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I2P: End-to-End encrypted and anonymous Internet
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2855 lines
100 KiB
2855 lines
100 KiB
/* |
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* Copyright (c) 2023, The PurpleI2P Project |
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* |
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* This file is part of Purple i2pd project and licensed under BSD3 |
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* |
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* See full license text in LICENSE file at top of project tree |
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*/ |
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#include <string.h> |
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#include <openssl/rand.h> |
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#include "Log.h" |
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#include "Transports.h" |
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#include "Gzip.h" |
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#include "NetDb.hpp" |
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#include "SSU2.h" |
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namespace i2p |
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{ |
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namespace transport |
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{ |
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void SSU2IncompleteMessage::AttachNextFragment (const uint8_t * fragment, size_t fragmentSize) |
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{ |
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if (msg->len + fragmentSize > msg->maxLen) |
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{ |
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LogPrint (eLogInfo, "SSU2: I2NP message size ", msg->maxLen, " is not enough"); |
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auto newMsg = NewI2NPMessage (); |
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*newMsg = *msg; |
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msg = newMsg; |
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} |
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if (msg->Concat (fragment, fragmentSize) < fragmentSize) |
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LogPrint (eLogError, "SSU2: I2NP buffer overflow ", msg->maxLen); |
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nextFragmentNum++; |
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} |
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SSU2Session::SSU2Session (SSU2Server& server, std::shared_ptr<const i2p::data::RouterInfo> in_RemoteRouter, |
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std::shared_ptr<const i2p::data::RouterInfo::Address> addr): |
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TransportSession (in_RemoteRouter, SSU2_CONNECT_TIMEOUT), |
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m_Server (server), m_Address (addr), m_RemoteTransports (0), |
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m_DestConnID (0), m_SourceConnID (0), m_State (eSSU2SessionStateUnknown), |
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m_SendPacketNum (0), m_ReceivePacketNum (0), m_IsDataReceived (false), |
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m_WindowSize (SSU2_MIN_WINDOW_SIZE), m_RTT (SSU2_RESEND_INTERVAL), |
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m_RTO (SSU2_RESEND_INTERVAL*SSU2_kAPPA), m_RelayTag (0), |
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m_ConnectTimer (server.GetService ()), m_TerminationReason (eSSU2TerminationReasonNormalClose), |
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m_MaxPayloadSize (SSU2_MIN_PACKET_SIZE - IPV6_HEADER_SIZE - UDP_HEADER_SIZE - 32) // min size |
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{ |
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m_NoiseState.reset (new i2p::crypto::NoiseSymmetricState); |
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if (in_RemoteRouter && m_Address) |
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{ |
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// outgoing |
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InitNoiseXKState1 (*m_NoiseState, m_Address->s); |
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m_RemoteEndpoint = boost::asio::ip::udp::endpoint (m_Address->host, m_Address->port); |
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m_RemoteTransports = in_RemoteRouter->GetCompatibleTransports (false); |
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RAND_bytes ((uint8_t *)&m_DestConnID, 8); |
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RAND_bytes ((uint8_t *)&m_SourceConnID, 8); |
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} |
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else |
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{ |
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// incoming |
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InitNoiseXKState1 (*m_NoiseState, i2p::context.GetSSU2StaticPublicKey ()); |
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} |
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} |
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SSU2Session::~SSU2Session () |
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{ |
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} |
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void SSU2Session::Connect () |
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{ |
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if (m_State == eSSU2SessionStateUnknown || m_State == eSSU2SessionStateTokenReceived) |
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{ |
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ScheduleConnectTimer (); |
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auto token = m_Server.FindOutgoingToken (m_RemoteEndpoint); |
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if (token) |
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SendSessionRequest (token); |
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else |
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{ |
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m_State = eSSU2SessionStateUnknown; |
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SendTokenRequest (); |
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} |
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} |
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} |
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void SSU2Session::ScheduleConnectTimer () |
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{ |
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m_ConnectTimer.cancel (); |
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m_ConnectTimer.expires_from_now (boost::posix_time::seconds(SSU2_CONNECT_TIMEOUT)); |
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m_ConnectTimer.async_wait (std::bind (&SSU2Session::HandleConnectTimer, |
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shared_from_this (), std::placeholders::_1)); |
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} |
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void SSU2Session::HandleConnectTimer (const boost::system::error_code& ecode) |
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{ |
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if (!ecode) |
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{ |
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// timeout expired |
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if (m_State == eSSU2SessionStateIntroduced) // WaitForIntroducer |
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LogPrint (eLogWarning, "SSU2: Session was not introduced after ", SSU2_CONNECT_TIMEOUT, " seconds"); |
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else |
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LogPrint (eLogWarning, "SSU2: Session with ", m_RemoteEndpoint, " was not established after ", SSU2_CONNECT_TIMEOUT, " seconds"); |
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Terminate (); |
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} |
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} |
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bool SSU2Session::Introduce (std::shared_ptr<SSU2Session> session, uint32_t relayTag) |
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{ |
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// we are Alice |
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if (!session || !relayTag) return false; |
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// find local address to introduce |
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auto localAddress = session->FindLocalAddress (); |
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if (!localAddress) return false; |
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// create nonce |
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uint32_t nonce; |
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RAND_bytes ((uint8_t *)&nonce, 4); |
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auto ts = i2p::util::GetSecondsSinceEpoch (); |
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// payload |
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uint8_t payload[SSU2_MAX_PACKET_SIZE]; |
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size_t payloadSize = 0; |
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payload[0] = eSSU2BlkRelayRequest; |
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payload[3] = 0; // flag |
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htobe32buf (payload + 4, nonce); |
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htobe32buf (payload + 8, relayTag); |
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htobe32buf (payload + 12, ts); |
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payload[16] = 2; // ver |
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size_t asz = CreateEndpoint (payload + 18, m_MaxPayloadSize - 18, boost::asio::ip::udp::endpoint (localAddress->host, localAddress->port)); |
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if (!asz) return false; |
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payload[17] = asz; |
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payloadSize += asz + 18; |
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SignedData s; |
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s.Insert ((const uint8_t *)"RelayRequestData", 16); // prologue |
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s.Insert (GetRemoteIdentity ()->GetIdentHash (), 32); // bhash |
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s.Insert (session->GetRemoteIdentity ()->GetIdentHash (), 32); // chash |
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s.Insert (payload + 4, 14 + asz); // nonce, relay tag, timestamp, ver, asz and Alice's endpoint |
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s.Sign (i2p::context.GetPrivateKeys (), payload + payloadSize); |
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payloadSize += i2p::context.GetIdentity ()->GetSignatureLen (); |
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htobe16buf (payload + 1, payloadSize - 3); // size |
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payloadSize += CreatePaddingBlock (payload + payloadSize, m_MaxPayloadSize - payloadSize); |
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// send |
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m_RelaySessions.emplace (nonce, std::make_pair (session, ts)); |
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session->m_SourceConnID = htobe64 (((uint64_t)nonce << 32) | nonce); |
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session->m_DestConnID = ~session->m_SourceConnID; |
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m_Server.AddSession (session); |
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SendData (payload, payloadSize); |
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return true; |
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} |
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void SSU2Session::WaitForIntroduction () |
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{ |
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m_State = eSSU2SessionStateIntroduced; |
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ScheduleConnectTimer (); |
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} |
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void SSU2Session::ConnectAfterIntroduction () |
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{ |
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if (m_State == eSSU2SessionStateIntroduced) |
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{ |
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// create new connID |
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uint64_t oldConnID = GetConnID (); |
