/* handle received packets for not yet established crypto connections. */
static void receive_crypto(void)
{
uint32_t i;
for (i = 0; i < MAX_CRYPTO_CONNECTIONS; ++i) {
if (crypto_connections[i].status == CONN_HANDSHAKE_SENT) {
uint8_t temp_data[MAX_DATA_SIZE];
uint8_t secret_nonce[crypto_box_NONCEBYTES];
uint8_t public_key[crypto_box_PUBLICKEYBYTES];
uint8_t session_key[crypto_box_PUBLICKEYBYTES];
uint16_t len;
if (id_packet(crypto_connections[i].number) == 1)
/* if the packet is a friend request drop it (because we are already friends) */
len = read_packet(crypto_connections[i].number, temp_data);
if (id_packet(crypto_connections[i].number) == 2) { /* handle handshake packet. */
len = read_packet(crypto_connections[i].number, temp_data);
if (handle_cryptohandshake(public_key, secret_nonce, session_key, temp_data, len)) {
if (memcmp(public_key, crypto_connections[i].public_key, crypto_box_PUBLICKEYBYTES) == 0) {
memcpy(crypto_connections[i].sent_nonce, secret_nonce, crypto_box_NONCEBYTES);
memcpy(crypto_connections[i].peersessionpublic_key, session_key, crypto_box_PUBLICKEYBYTES);
increment_nonce(crypto_connections[i].sent_nonce);
uint32_t zero = 0;
encrypt_precompute(crypto_connections[i].peersessionpublic_key,
crypto_connections[i].sessionsecret_key,
crypto_connections[i].shared_key);
crypto_connections[i].status = CONN_ESTABLISHED; /* connection status needs to be 3 for write_cryptpacket() to work */
write_cryptpacket(i, ((uint8_t *)&zero), sizeof(zero));
crypto_connections[i].status = CONN_NOT_CONFIRMED; /* set it to its proper value right after. */
}
}
} else if (id_packet(crypto_connections[i].number) != -1) // This should not happen kill the connection if it does
crypto_kill(crypto_connections[i].number);
}
if (crypto_connections[i].status == CONN_NOT_CONFIRMED) {
if (id_packet(crypto_connections[i].number) == 3) {
uint8_t temp_data[MAX_DATA_SIZE];
uint8_t data[MAX_DATA_SIZE];
int length = read_packet(crypto_connections[i].number, temp_data);
int len = decrypt_data(crypto_connections[i].peersessionpublic_key,
crypto_connections[i].sessionsecret_key,
crypto_connections[i].recv_nonce, temp_data + 1, length - 1, data);
uint32_t zero = 0;
if (len == sizeof(uint32_t) && memcmp(((uint8_t *)&zero), data, sizeof(uint32_t)) == 0) {
increment_nonce(crypto_connections[i].recv_nonce);
encrypt_precompute(crypto_connections[i].peersessionpublic_key,
crypto_connections[i].sessionsecret_key,
crypto_connections[i].shared_key);
crypto_connections[i].status = CONN_ESTABLISHED;
/* connection is accepted so we disable the auto kill by setting it to about 1 month from now. */
kill_connection_in(crypto_connections[i].number, 3000000);
} else
crypto_kill(crypto_connections[i].number); // This should not happen kill the connection if it does
} else if(id_packet(crypto_connections[i].number) != -1)
/* This should not happen
kill the connection if it does */
crypto_kill(crypto_connections[i].number);
}
}
}
int main(int argc, char *argv[])
{
if (argc < 2) {
printf("usage: %s filename\n", argv[0]);
exit(0);
}
uint8_t buffer[512];
int read;
FILE *file = fopen(argv[1], "wb");
if (file == NULL)
return 1;
//initialize networking
//bind to ip 0.0.0.0:PORT
IP ip;
ip.i = 0;
init_networking(ip, PORT);
perror("Initialization");
int connection;
uint64_t timer = current_time();
while (1) {
Lossless_UDP();
connection = incoming_connection();
if(connection != -1) {
if(is_connected(connection) == 2) {
printf("Recieved the connection.\n");
