return 0 on success. */ static int add_data_to_buffer(Packets_Array *array, uint32_t number, const Packet_Data *data) { if (number - array->buffer_start > CRYPTO_PACKET_BUFFER_SIZE) { return -1; } uint32_t num = number % CRYPTO_PACKET_BUFFER_SIZE; if (array->buffer[num]) { return -1; } Packet_Data *new_d = (Packet_Data *)malloc(sizeof(Packet_Data)); if (new_d == NULL) { return -1; } memcpy(new_d, data, sizeof(Packet_Data)); array->buffer[num] = new_d; if ((number - array->buffer_start) >= (array->buffer_end - array->buffer_start)) { array->buffer_end = number + 1; } return 0; } /* Get pointer of data with packet number. * * return -1 on failure. * return 0 if data at number is empty. * return 1 if data pointer was put in data. */ static int get_data_pointer(const Packets_Array *array, Packet_Data **data, uint32_t number) { uint32_t num_spots = array->buffer_end - array->buffer_start; if (array->buffer_end - number > num_spots || number - array->buffer_start >= num_spots) { return -1; } uint32_t num = number % CRYPTO_PACKET_BUFFER_SIZE; if (!array->buffer[num]) { return 0; } *data = array->buffer[num]; return 1; } /* Add data to end of array. * * return -1 on failure. * return packet number on success. */ static int64_t add_data_end_of_buffer(Packets_Array *array, const Packet_Data *data) { if (num_packets_array(array) >= CRYPTO_PACKET_BUFFER_SIZE) { return -1; } Packet_Data *new_d = (Packet_Data *)malloc(sizeof(Packet_Data)); if (new_d == NULL) { return -1; } memcpy(new_d, data, sizeof(Packet_Data)); uint32_t id = array->buffer_end; array->buffer[id % CRYPTO_PACKET_BUFFER_SIZE] = new_d; ++array->buffer_end; return id; } /* Read data from begginning of array. * * return -1 on failure. * return packet number on success. */ static int64_t read_data_beg_buffer(Packets_Array *array, Packet_Data *data) { if (array->buffer_end == array->buffer_start) { return -1; } uint32_t num = array->buffer_start % CRYPTO_PACKET_BUFFER_SIZE; if (!array->buffer[num]) { return -1; } memcpy(data, array->buffer[num], sizeof(Packet_Data)); uint32_t id = array->buffer_start; ++array->buffer_start; free(array->buffer[num]); array->buffer[num] = NULL; return id; } /* Delete all packets in array before number (but not number) * * return -1 on failure. * return 0 on success */ static int clear_buffer_until(Packets_Array *array, uint32_t number) { uint32_t num_spots = array->buffer_end - array->buffer_start; if (array->buffer_end - number >= num_spots || number - array->buffer_start > num_spots) { return -1; } uint32_t i; for (i = array->buffer_start; i != number; ++i) { uint32_t num = i % CRYPTO_PACKET_BUFFER_SIZE; if (array->buffer[num]) { free(array->buffer[num]); array->buffer[num] = NULL; } } array->buffer_start = i; return 0; } static int clear_buffer(Packets_Array *array) { uint32_t i; for (i = array->buffer_start; i != array->buffer_end; ++i) { uint32_t num = i % CRYPTO_PACKET_BUFFER_SIZE; if (array->buffer[num]) { free(array->buffer[num]); array->buffer[num] = NULL; } } array->buffer_start = i; return 0; } /* Set array buffer end to number. * * return -1 on failure. * return 0 on success. */ static int set_buffer_end(Packets_Array *array, uint32_t number) { if ((number - array->buffer_start) > CRYPTO_PACKET_BUFFER_SIZE) { return -1; } if ((number - array->buffer_end) > CRYPTO_PACKET_BUFFER_SIZE) { return -1; } array->buffer_end = number; return 0; } /* Create a packet request packet from recv_array and send_buffer_end into * data of length. * * return -1 on failure. * return length of packet on success. */ static int generate_request_packet(uint8_t *data, uint16_t length, const Packets_Array *recv_array) { if (length == 0) { return -1; } data[0] = PACKET_ID_REQUEST; uint16_t cur_len = 1; if (recv_array->buffer_start == recv_array->buffer_end) { return cur_len; } if (length <= cur_len) { return cur_len; } uint32_t i, n = 1; for (i = recv_array->buffer_start; i != recv_array->buffer_end; ++i) { uint32_t num = i % CRYPTO_PACKET_BUFFER_SIZE; if (!recv_array->buffer[num]) { data[cur_len] = n; n = 0; ++cur_len; if (length <= cur_len) { return cur_len; } } else if (n == 255) { data[cur_len] = 0; n = 0; ++cur_len; if (length <= cur_len) { return cur_len; } } ++n; } return cur_len; } /* Handle a request data packet. * Remove all the packets the other received from the array. * * return -1 on failure. * return number of requested packets on success. */ static int handle_request_packet(Packets_Array *send_array, const uint8_t *data, uint16_t length, uint64_t *latest_send_time, uint64_t rtt_time) { if (length < 1) { return -1; } if (data[0] != PACKET_ID_REQUEST) { return -1; } if (length == 1) { return 0; } ++data; --length; uint32_t i, n = 1; uint32_t requested = 0; uint64_t temp_time = current_time_monotonic(); uint64_t l_sent_time = ~0; for (i = send_array->buffer_start; i != send_array->buffer_end; ++i) { if (length == 0) { break; } uint32_t num = i % CRYPTO_PACKET_BUFFER_SIZE; if (n == data[0]) { if (send_array->buffer[num]) { uint64_t sent_time = send_array->buffer[num]->sent_time; if ((sent_time + rtt_time) < temp_time) { send_array->buffer[num]->sent_time = 0; } } ++data; --length; n = 0; ++requested; } else { if (send_array->buffer[num]) { uint64_t sent_time = send_array->buffer[num]->sent_time; if (l_sent_time < sent_time) { l_sent_time = sent_time; } free(send_array->buffer[num]); send_array->buffer[num] = NULL; } } if (n == 255) { n = 1; if (data[0] != 0) { return -1; } ++data; --length; } else { ++n; } } if (*latest_send_time < l_sent_time) { *latest_send_time = l_sent_time; } return requested; } /** END: Array Related functions **/ #define MAX_DATA_DATA_PACKET_SIZE (MAX_CRYPTO_PACKET_SIZE - (1 + sizeof(uint16_t) + crypto_box_MACBYTES)) /* Creates and sends a data packet to the peer using the fastest route. * * return -1 on failure. * return 0 on success. */ static int send_data_packet(Net_Crypto *c, int crypt_connection_id, const uint8_t *data, uint16_t length) { if (length == 0 || length + (1 + sizeof(uint16_t) + crypto_box_MACBYTES) > MAX_CRYPTO_PACKET_SIZE) { return -1; } Crypto_Connection *conn = get_crypto_connection(c, crypt_connection_id); if (conn == 0) { return -1; } pthread_mutex_lock(&conn->mutex); uint8_t packet[1 + sizeof(uint16_t) + length + crypto_box_MACBYTES]; packet[0] = NET_PACKET_CRYPTO_DATA; memcpy(packet + 1, conn->sent_nonce + (crypto_box_NONCEBYTES - sizeof(uint16_t)), sizeof(uint16_t)); int len = encrypt_data_symmetric(conn->shared_key, conn->sent_nonce, data, length, packet + 1 + sizeof(uint16_t)); if (len + 1 + sizeof(uint16_t) != sizeof(packet)) { pthread_mutex_unlock(&conn->mutex); return -1; } increment_nonce(conn->sent_nonce); pthread_mutex_unlock(&conn->mutex); return send_packet_to(c, crypt_connection_id, packet, sizeof(packet)); } /* Creates and sends a data packet with buffer_start and num to the peer using the fastest route. * * return -1 on failure. * return 0 on success. */ static int send_data_packet_helper(Net_Crypto *c, int crypt_connection_id, uint32_t buffer_start, uint32_t num, const uint8_t *data, uint16_t length) { if (length == 0 || length > MAX_CRYPTO_DATA_SIZE) { return -1; } num = htonl(num); buffer_start = htonl(buffer_start); uint16_t padding_length = (MAX_CRYPTO_DATA_SIZE - length) % CRYPTO_MAX_PADDING; uint8_t