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RAND_bytes ((uint8_t *)&m_DestConnID, 8); |
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RAND_bytes ((uint8_t *)&m_SourceConnID, 8); |
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// connect |
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m_State = eSSU2SessionStateTokenReceived; |
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m_Server.AddPendingOutgoingSession (shared_from_this ()); |
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m_Server.RemoveSession (oldConnID); |
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Connect (); |
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} |
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} |
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void SSU2Session::SendPeerTest () |
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{ |
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// we are Alice |
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uint32_t nonce; |
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RAND_bytes ((uint8_t *)&nonce, 4); |
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auto ts = i2p::util::GetMillisecondsSinceEpoch (); |
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// session for message 5 |
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auto session = std::make_shared<SSU2Session> (m_Server); |
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session->SetState (eSSU2SessionStatePeerTest); |
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m_PeerTests.emplace (nonce, std::make_pair (session, ts/1000)); |
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session->m_SourceConnID = htobe64 (((uint64_t)nonce << 32) | nonce); |
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session->m_DestConnID = ~session->m_SourceConnID; |
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m_Server.AddSession (session); |
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// peer test block |
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auto packet = m_Server.GetSentPacketsPool ().AcquireShared (); |
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packet->payloadSize = CreatePeerTestBlock (packet->payload, m_MaxPayloadSize, nonce); |
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if (packet->payloadSize > 0) |
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{ |
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packet->payloadSize += CreatePaddingBlock (packet->payload + packet->payloadSize, m_MaxPayloadSize - packet->payloadSize); |
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uint32_t packetNum = SendData (packet->payload, packet->payloadSize, SSU2_FLAG_IMMEDIATE_ACK_REQUESTED); |
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packet->sendTime = ts; |
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m_SentPackets.emplace (packetNum, packet); |
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LogPrint (eLogDebug, "SSU2: PeerTest msg=1 sent to ", i2p::data::GetIdentHashAbbreviation (GetRemoteIdentity ()->GetIdentHash ())); |
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} |
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} |
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void SSU2Session::SendKeepAlive () |
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{ |
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if (IsEstablished ()) |
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{ |
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uint8_t payload[20]; |
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size_t payloadSize = CreatePaddingBlock (payload, 20, 5); |
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SendData (payload, payloadSize); |
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} |
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} |
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void SSU2Session::Terminate () |
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{ |
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if (m_State != eSSU2SessionStateTerminated) |
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{ |
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m_State = eSSU2SessionStateTerminated; |
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m_ConnectTimer.cancel (); |
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m_OnEstablished = nullptr; |
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if (m_RelayTag) |
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m_Server.RemoveRelay (m_RelayTag); |
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m_SentHandshakePacket.reset (nullptr); |
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m_SessionConfirmedFragment.reset (nullptr); |
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m_PathChallenge.reset (nullptr); |
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m_SendQueue.clear (); |
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m_SendQueueSize = 0; |
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m_SentPackets.clear (); |
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m_IncompleteMessages.clear (); |
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m_RelaySessions.clear (); |
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m_PeerTests.clear (); |
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m_Server.RemoveSession (m_SourceConnID); |
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transports.PeerDisconnected (shared_from_this ()); |
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LogPrint (eLogDebug, "SSU2: Session terminated"); |
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} |
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} |
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void SSU2Session::RequestTermination (SSU2TerminationReason reason) |
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{ |
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if (m_State == eSSU2SessionStateEstablished || m_State == eSSU2SessionStateClosing) |
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{ |
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m_TerminationReason = reason; |
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SendTermination (); |
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} |
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m_State = eSSU2SessionStateClosing; |
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} |
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void SSU2Session::Established () |
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{ |
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m_State = eSSU2SessionStateEstablished; |
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m_EphemeralKeys = nullptr; |
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m_NoiseState.reset (nullptr); |
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m_SessionConfirmedFragment.reset (nullptr); |
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m_SentHandshakePacket.reset (nullptr); |
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m_ConnectTimer.cancel (); |
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SetTerminationTimeout (SSU2_TERMINATION_TIMEOUT); |
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transports.PeerConnected (shared_from_this ()); |
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if (m_OnEstablished) |
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{ |
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m_OnEstablished (); |
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m_OnEstablished = nullptr; |
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} |
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} |
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void SSU2Session::Done () |
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{ |
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m_Server.GetService ().post (std::bind (&SSU2Session::Terminate, shared_from_this ())); |
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} |
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void SSU2Session::SendLocalRouterInfo (bool update) |
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{ |
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if (update || !IsOutgoing ()) |
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{ |
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auto s = shared_from_this (); |
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m_Server.GetService ().post ([s]() |
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{ |
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if (!s->IsEstablished ()) return; |
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uint8_t payload[SSU2_MAX_PACKET_SIZE]; |
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size_t payloadSize = s->CreateRouterInfoBlock (payload, s->m_MaxPayloadSize - 32, i2p::context.GetSharedRouterInfo ()); |
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if (payloadSize) |
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{ |
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if (payloadSize < s->m_MaxPayloadSize) |
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payloadSize += s->CreatePaddingBlock (payload + payloadSize, s->m_MaxPayloadSize - payloadSize); |
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s->SendData (payload, payloadSize); |
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} |
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else |
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s->SendFragmentedMessage (CreateDatabaseStoreMsg ()); |
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}); |
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} |
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} |
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void SSU2Session::SendI2NPMessages (const std::vector<std::shared_ptr<I2NPMessage> >& msgs) |
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{ |
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m_Server.GetService ().post (std::bind (&SSU2Session::PostI2NPMessages, shared_from_this (), msgs)); |
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} |
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void SSU2Session::PostI2NPMessages (std::vector<std::shared_ptr<I2NPMessage> > msgs) |
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{ |
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if (m_State == eSSU2SessionStateTerminated) return; |
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for (auto it: msgs) |
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m_SendQueue.push_back (std::move (it)); |
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SendQueue (); |
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if (m_SendQueue.size () > 0) // windows is full |
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{ |
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if (m_SendQueue.size () <= SSU2_MAX_OUTGOING_QUEUE_SIZE) |
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Resend (i2p::util::GetMillisecondsSinceEpoch ()); |
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else |
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{ |
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LogPrint (eLogWarning, "SSU2: Outgoing messages queue size to ", |
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GetIdentHashBase64(), " exceeds ", SSU2_MAX_OUTGOING_QUEUE_SIZE); |
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RequestTermination (eSSU2TerminationReasonTimeout); |
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} |
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} |
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m_SendQueueSize = m_SendQueue.size (); |
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} |
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bool SSU2Session::SendQueue () |
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{ |
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if (!m_SendQueue.empty () && m_SentPackets.size () <= m_WindowSize) |
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{ |
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auto ts = i2p::util::GetMillisecondsSinceEpoch (); |
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auto packet = m_Server.GetSentPacketsPool ().AcquireShared (); |
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size_t ackBlockSize = CreateAckBlock (packet->payload, m_MaxPayloadSize); |
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bool ackBlockSent = false; |
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packet->payloadSize += ackBlockSize; |
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while (!m_SendQueue.empty () && m_SentPackets.size () <= m_WindowSize) |
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{ |
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auto msg = m_SendQueue.front (); |
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if (!msg) |