}
break;
}
c_sleep(1);
}
timer = current_time();
while (1) {
//printconnection(0);
Lossless_UDP();
if (is_connected(connection) >= 2) {
kill_connection_in(connection, 3000000);
read = read_packet(connection, buffer);
if (read != 0) {
// printf("Recieved data.\n");
if (!fwrite(buffer, read, 1, file))
printf("file write error\n");
}
}
if(is_connected(connection) == 4) {
printf("Connecting Lost after: %llu us\n", (unsigned long long)(current_time() - timer));
fclose(file);
return 1;
}
c_sleep(1);
}
return 0;
}
/* Handle received packets for not yet established crypto connections. */
static void receive_crypto(Net_Crypto *c)
{
uint32_t i;
for (i = 0; i < c->crypto_connections_length; ++i) {
if (c->crypto_connections[i].status == CONN_HANDSHAKE_SENT) {
uint8_t temp_data[MAX_DATA_SIZE];
uint8_t secret_nonce[crypto_box_NONCEBYTES];
uint8_t public_key[crypto_box_PUBLICKEYBYTES];
uint8_t session_key[crypto_box_PUBLICKEYBYTES];
uint16_t len;
if (id_packet(c->lossless_udp, c->crypto_connections[i].number) == 2) { /* Handle handshake packet. */
len = read_packet(c->lossless_udp, c->crypto_connections[i].number, temp_data);
if (handle_cryptohandshake(c, public_key, secret_nonce, session_key, temp_data, len)) {
if (memcmp(public_key, c->crypto_connections[i].public_key, crypto_box_PUBLICKEYBYTES) == 0) {
memcpy(c->crypto_connections[i].sent_nonce, secret_nonce, crypto_box_NONCEBYTES);
memcpy(c->crypto_connections[i].peersessionpublic_key, session_key, crypto_box_PUBLICKEYBYTES);
increment_nonce(c->crypto_connections[i].sent_nonce);
uint32_t zero = 0;
encrypt_precompute(c->crypto_connections[i].peersessionpublic_key,
c->crypto_connections[i].sessionsecret_key,
c->crypto_connections[i].shared_key);
c->crypto_connections[i].status =
CONN_ESTABLISHED; /* Connection status needs to be 3 for write_cryptpacket() to work. */
write_cryptpacket(c, i, ((uint8_t *)&zero), sizeof(zero));
c->crypto_connections[i].status = CONN_NOT_CONFIRMED; /* Set it to its proper value right after. */
}
}
} else if (id_packet(c->lossless_udp,
c->crypto_connections[i].number) != -1) { // This should not happen, kill the connection if it does.
crypto_kill(c, i);
return;
}
}
if (c->crypto_connections[i].status == CONN_NOT_CONFIRMED) {
if (id_packet(c->lossless_udp, c->crypto_connections[i].number) == 3) {
uint8_t temp_data[MAX_DATA_SIZE];
uint8_t data[MAX_DATA_SIZE];
int length = read_packet(c->lossless_udp, c->crypto_connections[i].number, temp_data);
int len = decrypt_data(c->crypto_connections[i].peersessionpublic_key,
c->crypto_connections[i].sessionsecret_key,
c->crypto_connections[i].recv_nonce, temp_data + 1, length - 1, data);
uint32_t zero = 0;
if (len == sizeof(uint32_t) && memcmp(((uint8_t *)&zero), data, sizeof(uint32_t)) == 0) {
increment_nonce(c->crypto_connections[i].recv_nonce);
encrypt_precompute(c->crypto_connections[i].peersessionpublic_key,
c->crypto_connections[i].sessionsecret_key,
c->crypto_connections[i].shared_key);
c->crypto_connections[i].status = CONN_ESTABLISHED;
/* Connection is accepted so we disable the auto kill by setting it to about 1 month from now. */
kill_connection_in(c->lossless_udp, c->crypto_connections[i].number, 3000000);
} else {
/* This should not happen, kill the connection if it does. */
crypto_kill(c, i);
return;
}
} else if (id_packet(c->lossless_udp, c->crypto_connections[i].number) != -1)
/* This should not happen, kill the connection if it does. */
crypto_kill(c, i);
return;
}
}
}