packet[sizeof(uint32_t) + sizeof(uint32_t) + padding_length + length]; memcpy(packet, &buffer_start, sizeof(uint32_t)); memcpy(packet + sizeof(uint32_t), &num, sizeof(uint32_t)); memset(packet + (sizeof(uint32_t) * 2), PACKET_ID_PADDING, padding_length); memcpy(packet + (sizeof(uint32_t) * 2) + padding_length, data, length); return send_data_packet(c, crypt_connection_id, packet, sizeof(packet)); } static int reset_max_speed_reached(Net_Crypto *c, int crypt_connection_id) { Crypto_Connection *conn = get_crypto_connection(c, crypt_connection_id); if (conn == 0) { return -1; } /* If last packet send failed, try to send packet again. If sending it fails we won't be able to send the new packet. */ if (conn->maximum_speed_reached) { Packet_Data *dt = NULL; uint32_t packet_num = conn->send_array.buffer_end - 1; int ret = get_data_pointer(&conn->send_array, &dt, packet_num); uint8_t send_failed = 0; if (ret == 1) { if (!dt->sent_time) { if (send_data_packet_helper(c, crypt_connection_id, conn->recv_array.buffer_start, packet_num, dt->data, dt->length) != 0) { send_failed = 1; } else { dt->sent_time = current_time_monotonic(); } } } if (!send_failed) { conn->maximum_speed_reached = 0; } else { return -1; } } return 0; } /* return -1 if data could not be put in packet queue. * return positive packet number if data was put into the queue. */ static int64_t send_lossless_packet(Net_Crypto *c, int crypt_connection_id, const uint8_t *data, uint16_t length, uint8_t congestion_control) { if (length == 0 || length > MAX_CRYPTO_DATA_SIZE) { return -1; } Crypto_Connection *conn = get_crypto_connection(c, crypt_connection_id); if (conn == 0) { return -1; } /* If last packet send failed, try to send packet again. If sending it fails we won't be able to send the new packet. */ reset_max_speed_reached(c, crypt_connection_id); if (conn->maximum_speed_reached && congestion_control) { return -1; } Packet_Data dt; dt.sent_time = 0; dt.length = length; memcpy(dt.data, data, length); pthread_mutex_lock(&conn->mutex); int64_t packet_num = add_data_end_of_buffer(&conn->send_array, &dt); pthread_mutex_unlock(&conn->mutex); if (packet_num == -1) { return -1; } if (!congestion_control && conn->maximum_speed_reached) { return packet_num; } if (send_data_packet_helper(c, crypt_connection_id, conn->recv_array.buffer_start, packet_num, data, length) == 0) { Packet_Data *dt1 = NULL; if (get_data_pointer(&conn->send_array, &dt1, packet_num) == 1) { dt1->sent_time = current_time_monotonic(); } } else { conn->maximum_speed_reached = 1; LOGGER_ERROR(c->log, "send_data_packet failed\n"); } return packet_num; } /* Get the lowest 2 bytes from the nonce and convert * them to host byte format before returning them. */ static uint16_t get_nonce_uint16(const uint8_t *nonce) { uint16_t num; memcpy(&num, nonce + (crypto_box_NONCEBYTES - sizeof(uint16_t)), sizeof(uint16_t)); return ntohs(num); } #define DATA_NUM_THRESHOLD 21845 /* Handle a data packet. * Decrypt packet of length and put it into data. * data must be at least MAX_DATA_DATA_PACKET_SIZE big. * * return -1 on failure. * return length of data on success. */ static int handle_data_packet(const Net_Crypto *c, int crypt_connection_id, uint8_t *data, const uint8_t *packet, uint16_t length) { if (length <= (1 + sizeof(uint16_t) + crypto_box_MACBYTES) || length > MAX_CRYPTO_PACKET_SIZE) { return -1; } Crypto_Connection *conn = get_crypto_connection(c, crypt_connection_id); if (conn == 0) { return -1; } uint8_t nonce[crypto_box_NONCEBYTES]; memcpy(nonce, conn->recv_nonce, crypto_box_NONCEBYTES); uint16_t num_cur_nonce = get_nonce_uint16(nonce); uint16_t num; memcpy(&num, packet + 1, sizeof(uint16_t)); num = ntohs(num); uint16_t diff = num - num_cur_nonce; increment_nonce_number(nonce, diff); int len = decrypt_data_symmetric(conn->shared_key, nonce, packet + 1 + sizeof(uint16_t), length - (1 + sizeof(uint16_t)), data); if ((unsigned int)len != length - (1 + sizeof(uint16_t) + crypto_box_MACBYTES)) { return -1; } if (diff > DATA_NUM_THRESHOLD * 2) { increment_nonce_number(conn->recv_nonce, DATA_NUM_THRESHOLD); } return len; } /* Send a request packet. * * return -1 on failure. * return 0 on success. */ static int send_request_packet(Net_Crypto *c, int crypt_connection_id) { Crypto_Connection *conn = get_crypto_connection(c, crypt_connection_id); if (conn == 0) { return -1; } uint8_t data[MAX_CRYPTO_DATA_SIZE]; int len = generate_request_packet(data, sizeof(data), &conn->recv_array); if (len == -1) { return -1; } return send_data_packet_helper(c, crypt_connection_id, conn->recv_array.buffer_start, conn->send_array.buffer_end, data, len); } /* Send up to max num previously requested data packets. * * return -1 on failure. * return number of packets sent on success. */ static int send_requested_packets(Net_Crypto *c, int crypt_connection_id, uint32_t max_num) { if (max_num == 0) { return -1; } Crypto_Connection *conn = get_crypto_connection(c, crypt_connection_id); if (conn == 0) { return -1; } uint64_t temp_time = current_time_monotonic(); uint32_t i, num_sent = 0, array_size = num_packets_array(&conn->send_array); for (i = 0; i < array_size; ++i) { Packet_Data *dt; uint32_t packet_num = (i + conn->send_array.buffer_start); int ret = get_data_pointer(&conn->send_array, &dt, packet_num); if (ret == -1) { return -1; } if (ret == 0) { continue; } if (dt->sent_time) { continue; } if (send_data_packet_helper(c, crypt_connection_id, conn->recv_array.buffer_start, packet_num, dt->data, dt->length) == 0) { dt->sent_time = temp_time; ++num_sent; } if (num_sent >= max_num) { break; } } return num_sent; } /* Add a new temp packet to send repeatedly. * * return -1 on failure. * return 0 on success. */ static int new_temp_packet(const Net_Crypto *c, int crypt_connection_id, const uint8_t *packet, uint16_t length) { if (length == 0 || length > MAX_CRYPTO_PACKET_SIZE) { return -1; } Crypto_Connection *conn = get_crypto_connection(c, crypt_connection_id); if (conn == 0) { return -1; } uint8_t *temp_packet = (uint8_t *)malloc(length); if (temp_packet == 0) { return -1; } if (conn->temp_packet) { free(conn->temp_packet); } memcpy(temp_packet, packet, length); conn->temp_packet = temp_packet; conn->temp_packet_length = length; conn->temp_packet_sent_time = 0; conn->temp_packet_num_sent = 0; return 0; } /* Clear the temp packet. * * return -1 on failure. * return 0 on success. */ static int clear_temp_packet(const Net_Crypto *c, int crypt_connection_id) { Crypto_Connection *conn = get_crypto_connection(c, crypt_connection_id); if (conn == 0) { return -1; } if (conn->temp_packet) { free(conn->temp_packet); } conn->temp_packet = 0; conn->temp_packet_length = 0; conn->temp_packet_sent_time = 0; conn->temp_packet_num_sent = 0; return 0; } /* Send the temp packet. * * return -1 on failure. * return 0 on success. */ static int send_temp_packet(Net_Crypto *c, int crypt_connection_id) { Crypto_Connection *conn = get_crypto_connection(c, crypt_connection_id); if (conn == 0) { return -1; } if (!conn->temp_packet) { return -1; } if (send_packet_to(c, crypt_connection_id, conn->temp_packet, conn->temp_packet_length) != 0) { return -1; } conn->temp_packet_sent_time = current_time_monotonic(); ++conn->temp_packet_num_sent; return 0; } /* Create a handshake packet and