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{ |
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m_SendQueue.pop_front (); |
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continue; |
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} |
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size_t len = msg->GetNTCP2Length () + 3; |
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if (len > m_MaxPayloadSize) // message too long |
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{ |
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m_SendQueue.pop_front (); |
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if (SendFragmentedMessage (msg)) |
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ackBlockSent = true; |
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} |
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else if (packet->payloadSize + len <= m_MaxPayloadSize) |
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{ |
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m_SendQueue.pop_front (); |
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packet->payloadSize += CreateI2NPBlock (packet->payload + packet->payloadSize, m_MaxPayloadSize - packet->payloadSize, std::move (msg)); |
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} |
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else |
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{ |
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// create new packet and copy ack block |
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auto newPacket = m_Server.GetSentPacketsPool ().AcquireShared (); |
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memcpy (newPacket->payload, packet->payload, ackBlockSize); |
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newPacket->payloadSize = ackBlockSize; |
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// complete current packet |
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if (packet->payloadSize > ackBlockSize) // more than just ack block |
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{ |
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ackBlockSent = true; |
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// try to add padding |
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if (packet->payloadSize + 16 < m_MaxPayloadSize) |
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packet->payloadSize += CreatePaddingBlock (packet->payload + packet->payloadSize, m_MaxPayloadSize - packet->payloadSize); |
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} |
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else |
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{ |
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// reduce ack block |
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if (len + 8 < m_MaxPayloadSize) |
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{ |
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// keep Ack block and drop some ranges |
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ackBlockSent = true; |
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packet->payloadSize = m_MaxPayloadSize - len; |
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if (packet->payloadSize & 0x01) packet->payloadSize--; // make it even |
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htobe16buf (packet->payload + 1, packet->payloadSize - 3); // new block size |
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} |
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else // drop Ack block completely |
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packet->payloadSize = 0; |
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// msg fits single packet |
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m_SendQueue.pop_front (); |
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packet->payloadSize += CreateI2NPBlock (packet->payload + packet->payloadSize, m_MaxPayloadSize - packet->payloadSize, std::move (msg)); |
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} |
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// send right a way |
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uint32_t packetNum = SendData (packet->payload, packet->payloadSize); |
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packet->sendTime = ts; |
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m_SentPackets.emplace (packetNum, packet); |
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packet = newPacket; // just ack block |
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} |
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}; |
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if (packet->payloadSize > ackBlockSize) |
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{ |
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// last |
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ackBlockSent = true; |
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if (packet->payloadSize + 16 < m_MaxPayloadSize) |
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packet->payloadSize += CreatePaddingBlock (packet->payload + packet->payloadSize, m_MaxPayloadSize - packet->payloadSize); |
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uint32_t packetNum = SendData (packet->payload, packet->payloadSize, SSU2_FLAG_IMMEDIATE_ACK_REQUESTED); |
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packet->sendTime = ts; |
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m_SentPackets.emplace (packetNum, packet); |
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} |
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return ackBlockSent; |
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} |
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return false; |
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} |
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bool SSU2Session::SendFragmentedMessage (std::shared_ptr<I2NPMessage> msg) |
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{ |
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if (!msg) return false; |
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size_t lastFragmentSize = (msg->GetNTCP2Length () + 3 - m_MaxPayloadSize) % (m_MaxPayloadSize - 8); |
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size_t extraSize = m_MaxPayloadSize - lastFragmentSize; |
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bool ackBlockSent = false; |
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uint32_t msgID; |
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memcpy (&msgID, msg->GetHeader () + I2NP_HEADER_MSGID_OFFSET, 4); |
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auto ts = i2p::util::GetMillisecondsSinceEpoch (); |
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auto packet = m_Server.GetSentPacketsPool ().AcquireShared (); |
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if (extraSize >= 8) |
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{ |
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packet->payloadSize = CreateAckBlock (packet->payload, extraSize); |
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ackBlockSent = true; |
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if (packet->payloadSize + 12 < m_MaxPayloadSize) |
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{ |
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uint32_t packetNum = SendData (packet->payload, packet->payloadSize); |
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packet->sendTime = ts; |
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m_SentPackets.emplace (packetNum, packet); |
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packet = m_Server.GetSentPacketsPool ().AcquireShared (); |
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} |
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else |
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extraSize -= packet->payloadSize; |
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} |
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size_t offset = extraSize > 0 ? (rand () % extraSize) : 0; |
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if (offset + packet->payloadSize >= m_MaxPayloadSize) offset = 0; |
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auto size = CreateFirstFragmentBlock (packet->payload + packet->payloadSize, m_MaxPayloadSize - offset - packet->payloadSize, msg); |
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if (!size) return false; |
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extraSize -= offset; |
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packet->payloadSize += size; |
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uint32_t firstPacketNum = SendData (packet->payload, packet->payloadSize); |
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packet->sendTime = ts; |
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m_SentPackets.emplace (firstPacketNum, packet); |
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uint8_t fragmentNum = 0; |
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while (msg->offset < msg->len) |
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{ |
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offset = extraSize > 0 ? (rand () % extraSize) : 0; |
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packet = m_Server.GetSentPacketsPool ().AcquireShared (); |
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packet->payloadSize = CreateFollowOnFragmentBlock (packet->payload, m_MaxPayloadSize - offset, msg, fragmentNum, msgID); |
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extraSize -= offset; |
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uint8_t flags = 0; |
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if (msg->offset >= msg->len && packet->payloadSize + 16 < m_MaxPayloadSize) // last fragment |
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{ |
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packet->payloadSize += CreatePaddingBlock (packet->payload + packet->payloadSize, m_MaxPayloadSize - packet->payloadSize); |
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if (fragmentNum > 2) // 3 or more fragments |
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flags |= SSU2_FLAG_IMMEDIATE_ACK_REQUESTED; |
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} |
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uint32_t followonPacketNum = SendData (packet->payload, packet->payloadSize, flags); |
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packet->sendTime = ts; |
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m_SentPackets.emplace (followonPacketNum, packet); |
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} |
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return ackBlockSent; |
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} |
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size_t SSU2Session::Resend (uint64_t ts) |
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{ |
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// resend handshake packet |
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if (m_SentHandshakePacket && ts >= m_SentHandshakePacket->sendTime + SSU2_HANDSHAKE_RESEND_INTERVAL) |
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{ |
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LogPrint (eLogDebug, "SSU2: Resending ", (int)m_State); |
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ResendHandshakePacket (); |
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m_SentHandshakePacket->sendTime = ts; |
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return 0; |
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} |
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// resend data packets |
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if (m_SentPackets.empty ()) return 0; |
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std::map<uint32_t, std::shared_ptr<SSU2SentPacket> > resentPackets; |
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for (auto it = m_SentPackets.begin (); it != m_SentPackets.end (); ) |
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if (ts >= it->second->sendTime + it->second->numResends*m_RTO) |
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{ |
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if (it->second->numResends > SSU2_MAX_NUM_RESENDS) |
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{ |
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LogPrint (eLogInfo, "SSU2: Packet was not Acked after ", it->second->numResends, " attempts. Terminate session"); |
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m_SentPackets.clear (); |
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m_SendQueue.clear (); |
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m_SendQueueSize = 0; |
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RequestTermination (eSSU2TerminationReasonTimeout); |
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return resentPackets.size (); |
