/* net_crypto.h * * Functions for the core network crypto. * * 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 . * */ #ifndef NET_CRYPTO_H #define NET_CRYPTO_H #include "DHT.h" #include "TCP_client.h" #define CRYPTO_CONN_NO_CONNECTION 0 #define CRYPTO_CONN_COOKIE_REQUESTING 1 //send cookie request packets #define CRYPTO_CONN_HANDSHAKE_SENT 2 //send handshake packets #define CRYPTO_CONN_NOT_CONFIRMED 3 //send handshake packets #define CRYPTO_CONN_ESTABLISHED 4 #define CRYPTO_CONN_TIMED_OUT 5 #define CRYPTO_PACKET_BUFFER_SIZE 16384 /* Must be a power of 2 */ /* Minimum packet rate per second. */ #define CRYPTO_PACKET_MIN_RATE 8.0 /* Minimum packet queue max length. */ #define CRYPTO_MIN_QUEUE_LENGTH 8 #define MAX_CRYPTO_PACKET_SIZE 1400 #define CRYPTO_DATA_PACKET_MIN_SIZE (1 + sizeof(uint16_t) + (sizeof(uint32_t) + sizeof(uint32_t)) + crypto_box_MACBYTES) /* Max size of data in packets TODO*/ #define MAX_CRYPTO_DATA_SIZE (MAX_CRYPTO_PACKET_SIZE - CRYPTO_DATA_PACKET_MIN_SIZE) /* Interval in ms between sending cookie request/handshake packets. */ #define CRYPTO_SEND_PACKET_INTERVAL 500 /* The maximum number of times we try to send the cookie request and handshake before giving up. */ #define MAX_NUM_SENDPACKET_TRIES 8 /* The timeout of no recieved UDP packets before the direct UDP connection is considered dead. */ #define UDP_DIRECT_TIMEOUT (MAX_NUM_SENDPACKET_TRIES * CRYPTO_SEND_PACKET_INTERVAL * 2) #define PACKET_ID_PADDING 0 #define PACKET_ID_REQUEST 1 #define PACKET_ID_KILL 2 #define CRYPTO_RESERVED_PACKETS 16 #define MAX_TCP_CONNECTIONS 32 #define MAX_TCP_RELAYS_PEER 4 #define STATUS_TCP_NULL 0 #define STATUS_TCP_OFFLINE 1 #define STATUS_TCP_INVISIBLE 2 /* we know the other peer is connected to this relay but he isn't appearing online */ #define STATUS_TCP_ONLINE 3 /* All packets starting with a byte in this range are considered lossy packets. */ #define PACKET_ID_LOSSY_RANGE_START 192 #define PACKET_ID_LOSSY_RANGE_SIZE 63 #define CRYPTO_MAX_PADDING 8 /* All packets will be padded a number of bytes based on this number. */ typedef struct { uint64_t time; uint16_t length; uint8_t data[MAX_CRYPTO_DATA_SIZE]; } Packet_Data; typedef struct { Packet_Data *buffer[CRYPTO_PACKET_BUFFER_SIZE]; uint32_t buffer_start; uint32_t buffer_end; /* packet numbers in array: {buffer_start, buffer_end) */ } Packets_Array; typedef struct { uint8_t public_key[crypto_box_PUBLICKEYBYTES]; /* The real public key of the peer. */ uint8_t recv_nonce[crypto_box_NONCEBYTES]; /* Nonce of received packets. */ uint8_t sent_nonce[crypto_box_NONCEBYTES]; /* Nonce of sent packets. */ uint8_t sessionpublic_key[crypto_box_PUBLICKEYBYTES]; /* Our public key for this session. */ uint8_t sessionsecret_key[crypto_box_SECRETKEYBYTES]; /* Our private key for this session. */ uint8_t peersessionpublic_key[crypto_box_PUBLICKEYBYTES]; /* The public key of the peer. */ uint8_t shared_key[crypto_box_BEFORENMBYTES]; /* The precomputed shared key from encrypt_precompute. */ uint8_t status; /* 0 if no connection, 1 we are sending cookie request packets, * 2 if we are sending handshake packets * 3 if connection is not confirmed yet (we have received a handshake but no data packets yet), * 4 if the connection is established. * 5 if the connection is timed out. */ uint64_t cookie_request_number; /* number used in the cookie request packets for this connection */ uint8_t dht_public_key[crypto_box_PUBLICKEYBYTES]; /* The dht public key of the peer */ uint8_t dht_public_key_set; /* True if the dht public key is set, false if it isn't. */ uint64_t dht_public_key_timestamp; /* Timestamp of the last time we confirmed the key was correct. */ uint8_t *temp_packet; /* Where the cookie request/handshake packet is stored while it is being sent. */ uint16_t temp_packet_length; uint64_t temp_packet_sent_time; /* The time at which the last temp_packet was sent in ms. */ uint32_t temp_packet_num_sent; IP_Port ip_port; /* The ip and port to contact this guy directly.*/ uint64_t direct_lastrecv_time; /* The Time at which we last received a direct packet in ms. */ Packets_Array send_array; Packets_Array recv_array; int (*connection_status_callback)(void *object, int id, uint8_t status); void *connection_status_callback_object; int connection_status_callback_id; int (*connection_data_callback)(void *object, int id, uint8_t *data, uint16_t length); void *connection_data_callback_object; int connection_data_callback_id; int (*connection_lossy_data_callback)(void *object, int id, uint8_t *data, uint16_t length); void *connection_lossy_data_callback_object; int connection_lossy_data_callback_id; uint64_t last_request_packet_sent; uint32_t packet_counter; double packet_recv_rate; uint64_t packet_counter_set; double packet_send_rate; uint32_t packets_left; uint64_t last_packets_left_set; double dropped, drop_ignore, rate_increase; uint64_t drop_ignore_start, rate_increase_stop_start; uint32_t packets_resent; uint8_t sending; /* indicates