set it as a temp packet. * cookie must be COOKIE_LENGTH. * * return -1 on failure. * return 0 on success. */ static int create_send_handshake(Net_Crypto *c, int crypt_connection_id, const uint8_t *cookie, const uint8_t *dht_public_key) { Crypto_Connection *conn = get_crypto_connection(c, crypt_connection_id); if (conn == 0) { return -1; } uint8_t handshake_packet[HANDSHAKE_PACKET_LENGTH]; if (create_crypto_handshake(c, handshake_packet, cookie, conn->sent_nonce, conn->sessionpublic_key, conn->public_key, dht_public_key) != sizeof(handshake_packet)) { return -1; } if (new_temp_packet(c, crypt_connection_id, handshake_packet, sizeof(handshake_packet)) != 0) { return -1; } send_temp_packet(c, crypt_connection_id); return 0; } /* Send a kill packet. * * return -1 on failure. * return 0 on success. */ static int send_kill_packet(Net_Crypto *c, int crypt_connection_id) { Crypto_Connection *conn = get_crypto_connection(c, crypt_connection_id); if (conn == 0) { return -1; } uint8_t kill_packet = PACKET_ID_KILL; return send_data_packet_helper(c, crypt_connection_id, conn->recv_array.buffer_start, conn->send_array.buffer_end, &kill_packet, sizeof(kill_packet)); } static void connection_kill(Net_Crypto *c, int crypt_connection_id, void *userdata) { Crypto_Connection *conn = get_crypto_connection(c, crypt_connection_id); if (conn == 0) { return; } if (conn->connection_status_callback) { conn->connection_status_callback(conn->connection_status_callback_object, conn->connection_status_callback_id, 0, userdata); } crypto_kill(c, crypt_connection_id); } /* Handle a received data packet. * * return -1 on failure. * return 0 on success. */ static int handle_data_packet_helper(Net_Crypto *c, int crypt_connection_id, const uint8_t *packet, uint16_t length, bool udp, void *userdata) { if (length > MAX_CRYPTO_PACKET_SIZE || length <= CRYPTO_DATA_PACKET_MIN_SIZE) { return -1; } Crypto_Connection *conn = get_crypto_connection(c, crypt_connection_id); if (conn == 0) { return -1; } uint8_t data[MAX_DATA_DATA_PACKET_SIZE]; int len = handle_data_packet(c, crypt_connection_id, data, packet, length); if (len <= (int)(sizeof(uint32_t) * 2)) { return -1; } uint32_t buffer_start, num; memcpy(&buffer_start, data, sizeof(uint32_t)); memcpy(&num, data + sizeof(uint32_t), sizeof(uint32_t)); buffer_start = ntohl(buffer_start); num = ntohl(num); uint64_t rtt_calc_time = 0; if (buffer_start != conn->send_array.buffer_start) { Packet_Data *packet_time; if (get_data_pointer(&conn->send_array, &packet_time, conn->send_array.buffer_start) == 1) { rtt_calc_time = packet_time->sent_time; } if (clear_buffer_until(&conn->send_array, buffer_start) != 0) { return -1; } } uint8_t *real_data = data + (sizeof(uint32_t) * 2); uint16_t real_length = len - (sizeof(uint32_t) * 2); while (real_data[0] == PACKET_ID_PADDING) { /* Remove Padding */ ++real_data; --real_length; if (real_length == 0) { return -1; } } if (real_data[0] == PACKET_ID_KILL) { connection_kill(c, crypt_connection_id, userdata); return 0; } if (conn->status == CRYPTO_CONN_NOT_CONFIRMED) { clear_temp_packet(c, crypt_connection_id); conn->status = CRYPTO_CONN_ESTABLISHED; if (conn->connection_status_callback) { conn->connection_status_callback(conn->connection_status_callback_object, conn->connection_status_callback_id, 1, userdata); } } if (real_data[0] == PACKET_ID_REQUEST) { uint64_t rtt_time; if (udp) { rtt_time = conn->rtt_time; } else { rtt_time = DEFAULT_TCP_PING_CONNECTION; } int requested = handle_request_packet(&conn->send_array, real_data, real_length, &rtt_calc_time, rtt_time); if (requested == -1) { return -1; } // else { /* TODO(irungentoo): ? */ } set_buffer_end(&conn->recv_array, num); } else if (real_data[0] >= CRYPTO_RESERVED_PACKETS && real_data[0] < PACKET_ID_LOSSY_RANGE_START) { Packet_Data dt; dt.length = real_length; memcpy(dt.data, real_data, real_length); if (add_data_to_buffer(&conn->recv_array, num, &dt) != 0) { return -1; } while (1) { pthread_mutex_lock(&conn->mutex); int ret = read_data_beg_buffer(&conn->recv_array, &dt); pthread_mutex_unlock(&conn->mutex); if (ret == -1) { break; } if (conn->connection_data_callback) { conn->connection_data_callback(conn->connection_data_callback_object, conn->connection_data_callback_id, dt.data, dt.length, userdata); } /* conn might get killed in callback. */ conn = get_crypto_connection(c, crypt_connection_id); if (conn == 0) { return -1; } } /* Packet counter. */ ++conn->packet_counter; } else if (real_data[0] >= PACKET_ID_LOSSY_RANGE_START && real_data[0] < (PACKET_ID_LOSSY_RANGE_START + PACKET_ID_LOSSY_RANGE_SIZE)) { set_buffer_end(&conn->recv_array, num); if (conn->connection_lossy_data_callback) { conn->connection_lossy_data_callback(conn->connection_lossy_data_callback_object, conn->connection_lossy_data_callback_id, real_data, real_length, userdata); } } else { return -1; } if (rtt_calc_time != 0) { uint64_t rtt_time = current_time_monotonic() - rtt_calc_time; if (rtt_time < conn->rtt_time) { conn->rtt_time = rtt_time; } } return 0; } /* Handle a packet that was received for the connection. * * return -1 on failure. * return 0 on success. */ static int handle_packet_connection(Net_Crypto *c, int crypt_connection_id, const uint8_t *packet, uint16_t length, bool udp, void *userdata) { if (length == 0 || length > MAX_CRYPTO_PACKET_SIZE) { return -1; } Crypto_Connection *conn = get_crypto_connection(c, crypt_connection_id); if (conn == 0) { return -1; } switch (packet[0]) { case NET_PACKET_COOKIE_RESPONSE: { if (conn->status != CRYPTO_CONN_COOKIE_REQUESTING) { return -1; } uint8_t cookie[COOKIE_LENGTH]; uint64_t number; if (handle_cookie_response(cookie, &number, packet, length, conn->shared_key) != sizeof(cookie)) { return -1; } if (number != conn->cookie_request_number) { return -1; } if (create_send_handshake(c, crypt_connection_id, cookie, conn->dht_public_key) != 0) { return -1; } conn->status = CRYPTO_CONN_HANDSHAKE_SENT; return 0; } case NET_PACKET_CRYPTO_HS: { if (conn->status == CRYPTO_CONN_COOKIE_REQUESTING || conn->status == CRYPTO_CONN_HANDSHAKE_SENT || conn->status == CRYPTO_CONN_NOT_CONFIRMED) { uint8_t peer_real_pk[crypto_box_PUBLICKEYBYTES]; uint8_t dht_public_key[crypto_box_PUBLICKEYBYTES]; uint8_t cookie[COOKIE_LENGTH]; if (handle_crypto_handshake(c, conn->recv_nonce, conn->peersessionpublic_key, peer_real_pk, dht_public_key, cookie, packet, length, conn->public_key) != 0) { return -1; } if (public_key_cmp(dht_public_key, conn->dht_public_key) == 0) { encrypt_precompute(conn->peersessionpublic_key, conn->sessionsecret_key, conn->shared_key); if (conn->status == CRYPTO_CONN_COOKIE_REQUESTING) { if (create_send_handshake(c, crypt_connection_id, cookie, dht_public_key) != 0) { return -1; } } conn->status = CRYPTO_CONN_NOT_CONFIRMED; } else { if (conn->dht_pk_callback) { conn->dht_pk_callback(conn->dht_pk_callback_object, conn->dht_pk_callback_number, dht_public_key, userdata); } } } else { return -1; } return 0; } case NET_PACKET_CRYPTO_DATA: { if (conn->status == CRYPTO_CONN_NOT_CONFIRMED || conn->status == CRYPTO_CONN_ESTABLISHED) { return handle_data_packet_helper(c, crypt_connection_id, packet, length, udp, userdata); } return -1; } default: { return -1; } } return 0; } /* Set the size of the friend list to numfriends. * * return -1 if