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} |
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else |
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{ |
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uint32_t packetNum = SendData (it->second->payload, it->second->payloadSize); |
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it->second->numResends++; |
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it->second->sendTime = ts; |
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resentPackets.emplace (packetNum, it->second); |
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it = m_SentPackets.erase (it); |
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} |
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} |
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else |
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it++; |
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if (!resentPackets.empty ()) |
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{ |
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#if (__cplusplus >= 201703L) // C++ 17 or higher |
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m_SentPackets.merge (resentPackets); |
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#else |
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m_SentPackets.insert (resentPackets.begin (), resentPackets.end ()); |
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#endif |
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m_WindowSize >>= 1; // /2 |
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if (m_WindowSize < SSU2_MIN_WINDOW_SIZE) m_WindowSize = SSU2_MIN_WINDOW_SIZE; |
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return resentPackets.size (); |
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} |
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return 0; |
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} |
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|
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void SSU2Session::ResendHandshakePacket () |
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{ |
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if (m_SentHandshakePacket) |
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{ |
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m_Server.Send (m_SentHandshakePacket->header.buf, 16, m_SentHandshakePacket->headerX, 48, |
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m_SentHandshakePacket->payload, m_SentHandshakePacket->payloadSize, m_RemoteEndpoint); |
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if (m_SessionConfirmedFragment && m_State == eSSU2SessionStateSessionConfirmedSent) |
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// resend second fragment of SessionConfirmed |
|
m_Server.Send (m_SessionConfirmedFragment->header.buf, 16, |
|
m_SessionConfirmedFragment->payload, m_SessionConfirmedFragment->payloadSize, m_RemoteEndpoint); |
|
} |
|
} |
|
|
|
bool SSU2Session::ProcessFirstIncomingMessage (uint64_t connID, uint8_t * buf, size_t len) |
|
{ |
|
// we are Bob |
|
m_SourceConnID = connID; |
|
Header header; |
|
header.h.connID = connID; |
|
memcpy (header.buf + 8, buf + 8, 8); |
|
header.ll[1] ^= CreateHeaderMask (i2p::context.GetSSU2IntroKey (), buf + (len - 12)); |
|
switch (header.h.type) |
|
{ |
|
case eSSU2SessionRequest: |
|
ProcessSessionRequest (header, buf, len); |
|
break; |
|
case eSSU2TokenRequest: |
|
ProcessTokenRequest (header, buf, len); |
|
break; |
|
case eSSU2PeerTest: |
|
{ |
|
// TODO: remove later |
|
if (len < 32) |
|
{ |
|
LogPrint (eLogWarning, "SSU2: PeerTest message too short ", len); |
|
break; |
|
} |
|
const uint8_t nonce[12] = {0}; |
|
uint64_t headerX[2]; |
|
i2p::crypto::ChaCha20 (buf + 16, 16, i2p::context.GetSSU2IntroKey (), nonce, (uint8_t *)headerX); |
|
LogPrint (eLogWarning, "SSU2: Unexpected PeerTest message SourceConnID=", connID, " DestConnID=", headerX[0]); |
|
break; |
|
} |
|
case eSSU2HolePunch: |
|
LogPrint (eLogDebug, "SSU2: Late HolePunch for ", connID); |
|
break; |
|
default: |
|
{ |
|
LogPrint (eLogWarning, "SSU2: Unexpected message type ", (int)header.h.type, " from ", m_RemoteEndpoint, " of ", len, " bytes"); |
|
return false; |
|
} |
|
} |
|
return true; |
|
} |
|
|
|
void SSU2Session::SendSessionRequest (uint64_t token) |
|
{ |
|
// we are Alice |
|
m_EphemeralKeys = i2p::transport::transports.GetNextX25519KeysPair (); |
|
m_SentHandshakePacket.reset (new HandshakePacket); |
|
auto ts = i2p::util::GetMillisecondsSinceEpoch (); |
|
m_SentHandshakePacket->sendTime = ts; |
|
|
|
Header& header = m_SentHandshakePacket->header; |
|
uint8_t * headerX = m_SentHandshakePacket->headerX, |
|
* payload = m_SentHandshakePacket->payload; |
|
// fill packet |
|
header.h.connID = m_DestConnID; // dest id |
|
header.h.packetNum = 0; |
|
header.h.type = eSSU2SessionRequest; |
|
header.h.flags[0] = 2; // ver |
|
header.h.flags[1] = (uint8_t)i2p::context.GetNetID (); // netID |
|
header.h.flags[2] = 0; // flag |
|
memcpy (headerX, &m_SourceConnID, 8); // source id |
|
memcpy (headerX + 8, &token, 8); // token |
|
memcpy (headerX + 16, m_EphemeralKeys->GetPublicKey (), 32); // X |
|
// payload |
|
payload[0] = eSSU2BlkDateTime; |
|
htobe16buf (payload + 1, 4); |
|
htobe32buf (payload + 3, (ts + 500)/1000); |
|
size_t payloadSize = 7; |
|
if (GetRouterStatus () == eRouterStatusFirewalled && m_Address->IsIntroducer ()) |
|
{ |
|
// relay tag request |
|
payload[payloadSize] = eSSU2BlkRelayTagRequest; |
|
memset (payload + payloadSize + 1, 0, 2); // size = 0 |
|
payloadSize += 3; |
|
} |
|
payloadSize += CreatePaddingBlock (payload + payloadSize, 40 - payloadSize, 1); |
|
// KDF for session request |
|
m_NoiseState->MixHash ({ {header.buf, 16}, {headerX, 16} }); // h = SHA256(h || header) |
|
m_NoiseState->MixHash (m_EphemeralKeys->GetPublicKey (), 32); // h = SHA256(h || aepk); |
|
uint8_t sharedSecret[32]; |
|
m_EphemeralKeys->Agree (m_Address->s, sharedSecret); |
|
m_NoiseState->MixKey (sharedSecret); |
|
// encrypt |
|
const uint8_t nonce[12] = {0}; |
|
i2p::crypto::AEADChaCha20Poly1305 (payload, payloadSize, m_NoiseState->m_H, 32, m_NoiseState->m_CK + 32, nonce, payload, payloadSize + 16, true); |
|
payloadSize += 16; |
|
header.ll[0] ^= CreateHeaderMask (m_Address->i, payload + (payloadSize - 24)); |
|
header.ll[1] ^= CreateHeaderMask (m_Address->i, payload + (payloadSize - 12)); |
|
i2p::crypto::ChaCha20 (headerX, 48, m_Address->i, nonce, headerX); |
|
m_NoiseState->MixHash (payload, payloadSize); // h = SHA256(h || encrypted payload from Session Request) for SessionCreated |
|
m_SentHandshakePacket->payloadSize = payloadSize; |
|
// send |
|
if (m_State == eSSU2SessionStateTokenReceived || m_Server.AddPendingOutgoingSession (shared_from_this ())) |
|
{ |
|
m_State = eSSU2SessionStateSessionRequestSent; |
|
m_Server.Send (header.buf, 16, headerX, 48, payload, payloadSize, m_RemoteEndpoint); |
|
} |
|
else |
|
{ |
|
LogPrint (eLogWarning, "SSU2: SessionRequest request to ", m_RemoteEndpoint, " already pending"); |
|
Terminate (); |
|
} |
|
} |
|
|
|
void SSU2Session::ProcessSessionRequest (Header& header, uint8_t * buf, size_t len) |
|
{ |
|
// we are Bob |
|
if (len < 88) |
|
{ |
|
LogPrint (eLogWarning, "SSU2: SessionRequest message too short ", len); |
|
return; |
|
} |
|
const uint8_t nonce[12] = {0}; |
|
uint8_t headerX[48]; |
|
i2p::crypto::ChaCha20 (buf + 16, 48, i2p::context.GetSSU2IntroKey (), nonce, headerX); |
|
memcpy (&m_DestConnID, headerX, 8); |
|
uint64_t token; |
|
memcpy (&token, headerX + 8, 8); |
|
if (!token || token != m_Server.GetIncomingToken (m_RemoteEndpoint)) |
|
{ |
|
LogPrint (eLogDebug, "SSU2: SessionRequest token mismatch. Retry"); |
|
SendRetry (); |
|
return; |
|
} |
|
// KDF for session request |
|
m_NoiseState->MixHash ( { {header.buf, 16}, {headerX, 16} } ); // h = SHA256(h || header) |
|
m_NoiseState->MixHash (headerX + 16, 32); // h = SHA256(h || aepk); |
|
uint8_t sharedSecret[32]; |
|
i2p::context.GetSSU2StaticKeys ().Agree (headerX + 16, sharedSecret); |
|
m_NoiseState->MixKey (sharedSecret); |
|
// decrypt |
|
uint8_t * payload = buf + 64; |
|
std::vector<uint8_t> decryptedPayload(len - 80); |
|
if (!i2p::crypto::AEADChaCha20Poly1305 (payload, len - 80, m_NoiseState->m_H, 32, |
|
m_NoiseState->m_CK + 32, nonce, decryptedPayload.data (), decryptedPayload.size (), false)) |
|
{ |
|
LogPrint (eLogWarning, "SSU2: SessionRequest AEAD verification failed "); |
|
return; |
|
} |
|
m_NoiseState->MixHash (payload, len - 64); // h = SHA256(h || encrypted payload from Session Request) for SessionCreated |
|
// payload |
|
m_State = eSSU2SessionStateSessionRequestReceived; |
|
HandlePayload (decryptedPayload.data (), decryptedPayload.size ()); |
|
|
|
if (m_TerminationReason == eSSU2TerminationReasonNormalClose) |
|
{ |
|
m_Server.AddSession (shared_from_this ()); |
|
SendSessionCreated (headerX + 16); |
|
} |
|
else |
|
SendRetry (); |
|
} |
|
|
|
void SSU2Session::SendSessionCreated (const uint8_t * X) |
|
{ |
|
// we are Bob |
|
m_EphemeralKeys = i2p::transport::transports.GetNextX25519KeysPair (); |
|
m_SentHandshakePacket.reset (new HandshakePacket); |
|
auto ts = i2p::util::GetMillisecondsSinceEpoch (); |
|
m_SentHandshakePacket->sendTime = ts; |
|
|
|
uint8_t kh2[32]; |
|
i2p::crypto::HKDF (m_NoiseState->m_CK, nullptr, 0, "SessCreateHeader", kh2, 32); // k_header_2 = HKDF(chainKey, ZEROLEN, "SessCreateHeader", 32) |
|
// fill packet |
|
Header& header = m_SentHandshakePacket->header; |
|
uint8_t * headerX = m_SentHandshakePacket->headerX, |
|
* payload = m_SentHandshakePacket->payload; |
|
header.h.connID = m_DestConnID; // dest id |
|
header.h.packetNum = 0; |
|
header.h.type = eSSU2SessionCreated; |
|
header.h.flags[0] = 2; // ver |
|
header.h.flags[1] = (uint8_t)i2p::context.GetNetID (); // netID |
|
header.h.flags[2] = 0; // flag |
|
memcpy (headerX, &m_SourceConnID, 8); // source id |
|
memset (headerX + 8, 0, 8); // token = 0 |
|
memcpy (headerX + 16, m_EphemeralKeys->GetPublicKey (), 32); // Y |
|
// payload |
|
size_t maxPayloadSize = m_MaxPayloadSize - 48; |
|
payload[0] = eSSU2BlkDateTime; |
|
htobe16buf (payload + 1, 4); |
|
htobe32buf (payload + 3, (ts + 500)/1000); |
|
size_t payloadSize = 7; |
|
payloadSize += CreateAddressBlock (payload + payloadSize, maxPayloadSize - payloadSize, m_RemoteEndpoint); |
|
if (m_RelayTag) |
|
{ |
|
payload[payloadSize] = eSSU2BlkRelayTag; |
|
htobe16buf (payload + payloadSize + 1, 4); |
|
htobe32buf (payload + payloadSize + 3, m_RelayTag); |
|
payloadSize += 7; |
|
} |
|
auto token = m_Server.NewIncomingToken (m_RemoteEndpoint); |
|
if (ts + SSU2_TOKEN_EXPIRATION_THRESHOLD > token.second) // not expired? |
|
{ |
|
payload[payloadSize] = eSSU2BlkNewToken; |
|
htobe16buf (payload + payloadSize + 1, 12); |
|
htobe32buf (payload + payloadSize + 3, token.second - SSU2_TOKEN_EXPIRATION_THRESHOLD); // expires |
|
memcpy (payload + payloadSize + 7, &token.first, 8); // token |
|
payloadSize += 15; |
|
} |
|
payloadSize += CreatePaddingBlock (payload + payloadSize, maxPayloadSize - payloadSize); |
|
// KDF for SessionCreated |
|
m_NoiseState->MixHash ( { {header.buf, 16}, {headerX, 16} } ); // h = SHA256(h || header) |
|
m_NoiseState->MixHash (headerX + 16, 32); // h = SHA256(h || bepk); |
|
uint8_t sharedSecret[32]; |
|
m_EphemeralKeys->Agree (X, sharedSecret); |
|
m_NoiseState->MixKey (sharedSecret); |
|
// encrypt |
|
const uint8_t nonce[12] = {0}; |
|
i2p::crypto::AEADChaCha20Poly1305 (payload, payloadSize, m_NoiseState->m_H, 32, m_NoiseState->m_CK + 32, nonce, payload, payloadSize + 16, true); |
|
payloadSize += 16; |
|
m_NoiseState->MixHash (payload, payloadSize); // h = SHA256(h || encrypted Noise payload from Session Created) |
|
header.ll[0] ^= CreateHeaderMask (i2p::context.GetSSU2IntroKey (), payload + (payloadSize - 24)); |
|
header.ll[1] ^= CreateHeaderMask (kh2, payload + (payloadSize - 12)); |
|
i2p::crypto::ChaCha20 (headerX, 48, kh2, nonce, headerX); |
|
m_State = eSSU2SessionStateSessionCreatedSent; |
|
m_SentHandshakePacket->payloadSize = payloadSize; |
|
// send |
|
m_Server.Send (header.buf, 16, headerX, 48, payload, payloadSize, m_RemoteEndpoint); |
|
} |
|
|
|
bool SSU2Session::ProcessSessionCreated (uint8_t * buf, size_t len) |
|
{ |
|
// we are Alice |
|
Header header; |
|
memcpy (header.buf, buf, 16); |
|
header.ll[0] ^= CreateHeaderMask (m_Address->i, buf + (len - 24)); |
|
uint8_t kh2[32]; |
|
i2p::crypto::HKDF (m_NoiseState->m_CK, nullptr, 0, "SessCreateHeader", kh2, 32); // k_header_2 = HKDF(chainKey, ZEROLEN, "SessCreateHeader", 32) |
|
header.ll[1] ^= CreateHeaderMask (kh2, buf + (len - 12)); |
|
if (header.h.type != eSSU2SessionCreated) |
|
// this situation is valid, because it might be Retry with different encryption |
|
return false; |
|
if (len < 80) |
|
{ |
|
LogPrint (eLogWarning, "SSU2: SessionCreated message too short ", len); |
|
return false; |
|
} |
|
const uint8_t nonce[12] = {0}; |
|
uint8_t headerX[48]; |
|
i2p::crypto::ChaCha20 (buf + 16, 48, kh2, nonce, headerX); |
|
// KDF for SessionCreated |
|
m_NoiseState->MixHash ( { {header.buf, 16}, {headerX, 16} } ); // h = SHA256(h || header) |
|