if data is being sent or not. */ uint8_t killed; /* set to 1 to kill the connection. */ uint8_t status_tcp[MAX_TCP_CONNECTIONS]; /* set to one of STATUS_TCP_* */ uint8_t con_number_tcp[MAX_TCP_CONNECTIONS]; Node_format tcp_relays[MAX_TCP_RELAYS_PEER]; uint16_t num_tcp_relays; } Crypto_Connection; typedef struct { IP_Port source; uint8_t public_key[crypto_box_PUBLICKEYBYTES]; /* The real public key of the peer. */ uint8_t dht_public_key[crypto_box_PUBLICKEYBYTES]; /* The dht public key of the peer. */ uint8_t recv_nonce[crypto_box_NONCEBYTES]; /* Nonce of received packets. */ uint8_t peersessionpublic_key[crypto_box_PUBLICKEYBYTES]; /* The public key of the peer. */ uint8_t *cookie; uint8_t cookie_length; } New_Connection; typedef struct { DHT *dht; Crypto_Connection *crypto_connections; TCP_Client_Connection *tcp_connections_new[MAX_TCP_CONNECTIONS]; TCP_Client_Connection *tcp_connections[MAX_TCP_CONNECTIONS]; uint32_t crypto_connections_length; /* Length of connections array. */ /* Our public and secret keys. */ uint8_t self_public_key[crypto_box_PUBLICKEYBYTES]; uint8_t self_secret_key[crypto_box_SECRETKEYBYTES]; /* The secret key used for cookies */ uint8_t secret_symmetric_key[crypto_box_KEYBYTES]; int (*new_connection_callback)(void *object, New_Connection *n_c); void *new_connection_callback_object; /* The current optimal sleep time */ uint32_t current_sleep_time; } Net_Crypto; /* 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); /* Accept a crypto connection. * * return -1 on failure. * return connection id on success. */ int accept_crypto_connection(Net_Crypto *c, New_Connection *n_c); /* 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, uint8_t *real_public_key); /* Copy friends DHT public key into dht_key. * * return 0 on failure (no key copied). * return timestamp on success (key copied). */ uint64_t get_connection_dht_key(Net_Crypto *c, int crypt_connection_id, uint8_t *dht_public_key); /* Set the DHT public key of the crypto connection. * timestamp is the time (current_time_monotonic()) at which the key was last confirmed belonging to * the other peer. * * return -1 on failure. * return 0 on success. */ int set_connection_dht_public_key(Net_Crypto *c, int crypt_connection_id, uint8_t *dht_public_key, uint64_t timestamp); /* Set the direct ip of the crypto connection. * * return -1 on failure. * return 0 on success. */ int set_direct_ip_port(Net_Crypto *c, int crypt_connection_id, IP_Port ip_port); /* 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(Net_Crypto *c, int crypt_connection_id, int (*connection_status_callback)(void *object, int id, uint8_t status), void *object, int id); /* Set function to be called when connection with crypt_connection_id receives a lossless 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(Net_Crypto *c, int crypt_connection_id, int (*connection_data_callback)(void *object, int id, uint8_t *data, uint16_t length), void *object, int id); /* 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, uint8_t *data, uint16_t length), void *object, int id); /* returns the number of packet slots left in the sendbuffer. * return 0 if failure. */ uint32_t crypto_num_free_sendqueue_slots(Net_Crypto *c, int crypt_connection_id); /* 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. * * The first byte of data must be in the CRYPTO_RESERVED_PACKETS to PACKET_ID_LOSSY_RANGE_START range. */ int64_t write_cryptpacket(Net_Crypto *c, int crypt_connection_id, uint8_t *data, uint32_t length); /* 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, uint8_t *data, uint32_t length); /* 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, uint8_t *public_key); /* 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, uint8_t *public_key); /* 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); /* Kill a crypto connection. * * return -1 on failure. * return 0 on success. */ int crypto_kill(Net_Crypto *c, int crypt_connection_id); /* 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. */ unsigned int crypto_connection_status(Net_Crypto *c, int crypt_connection_id, uint8_t *direct_connected); /* Generate our public and private keys. * Only call this function the first time the program starts. */ void new_keys(Net_Crypto *c); /* Save the public and private keys to the keys array. * Length must be crypto_box_PUBLICKEYBYTES + crypto_box_SECRETKEYBYTES. */ void save_keys(Net_Crypto *c, uint8_t *keys); /* Load the public and private keys from the keys array. * Length must be crypto_box_PUBLICKEYBYTES + crypto_box_SECRETKEYBYTES. */ void load_keys(Net_Crypto *c, uint8_t *keys); /* Create new instance of Net_Crypto. * Sets all the global connection variables to their default values. */ Net_Crypto *new_net_crypto(DHT *dht); /* return the optimal interval in ms for running do_net_crypto. */ uint32_t crypto_run_interval(Net_Crypto *c); /* Main loop. */ void do_net_crypto(Net_Crypto *c); void kill_net_crypto(Net_Crypto *c); #endif