realloc fails. * return 0 if it succeeds. */ static int realloc_cryptoconnection(Net_Crypto *c, uint32_t num) { if (num == 0) { free(c->crypto_connections); c->crypto_connections = NULL; return 0; } Crypto_Connection *newcrypto_connections = (Crypto_Connection *)realloc(c->crypto_connections, num * sizeof(Crypto_Connection)); if (newcrypto_connections == NULL) { return -1; } c->crypto_connections = newcrypto_connections; return 0; } /* Create a new empty crypto connection. * * return -1 on failure. * return connection id on success. */ static int create_crypto_connection(Net_Crypto *c) { uint32_t i; for (i = 0; i < c->crypto_connections_length; ++i) { if (c->crypto_connections[i].status == CRYPTO_CONN_NO_CONNECTION) { return i; } } while (1) { /* TODO(irungentoo): is this really the best way to do this? */ pthread_mutex_lock(&c->connections_mutex); if (!c->connection_use_counter) { break; } pthread_mutex_unlock(&c->connections_mutex); } int id = -1; if (realloc_cryptoconnection(c, c->crypto_connections_length + 1) == 0) { id = c->crypto_connections_length; ++c->crypto_connections_length; memset(&(c->crypto_connections[id]), 0, sizeof(Crypto_Connection)); if (pthread_mutex_init(&c->crypto_connections[id].mutex, NULL) != 0) { pthread_mutex_unlock(&c->connections_mutex); return -1; } } pthread_mutex_unlock(&c->connections_mutex); return id; } /* Wipe a crypto connection. * * return -1 on failure. * return 0 on success. */ static int wipe_crypto_connection(Net_Crypto *c, int crypt_connection_id) { if (crypt_connection_id_not_valid(c, crypt_connection_id)) { return -1; } uint32_t i; /* Keep mutex, only destroy it when connection is realloced out. */ pthread_mutex_t mutex = c->crypto_connections[crypt_connection_id].mutex; sodium_memzero(&(c->crypto_connections[crypt_connection_id]), sizeof(Crypto_Connection)); c->crypto_connections[crypt_connection_id].mutex = mutex; for (i = c->crypto_connections_length; i != 0; --i) { if (c->crypto_connections[i - 1].status == CRYPTO_CONN_NO_CONNECTION) { pthread_mutex_destroy(&c->crypto_connections[i - 1].mutex); } else { break; } } if (c->crypto_connections_length != i) { c->crypto_connections_length = i; realloc_cryptoconnection(c, c->crypto_connections_length); } return 0; } /* Get crypto connection id from public key of peer. * * return -1 if there are no connections like we are looking for. * return id if it found it. */ static int getcryptconnection_id(const Net_Crypto *c, const uint8_t *public_key) { uint32_t i; for (i = 0; i < c->crypto_connections_length; ++i) { if (c->crypto_connections[i].status != CRYPTO_CONN_NO_CONNECTION) { if (public_key_cmp(public_key, c->crypto_connections[i].public_key) == 0) { return i; } } } return -1; } /* Add a source to the crypto connection. * This is to be used only when we have received a packet from that source. * * return -1 on failure. * return positive number on success. * 0 if source was a direct UDP connection. */ static int crypto_connection_add_source(Net_Crypto *c, int crypt_connection_id, IP_Port source) { Crypto_Connection *conn = get_crypto_connection(c, crypt_connection_id); if (conn == 0) { return -1; } if (source.ip.family == AF_INET || source.ip.family == AF_INET6) { if (add_ip_port_connection(c, crypt_connection_id, source) != 0) { return -1; } if (source.ip.family == AF_INET) { conn->direct_lastrecv_timev4 = unix_time(); } else { conn->direct_lastrecv_timev6 = unix_time(); } return 0; } if (source.ip.family == TCP_FAMILY) { if (add_tcp_number_relay_connection(c->tcp_c, conn->connection_number_tcp, source.ip.ip6.uint32[0]) == 0) { return 1; } } return -1; } /* Set function to be called when someone requests a new connection to us. * * The set function should return -1 on failure and 0 on success. * * n_c is only valid for the duration of the function call. */ void new_connection_handler(Net_Crypto *c, int (*new_connection_callback)(void *object, New_Connection *n_c), void *object) { c->new_connection_callback = new_connection_callback; c->new_connection_callback_object = object; } /* Handle a handshake packet by someone who wants to initiate a new connection with us. * This calls the callback set by new_connection_handler() if the handshake is ok. * * return -1 on failure. * return 0 on success. */ static int handle_new_connection_handshake(Net_Crypto *c, IP_Port source, const uint8_t *data, uint16_t length, void *userdata) { New_Connection n_c; n_c.cookie = (uint8_t *)malloc(COOKIE_LENGTH); if (n_c.cookie == NULL) { return -1; } n_c.source = source; n_c.cookie_length = COOKIE_LENGTH; if (handle_crypto_handshake(c, n_c.recv_nonce, n_c.peersessionpublic_key, n_c.public_key, n_c.dht_public_key, n_c.cookie, data, length, 0) != 0) { free(n_c.cookie); return -1; } int crypt_connection_id = getcryptconnection_id(c, n_c.public_key); if (crypt_connection_id != -1) { Crypto_Connection *conn = get_crypto_connection(c, crypt_connection_id); if (public_key_cmp(n_c.dht_public_key, conn->dht_public_key) != 0) { connection_kill(c, crypt_connection_id, userdata); } else { int ret = -1; if (conn && (conn->status == CRYPTO_CONN_COOKIE_REQUESTING || conn->status == CRYPTO_CONN_HANDSHAKE_SENT)) { memcpy(conn->recv_nonce, n_c.recv_nonce, crypto_box_NONCEBYTES); memcpy(conn->peersessionpublic_key, n_c.peersessionpublic_key, crypto_box_PUBLICKEYBYTES); encrypt_precompute(conn->peersessionpublic_key, conn->sessionsecret_key, conn->shared_key); crypto_connection_add_source(c, crypt_connection_id, source); if (create_send_handshake(c, crypt_connection_id, n_c.cookie, n_c.dht_public_key) == 0) { conn->status = CRYPTO_CONN_NOT_CONFIRMED; ret = 0; } } free(n_c.cookie); return ret; } } int ret = c->new_connection_callback(c->new_connection_callback_object, &n_c); free(n_c.cookie); return ret; } /* Accept a crypto connection. * * return -1 on failure. * return connection id on success. */ int accept_crypto_connection(Net_Crypto *c, New_Connection *n_c) { if (getcryptconnection_id(c, n_c->public_key) != -1) { return -1; } int crypt_connection_id = create_crypto_connection(c); if (crypt_connection_id == -1) { return -1; } Crypto_Connection *conn = &c->crypto_connections[crypt_connection_id]; if (n_c->cookie_length != COOKIE_LENGTH) { return -1; } pthread_mutex_lock(&c->tcp_mutex); int connection_number_tcp = new_tcp_connection_to(c->tcp_c, n_c->dht_public_key, crypt_connection_id); pthread_mutex_unlock(&c->tcp_mutex); if (connection_number_tcp == -1) { return -1; } conn->connection_number_tcp = connection_number_tcp; memcpy(conn->public_key, n_c->public_key, crypto_box_PUBLICKEYBYTES); memcpy(conn->recv_nonce, n_c->recv_nonce, crypto_box_NONCEBYTES); memcpy(conn->peersessionpublic_key, n_c->peersessionpublic_key, crypto_box_PUBLICKEYBYTES); random_nonce(conn->sent_nonce); crypto_box_keypair(conn->sessionpublic_key, conn->sessionsecret_key); encrypt_precompute(conn->peersessionpublic_key, conn->sessionsecret_key, conn->shared_key); conn->status = CRYPTO_CONN_NOT_CONFIRMED; if (create_send_handshake(c, crypt_connection_id, n_c->cookie, n_c->dht_public_key) != 0) { pthread_mutex_lock(&c->tcp_mutex); kill_tcp_connection_to(c->tcp_c, conn->connection_number_tcp); pthread_mutex_unlock(&c->tcp_mutex); conn->status = CRYPTO_CONN_NO_CONNECTION; return -1; } memcpy(conn->dht_public_key, n_c->dht_public_key, crypto_box_PUBLICKEYBYTES); conn->packet_send_rate = CRYPTO_PACKET_MIN_RATE; conn->packet_send_rate_requested = CRYPTO_PACKET_MIN_RATE; conn->packets_left = CRYPTO_MIN_QUEUE_LENGTH; conn->rtt_time = DEFAULT_PING_CONNECTION; crypto_connection_add_source(c, crypt_connection_id, n_c->source); return crypt_connection_id; } /* Create a crypto connection. * If one to that real public key already exists, return it. * * return -1 on failure. * return connection id on success. */ int new_crypto_connection(Net_Crypto *c, const uint8_t *real_public_key, const uint8_t *dht_public_key) { int crypt_connection_id = getcryptconnection_id(c, real_public_key); if (crypt_connection_id != -1) { return crypt_connection_id; } crypt_connection_id = create_crypto_connection(c); if (crypt_connection_id == -1) { return -1; } Crypto_Connection *conn = &c->crypto_connections[crypt_connection_id]; if (conn == 0) { return -1; } pthread_mutex_lock(&c->tcp_mutex); int connection_number_tcp = new_tcp_connection_to(c->tcp_c, dht_public_key, crypt_connection_id); pthread_mutex_unlock(&c->tcp_mutex); if (connection_number_tcp == -1) { return -1; } conn->connection_number_tcp = connection_number_tcp; memcpy(conn->public_key, real_public_key, crypto_box_PUBLICKEYBYTES); random_nonce(conn->sent_nonce); crypto_box_keypair(conn->sessionpublic_key, conn->sessionsecret_key); conn->status = CRYPTO_CONN_COOKIE_REQUESTING; conn->packet_send_rate = CRYPTO_PACKET_MIN_RATE; conn->packet_send_rate_requested = CRYPTO_PACKET_MIN_RATE; conn->packets_left = CRYPTO_MIN_QUEUE_LENGTH; conn->rtt_time = DEFAULT_PING_CONNECTION; memcpy(conn->dht_public_key, dht_public_key, crypto_box_PUBLICKEYBYTES); conn->cookie_request_number = random_64b(); uint8_t cookie_request[COOKIE_REQUEST_LENGTH]; if (create_cookie_request(c, cookie_request, conn->dht_public_key, conn->cookie_request_number, conn->shared_key) != sizeof(cookie_request) || new_temp_packet(c, crypt_connection_id, cookie_request, sizeof(cookie_request)) != 0) { pthread_mutex_lock(&c->tcp_mutex); kill_tcp_connection_to(c->tcp_c, conn->connection_number_tcp); pthread_mutex_unlock(&c->tcp_mutex); conn->status = CRYPTO_CONN_NO_CONNECTION; return -1; } return crypt_connection_id; } /* Set the direct ip of the crypto connection. * * Connected is 0 if we are not sure we are connected to that person, 1 if we are sure. * * return -1 on failure. * return 0 on success. */ int set_direct_ip_port(Net_Crypto *c, int crypt_connection_id, IP_Port ip_port, bool connected) { Crypto_Connection *conn = get_crypto_connection(c, crypt_connection_id); if (conn == 0) { return -1; } if (add_ip_port_connection(c, crypt_connection_id, ip_port) == 0) { if (connected) { if (ip_port.ip.family == AF_INET) { conn->direct_lastrecv_timev4 = unix_time(); } else { conn->direct_lastrecv_timev6 = unix_time(); } } else { if (ip_port.ip.family == AF_INET) { conn->direct_lastrecv_timev4 = 0; } else { conn->direct_lastrecv_timev6 = 0; } } return 0; } return -1; } static int tcp_data_callback(void *object, int id, const uint8_t *data, uint16_t length, void *userdata) { if (length == 0 || length > MAX_CRYPTO_PACKET_SIZE) { return -1; } Net_Crypto *c = (Net_Crypto *)object; Crypto_Connection *conn = get_crypto_connection(c, id); if (conn == 0) { return -1; } if (data[0] == NET_PACKET_COOKIE_REQUEST) { return tcp_handle_cookie_request(c, conn->connection_number_tcp, data, length); } pthread_mutex_unlock(&c->tcp_mutex); int ret = handle_packet_connection(c, id, data, length, 0, userdata); pthread_mutex_lock(&c->tcp_mutex); if (ret != 0) { return -1; } // TODO(irungentoo): detect and kill bad TCP connections. return 0; } static int tcp_oob_callback(void *object, const uint8_t *public_key, unsigned int tcp_connections_number, const uint8_t *data, uint16_t length, void *userdata) { if (length == 0 || length > MAX_CRYPTO_PACKET_SIZE) { return -1; } Net_Crypto *c = (Net_Crypto *)object; if (data[0] == NET_PACKET_COOKIE_REQUEST) { return tcp_oob_handle_cookie_request(c, tcp_connections_number, public_key, data, length); } if (data[0] == NET_PACKET_CRYPTO_HS) { IP_Port source; source.port = 0; source.ip.family = TCP_FAMILY; source.ip.ip6.uint32[0] = tcp_connections_number; if (handle_new_connection_handshake(c, source, data, length, userdata) != 0) { return -1; } return 0; } return -1; } /* Add a tcp relay, associating it to a crypt_connection_id. * * return 0 if it was added. * return -1 if it wasn't. */ int add_tcp_relay_peer(Net_Crypto *c, int crypt_connection_id, IP_Port ip_port, const uint8_t *public_key) { Crypto_Connection *conn = get_crypto_connection(c, crypt_connection_id); if (conn == 0) { return -1; } pthread_mutex_lock(&c->tcp_mutex); int ret = add_tcp_relay_connection(c->tcp_c, conn->connection_number_tcp, ip_port, public_key); pthread_mutex_unlock(&c->tcp_mutex); return ret; } /* Add a tcp relay to the array. * * return 0 if it was added. * return -1 if it wasn't. */ int add_tcp_relay(Net_Crypto *c, IP_Port ip_port, const uint8_t *public_key) { pthread_mutex_lock(&c->tcp_mutex); int ret = add_tcp_relay_global(c->tcp_c, ip_port, public_key); pthread_mutex_unlock(&c->tcp_mutex); return ret; } /* Return a random TCP connection number for use in send_tcp_onion_request. * * TODO(irungentoo): This number is just the index of an array that the elements can * change without warning. * * return TCP connection number on success. * return -1 on failure. */ int get_random_tcp_con_number(Net_Crypto *c) { pthread_mutex_lock(&c->tcp_mutex); int ret = get_random_tcp_onion_conn_number(c->tcp_c); pthread_mutex_unlock(&c->tcp_mutex); return ret; } /* Send an onion packet via the TCP relay corresponding to tcp_connections_number. * * return 0 on success. * return -1 on failure. */ int send_tcp_onion_request(Net_Crypto *c, unsigned int tcp_connections_number, const uint8_t *data, uint16_t length) { pthread_mutex_lock(&c->tcp_mutex); int ret = tcp_send_onion_request(c->tcp_c, tcp_connections_number, data, length); pthread_mutex_unlock(&c->tcp_mutex); return ret; } /* Copy a maximum of num TCP relays we are connected to to tcp_relays. * NOTE that the family of the copied ip ports will be set to TCP_INET or TCP_INET6. * * return number of relays copied to tcp_relays on success. * return 0 on failure. */ unsigned int copy_connected_tcp_relays(Net_Crypto *c, Node_format *tcp_relays, uint16_t num) { if (num == 0) { return 0; } pthread_mutex_lock(&c->tcp_mutex); unsigned int ret = tcp_copy_connected_relays(c->tcp_c, tcp_relays, num); pthread_mutex_unlock(&c->tcp_mutex); return ret; } static void do_tcp(Net_Crypto *c, void *userdata) { pthread_mutex_lock(&c->tcp_mutex); do_tcp_connections(c->tcp_c, userdata); pthread_mutex_unlock(&c->tcp_mutex); uint32_t i; for (i = 0; i < c->crypto_connections_length; ++i) { Crypto_Connection *conn = get_crypto_connection(c, i); if (conn == 0) { return; } if (conn->status == CRYPTO_CONN_ESTABLISHED) { bool direct_connected = 0; crypto_connection_status(c, i, &direct_connected, NULL); if (direct_connected) { pthread_mutex_lock(&c->tcp_mutex); set_tcp_connection_to_status(c->tcp_c, conn->connection_number_tcp, 0); pthread_mutex_unlock(&c->tcp_mutex); } else { pthread_mutex_lock(&c->tcp_mutex); set_tcp_connection_to_status(c->tcp_c, conn->connection_number_tcp, 