m_NoiseState->MixHash (headerX + 16, 32); // h = SHA256(h || bepk); |
|
uint8_t sharedSecret[32]; |
|
m_EphemeralKeys->Agree (headerX + 16, sharedSecret); |
|
m_NoiseState->MixKey (sharedSecret); |
|
// decrypt |
|
uint8_t * payload = buf + 64; |
|
std::vector<uint8_t> decryptedPayload(len - 80); |
|
if (!i2p::crypto::AEADChaCha20Poly1305 (payload, len - 80, m_NoiseState->m_H, 32, |
|
m_NoiseState->m_CK + 32, nonce, decryptedPayload.data (), decryptedPayload.size (), false)) |
|
{ |
|
LogPrint (eLogWarning, "SSU2: SessionCreated AEAD verification failed "); |
|
return false; |
|
} |
|
m_NoiseState->MixHash (payload, len - 64); // h = SHA256(h || encrypted payload from SessionCreated) for SessionConfirmed |
|
// payload |
|
m_State = eSSU2SessionStateSessionCreatedReceived; |
|
HandlePayload (decryptedPayload.data (), decryptedPayload.size ()); |
|
|
|
m_Server.AddSession (shared_from_this ()); |
|
AdjustMaxPayloadSize (); |
|
SendSessionConfirmed (headerX + 16); |
|
KDFDataPhase (m_KeyDataSend, m_KeyDataReceive); |
|
|
|
return true; |
|
} |
|
|
|
void SSU2Session::SendSessionConfirmed (const uint8_t * Y) |
|
{ |
|
// we are Alice |
|
m_SentHandshakePacket.reset (new HandshakePacket); |
|
m_SentHandshakePacket->sendTime = i2p::util::GetMillisecondsSinceEpoch (); |
|
|
|
uint8_t kh2[32]; |
|
i2p::crypto::HKDF (m_NoiseState->m_CK, nullptr, 0, "SessionConfirmed", kh2, 32); // k_header_2 = HKDF(chainKey, ZEROLEN, "SessionConfirmed", 32) |
|
// fill packet |
|
Header& header = m_SentHandshakePacket->header; |
|
header.h.connID = m_DestConnID; // dest id |
|
header.h.packetNum = 0; |
|
header.h.type = eSSU2SessionConfirmed; |
|
memset (header.h.flags, 0, 3); |
|
header.h.flags[0] = 1; // frag, total fragments always 1 |
|
// payload |
|
size_t maxPayloadSize = m_MaxPayloadSize - 48; // for part 2, 48 is part1 |
|
uint8_t * payload = m_SentHandshakePacket->payload; |
|
size_t payloadSize = CreateRouterInfoBlock (payload, maxPayloadSize, i2p::context.GetSharedRouterInfo ()); |
|
if (!payloadSize) |
|
{ |
|
// split by two fragments |
|
maxPayloadSize += m_MaxPayloadSize; |
|
payloadSize = CreateRouterInfoBlock (payload, maxPayloadSize, i2p::context.GetSharedRouterInfo ()); |
|
header.h.flags[0] = 0x02; // frag 0, total fragments 2 |
|
// TODO: check if we need more fragments |
|
} |
|
if (payloadSize < maxPayloadSize) |
|
payloadSize += CreatePaddingBlock (payload + payloadSize, maxPayloadSize - payloadSize); |
|
// KDF for Session Confirmed part 1 |
|
m_NoiseState->MixHash (header.buf, 16); // h = SHA256(h || header) |
|
// Encrypt part 1 |
|
uint8_t * part1 = m_SentHandshakePacket->headerX; |
|
uint8_t nonce[12]; |
|
CreateNonce (1, nonce); |
|
i2p::crypto::AEADChaCha20Poly1305 (i2p::context.GetSSU2StaticPublicKey (), 32, m_NoiseState->m_H, 32, m_NoiseState->m_CK + 32, nonce, part1, 48, true); |
|
m_NoiseState->MixHash (part1, 48); // h = SHA256(h || ciphertext); |
|
// KDF for Session Confirmed part 2 |
|
uint8_t sharedSecret[32]; |
|
i2p::context.GetSSU2StaticKeys ().Agree (Y, sharedSecret); |
|
m_NoiseState->MixKey (sharedSecret); |
|
// Encrypt part2 |
|
memset (nonce, 0, 12); |
|
i2p::crypto::AEADChaCha20Poly1305 (payload, payloadSize, m_NoiseState->m_H, 32, m_NoiseState->m_CK + 32, nonce, payload, payloadSize + 16, true); |
|
payloadSize += 16; |
|
m_NoiseState->MixHash (payload, payloadSize); // h = SHA256(h || ciphertext); |
|
m_SentHandshakePacket->payloadSize = payloadSize; |
|
if (header.h.flags[0] > 1) |
|
{ |
|
if (payloadSize > m_MaxPayloadSize - 48) |
|
{ |
|
payloadSize = m_MaxPayloadSize - 48 - (rand () % 16); |
|
if (m_SentHandshakePacket->payloadSize - payloadSize < 24) |
|
payloadSize -= 24; |
|
} |
|
else |
|
header.h.flags[0] = 1; |
|
} |
|
// Encrypt header |
|
header.ll[0] ^= CreateHeaderMask (m_Address->i, payload + (payloadSize - 24)); |
|
header.ll[1] ^= CreateHeaderMask (kh2, payload + (payloadSize - 12)); |
|
m_State = eSSU2SessionStateSessionConfirmedSent; |
|
// send |
|
m_Server.Send (header.buf, 16, part1, 48, payload, payloadSize, m_RemoteEndpoint); |
|
m_SendPacketNum++; |
|
if (m_SentHandshakePacket->payloadSize > payloadSize) |
|
{ |
|
// send second fragment |
|
m_SessionConfirmedFragment.reset (new HandshakePacket); |
|
Header& header = m_SessionConfirmedFragment->header; |
|
header.h.connID = m_DestConnID; // dest id |
|
header.h.packetNum = 0; |
|
header.h.type = eSSU2SessionConfirmed; |
|
memset (header.h.flags, 0, 3); |
|
header.h.flags[0] = 0x12; // frag 1, total fragments 2 |
|
m_SessionConfirmedFragment->payloadSize = m_SentHandshakePacket->payloadSize - payloadSize; |
|
memcpy (m_SessionConfirmedFragment->payload, m_SentHandshakePacket->payload + payloadSize, m_SessionConfirmedFragment->payloadSize); |
|
m_SentHandshakePacket->payloadSize = payloadSize; |
|
header.ll[0] ^= CreateHeaderMask (m_Address->i, m_SessionConfirmedFragment->payload + (m_SessionConfirmedFragment->payloadSize - 24)); |
|
header.ll[1] ^= CreateHeaderMask (kh2, m_SessionConfirmedFragment->payload + (m_SessionConfirmedFragment->payloadSize - 12)); |
|
m_Server.Send (header.buf, 16, m_SessionConfirmedFragment->payload, m_SessionConfirmedFragment->payloadSize, m_RemoteEndpoint); |
|
} |
|
} |
|
|
|
bool SSU2Session::ProcessSessionConfirmed (uint8_t * buf, size_t len) |
|
{ |
|
// we are Bob |
|
Header header; |
|
memcpy (header.buf, buf, 16); |
|
header.ll[0] ^= CreateHeaderMask (i2p::context.GetSSU2IntroKey (), buf + (len - 24)); |
|
uint8_t kh2[32]; |
|
i2p::crypto::HKDF (m_NoiseState->m_CK, nullptr, 0, "SessionConfirmed", kh2, 32); // k_header_2 = HKDF(chainKey, ZEROLEN, "SessionConfirmed", 32) |
|
header.ll[1] ^= CreateHeaderMask (kh2, buf + (len - 12)); |
|
if (header.h.type != eSSU2SessionConfirmed) |
|
{ |
|
LogPrint (eLogInfo, "SSU2: Unexpected message type ", (int)header.h.type, " instead ", (int)eSSU2SessionConfirmed); |
|
// TODO: queue up |
|
return true; |
|
} |
|
// check if fragmented |
|
uint8_t numFragments = header.h.flags[0] & 0x0F; |
|
if (numFragments > 1) |
|
{ |
|
// fragmented |
|
if (numFragments > 2) |
|
{ |
|
LogPrint (eLogError, "SSU2: Too many fragments ", (int)numFragments, " in SessionConfirmed from ", m_RemoteEndpoint); |
|
return false; |
|
} |
|
if (len < 32) |
|
{ |
|
LogPrint (eLogWarning, "SSU2: SessionConfirmed fragment too short ", len); |
|
if (m_SessionConfirmedFragment) m_SessionConfirmedFragment.reset (nullptr); |
|
return false; |
|
} |
|
if (!(header.h.flags[0] & 0xF0)) |
|
{ |
|
// first fragment |
|
if (!m_SessionConfirmedFragment) |
|
{ |
|
m_SessionConfirmedFragment.reset (new HandshakePacket); |
|
m_SessionConfirmedFragment->header = header; |
|
memcpy (m_SessionConfirmedFragment->payload, buf + 16, len - 16); |
|
m_SessionConfirmedFragment->payloadSize = len - 16; |
|
return true; // wait for second fragment |
|
} |
|
else if (m_SessionConfirmedFragment->isSecondFragment) |
|
{ |
|
// we have second fragment |
|
m_SessionConfirmedFragment->header = header; |
|
memmove (m_SessionConfirmedFragment->payload + (len - 16), m_SessionConfirmedFragment->payload, m_SessionConfirmedFragment->payloadSize); |
|
memcpy (m_SessionConfirmedFragment->payload, buf + 16, len - 16); |
|
m_SessionConfirmedFragment->payloadSize += (len - 16); |
|
m_SessionConfirmedFragment->isSecondFragment = false; |
|
buf = m_SessionConfirmedFragment->payload - 16; |
|
len = m_SessionConfirmedFragment->payloadSize + 16; |
|
} |
|
else |
|
return true; |
|
} |
|
else |
|
{ |
|
// second fragment |
|
if (!m_SessionConfirmedFragment) |
|
{ |
|
// out of sequence, save it |
|
m_SessionConfirmedFragment.reset (new HandshakePacket); |
|
memcpy (m_SessionConfirmedFragment->payload, buf + 16, len - 16); |
|
m_SessionConfirmedFragment->payloadSize = len - 16; |
|
m_SessionConfirmedFragment->isSecondFragment = true; |
|
return true; |
|
} |
|
header = m_SessionConfirmedFragment->header; |
|
if (m_SessionConfirmedFragment->payloadSize + (len - 16) <= SSU2_MAX_PACKET_SIZE*2) |
|
{ |
|
memcpy (m_SessionConfirmedFragment->payload + m_SessionConfirmedFragment->payloadSize, buf + 16, len - 16); |
|
m_SessionConfirmedFragment->payloadSize += (len - 16); |
|
} |
|
buf = m_SessionConfirmedFragment->payload - 16; |
|
len = m_SessionConfirmedFragment->payloadSize + 16; |
|
} |
|
} |
|
if (len < 80) |
|
{ |
|
LogPrint (eLogWarning, "SSU2: SessionConfirmed message too short ", len); |
|
if (m_SessionConfirmedFragment) m_SessionConfirmedFragment.reset (nullptr); |
|
return false; |
|
} |
|
// KDF for Session Confirmed part 1 |
|
m_NoiseState->MixHash (header.buf, 16); // h = SHA256(h || header) |
|
// decrypt part1 |
|
uint8_t nonce[12]; |
|
CreateNonce (1, nonce); |
|
uint8_t S[32]; |
|
if (!i2p::crypto::AEADChaCha20Poly1305 (buf + 16, 32, m_NoiseState->m_H, 32, |
|
m_NoiseState->m_CK + 32, nonce, S, 32, false)) |
|
{ |
|
LogPrint (eLogWarning, "SSU2: SessionConfirmed part 1 AEAD verification failed "); |
|
if (m_SessionConfirmedFragment) m_SessionConfirmedFragment.reset (nullptr); |
|
return false; |
|
} |
|
m_NoiseState->MixHash (buf + 16, 48); // h = SHA256(h || ciphertext); |
|
// KDF for Session Confirmed part 2 and data phase |
|
uint8_t sharedSecret[32]; |
|
m_EphemeralKeys->Agree (S, sharedSecret); |
|
m_NoiseState->MixKey (sharedSecret); |
|
KDFDataPhase (m_KeyDataReceive, m_KeyDataSend); |
|
// decrypt part2 |
|
memset (nonce, 0, 12); |
|
uint8_t * payload = buf + 64; |
|
std::vector<uint8_t> decryptedPayload(len - 80); |
|
if (!i2p::crypto::AEADChaCha20Poly1305 (payload, len - 80, m_NoiseState->m_H, 32, |
|
m_NoiseState->m_CK + 32, nonce, decryptedPayload.data (), decryptedPayload.size (), false)) |
|
{ |
|
LogPrint (eLogWarning, "SSU2: SessionConfirmed part 2 AEAD verification failed "); |
|
if (m_SessionConfirmedFragment) m_SessionConfirmedFragment.reset (nullptr); |
|
return false; |
|
} |
|
m_NoiseState->MixHash (payload, len - 64); // h = SHA256(h || ciphertext); |
|
if (m_SessionConfirmedFragment) m_SessionConfirmedFragment.reset (nullptr); |
|
// payload |
|
// handle RouterInfo block that must be first |
|
if (decryptedPayload[0] != eSSU2BlkRouterInfo) |
|
{ |
|
LogPrint (eLogError, "SSU2: SessionConfirmed unexpected first block type ", (int)decryptedPayload[0]); |
|
return false; |
|
} |
|
size_t riSize = bufbe16toh (decryptedPayload.data () + 1); |
|
if (riSize + 3 > decryptedPayload.size ()) |
|
{ |
|
LogPrint (eLogError, "SSU2: SessionConfirmed RouterInfo block is too long ", riSize); |
|
return false; |
|
} |
|
LogPrint (eLogDebug, "SSU2: RouterInfo in SessionConfirmed"); |
|
auto ri = ExtractRouterInfo (decryptedPayload.data () + 3, riSize); |
|
if (!ri) |
|
{ |
|
LogPrint (eLogError, "SSU2: SessionConfirmed malformed RouterInfo block"); |
|
return false; |
|
} |
|
m_Address = ri->GetSSU2AddressWithStaticKey (S, m_RemoteEndpoint.address ().is_v6 ()); |
|
if (!m_Address) |
|
{ |
|
LogPrint (eLogError, "SSU2: No SSU2 address with static key found in SessionConfirmed from ", i2p::data::GetIdentHashAbbreviation (ri->GetIdentHash ())); |
|
return false; |
|
} |
|
// update RouterInfo in netdb |
|
ri = i2p::data::netdb.AddRouterInfo (ri->GetBuffer (), ri->GetBufferLen ()); // ri points to one from netdb now |
|
if (!ri) |
|
{ |
|
LogPrint (eLogError, "SSU2: Couldn't update RouterInfo from SessionConfirmed in netdb"); |
|
return false; |
|
} |
|
SetRemoteIdentity (ri->GetRouterIdentity ()); |
|
AdjustMaxPayloadSize (); |
|
m_Server.AddSessionByRouterHash (shared_from_this ()); // we know remote router now |
|
m_RemoteTransports = ri->GetCompatibleTransports (false); |
|
// handle other blocks |
|
HandlePayload (decryptedPayload.data () + riSize + 3, decryptedPayload.size () - riSize - 3); |
|
Established (); |
|
|
|
SendQuickAck (); |
|
|
|
return true; |
|
} |
|
|
|
void SSU2Session::KDFDataPhase (uint8_t * keydata_ab, uint8_t * keydata_ba) |
|
{ |
|
uint8_t keydata[64]; |
|
i2p::crypto::HKDF (m_NoiseState->m_CK, nullptr, 0, "", keydata); // keydata = HKDF(chainKey, ZEROLEN, "", 64) |
|
// ab |
|
i2p::crypto::HKDF (keydata, nullptr, 0, "HKDFSSU2DataKeys", keydata_ab); // keydata_ab = HKDF(keydata, ZEROLEN, "HKDFSSU2DataKeys", 64) |
|
// ba |
|
i2p::crypto::HKDF (keydata + 32, nullptr, 0, "HKDFSSU2DataKeys", keydata_ba); // keydata_ba = HKDF(keydata + 32, ZEROLEN, "HKDFSSU2DataKeys", 64) |
|
} |
|
|
|
void SSU2Session::SendTokenRequest () |
|
{ |
|
// we are Alice |
|
Header header; |
|
uint8_t h[32], payload[41]; |
|
// fill packet |
|
header.h.connID = m_DestConnID; // dest id |
|
RAND_bytes (header.buf + 8, 4); // random packet num |
|
header.h.type = eSSU2TokenRequest; |
|
header.h.flags[0] = 2; // ver |
|
header.h.flags[1] = (uint8_t)i2p::context.GetNetID (); // netID |
|
header.h.flags[2] = 0; // flag |
|
memcpy (h, header.buf, 16); |
|
memcpy (h + 16, &m_SourceConnID, 8); // source id |
|
memset (h + 24, 0, 8); // zero token |
|
// payload |
|
payload[0] = eSSU2BlkDateTime; |
|
htobe16buf (payload + 1, 4); |
|
htobe32buf (payload + 3, (i2p::util::GetMillisecondsSinceEpoch () + 500)/1000); |
|
size_t payloadSize = 7; |
|
payloadSize += CreatePaddingBlock (payload + payloadSize, 25 - payloadSize, 1); |
|
// encrypt |
|
uint8_t nonce[12]; |
|
CreateNonce (be32toh (header.h.packetNum), nonce); |
|
i2p::crypto::AEADChaCha20Poly1305 (payload, payloadSize, h, 32, m_Address->i, nonce, payload, payloadSize + 16, true); |
