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handle RelayResponse

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orignal 2022-04-26 13:59:59 -04:00
parent eb6437050f
commit 40340cf9c2
2 changed files with 48 additions and 25 deletions
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65
libi2pd/SSU2.cpp
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@ -823,6 +823,8 @@ namespace transport
HandleRelayRequest (buf + offset, size);
break;
case eSSU2BlkRelayResponse:
LogPrint (eLogDebug, "SSU2: RelayResponse");
HandleRelayResponse (buf + offset, size);
break;
case eSSU2BlkRelayIntro:
break;
@ -1023,19 +1025,9 @@ namespace transport
LogPrint (eLogWarning, "SSU2: Session with relay tag ", relayTag, " not found");
return; // TODO: send relay response
}
SignedData s;
s.Insert ((const uint8_t *)"RelayRequestData", 16); // prologue
s.Insert (i2p::context.GetIdentHash (), 32); // bhash
s.Insert (session->GetRemoteIdentity ()->GetIdentHash (), 32); // chash
s.Insert (buf + 1, 14); // nonce, relay tag, timestamp, ver, asz
uint8_t asz = buf[14];
s.Insert (buf + 15, asz); // Alice Port, Alice IP
if (!s.Verify (GetRemoteIdentity (), buf + 15 + asz))
{
LogPrint (eLogWarning, "SSU2: RelayRequest signature verification failed");
return; // TODO: send relay response
}
session->m_RelaySessions.emplace (bufbe32toh (buf + 1), // nonce
std::make_pair (shared_from_this (), i2p::util::GetSecondsSinceEpoch ()) );
// send relay intro to Charlie
uint8_t payload[SSU2_MTU];
size_t payloadSize = CreateRelayIntroBlock (payload, SSU2_MTU, buf + 1, len -1);
@ -1067,7 +1059,7 @@ namespace transport
// send relay response to Bob
uint8_t payload[SSU2_MTU];
size_t payloadSize = CreateRelayResponseBlock (payload, SSU2_MTU, bufbe32toh (buf + 33), bufbe32toh (buf + 37));
size_t payloadSize = CreateRelayResponseBlock (payload, SSU2_MTU, bufbe32toh (buf + 33));
payloadSize += CreatePaddingBlock (payload + payloadSize, SSU2_MTU - payloadSize);
SendData (payload, payloadSize);
@ -1076,6 +1068,24 @@ namespace transport
if (ExtractEndpoint (buf + 47, asz, ep))
m_Server.SendHolePunch (ep);
}
void SSU2Session::HandleRelayResponse (const uint8_t * buf, size_t len)
{
auto it = m_RelaySessions.find (bufbe32toh (buf + 2)); // nonce
if (it != m_RelaySessions.end ())
{
if (it->second.first && it->second.first->IsEstablished ())
// we are Bob, message from Charlie
it->second.first->SendData (buf, len); // forward to Alice as is
else
{
// we are Alice, message from Bob
}
m_RelaySessions.erase (it);
}
else
LogPrint (eLogWarning, "SSU2: RelayResponse unknown nonce ", bufbe32toh (buf + 2));
}
bool SSU2Session::ExtractEndpoint (const uint8_t * buf, size_t size, boost::asio::ip::udp::endpoint& ep)
{
@ -1261,25 +1271,24 @@ namespace transport
return payloadSize + 3;
}
size_t SSU2Session::CreateRelayResponseBlock (uint8_t * buf, size_t len, uint32_t nonce, uint32_t relayTag)
size_t SSU2Session::CreateRelayResponseBlock (uint8_t * buf, size_t len, uint32_t nonce)
{
buf[0] = eSSU2BlkRelayResponse;
buf[3] = 0; // flag
buf[4] = 0; // code, accept
htobe32buf (buf + 5, nonce); // nonce
htobe32buf (buf + 9, relayTag); // relayTag
htobe32buf (buf + 13, i2p::util::GetSecondsSinceEpoch ()); // timestamp
buf[17] = 2; // ver
size_t csz = CreateEndpoint (buf + 19, len - 19, boost::asio::ip::udp::endpoint (m_Address->host, m_Address->port));
htobe32buf (buf + 9, i2p::util::GetSecondsSinceEpoch ()); // timestamp
buf[13] = 2; // ver
size_t csz = CreateEndpoint (buf + 15, len - 15, boost::asio::ip::udp::endpoint (m_Address->host, m_Address->port));
if (!csz) return 0;
buf[18] = csz; // csz
buf[14] = csz; // csz
// signature
SignedData s;
s.Insert ((const uint8_t *)"RelayAgreementOK", 16); // prologue
s.Insert (GetRemoteIdentity ()->GetIdentHash (), 32); // bhash
s.Insert (buf + 9, 10 + csz); // relay tag, timestamp, ver, csz and Charlie's endpoint
s.Sign (i2p::context.GetPrivateKeys (), buf + 19 + csz);
size_t payloadSize = 16 + csz + i2p::context.GetIdentity ()->GetSignatureLen ();
s.Insert (buf + 5, 10 + csz); // nonce, timestamp, ver, csz and Charlie's endpoint
s.Sign (i2p::context.GetPrivateKeys (), buf + 15 + csz);
size_t payloadSize = 12 + csz + i2p::context.GetIdentity ()->GetSignatureLen ();
htobe16buf (buf + 1, payloadSize); // size
return payloadSize + 3;
}
@ -1368,6 +1377,16 @@ namespace transport
m_ReceivePacketNum = *m_OutOfSequencePackets.rbegin ();
m_OutOfSequencePackets.clear ();
}
for (auto it = m_RelaySessions.begin (); it != m_RelaySessions.end ();)
{
if (ts > it->second.second + SSU2_RELAY_NONCE_EXPIRATION_TIMEOUT)
{
LogPrint (eLogWarning, "SSU2: noce ", it->first, " was not responded in ", SSU2_RELAY_NONCE_EXPIRATION_TIMEOUT, " seconds, deleted");
it = m_RelaySessions.erase (it);
}
else
++it;
}
}
void SSU2Session::FlushData ()