1); pthread_mutex_unlock(&c->tcp_mutex); } } } } /* Set function to be called when connection with crypt_connection_id goes connects/disconnects. * * The set function should return -1 on failure and 0 on success. * Note that if this function is set, the connection will clear itself on disconnect. * Object and id will be passed to this function untouched. * status is 1 if the connection is going online, 0 if it is going offline. * * return -1 on failure. * return 0 on success. */ int connection_status_handler(const Net_Crypto *c, int crypt_connection_id, int (*connection_status_callback)(void *object, int id, uint8_t status, void *userdata), void *object, int id) { Crypto_Connection *conn = get_crypto_connection(c, crypt_connection_id); if (conn == 0) { return -1; } conn->connection_status_callback = connection_status_callback; conn->connection_status_callback_object = object; conn->connection_status_callback_id = id; return 0; } /* Set function to be called when connection with crypt_connection_id receives a data packet of length. * * The set function should return -1 on failure and 0 on success. * Object and id will be passed to this function untouched. * * return -1 on failure. * return 0 on success. */ int connection_data_handler(const Net_Crypto *c, int crypt_connection_id, int (*connection_data_callback)(void *object, int id, const uint8_t *data, uint16_t length, void *userdata), void *object, int id) { Crypto_Connection *conn = get_crypto_connection(c, crypt_connection_id); if (conn == 0) { return -1; } conn->connection_data_callback = connection_data_callback; conn->connection_data_callback_object = object; conn->connection_data_callback_id = id; return 0; } /* Set function to be called when connection with crypt_connection_id receives a lossy data packet of length. * * The set function should return -1 on failure and 0 on success. * Object and id will be passed to this function untouched. * * return -1 on failure. * return 0 on success. */ int connection_lossy_data_handler(Net_Crypto *c, int crypt_connection_id, int (*connection_lossy_data_callback)(void *object, int id, const uint8_t *data, uint16_t length, void *userdata), void *object, int id) { Crypto_Connection *conn = get_crypto_connection(c, crypt_connection_id); if (conn == 0) { return -1; } conn->connection_lossy_data_callback = connection_lossy_data_callback; conn->connection_lossy_data_callback_object = object; conn->connection_lossy_data_callback_id = id; return 0; } /* Set the function for this friend that will be callbacked with object and number if * the friend sends us a different dht public key than we have associated to him. * * If this function is called, the connection should be recreated with the new public key. * * object and number will be passed as argument to this function. * * return -1 on failure. * return 0 on success. */ int nc_dht_pk_callback(Net_Crypto *c, int crypt_connection_id, void (*function)(void *data, int32_t number, const uint8_t *dht_public_key, void *userdata), void *object, uint32_t number) { Crypto_Connection *conn = get_crypto_connection(c, crypt_connection_id); if (conn == 0) { return -1; } conn->dht_pk_callback = function; conn->dht_pk_callback_object = object; conn->dht_pk_callback_number = number; return 0; } /* Get the crypto connection id from the ip_port. * * return -1 on failure. * return connection id on success. */ static int crypto_id_ip_port(const Net_Crypto *c, IP_Port ip_port) { return bs_list_find(&c->ip_port_list, (uint8_t *)&ip_port); } #define CRYPTO_MIN_PACKET_SIZE (1 + sizeof(uint16_t) + crypto_box_MACBYTES) /* Handle raw UDP packets coming directly from the socket. * * Handles: * Cookie response packets. * Crypto handshake packets. * Crypto data packets. * */ static int udp_handle_packet(void *object, IP_Port source, const uint8_t *packet, uint16_t length, void *userdata) { if (length <= CRYPTO_MIN_PACKET_SIZE || length > MAX_CRYPTO_PACKET_SIZE) { return 1; } Net_Crypto *c = (Net_Crypto *)object; int crypt_connection_id = crypto_id_ip_port(c, source); if (crypt_connection_id == -1) { if (packet[0] != NET_PACKET_CRYPTO_HS) { return 1; } if (handle_new_connection_handshake(c, source, packet, length, userdata) != 0) { return 1; } return 0; } if (handle_packet_connection(c, crypt_connection_id, packet, length, 1, userdata) != 0) { return 1; } Crypto_Connection *conn = get_crypto_connection(c, crypt_connection_id); if (conn == 0) { return -1; } pthread_mutex_lock(&conn->mutex); if (source.ip.family == AF_INET) { conn->direct_lastrecv_timev4 = unix_time(); } else { conn->direct_lastrecv_timev6 = unix_time(); } pthread_mutex_unlock(&conn->mutex); return 0; } /* The dT for the average packet receiving rate calculations. Also used as the */ #define PACKET_COUNTER_AVERAGE_INTERVAL 50 /* Ratio of recv queue size / recv packet rate (in seconds) times * the number of ms between request packets to send at that ratio */ #define REQUEST_PACKETS_COMPARE_CONSTANT (0.125 * 100.0) /* Timeout for increasing speed after congestion event (in ms). */ #define CONGESTION_EVENT_TIMEOUT 1000 /* If the send queue is SEND_QUEUE_RATIO times larger than the * calculated link speed the packet send speed will be reduced * by a value depending on this number. */ #define SEND_QUEUE_RATIO 2.0 static void send_crypto_packets(Net_Crypto *c) { uint32_t i; uint64_t temp_time = current_time_monotonic(); double total_send_rate = 0; uint32_t peak_request_packet_interval = ~0; for (i = 0; i < c->crypto_connections_length; ++i) { Crypto_Connection *conn = get_crypto_connection(c, i); if (conn == 0) { return; } if (CRYPTO_SEND_PACKET_INTERVAL + conn->temp_packet_sent_time < temp_time) { send_temp_packet(c, i); } if ((conn->status == CRYPTO_CONN_NOT_CONFIRMED || conn->status == CRYPTO_CONN_ESTABLISHED) && ((CRYPTO_SEND_PACKET_INTERVAL) + conn->last_request_packet_sent) < temp_time) { if (send_request_packet(c, i) == 0) { conn->last_request_packet_sent = temp_time; } } if (conn->status == CRYPTO_CONN_ESTABLISHED) { if (conn->packet_recv_rate > CRYPTO_PACKET_MIN_RATE) { double request_packet_interval = (REQUEST_PACKETS_COMPARE_CONSTANT / (((double)num_packets_array( &conn->recv_array) + 1.0) / (conn->packet_recv_rate + 1.0))); double request_packet_interval2 = ((CRYPTO_PACKET_MIN_RATE / conn->packet_recv_rate) * (double)CRYPTO_SEND_PACKET_INTERVAL) + (double)PACKET_COUNTER_AVERAGE_INTERVAL; if (request_packet_interval2 < request_packet_interval) { request_packet_interval = request_packet_interval2; } if (request_packet_interval < PACKET_COUNTER_AVERAGE_INTERVAL) { request_packet_interval = PACKET_COUNTER_AVERAGE_INTERVAL; } if (request_packet_interval > CRYPTO_SEND_PACKET_INTERVAL) { request_packet_interval = CRYPTO_SEND_PACKET_INTERVAL; } if (temp_time - conn->last_request_packet_sent > (uint64_t)request_packet_interval) { if (send_request_packet(c, i) == 0) { conn->last_request_packet_sent = temp_time; } } if (request_packet_interval < peak_request_packet_interval) { peak_request_packet_interval = request_packet_interval; } } if ((PACKET_COUNTER_AVERAGE_INTERVAL + conn->packet_counter_set) < temp_time) { double dt = temp_time - conn->packet_counter_set; conn->packet_recv_rate = (double)conn->packet_counter / (dt / 1000.0); conn->packet_counter = 0; conn->packet_counter_set = temp_time; uint32_t packets_sent = conn->packets_sent; conn->packets_sent = 0; uint32_t packets_resent = conn->packets_resent; conn->packets_resent = 0; /* conjestion control calculate a new value of conn->packet_send_rate based on some data */ unsigned int pos = conn->last_sendqueue_counter % CONGESTION_QUEUE_ARRAY_SIZE; conn->last_sendqueue_size[pos] = num_packets_array(&conn->send_array); ++conn->last_sendqueue_counter; unsigned int j; long signed int sum = 0; sum = (long signed int)conn->last_sendqueue_size[(pos) % CONGESTION_QUEUE_ARRAY_SIZE] - (long signed int)conn->last_sendqueue_size[(pos - (CONGESTION_QUEUE_ARRAY_SIZE - 1)) % CONGESTION_QUEUE_ARRAY_SIZE]; unsigned int n_p_pos = conn->last_sendqueue_counter % CONGESTION_LAST_SENT_ARRAY_SIZE; conn->last_num_packets_sent[n_p_pos] = packets_sent; conn->last_num_packets_resent[n_p_pos] = packets_resent; bool direct_connected = 0; crypto_connection_status(c, i, &direct_connected, NULL); if (direct_connected && conn->last_tcp_sent + CONGESTION_EVENT_TIMEOUT > temp_time) { /* When switching from TCP to UDP, don't change the packet send rate for CONGESTION_EVENT_TIMEOUT ms. */ } else { long signed int total_sent = 0, total_resent = 0; // TODO(irungentoo): use real delay unsigned int delay = (unsigned int)((conn->rtt_time / PACKET_COUNTER_AVERAGE_INTERVAL) + 0.5); unsigned int packets_set_rem_array = (CONGESTION_LAST_SENT_ARRAY_SIZE - CONGESTION_QUEUE_ARRAY_SIZE); if (delay > packets_set_rem_array) { delay = packets_set_rem_array; } for (j = 0; j < CONGESTION_QUEUE_ARRAY_SIZE; ++j) { unsigned int ind = (j + (packets_set_rem_array - delay) + n_p_pos) % CONGESTION_LAST_SENT_ARRAY_SIZE; total_sent += conn->last_num_packets_sent[ind]; total_resent += conn->last_num_packets_resent[ind]; } if (sum > 0) { total_sent -= sum; } else { if (total_resent > -sum) { total_resent = -sum; } } /* if queue is too big only allow resending packets. */ uint32_t npackets = num_packets_array(&conn->send_array); double min_speed = 1000.0 * (((double)(total_sent)) / ((double)(CONGESTION_QUEUE_ARRAY_SIZE) * PACKET_COUNTER_AVERAGE_INTERVAL)); double min_speed_request = 1000.0 * (((double)(total_sent + total_resent)) / ((double)( CONGESTION_QUEUE_ARRAY_SIZE) * PACKET_COUNTER_AVERAGE_INTERVAL)); if (min_speed < CRYPTO_PACKET_MIN_RATE) { min_speed = CRYPTO_PACKET_MIN_RATE; } double send_array_ratio = (((double)npackets) / min_speed); // TODO(irungentoo): Improve formula? if (send_array_ratio > SEND_QUEUE_RATIO && CRYPTO_MIN_QUEUE_LENGTH < npackets) { conn->packet_send_rate = min_speed * (1.0 / (send_array_ratio / SEND_QUEUE_RATIO)); } else if (conn->last_congestion_event + CONGESTION_EVENT_TIMEOUT < temp_time) { conn->packet_send_rate = min_speed * 1.2; } else { conn->packet_send_rate = min_speed * 0.9; } conn->packet_send_rate_requested = min_speed_request * 1.2; if (conn->packet_send_rate < CRYPTO_PACKET_MIN_RATE) { conn->packet_send_rate = CRYPTO_PACKET_MIN_RATE; } if (conn->packet_send_rate_requested < conn->packet_send_rate) { conn->packet_send_rate_requested = conn->packet_send_rate; } } } if (conn->last_packets_left_set == 0 || conn->last_packets_left_requested_set == 0) { conn->last_packets_left_requested_set = conn->last_packets_left_set = temp_time; conn->packets_left_requested = conn->packets_left = CRYPTO_MIN_QUEUE_LENGTH; } else { if (((uint64_t)((1000.0 / conn->packet_send_rate) + 0.5) + conn->last_packets_left_set) <= temp_time) { double n_packets = conn->packet_send_rate * (((double)(temp_time - conn->last_packets_left_set)) / 1000.0); n_packets += conn->last_packets_left_rem; uint32_t num_packets = n_packets; double rem = n_packets - (double)num_packets; if (conn->packets_left > num_packets * 4 + CRYPTO_MIN_QUEUE_LENGTH) { conn->packets_left = num_packets * 4 + CRYPTO_MIN_QUEUE_LENGTH; } else { conn->packets_left += num_packets; } conn->last_packets_left_set = temp_time; conn->last_packets_left_rem = rem; } if (((uint64_t)((1000.0 / conn->packet_send_rate_requested) + 0.5) + conn->last_packets_left_requested_set) <= temp_time) { double n_packets = conn->packet_send_rate_requested * (((double)(temp_time - conn->last_packets_left_requested_set)) / 1000.0); n_packets += conn->last_packets_left_requested_rem; uint32_t num_packets = n_packets; double rem = n_packets - (double)num_packets; conn->packets_left_requested = num_packets; conn->last_packets_left_requested_set = temp_time; conn->last_packets_left_requested_rem = rem; } if (conn->packets_left > conn->packets_left_requested) { conn->packets_left_requested = conn->packets_left; } } int ret = send_requested_packets(c, i, conn->packets_left_requested); if (ret != -1) { conn->packets_left_requested -= ret; conn->packets_resent += ret; if ((unsigned int)ret < conn->packets_left) { conn->packets_left -= ret; } else { conn->last_congestion_event = temp_time; conn->packets_left = 0; } } if (conn->packet_send_rate > CRYPTO_PACKET_MIN_RATE * 1.5) { total_send_rate += conn->packet_send_rate; } } } c->current_sleep_time = ~0; uint32_t sleep_time = peak_request_packet_interval; if (c->current_sleep_time > sleep_time) { c->current_sleep_time = sleep_time; } if (total_send_rate > CRYPTO_PACKET_MIN_RATE) { sleep_time = (1000.0 / total_send_rate); if (c->current_sleep_time > sleep_time) { c->current_sleep_time = sleep_time + 1; } } sleep_time = CRYPTO_SEND_PACKET_INTERVAL; if (c->current_sleep_time > sleep_time) { c->current_sleep_time = sleep_time; } } /* Return 1 if max speed was reached for this connection (no more data can be physically through the pipe). * Return 0 if it wasn't reached. */ bool max_speed_reached(Net_Crypto *c, int crypt_connection_id) { return reset_max_speed_reached(c, crypt_connection_id) != 0; } /* returns the number of packet slots left in the sendbuffer. * return 0 if failure. */ uint32_t crypto_num_free_sendqueue_slots(const Net_Crypto *c, int crypt_connection_id) { Crypto_Connection *conn = get_crypto_connection(c, crypt_connection_id); if (conn == 0) { return 0; } uint32_t max_packets = CRYPTO_PACKET_BUFFER_SIZE - num_packets_array(&conn->send_array); if (conn->packets_left < max_packets) { return conn->packets_left; } return max_packets; } /* Sends a lossless cryptopacket. * * return -1 if data could not be put in packet queue. * return positive packet number if data was put into the queue. * * congestion_control: should congestion control apply to this packet? */ int64_t write_cryptpacket(Net_Crypto *c, int crypt_connection_id, const uint8_t *data, uint16_t length, uint8_t congestion_control) { if (length == 0) { return -1; } if (data[0] < CRYPTO_RESERVED_PACKETS) { return -1; } if (data[0] >= PACKET_ID_LOSSY_RANGE_START) { return -1; } Crypto_Connection *conn = get_crypto_connection(c, crypt_connection_id); if (conn == 0) { return -1; } if (conn->status != CRYPTO_CONN_ESTABLISHED) { return -1; } if (congestion_control && conn->packets_left == 0) { return -1; } int64_t ret = send_lossless_packet(c, crypt_connection_id, data, length, congestion_control); if (ret == -1) { return -1; } if (congestion_control) { --conn->packets_left; --conn->packets_left_requested; conn->packets_sent++; } return ret; } /* Check if packet_number was received by the other side. * * packet_number must be a valid packet number of a packet sent on this