|
payloadSize += 16; |
|
header.ll[0] ^= CreateHeaderMask (m_Address->i, payload + (payloadSize - 24)); |
|
header.ll[1] ^= CreateHeaderMask (m_Address->i, payload + (payloadSize - 12)); |
|
memset (nonce, 0, 12); |
|
i2p::crypto::ChaCha20 (h + 16, 16, m_Address->i, nonce, h + 16); |
|
// send |
|
if (m_Server.AddPendingOutgoingSession (shared_from_this ())) |
|
m_Server.Send (header.buf, 16, h + 16, 16, payload, payloadSize, m_RemoteEndpoint); |
|
else |
|
{ |
|
LogPrint (eLogWarning, "SSU2: TokenRequest request to ", m_RemoteEndpoint, " already pending"); |
|
Terminate (); |
|
} |
|
} |
|
|
|
void SSU2Session::ProcessTokenRequest (Header& header, uint8_t * buf, size_t len) |
|
{ |
|
// we are Bob |
|
if (len < 48) |
|
{ |
|
LogPrint (eLogWarning, "SSU2: Incorrect TokenRequest len ", len); |
|
return; |
|
} |
|
uint8_t nonce[12] = {0}; |
|
uint8_t h[32]; |
|
memcpy (h, header.buf, 16); |
|
i2p::crypto::ChaCha20 (buf + 16, 16, i2p::context.GetSSU2IntroKey (), nonce, h + 16); |
|
memcpy (&m_DestConnID, h + 16, 8); |
|
// decrypt |
|
CreateNonce (be32toh (header.h.packetNum), nonce); |
|
uint8_t * payload = buf + 32; |
|
if (!i2p::crypto::AEADChaCha20Poly1305 (payload, len - 48, h, 32, |
|
i2p::context.GetSSU2IntroKey (), nonce, payload, len - 48, false)) |
|
{ |
|
LogPrint (eLogWarning, "SSU2: TokenRequest AEAD verification failed "); |
|
return; |
|
} |
|
// payload |
|
m_State = eSSU2SessionStateTokenRequestReceived; |
|
HandlePayload (payload, len - 48); |
|
SendRetry (); |
|
} |
|
|
|
void SSU2Session::SendRetry () |
|
{ |
|
// we are Bob |
|
Header header; |
|
uint8_t h[32], payload[72]; |
|
// fill packet |
|
header.h.connID = m_DestConnID; // dest id |
|
RAND_bytes (header.buf + 8, 4); // random packet num |
|
header.h.type = eSSU2Retry; |
|
header.h.flags[0] = 2; // ver |
|
header.h.flags[1] = (uint8_t)i2p::context.GetNetID (); // netID |
|
header.h.flags[2] = 0; // flag |
|
memcpy (h, header.buf, 16); |
|
memcpy (h + 16, &m_SourceConnID, 8); // source id |
|
uint64_t token = 0; |
|
if (m_TerminationReason == eSSU2TerminationReasonNormalClose) |
|
token = m_Server.GetIncomingToken (m_RemoteEndpoint); |
|
memcpy (h + 24, &token, 8); // token |
|
// payload |
|
payload[0] = eSSU2BlkDateTime; |
|
htobe16buf (payload + 1, 4); |
|
htobe32buf (payload + 3, (i2p::util::GetMillisecondsSinceEpoch () + 500)/1000); |
|
size_t payloadSize = 7; |
|
payloadSize += CreateAddressBlock (payload + payloadSize, 56 - payloadSize, m_RemoteEndpoint); |
|
if (m_TerminationReason != eSSU2TerminationReasonNormalClose) |
|
payloadSize += CreateTerminationBlock (payload + payloadSize, 56 - payloadSize); |
|
payloadSize += CreatePaddingBlock (payload + payloadSize, 56 - payloadSize); |
|
// encrypt |
|
uint8_t nonce[12]; |
|
CreateNonce (be32toh (header.h.packetNum), nonce); |
|
i2p::crypto::AEADChaCha20Poly1305 (payload, payloadSize, h, 32, i2p::context.GetSSU2IntroKey (), nonce, payload, payloadSize + 16, true); |
|
payloadSize += 16; |
|
header.ll[0] ^= CreateHeaderMask (i2p::context.GetSSU2IntroKey (), payload + (payloadSize - 24)); |
|
header.ll[1] ^= CreateHeaderMask (i2p::context.GetSSU2IntroKey (), payload + (payloadSize - 12)); |
|
memset (nonce, 0, 12); |
|
i2p::crypto::ChaCha20 (h + 16, 16, i2p::context.GetSSU2IntroKey (), nonce, h + 16); |
|
// send |
|
m_Server.Send (header.buf, 16, h + 16, 16, payload, payloadSize, m_RemoteEndpoint); |
|
} |
|
|
|
bool SSU2Session::ProcessRetry (uint8_t * buf, size_t len) |
|
{ |
|
// we are Alice |
|
Header header; |
|
memcpy (header.buf, buf, 16); |
|
header.ll[0] ^= CreateHeaderMask (m_Address->i, buf + (len - 24)); |
|
header.ll[1] ^= CreateHeaderMask (m_Address->i, buf + (len - 12)); |
|
if (header.h.type != eSSU2Retry) |
|
{ |
|
LogPrint (eLogWarning, "SSU2: Unexpected message type ", (int)header.h.type, " instead ", (int)eSSU2Retry); |
|
return false; |
|
} |
|
if (len < 48) |
|
{ |
|
LogPrint (eLogWarning, "SSU2: Retry message too short ", len); |
|
return false; |
|
} |
|
uint8_t nonce[12] = {0}; |
|
uint64_t headerX[2]; // sourceConnID, token |
|
i2p::crypto::ChaCha20 (buf + 16, 16, m_Address->i, nonce, (uint8_t *)headerX); |
|
uint64_t token = headerX[1]; |
|
if (token) |
|
m_Server.UpdateOutgoingToken (m_RemoteEndpoint, token, i2p::util::GetSecondsSinceEpoch () + SSU2_TOKEN_EXPIRATION_TIMEOUT); |
|
// decrypt and handle payload |
|
uint8_t * payload = buf + 32; |
|
CreateNonce (be32toh (header.h.packetNum), nonce); |
|
uint8_t h[32]; |
|
memcpy (h, header.buf, 16); |
|
memcpy (h + 16, &headerX, 16); |
|
if (!i2p::crypto::AEADChaCha20Poly1305 (payload, len - 48, h, 32, |
|
m_Address->i, nonce, payload, len - 48, false)) |
|
{ |
|
LogPrint (eLogWarning, "SSU2: Retry AEAD verification failed"); |
|
return false; |
|
} |
|
m_State = eSSU2SessionStateTokenReceived; |
|
HandlePayload (payload, len - 48); |
|
if (!token) |
|
{ |
|
// we should handle payload even for zero token to handle Datetime block and adjust clock in case of clock skew |
|
LogPrint (eLogWarning, "SSU2: Retry token is zero"); |
|
return false; |
|
} |
|
InitNoiseXKState1 (*m_NoiseState, m_Address->s); // reset Noise TODO: check state |
|
SendSessionRequest (token); |
|
return true; |
|
} |
|
|
|
void SSU2Session::SendHolePunch (uint32_t nonce, const boost::asio::ip::udp::endpoint& ep, |
|
const uint8_t * introKey, uint64_t token) |
|
{ |
|
// we are Charlie |
|
LogPrint (eLogDebug, "SSU2: Sending HolePunch to ", ep); |
|
Header header; |
|
uint8_t h[32], payload[SSU2_MAX_PACKET_SIZE]; |
|
// fill packet |
|
header.h.connID = htobe64 (((uint64_t)nonce << 32) | nonce); // dest id |
|
RAND_bytes (header.buf + 8, 4); // random packet num |
|
header.h.type = eSSU2HolePunch; |
|
header.h.flags[0] = 2; // ver |
|
header.h.flags[1] = (uint8_t)i2p::context.GetNetID (); // netID |
|
header.h.flags[2] = 0; // flag |
|
memcpy (h, header.buf, 16); |
|
uint64_t c = ~header.h.connID; |
|
memcpy (h + 16, &c, 8); // source id |
|
RAND_bytes (h + 24, 8); // token |
|
// payload |
|
payload[0] = eSSU2BlkDateTime; |
|
htobe16buf (payload + 1, 4); |
|
htobe32buf (payload + 3, (i2p::util::GetMillisecondsSinceEpoch () + 500)/1000); |
|
size_t payloadSize = 7; |
|
payloadSize += CreateAddressBlock (payload + payloadSize, m_MaxPayloadSize - payloadSize, ep); |
|
payloadSize += CreateRelayResponseBlock (payload + payloadSize, m_MaxPayloadSize - payloadSize, |
|
eSSU2RelayResponseCodeAccept, nonce, token, ep.address ().is_v4 ()); |
|
payloadSize += CreatePaddingBlock (payload + payloadSize, m_MaxPayloadSize - payloadSize); |
|
// encrypt |
|
uint8_t n[12]; |
|
CreateNonce (be32toh (header.h.packetNum), n); |
|
i2p::crypto::AEADChaCha20Poly1305 (payload, payloadSize, h, 32, introKey, n, payload, payloadSize + 16, true); |
|
payloadSize += 16; |
|
header.ll[0] ^= CreateHeaderMask (introKey, payload + (payloadSize - 24)); |
|
header.ll[1] ^= CreateHeaderMask (introKey, payload + (payloadSize - 12)); |
|
memset (n, 0, 12); |
|
i2p::crypto::ChaCha20 (h + 16, 16, introKey, n, h + 16); |
|
// send |
|
m_Server.Send (header.buf, 16, h + 16, 16, payload, payloadSize, ep); |
|
} |
|
|
|
bool SSU2Session::ProcessHolePunch (uint8_t * buf, size_t len) |
|
{ |
|
// we are Alice |
|
LogPrint (eLogDebug, "SSU2: HolePunch"); |
|
Header header; |
|
memcpy (header.buf, buf, 16); |
|
header.ll[0] ^= CreateHeaderMask (i2p::context.GetSSU2IntroKey (), buf + (len - 24)); |
|
header.ll[1] ^= CreateHeaderMask (i2p::context.GetSSU2IntroKey (), buf + (len - 12)); |
|
if (header.h.type != eSSU2HolePunch) |
|
{ |
|
LogPrint (eLogWarning, "SSU2: Unexpected message type ", (int)header.h.type, " instead ", (int)eSSU2HolePunch); |
|
return false; |
|
} |
|
if (len < 48) |
|
{ |
|
LogPrint (eLogWarning, "SSU2: HolePunch message too short ", len); |
|
return false; |
|
} |
|
uint8_t nonce[12] = {0}; |
|
uint64_t headerX[2]; // sourceConnID, token |
|
i2p::crypto::ChaCha20 (buf + 16, 16, i2p::context.GetSSU2IntroKey (), nonce, (uint8_t *)headerX); |
|
m_DestConnID = headerX[0]; |
|
// decrypt and handle payload |
|
uint8_t * payload = buf + 32; |
|
CreateNonce (be32toh (header.h.packetNum), nonce); |
|
uint8_t h[32]; |
|
memcpy (h, header.buf, 16); |
|
memcpy (h + 16, &headerX, 16); |
|
if (!i2p::crypto::AEADChaCha20Poly1305 (payload, len - 48, h, 32, |
|
i2p::context.GetSSU2IntroKey (), nonce, payload, len - 48, false)) |
|
{ |
|
LogPrint (eLogWarning, "SSU2: HolePunch AEAD verification failed "); |
|
return false; |
|
} |
|
HandlePayload (payload, len - 48); |
|
// connect to Charlie |
|
ConnectAfterIntroduction (); |
|
|
|
return true; |
|
} |
|
|
|
void SSU2Session::SendPeerTest (uint8_t msg, const uint8_t * signedData, size_t signedDataLen, const uint8_t * introKey) |
|
{ |
|
Header header; |
|
uint8_t h[32], payload[SSU2_MAX_PACKET_SIZE]; |
|
// fill packet |
|
header.h.connID = m_DestConnID; // dest id |
|
RAND_bytes (header.buf + 8, 4); // random packet num |
|
header.h.type = eSSU2PeerTest; |
|
header.h.flags[0] = 2; // ver |
|
header.h.flags[1] = (uint8_t)i2p::context.GetNetID (); // netID |
|
header.h.flags[2] = 0; // flag |
|
memcpy (h, header.buf, 16); |
|
memcpy (h + 16, &m_SourceConnID, 8); // source id |
|
// payload |
|
payload[0] = eSSU2BlkDateTime; |
|
htobe16buf (payload + 1, 4); |
|
htobe32buf (payload + 3, (i2p::util::GetMillisecondsSinceEpoch () + 500)/1000); |
|
size_t payloadSize = 7; |
|
if (msg == 6 || msg == 7) |
|
payloadSize += CreateAddressBlock (payload + payloadSize, m_MaxPayloadSize - payloadSize, m_RemoteEndpoint); |
|
payloadSize += CreatePeerTestBlock (payload + payloadSize, m_MaxPayloadSize - payloadSize, |
|
msg, eSSU2PeerTestCodeAccept, nullptr, signedData, signedDataLen); |
|
payloadSize += CreatePaddingBlock (payload + payloadSize, m_MaxPayloadSize - payloadSize); |
|
// encrypt |
|
uint8_t n[12]; |
|
CreateNonce (be32toh (header.h.packetNum), n); |
|
i2p::crypto::AEADChaCha20Poly1305 (payload, payloadSize, h, 32, introKey, n, payload, payloadSize + 16, true); |
|
payloadSize += 16; |
|
header.ll[0] ^= CreateHeaderMask (introKey, payload + (payloadSize - 24)); |
|
header.ll[1] ^= CreateHeaderMask (introKey, payload + (payloadSize - 12)); |
|
memset (n, 0, 12); |
|
i2p::crypto::ChaCha20 (h + 16, 16, introKey, n, h + 16); |
|
// send |
|
m_Server.Send (header.buf, 16, h + 16, 16, payload, payloadSize, m_RemoteEndpoint); |
|
} |
|
|
|
bool SSU2Session::ProcessPeerTest (uint8_t * buf, size_t len) |
|
{ |
|
// we are Alice or Charlie |
|
Header header; |
|
memcpy (header.buf, buf, 16); |
|
header.ll[0] ^= CreateHeaderMask (i2p::context.GetSSU2IntroKey (), buf + (len - 24)); |
|
header.ll[1] ^= CreateHeaderMask (i2p::context.GetSSU2IntroKey (), buf + (len - 12)); |
|
if (header.h.type != eSSU2PeerTest) |
|
{ |
|
LogPrint (eLogWarning, "SSU2: Unexpected message type ", (int)header.h.type, " instead ", (int)eSSU2PeerTest); |
|
return false; |
|
} |
|
if (len < 48) |
|
{ |
|
LogPrint (eLogWarning, "SSU2: PeerTest message too short ", len); |
|
return false; |
|
} |
|
uint8_t nonce[12] = {0}; |
|
uint64_t headerX[2]; // sourceConnID, token |
|
i2p::crypto::ChaCha20 (buf + 16, 16, i2p::context.GetSSU2IntroKey (), nonce, (uint8_t *)headerX); |
|
m_DestConnID = headerX[0]; |
|
// decrypt and handle payload |
|
uint8_t * payload = buf + 32; |
|
CreateNonce (be32toh (header.h.packetNum), nonce); |
|
uint8_t h[32]; |
|
memcpy (h, header.buf, 16); |
|
memcpy (h + 16, &headerX, 16); |
|
if (!i2p::crypto::AEADChaCha20Poly1305 (payload, len - 48, h, 32, |
|
i2p::context.GetSSU2IntroKey (), nonce, payload, len - 48, false)) |
|
{ |
|
LogPrint (eLogWarning, "SSU2: PeerTest AEAD verification failed "); |
|
return false; |
|
} |
|
HandlePayload (payload, len - 48); |
|
return true; |
|
} |
|
|
|
uint32_t SSU2Session::SendData (const uint8_t * buf, size_t len, uint8_t flags) |
|
{ |
|
if (len < 8) |
|
{ |
|
LogPrint (eLogWarning, "SSU2: Data message payload is too short ", (int)len); |
|
return 0; |
|
} |
|
Header header; |
|
header.h.connID = m_DestConnID; |
|
header.h.packetNum = htobe32 (m_SendPacketNum); |
|
header.h.type = eSSU2Data; |
|
memset (header.h.flags, 0, 3); |
|
if (flags) header.h.flags[0] = flags; |
|
uint8_t nonce[12]; |
|
CreateNonce (m_SendPacketNum, nonce); |
|
uint8_t payload[SSU2_MAX_PACKET_SIZE]; |
|
i2p::crypto::AEADChaCha20Poly1305 (buf, len, header.buf, 16, m_KeyDataSend, nonce, payload, SSU2_MAX_PACKET_SIZE, true); |
|
header.ll[0] ^= CreateHeaderMask (m_Address->i, payload + (len - 8)); |
|
header.ll[1] ^= CreateHeaderMask (m_KeyDataSend + 32, payload + (len + 4)); |
|
m_Server.Send (header.buf, 16, payload, len + 16, m_RemoteEndpoint); |
|
m_SendPacketNum++; |
|
m_LastActivityTimestamp = i2p::util::GetSecondsSinceEpoch (); |
|
m_NumSentBytes += len + 32; |
|
return m_SendPacketNum - 1; |
|
} |
|
|
|
void SSU2Session::ProcessData (uint8_t * buf, size_t len, const boost::asio::ip::udp::endpoint& from) |
|
{ |
|
Header header; |
|
header.ll[0] = m_SourceConnID; |
|
memcpy (header.buf + 8, buf + 8, 8); |
|
header.ll[1] ^= CreateHeaderMask (m_KeyDataReceive + 32, buf + (len - 12)); |
|
if (header.h.type != eSSU2Data) |
|
{ |
|
LogPrint (eLogWarning, "SSU2: Unexpected message type ", (int)header.h.type, " instead ", (int)eSSU2Data); |
|
