Blob
PrivateKey::decrypt(const Blob& cipher) const
{
if (!key)
throw CryptoException("Can't decrypt data without private key !");
unsigned key_len = 0;
int err = gnutls_privkey_get_pk_algorithm(key, &key_len);
if (err < 0)
throw CryptoException("Can't read public key length !");
if (err != GNUTLS_PK_RSA)
throw CryptoException("Must be an RSA key");
unsigned cypher_block_sz = key_len / 8;
if (cipher.size() % cypher_block_sz)
throw CryptoException("Unexpected cipher length");
Blob ret;
for (auto cb = cipher.cbegin(), ce = cipher.cend(); cb < ce; cb += cypher_block_sz) {
const gnutls_datum_t dat {(uint8_t*)(&(*cb)), cypher_block_sz};
gnutls_datum_t out;
int err = gnutls_privkey_decrypt_data(key, 0, &dat, &out);
if (err != GNUTLS_E_SUCCESS)
throw DhtException(std::string("Can't decrypt data: ") + gnutls_strerror(err));
ret.insert(ret.end(), out.data, out.data+out.size);
gnutls_free(out.data);
}
return ret;
}
DhtRunner::DhtRunner()
{
#ifdef _WIN32
WSADATA wsd;
if (WSAStartup(MAKEWORD(2,2), &wsd) != 0)
throw DhtException("Can't initialize Winsock2");
#endif
}
void
DhtRunner::doRun(const sockaddr_in* sin4, const sockaddr_in6* sin6, SecureDht::Config config)
{
dht_.reset();
int s4 = -1,
s6 = -1;
if (sin4) {
s4 = socket(PF_INET, SOCK_DGRAM, 0);
if(s4 >= 0) {
int rc = bind(s4, (sockaddr*)sin4, sizeof(sockaddr_in));
if(rc < 0)
throw DhtException("Can't bind IPv4 socket on " + dht::print_addr((sockaddr*)sin4, sizeof(sockaddr_in)));
}
}
#if 0
if (sin6) {
s6 = socket(PF_INET6, SOCK_DGRAM, 0);
if(s6 >= 0) {
int val = 1;
int rc = setsockopt(s6, IPPROTO_IPV6, IPV6_V6ONLY, (char *)&val, sizeof(val));
if(rc < 0)
throw DhtException("Can't set IPV6_V6ONLY");
rc = bind(s6, (sockaddr*)sin6, sizeof(sockaddr_in6));
if(rc < 0)
throw DhtException("Can't bind IPv6 socket on " + dht::print_addr((sockaddr*)sin6, sizeof(sockaddr_in6)));
}
}
#endif
dht_ = std::unique_ptr<SecureDht>(new SecureDht {s4, s6, config});
rcv_thread = std::thread([this,s4,s6]() {
try {
while (true) {
uint8_t buf[4096 * 64];
sockaddr_storage from;
socklen_t fromlen;
struct timeval tv {.tv_sec = 0, .tv_usec = 250000};
fd_set readfds;
FD_ZERO(&readfds);
if(s4 >= 0)
FD_SET(s4, &readfds);
if(s6 >= 0)
FD_SET(s6, &readfds);
int rc = select(s4 > s6 ? s4 + 1 : s6 + 1, &readfds, nullptr, nullptr, &tv);
if(rc < 0) {
if(errno != EINTR) {
perror("select");
std::this_thread::sleep_for( std::chrono::seconds(1) );
}
}
if(!running)
break;
if(rc > 0) {
fromlen = sizeof(from);
if(s4 >= 0 && FD_ISSET(s4, &readfds))
rc = recvfrom(s4, (char*)buf, sizeof(buf) - 1, 0, (struct sockaddr*)&from, &fromlen);
else if(s6 >= 0 && FD_ISSET(s6, &readfds))
rc = recvfrom(s6, (char*)buf, sizeof(buf) - 1, 0, (struct sockaddr*)&from, &fromlen);
else
break;
if (rc > 0) {
buf[rc] = 0;
{
std::lock_guard<std::mutex> lck(sock_mtx);
rcv.emplace_back(Blob {buf, buf+rc+1}, std::make_pair(from, fromlen));
}
cv.notify_all();
}
}
}
} catch (const std::exception& e) {
std::cerr << "Error int DHT networking thread: " << e.what() << std::endl;
}
if (s4 >= 0)
close(s4);
if (s6 >= 0)
close(s6);
});