connection. * * return -1 on failure. * return 0 on success. */ int cryptpacket_received(Net_Crypto *c, int crypt_connection_id, uint32_t packet_number) { Crypto_Connection *conn = get_crypto_connection(c, crypt_connection_id); if (conn == 0) { return -1; } uint32_t num = conn->send_array.buffer_end - conn->send_array.buffer_start; uint32_t num1 = packet_number - conn->send_array.buffer_start; if (num < num1) { return 0; } return -1; } /* return -1 on failure. * return 0 on success. * * Sends a lossy cryptopacket. (first byte must in the PACKET_ID_LOSSY_RANGE_*) */ int send_lossy_cryptpacket(Net_Crypto *c, int crypt_connection_id, const uint8_t *data, uint16_t length) { if (length == 0 || length > MAX_CRYPTO_DATA_SIZE) { return -1; } if (data[0] < PACKET_ID_LOSSY_RANGE_START) { return -1; } if (data[0] >= (PACKET_ID_LOSSY_RANGE_START + PACKET_ID_LOSSY_RANGE_SIZE)) { return -1; } pthread_mutex_lock(&c->connections_mutex); ++c->connection_use_counter; pthread_mutex_unlock(&c->connections_mutex); Crypto_Connection *conn = get_crypto_connection(c, crypt_connection_id); int ret = -1; if (conn) { pthread_mutex_lock(&conn->mutex); uint32_t buffer_start = conn->recv_array.buffer_start; uint32_t buffer_end = conn->send_array.buffer_end; pthread_mutex_unlock(&conn->mutex); ret = send_data_packet_helper(c, crypt_connection_id, buffer_start, buffer_end, data, length); } pthread_mutex_lock(&c->connections_mutex); --c->connection_use_counter; pthread_mutex_unlock(&c->connections_mutex); return ret; } /* Kill a crypto connection. * * return -1 on failure. * return 0 on success. */ int crypto_kill(Net_Crypto *c, int crypt_connection_id) { while (1) { /* TODO(irungentoo): is this really the best way to do this? */ pthread_mutex_lock(&c->connections_mutex); if (!c->connection_use_counter) { break; } pthread_mutex_unlock(&c->connections_mutex); } Crypto_Connection *conn = get_crypto_connection(c, crypt_connection_id); int ret = -1; if (conn) { if (conn->status == CRYPTO_CONN_ESTABLISHED) { send_kill_packet(c, crypt_connection_id); } pthread_mutex_lock(&c->tcp_mutex); kill_tcp_connection_to(c->tcp_c, conn->connection_number_tcp); pthread_mutex_unlock(&c->tcp_mutex); bs_list_remove(&c->ip_port_list, (uint8_t *)&conn->ip_portv4, crypt_connection_id); bs_list_remove(&c->ip_port_list, (uint8_t *)&conn->ip_portv6, crypt_connection_id); clear_temp_packet(c, crypt_connection_id); clear_buffer(&conn->send_array); clear_buffer(&conn->recv_array); ret = wipe_crypto_connection(c, crypt_connection_id); } pthread_mutex_unlock(&c->connections_mutex); return ret; } /* return one of CRYPTO_CONN_* values indicating the state of the connection. * * sets direct_connected to 1 if connection connects directly to other, 0 if it isn't. * sets online_tcp_relays to the number of connected tcp relays this connection has. */ unsigned int crypto_connection_status(const Net_Crypto *c, int crypt_connection_id, bool *direct_connected, unsigned int *online_tcp_relays) { Crypto_Connection *conn = get_crypto_connection(c, crypt_connection_id); if (conn == 0) { return CRYPTO_CONN_NO_CONNECTION; } if (direct_connected) { *direct_connected = 0; uint64_t current_time = unix_time(); if ((UDP_DIRECT_TIMEOUT + conn->direct_lastrecv_timev4) > current_time) { *direct_connected = 1; } if ((UDP_DIRECT_TIMEOUT + conn->direct_lastrecv_timev6) > current_time) { *direct_connected = 1; } } if (online_tcp_relays) { *online_tcp_relays = tcp_connection_to_online_tcp_relays(c->tcp_c, conn->connection_number_tcp); } return conn->status; } void new_keys(Net_Crypto *c) { crypto_box_keypair(c->self_public_key, c->self_secret_key); } /* Save the public and private keys to the keys array. * Length must be crypto_box_PUBLICKEYBYTES + crypto_box_SECRETKEYBYTES. * * TODO(irungentoo): Save only secret key. */ void save_keys(const Net_Crypto *c, uint8_t *keys) { memcpy(keys, c->self_public_key, crypto_box_PUBLICKEYBYTES); memcpy(keys + crypto_box_PUBLICKEYBYTES, c->self_secret_key, crypto_box_SECRETKEYBYTES); } /* Load the secret key. * Length must be crypto_box_SECRETKEYBYTES. */ void load_secret_key(Net_Crypto *c, const uint8_t *sk) { memcpy(c->self_secret_key, sk, crypto_box_SECRETKEYBYTES); crypto_scalarmult_curve25519_base(c->self_public_key, c->self_secret_key); } /* Run this to (re)initialize net_crypto. * Sets all the global connection variables to their default values. */ Net_Crypto *new_net_crypto(Logger *log, DHT *dht, TCP_Proxy_Info *proxy_info) { unix_time_update(); if (dht == NULL) { return NULL; } Net_Crypto *temp = (Net_Crypto *)calloc(1, sizeof(Net_Crypto)); if (temp == NULL) { return NULL; } temp->log = log; temp->tcp_c = new_tcp_connections(dht->self_secret_key, proxy_info); if (temp->tcp_c == NULL) { free(temp); return NULL; } set_packet_tcp_connection_callback(temp->tcp_c, &tcp_data_callback, temp); set_oob_packet_tcp_connection_callback(temp->tcp_c, &tcp_oob_callback, temp); if (create_recursive_mutex(&temp->tcp_mutex) != 0 || pthread_mutex_init(&temp->connections_mutex, NULL) != 0) { kill_tcp_connections(temp->tcp_c); free(temp); return NULL; } temp->dht = dht; new_keys(temp); new_symmetric_key(temp->secret_symmetric_key); temp->current_sleep_time = CRYPTO_SEND_PACKET_INTERVAL; networking_registerhandler(dht->net, NET_PACKET_COOKIE_REQUEST, &udp_handle_cookie_request, temp); networking_registerhandler(dht->net, NET_PACKET_COOKIE_RESPONSE, &udp_handle_packet, temp); networking_registerhandler(dht->net, NET_PACKET_CRYPTO_HS, &udp_handle_packet, temp); networking_registerhandler(dht->net, NET_PACKET_CRYPTO_DATA, &udp_handle_packet, temp); bs_list_init(&temp->ip_port_list, sizeof(IP_Port), 8); return temp; } static void kill_timedout(Net_Crypto *c, void *userdata) { uint32_t i; //uint64_t temp_time = current_time_monotonic(); for (i = 0; i < c->crypto_connections_length; ++i) { Crypto_Connection *conn = get_crypto_connection(c, i); if (conn == 0) { return; } if (conn->status == CRYPTO_CONN_NO_CONNECTION) { continue; } if (conn->status == CRYPTO_CONN_COOKIE_REQUESTING || conn->status == CRYPTO_CONN_HANDSHAKE_SENT || conn->status == CRYPTO_CONN_NOT_CONFIRMED) { if (conn->temp_packet_num_sent < MAX_NUM_SENDPACKET_TRIES) { continue; } connection_kill(c, i, userdata); } #if 0 if (conn->status == CRYPTO_CONN_ESTABLISHED) { // TODO(irungentoo): add a timeout here? } #endif } } /* return the optimal interval in ms for running do_net_crypto. */ uint32_t crypto_run_interval(const Net_Crypto *c) { return c->current_sleep_time; } /* Main loop. */ void do_net_crypto(Net_Crypto *c, void *userdata) { unix_time_update(); kill_timedout(c, userdata); do_tcp(c, userdata); send_crypto_packets(c); } void kill_net_crypto(Net_Crypto *c) { uint32_t i; for (i = 0; i < c->crypto_connections_length; ++i) { crypto_kill(c, i); } pthread_mutex_destroy(&c->tcp_mutex); pthread_mutex_destroy(&c->connections_mutex); kill_tcp_connections(c->tcp_c); bs_list_free(&c->ip_port_list); networking_registerhandler(c->dht->net, NET_PACKET_COOKIE_REQUEST, NULL, NULL); networking_registerhandler(c->dht->net, NET_PACKET_COOKIE_RESPONSE, NULL, NULL); networking_registerhandler(c->dht->net, NET_PACKET_CRYPTO_HS, NULL, NULL); networking_registerhandler(c->dht->net, NET_PACKET_CRYPTO_DATA, NULL, NULL); sodium_memzero(c, sizeof(Net_Crypto)); free(c); }