if (IsEstablished ()) |
|
SendQuickAck (); // in case it was SessionConfirmed |
|
else |
|
ResendHandshakePacket (); // assume we receive |
|
return; |
|
} |
|
if (from != m_RemoteEndpoint && !i2p::util::net::IsInReservedRange (from.address ())) |
|
{ |
|
LogPrint (eLogInfo, "SSU2: Remote endpoint update ", m_RemoteEndpoint, "->", from); |
|
m_RemoteEndpoint = from; |
|
SendPathChallenge (); |
|
} |
|
if (len < 32) |
|
{ |
|
LogPrint (eLogWarning, "SSU2: Data message too short ", len); |
|
return; |
|
} |
|
uint8_t payload[SSU2_MAX_PACKET_SIZE]; |
|
size_t payloadSize = len - 32; |
|
uint32_t packetNum = be32toh (header.h.packetNum); |
|
uint8_t nonce[12]; |
|
CreateNonce (packetNum, nonce); |
|
if (!i2p::crypto::AEADChaCha20Poly1305 (buf + 16, payloadSize, header.buf, 16, |
|
m_KeyDataReceive, nonce, payload, payloadSize, false)) |
|
{ |
|
LogPrint (eLogWarning, "SSU2: Data AEAD verification failed "); |
|
return; |
|
} |
|
m_LastActivityTimestamp = i2p::util::GetSecondsSinceEpoch (); |
|
m_NumReceivedBytes += len; |
|
if (!packetNum || UpdateReceivePacketNum (packetNum)) |
|
HandlePayload (payload, payloadSize); |
|
} |
|
|
|
void SSU2Session::HandlePayload (const uint8_t * buf, size_t len) |
|
{ |
|
size_t offset = 0; |
|
while (offset < len) |
|
{ |
|
uint8_t blk = buf[offset]; |
|
offset++; |
|
auto size = bufbe16toh (buf + offset); |
|
offset += 2; |
|
LogPrint (eLogDebug, "SSU2: Block type ", (int)blk, " of size ", size); |
|
if (size > len) |
|
{ |
|
LogPrint (eLogError, "SSU2: Unexpected block length ", size); |
|
break; |
|
} |
|
switch (blk) |
|
{ |
|
case eSSU2BlkDateTime: |
|
LogPrint (eLogDebug, "SSU2: Datetime"); |
|
HandleDateTime (buf + offset, size); |
|
break; |
|
case eSSU2BlkOptions: |
|
LogPrint (eLogDebug, "SSU2: Options"); |
|
break; |
|
case eSSU2BlkRouterInfo: |
|
{ |
|
// not from SessionConfirmed, we must add it instantly to use in next block |
|
LogPrint (eLogDebug, "SSU2: RouterInfo"); |
|
auto ri = ExtractRouterInfo (buf + offset, size); |
|
if (ri) |
|
i2p::data::netdb.AddRouterInfo (ri->GetBuffer (), ri->GetBufferLen ()); // TODO: add ri |
|
break; |
|
} |
|
case eSSU2BlkI2NPMessage: |
|
{ |
|
LogPrint (eLogDebug, "SSU2: I2NP message"); |
|
auto nextMsg = (buf[offset] == eI2NPTunnelData) ? NewI2NPTunnelMessage (true) : NewI2NPShortMessage (); |
|
nextMsg->len = nextMsg->offset + size + 7; // 7 more bytes for full I2NP header |
|
memcpy (nextMsg->GetNTCP2Header (), buf + offset, size); |
|
nextMsg->FromNTCP2 (); // SSU2 has the same format as NTCP2 |
|
m_Handler.PutNextMessage (std::move (nextMsg)); |
|
m_IsDataReceived = true; |
|
break; |
|
} |
|
case eSSU2BlkFirstFragment: |
|
LogPrint (eLogDebug, "SSU2: First fragment"); |
|
HandleFirstFragment (buf + offset, size); |
|
m_IsDataReceived = true; |
|
break; |
|
case eSSU2BlkFollowOnFragment: |
|
LogPrint (eLogDebug, "SSU2: Follow-on fragment"); |
|
HandleFollowOnFragment (buf + offset, size); |
|
m_IsDataReceived = true; |
|
break; |
|
case eSSU2BlkTermination: |
|
{ |
|
uint8_t rsn = buf[11]; // reason |
|
LogPrint (eLogDebug, "SSU2: Termination reason=", (int)rsn); |
|
if (IsEstablished () && rsn != eSSU2TerminationReasonTerminationReceived) |
|
RequestTermination (eSSU2TerminationReasonTerminationReceived); |
|
else if (m_State != eSSU2SessionStateTerminated) |
|
{ |
|
if (m_State == eSSU2SessionStateClosing && rsn == eSSU2TerminationReasonTerminationReceived) |
|
m_State = eSSU2SessionStateClosingConfirmed; |
|
Done (); |
|
} |
|
break; |
|
} |
|
case eSSU2BlkRelayRequest: |
|
LogPrint (eLogDebug, "SSU2: RelayRequest"); |
|
HandleRelayRequest (buf + offset, size); |
|
break; |
|
case eSSU2BlkRelayResponse: |
|
LogPrint (eLogDebug, "SSU2: RelayResponse"); |
|
HandleRelayResponse (buf + offset, size); |
|
break; |
|
case eSSU2BlkRelayIntro: |
|
LogPrint (eLogDebug, "SSU2: RelayIntro"); |
|
HandleRelayIntro (buf + offset, size); |
|
break; |
|
case eSSU2BlkPeerTest: |
|
LogPrint (eLogDebug, "SSU2: PeerTest msg=", (int)buf[offset], " code=", (int)buf[offset+1]); |
|
HandlePeerTest (buf + offset, size); |
|
if (buf[offset] < 5) |
|
m_IsDataReceived = true; |
|
break; |
|
case eSSU2BlkNextNonce: |
|
break; |
|
case eSSU2BlkAck: |
|
LogPrint (eLogDebug, "SSU2: Ack"); |
|
HandleAck (buf + offset, size); |
|
break; |
|
case eSSU2BlkAddress: |
|
LogPrint (eLogDebug, "SSU2: Address"); |
|
HandleAddress (buf + offset, size); |
|
break; |
|
case eSSU2BlkIntroKey: |
|
break; |
|
case eSSU2BlkRelayTagRequest: |
|
LogPrint (eLogDebug, "SSU2: RelayTagRequest"); |
|
if (!m_RelayTag) |
|
{ |
|
RAND_bytes ((uint8_t *)&m_RelayTag, 4); |
|
m_Server.AddRelay (m_RelayTag, shared_from_this ()); |
|
} |
|
break; |
|
case eSSU2BlkRelayTag: |
|
LogPrint (eLogDebug, "SSU2: RelayTag"); |
|
m_RelayTag = bufbe32toh (buf + offset); |
|
break; |
|
case eSSU2BlkNewToken: |
|
{ |
|
LogPrint (eLogDebug, "SSU2: New token"); |
|
uint64_t token; |
|
memcpy (&token, buf + offset + 4, 8); |
|
m_Server.UpdateOutgoingToken (m_RemoteEndpoint, token, bufbe32toh (buf + offset)); |
|
break; |
|
} |
|
case eSSU2BlkPathChallenge: |
|
LogPrint (eLogDebug, "SSU2: Path challenge"); |
|
SendPathResponse (buf + offset, size); |
|
break; |
|
case eSSU2BlkPathResponse: |
|
{ |
|
LogPrint (eLogDebug, "SSU2: Path response"); |
|
if (m_PathChallenge) |
|
{ |
|
i2p::data::IdentHash hash; |
|
SHA256 (buf + offset, size, hash); |
|
if (hash == *m_PathChallenge) |
|
m_PathChallenge.reset (nullptr); |
|
} |
|
break; |
|
} |
|
case eSSU2BlkFirstPacketNumber: |
|
break; |
|
case eSSU2BlkPadding: |
|
LogPrint (eLogDebug, "SSU2: Padding"); |
|
break; |
|
default: |
|
LogPrint (eLogWarning, "SSU2: Unknown block type ", (int)blk); |
|
} |
|
offset += size; |
|
} |
|
} |
|
|
|
void SSU2Session::HandleDateTime (const uint8_t * buf, size_t len) |
|
{ |
|
int64_t offset = (int64_t)i2p::util::GetSecondsSinceEpoch () - (int64_t)bufbe32toh (buf); |
|
switch (m_State) |
|
{ |
|
case eSSU2SessionStateSessionRequestReceived: |
|
case eSSU2SessionStateTokenRequestReceived: |
|
if (std::abs (offset) > SSU2_CLOCK_SKEW) |
|
m_TerminationReason = eSSU2TerminationReasonClockSkew; |
|
break; |
|
case eSSU2SessionStateSessionCreatedReceived: |
|
case eSSU2SessionStateTokenReceived: |
|
if ((m_RemoteEndpoint.address ().is_v4 () && i2p::context.GetStatus () == eRouterStatusTesting) || |
|
(m_RemoteEndpoint.address ().is_v6 () && i2p::context.GetStatusV6 () == eRouterStatusTesting)) |
|
{ |
|
if (m_Server.IsSyncClockFromPeers ()) |
|
{ |
|
if (std::abs (offset) > SSU2_CLOCK_THRESHOLD) |
|
{ |
|
LogPrint (eLogWarning, "SSU2: Clock adjusted by ", -offset, " seconds"); |
|
i2p::util::AdjustTimeOffset (-offset); |
|
} |
|
} |
|
else if (std::abs (offset) > SSU2_CLOCK_SKEW) |
|
{ |
|
LogPrint (eLogError, "SSU2: Clock skew detected ", offset, ". Check your clock"); |
|
i2p::context.SetError (eRouterErrorClockSkew); |
|
} |
|
} |
|
break; |
|
default: ; |
|
}; |
|
} |
|
|
|
void SSU2Session::HandleAck (const uint8_t * buf, size_t len) |
|
{ |
|
if (m_State == eSSU2SessionStateSessionConfirmedSent) |
|
{ |
|
Established (); |
|
return; |
|
} |
|
if (m_SentPackets.empty ()) return; |
|
if (len < 5) return; |
|
// acnt |
|
uint32_t ackThrough = bufbe32toh (buf); |
|
uint32_t firstPacketNum = ackThrough > buf[4] ? ackThrough - buf[4] : 0; |
|
HandleAckRange (firstPacketNum, ackThrough, i2p::util::GetMillisecondsSinceEpoch ()); // acnt |
|
// ranges |
|
len -= 5; |
|
const uint8_t * ranges = buf + 5; |
|
while (len > 0 && firstPacketNum) |
|
{ |
|
uint32_t lastPacketNum = firstPacketNum - 1; |
|
if (*ranges > lastPacketNum) break; |
|
lastPacketNum -= *ranges; ranges++; // nacks |
|
if (*ranges > lastPacketNum + 1) break; |
|
firstPacketNum = lastPacketNum - *ranges + 1; ranges++; // acks |
|
len -= 2; |
|
HandleAckRange (firstPacketNum, lastPacketNum, 0); |
|
} |
|
} |
|
|
|
void SSU2Session::HandleAckRange (uint32_t firstPacketNum, uint32_t lastPacketNum, uint64_t ts) |
|
{ |
|
if (firstPacketNum > lastPacketNum) return; |
|
auto it = m_SentPackets.begin (); |
|
while (it != m_SentPackets.end () && it->first < firstPacketNum) it++; // find first acked packet |
|
if (it == m_SentPackets.end () || it->first > lastPacketNum) return; // not found |
|
auto it1 = it; |
|
int numPackets = 0; |
|
while (it1 != m_SentPackets.end () && it1->first <= lastPacketNum) |
|
{ |
|
if (ts && !it1->second->numResends) |
|
{ |
|
if (ts > it1->second->sendTime) |
|
{ |
|
auto rtt = ts - it1->second->sendTime; |
|
m_RTT = std::round ((m_RTT*m_SendPacketNum + rtt)/(m_SendPacketNum + 1.0)); |
|
m_RTO = m_RTT*SSU2_kAPPA; |
|
if (m_RTO < SSU2_MIN_RTO) m_RTO = SSU2_MIN_RTO; |
|
if (m_RTO > SSU2_MAX_RTO) m_RTO = SSU2_MAX_RTO; |
|
} |
|
ts = 0; // update RTT one time per range |
|
} |
|
it1++; |
|
numPackets++; |
|
} |
|
m_SentPackets.erase (it, it1); |
|
if (numPackets > 0) |
|
{ |
|
m_WindowSize += numPackets; |
|
if (m_WindowSize > SSU2_MAX_WINDOW_SIZE) m_WindowSize = SSU2_MAX_WINDOW_SIZE; |
|
} |
|
} |
|
|
|
void SSU2Session::HandleAddress (const uint8_t * buf, size_t len) |
|
{ |
|
boost::asio::ip::udp::endpoint ep; |
|
if (ExtractEndpoint (buf, len, ep)) |
|
{ |
|
LogPrint (eLogInfo, "SSU2: Our external address is ", ep); |
|
if (!i2p::util::net::IsInReservedRange (ep.address ())) |
|
{ |
|
i2p::context.UpdateAddress (ep.address ()); |
|
// check our port |
|
bool isV4 = ep.address ().is_v4 (); |
|
if (ep.port () != m_Server.GetPort (isV4)) |
|
{ |
|
LogPrint (eLogInfo, "SSU2: Our port ", ep.port (), " received from ", m_RemoteEndpoint, " is different from ", m_Server.GetPort (isV4)); |
|
if (isV4) |
|
{ |
|
if (i2p::context.GetStatus () == eRouterStatusTesting || |
|
m_State == eSSU2SessionStatePeerTest) |
|
{ |
|
i2p::context.SetStatus (eRouterStatusFirewalled); |
|
i2p::context.SetError (eRouterErrorSymmetricNAT); |
|
m_Server.RescheduleIntroducersUpdateTimer (); |
|
} |
|
} |
|
else |
|
{ |
|
if (i2p::context.GetStatusV6 () == eRouterStatusTesting || |
|
m_State == eSSU2SessionStatePeerTest) |
|
{ |
|
i2p::context.SetStatusV6 (eRouterStatusFirewalled); |
|
i2p::context.SetErrorV6 (eRouterErrorSymmetricNAT); |
|
m_Server.RescheduleIntroducersUpdateTimerV6 (); |
|
} |
|
} |
|
} |
|
else |
|
{ |
|
if (isV4) |
|
{ |
|
if (i2p::context.GetError () == eRouterErrorSymmetricNAT) |
|
{ |
|
if (m_State == eSSU2SessionStatePeerTest) |
|
i2p::context.SetStatus (eRouterStatusOK); |
|
i2p::context.SetError (eRouterErrorNone); |
|
} |
|
} |
|
else |
|
{ |
|
if (i2p::context.GetErrorV6 () == eRouterErrorSymmetricNAT) |
|
{ |
|
if (m_State == eSSU2SessionStatePeerTest) |
|
i2p::context.SetStatusV6 (eRouterStatusOK); |
|
i2p::context.SetErrorV6 (eRouterErrorNone); |
|
} |
|
} |
|
} |
|
} |
|
} |
|
} |
|
|
|
void SSU2Session::HandleFirstFragment (const uint8_t * buf, size_t len) |
|
{ |
|
uint32_t msgID; memcpy (&msgID, buf + 1, 4); |
|
auto msg = NewI2NPShortMessage (); |
|
// same format as I2NP message block |
|
msg->len = msg->offset + len + 7; |
|
memcpy (msg->GetNTCP2Header (), buf, len); |
|
std::shared_ptr<SSU2IncompleteMessage> m; |
|
bool found = false; |
|
auto it = m_IncompleteMessages.find (msgID); |
|
if (it != m_IncompleteMessages.end ()) |
|
{ |
|
found = true; |
|
m = it->second; |
|
} |
|
else |
|
{ |
|
m = std::make_shared<SSU2IncompleteMessage>(); |
|
m_IncompleteMessages.emplace (msgID, m); |
|
} |
|
m->msg = msg; |
|
m->nextFragmentNum = 1; |
|
m->lastFragmentInsertTime = i2p::util::GetSecondsSinceEpoch (); |
|
if (found && ConcatOutOfSequenceFragments (m)) |
|
{ |
|
// we have all follow-on fragments already |
|
m->msg->FromNTCP2 (); |
|
m_Handler.PutNextMessage (std::move (m->msg)); |
|
m_IncompleteMessages.erase (it); |
|
} |
|
} |
|
|
|
void SSU2Session::HandleFollowOnFragment (const uint8_t * buf, size_t len) |
|
{ |
|
if (len < 5) return; |
|
uint8_t fragmentNum = buf[0] >> 1; |
|
bool isLast = buf[0] & 0x01; |
|
uint32_t msgID; memcpy (&msgID, buf + 1, 4); |
|
auto it = m_IncompleteMessages.find (msgID); |
|
if (it != m_IncompleteMessages.end ()) |
|
{ |
|
if (it->second->nextFragmentNum == fragmentNum && fragmentNum < SSU2_MAX_NUM_FRAGMENTS && |
|
it->second->msg) |
|
{ |
|
// in sequence |
|
it->second->AttachNextFragment (buf + 5, len - 5); |
|
if (isLast) |
|
{ |
|
it->second->msg->FromNTCP2 (); |
|
m_Handler.PutNextMessage (std::move (it->second->msg)); |
|
m_IncompleteMessages.erase (it); |
|
} |
|
else |
|
{ |
|
if (ConcatOutOfSequenceFragments (it->second)) |
|
{ |
|
m_Handler.PutNextMessage (std::move (it->second->msg)); |
|
m_IncompleteMessages.erase (it); |
|
} |
|
else |
|
it->second->lastFragmentInsertTime = i2p::util::GetSecondsSinceEpoch (); |
|
} |
|
return; |
|
} |
|
} |
|
else |
|
{ |
|
// follow-on fragment before first fragment |
|
auto msg = std::make_shared<SSU2IncompleteMessage> (); |
|
msg->nextFragmentNum = 0; |
|
it = m_IncompleteMessages.emplace (msgID, msg).first; |
|
} |
|
// insert out of sequence fragment |
|
if (fragmentNum >= SSU2_MAX_NUM_FRAGMENTS) |
|
{ |
|
LogPrint (eLogWarning, "SSU2: Fragment number ", fragmentNum, " exceeds ", SSU2_MAX_NUM_FRAGMENTS); |
|
return; |
|
} |
|
auto fragment = std::make_shared<SSU2IncompleteMessage::Fragment> (); |
|
memcpy (fragment->buf, buf + 5, len -5); |
|
fragment->len = len - 5; |
|
fragment->isLast = isLast; |
|
it->second->outOfSequenceFragments.emplace (fragmentNum, fragment); |
|
it->second->lastFragmentInsertTime = i2p::util::GetSecondsSinceEpoch (); |
|
} |
|
|
|
bool SSU2Session::ConcatOutOfSequenceFragments (std::shared_ptr<SSU2IncompleteMessage> m) |
|
{ |
|
if (!m) return false; |
|
bool isLast = false; |
|
for (auto it = m->outOfSequenceFragments.begin (); it != m->outOfSequenceFragments.end ();) |
|
if (it->first == m->nextFragmentNum) |
|
{ |
|
m->AttachNextFragment (it->second->buf, it->second->len); |
|
isLast = it->second->isLast; |
|
it = m->outOfSequenceFragments.erase (it); |
|
} |
|
else |
|
break; |
|
return isLast; |
|
} |
|
|
|
void SSU2Session::HandleRelayRequest (const uint8_t * buf, size_t len) |
|
{ |
|
// we are Bob |
|
uint32_t relayTag = bufbe32toh (buf + 5); // relay tag |
|
auto session = m_Server.FindRelaySession (relayTag); |
|
if (!session) |
|
{ |
|
LogPrint (eLogWarning, "SSU2: RelayRequest session with relay tag ", relayTag, " not found"); |
|
// send relay response back to Alice |
|
uint8_t payload[SSU2_MAX_PACKET_SIZE]; |
|
size_t payloadSize = CreateRelayResponseBlock (payload, m_MaxPayloadSize, |
|
eSSU2RelayResponseCodeBobRelayTagNotFound, bufbe32toh (buf + 1), 0, false); |
|
payloadSize += CreatePaddingBlock (payload + payloadSize, m_MaxPayloadSize - payloadSize); |
|
SendData (payload, payloadSize); |
|
return; |
|
} |
|
session->m_RelaySessions.emplace (bufbe32toh (buf + 1), // nonce |
|
std::make_pair (shared_from_this (), i2p::util::GetSecondsSinceEpoch ()) ); |
|
|
|
// send relay intro to Charlie |
|
auto r = i2p::data::netdb.FindRouter (GetRemoteIdentity ()->GetIdentHash ()); // Alice's RI |
|
if (r) |
|
i2p::data::netdb.PopulateRouterInfoBuffer (r); |
|
else |
|
LogPrint (eLogWarning, "SSU2: RelayRequest Alice's router info not found"); |
|
uint8_t payload[SSU2_MAX_PACKET_SIZE]; |
|
size_t payloadSize = r ? CreateRouterInfoBlock (payload, m_MaxPayloadSize - len - 32, r) : 0; |
|
if (!payloadSize && r) |
|
session->SendFragmentedMessage (CreateDatabaseStoreMsg (r)); |
|
payloadSize += CreateRelayIntroBlock (payload + payloadSize, m_MaxPayloadSize - payloadSize, buf + 1, len -1); |
|
if (payloadSize < m_MaxPayloadSize) |
|
payloadSize += CreatePaddingBlock (payload + payloadSize, m_MaxPayloadSize - payloadSize); |
|
session->SendData (payload, payloadSize); |
|
} |
|
|
|
void SSU2Session::HandleRelayIntro (const uint8_t * buf, size_t len, int attempts) |
|
{ |
|
// we are Charlie |
|
SSU2RelayResponseCode code = eSSU2RelayResponseCodeAccept; |
|
uint64_t token = 0; |
|
bool isV4 = false; |
|
auto r = i2p::data::netdb.FindRouter (buf + 1); // Alice |
|
if (r) |
|
{ |
|
SignedData s; |
|
s.Insert ((const uint8_t *)"RelayRequestData", 16); // prologue |
|
s.Insert (GetRemoteIdentity ()->GetIdentHash (), 32); // bhash |
|
s.Insert (i2p::context.GetIdentHash (), 32); // chash |
|
s.Insert (buf + 33, 14); // nonce, relay tag, timestamp, ver, asz |
|
uint8_t asz = buf[46]; |
|
s.Insert (buf + 47, asz); // Alice Port, Alice IP |
|
if (s.Verify (r->GetIdentity (), buf + 47 + asz)) |
|
{ |
|
// send HolePunch |
|
boost::asio::ip::udp::endpoint ep; |
|
if (ExtractEndpoint (buf + 47, asz, ep)) |
|
{ |
|
auto addr = ep.address ().is_v6 () ? r->GetSSU2V6Address () : r->GetSSU2V4Address (); |
|
if (addr) |
|
{ |
|
if (m_Server.IsSupported (ep.address ())) |
|
{ |
|
token = m_Server.GetIncomingToken (ep); |
|
isV4 = ep.address ().is_v4 (); |
|
SendHolePunch (bufbe32toh (buf + 33), ep, addr->i, token); |
|
} |
|
else |
|
{ |
|
LogPrint (eLogWarning, "SSU2: RelayIntro unsupported address"); |
|
code = eSSU2RelayResponseCodeCharlieUnsupportedAddress; |
|
} |
|
} |
|
else |
|
{ |
|
LogPrint (eLogWarning, "SSU2: RelayIntro unknown address"); |
|
code = eSSU2RelayResponseCodeCharlieAliceIsUnknown; |
|
} |
|
} |
|
else |
|
{ |
|
LogPrint (eLogWarning, "SSU2: RelayIntro can't extract endpoint"); |
|
code = eSSU2RelayResponseCodeCharlieAliceIsUnknown; |
|
} |
|
} |
|
else |
|
{ |
|
LogPrint (eLogWarning, "SSU2: RelayIntro signature verification failed"); |
|
code = eSSU2RelayResponseCodeCharlieSignatureFailure; |
|
} |
|
} |
|
else if (!attempts) |
|
{ |
|
// RouterInfo might come in the next packet, try again |
|
auto vec = std::make_shared<std::vector<uint8_t> >(len); |
|
memcpy (vec->data (), buf, len); |
|
auto s = shared_from_this (); |
|
m_Server.GetService ().post ([s, vec, attempts]() |
|
{ |
|
LogPrint (eLogDebug, "SSU2: RelayIntro attempt ", attempts + 1); |
|
s->HandleRelayIntro (vec->data (), vec->size (), attempts + 1); |
|
}); |
|
return; |
|
} |
|
else |
|
{ |
|
LogPrint (eLogWarning, "SSU2: RelayIntro unknown router to introduce"); |
|
code = eSSU2RelayResponseCodeCharlieAliceIsUnknown; |
|
} |
|
// send relay response to Bob |
|
uint8_t payload[SSU2_MAX_PACKET_SIZE]; |
|
size_t payloadSize = CreateRelayResponseBlock (payload, m_MaxPayloadSize, |
|
code, bufbe32toh (buf + 33), token, isV4); |
|
payloadSize += CreatePaddingBlock (payload + payloadSize, m_MaxPayloadSize - payloadSize); |
|
SendData (payload, payloadSize); |
|
} |
|
|
|
void SSU2Session::HandleRelayResponse (const uint8_t * buf, size_t len) |
|
{ |
|
uint32_t nonce = bufbe32toh (buf + 2); |
|
if (m_State == eSSU2SessionStateIntroduced) |
|
{ |
|
// HolePunch from Charlie |
|
// TODO: verify address and signature |
|
// verify nonce |
|
if (~htobe64 (((uint64_t)nonce << 32) | nonce) != m_DestConnID) |
|
LogPrint (eLogWarning, "SSU2: Relay response nonce mismatch ", nonce, " connID=", m_DestConnID); |
|
if (len >= 8) |
|
{ |
|
// new token |
|
uint64_t token; |
|
memcpy (&token, buf + len - 8, 8); |
|
m_Server.UpdateOutgoingToken (m_RemoteEndpoint, token, i2p::util::GetSecondsSinceEpoch () + SSU2_TOKEN_EXPIRATION_TIMEOUT); |
|
} |
|
return; |
|
} |
|
auto it = m_RelaySessions.find (nonce); |
|
if (it != m_RelaySessions.end ()) |
|
{ |
|
if (it->second.first && it->second.first->IsEstablished ()) |
|
{ |
|
// we are Bob, message from Charlie |
|
uint8_t payload[SSU2_MAX_PACKET_SIZE]; |
|
payload[0] = eSSU2BlkRelayResponse; |
|
htobe16buf (payload + 1, len); |
|
memcpy (payload + 3, buf, len); // forward to Alice as is |
|
size_t payloadSize = len + 3; |
|
payloadSize += CreatePaddingBlock (payload + payloadSize, m_MaxPayloadSize - payloadSize); |
|
it->second.first->SendData (payload, payloadSize); |
|
} |
|
else |
|
{ |
|
// we are Alice, message from Bob |
|
if (!buf[1]) // status code accepted? |
|
{ |
|
// verify signature |
|
uint8_t csz = buf[11]; |
|
SignedData s; |
|
s.Insert ((const uint8_t *)"RelayAgreementOK", 16); // prologue |
|
s.Insert (GetRemoteIdentity ()->GetIdentHash (), 32); // bhash |
|
s.Insert (buf + 2, 10 + csz); // nonce, timestamp, ver, csz and Charlie's endpoint |
|
if (s.Verify (it->second.first->GetRemoteIdentity (), buf + 12 + csz)) |
|
{ |
|
if (it->second.first->m_State == eSSU2SessionStateIntroduced) // HolePunch not received yet |
|
{ |
|
// update Charlie's endpoint |
|
if (ExtractEndpoint (buf + 12, csz, it->second.first->m_RemoteEndpoint)) |
|
{ |
|
// update token |
|
uint64_t token; |
|
memcpy (&token, buf + len - 8, 8); |
|
m_Server.UpdateOutgoingToken (it->second.first->m_RemoteEndpoint, |
|
token, i2p::util::GetSecondsSinceEpoch () + SSU2_TOKEN_EXPIRATION_TIMEOUT); |
|
// connect to Charlie, HolePunch will be ignored |
|
it->second.first->ConnectAfterIntroduction (); |
|
} |
|
else |
|
LogPrint (eLogWarning, "SSU2: RelayResponse can't extract endpoint"); |
|
} |
|
} |
|
else |
|
{ |
|
LogPrint (eLogWarning, "SSU2: RelayResponse signature verification failed"); |
|
it->second.first->Done (); |
|
} |
|
} |
|
else |
|
{ |
|
LogPrint (eLogInfo, "SSU2: RelayResponse status code=", (int)buf[1]); |
|
it->second.first->Done (); |
|
} |
|
} |
|
m_RelaySessions.erase (it); |
|
} |
|
else |
|
LogPrint (eLogWarning, "SSU2: RelayResponse unknown nonce ", bufbe32toh (buf + 2)); |
|
} |
|
|
|
void SSU2Session::HandlePeerTest (const uint8_t * buf, size_t len) |
|
{ |
|
if (len < 3) return; |
|
uint8_t msg = buf[0]; |
|
size_t offset = 3; // points to signed data |
|
if (msg == 2 || msg == 4) offset += 32; // hash is presented for msg 2 and 4 only |
|
if (len < offset + 5) return; |
|
auto ts = i2p::util::GetMillisecondsSinceEpoch (); |
|
uint32_t nonce = bufbe32toh (buf + offset + 1); |
|
switch (msg) // msg |
|
{ |
|
case 1: // Bob from Alice |
|
{ |
|
auto session = m_Server.GetRandomSession ((buf[12] == 6) ? i2p::data::RouterInfo::eSSU2V4 : i2p::data::RouterInfo::eSSU2V6, |
|
GetRemoteIdentity ()->GetIdentHash ()); |
|
if (session) // session with Charlie |
|
{ |
|
session->m_PeerTests.emplace (nonce, std::make_pair (shared_from_this (), i2p::util::GetSecondsSinceEpoch ())); |
|
auto packet = m_Server.GetSentPacketsPool ().AcquireShared (); |
|
// Alice's RouterInfo |
|
auto r = i2p::data::netdb.FindRouter (GetRemoteIdentity ()->GetIdentHash ()); |
|
if (r) i2p::data::netdb.PopulateRouterInfoBuffer (r); |
|
packet->payloadSize = r ? CreateRouterInfoBlock (packet->payload, m_MaxPayloadSize - len - 32, r) : 0; |
|
if (!packet->payloadSize && r) |
|
session->SendFragmentedMessage (CreateDatabaseStoreMsg (r)); |
|
if (packet->payloadSize + len + 48 > m_MaxPayloadSize) |
|
{ |
|
// doesn't fit one message, send RouterInfo in separate message |
|
uint32_t packetNum = session->SendData (packet->payload, packet->payloadSize, SSU2_FLAG_IMMEDIATE_ACK_REQUESTED); |
|
packet->sendTime = ts; |
|
session->m_SentPackets.emplace (packetNum, packet); |
|
packet = m_Server.GetSentPacketsPool ().AcquireShared (); // new packet |
|
} |
|
// PeerTest to Charlie |
|
packet->payloadSize += CreatePeerTestBlock (packet->payload + packet->payloadSize, m_MaxPayloadSize - packet->payloadSize, 2, |
|
eSSU2PeerTestCodeAccept, GetRemoteIdentity ()->GetIdentHash (), buf + offset, len - offset); |
|
packet->payloadSize += CreatePaddingBlock (packet->payload + packet->payloadSize, m_MaxPayloadSize - packet->payloadSize); |
|
uint32_t packetNum = session->SendData (packet->payload, packet->payloadSize, SSU2_FLAG_IMMEDIATE_ACK_REQUESTED); |
|
packet->sendTime = ts; |
|
session->m_SentPackets.emplace (packetNum, packet); |
|
} |
|
else |
|
{ |
|
// Charlie not found, send error back to Alice |
|
uint8_t payload[SSU2_MAX_PACKET_SIZE], zeroHash[32] = {0}; |
|
size_t payloadSize = CreatePeerTestBlock (payload, m_MaxPayloadSize, 4, |
|
eSSU2PeerTestCodeBobNoCharlieAvailable, zeroHash, buf + offset, len - offset); |
|
payloadSize += CreatePaddingBlock (payload + payloadSize, m_MaxPayloadSize - payloadSize); |
|
SendData (payload, payloadSize); |
|
} |
|
break; |
|
} |
|
case 2: // Charlie from Bob |
|
{ |
|
// sign with Charlie's key |
|
uint8_t asz = buf[offset + 9]; |
|
std::vector<uint8_t> newSignedData (asz + 10 + i2p::context.GetIdentity ()->GetSignatureLen ()); |
|
memcpy (newSignedData.data (), buf + offset, asz + 10); |
|
SignedData s; |
|
s.Insert ((const uint8_t *)"PeerTestValidate", 16); // prologue |
|
s.Insert (GetRemoteIdentity ()->GetIdentHash (), 32); // bhash |
|
s.Insert (buf + 3, 32); // ahash |
|
s.Insert (newSignedData.data (), asz + 10); // ver, nonce, ts, asz, Alice's endpoint |
|
s.Sign (i2p::context.GetPrivateKeys (), newSignedData.data () + 10 + asz); |
|
// send response (msg 3) back and msg 5 if accepted |
|
SSU2PeerTestCode code = eSSU2PeerTestCodeAccept; |
|
auto r = i2p::data::netdb.FindRouter (buf + 3); // find Alice |
|
if (r) |
|
{ |
|
size_t signatureLen = r->GetIdentity ()->GetSignatureLen (); |
|
if (len >= offset + asz + 10 + signatureLen) |
|
{ |
|
s.Reset (); |
|
s.Insert ((const uint8_t *)"PeerTestValidate", 16); // prologue |
|
s.Insert (GetRemoteIdentity ()->GetIdentHash (), 32); // bhash |
|
s.Insert (buf + offset, asz + 10); // signed data |
|
if (s.Verify (r->GetIdentity (), buf + offset + asz + 10)) |
|
{ |
|
if (!m_Server.FindSession (r->GetIdentity ()->GetIdentHash ())) |
|
{ |
|
boost::asio::ip::udp::endpoint ep; |
|
std::shared_ptr<const i2p::data::RouterInfo::Address> addr; |
|
if (ExtractEndpoint (buf + offset + 10, asz, ep)) |
|
addr = r->GetSSU2Address (ep.address ().is_v4 ()); |
|
if (addr && m_Server.IsSupported (ep.address ())) |
|
{ |
|
// send msg 5 to Alice |
|
auto session = std::make_shared<SSU2Session> (m_Server, r, addr); |
|
session->SetState (eSSU2SessionStatePeerTest); |
|
session->m_RemoteEndpoint = ep; // might be different |
|
session->m_DestConnID = htobe64 (((uint64_t)nonce << 32) | nonce); |
|
session->m_SourceConnID = ~session->m_DestConnID; |
|
m_Server.AddSession (session); |
|
session->SendPeerTest (5, newSignedData.data (), newSignedData.size (), addr->i); |
|
} |
|
else |
|
code = eSSU2PeerTestCodeCharlieUnsupportedAddress; |
|
} |
|
else |
|
code = eSSU2PeerTestCodeCharlieAliceIsAlreadyConnected; |
|
} |
|
else |
|
code = eSSU2PeerTestCodeCharlieSignatureFailure; |
|
} |
|
else // maformed message |
|
code = eSSU2PeerTestCodeCharlieReasonUnspecified; |
|
} |
|
else |
|
code = eSSU2PeerTestCodeCharlieAliceIsUnknown; |
|
// send msg 3 back to Bob |
|
uint8_t payload[SSU2_MAX_PACKET_SIZE]; |
|
size_t payloadSize = CreatePeerTestBlock (payload, m_MaxPayloadSize, 3, |
|
code, nullptr, newSignedData.data (), newSignedData.size ()); |
|
payloadSize += CreatePaddingBlock (payload + payloadSize, m_MaxPayloadSize - payloadSize); |
|
SendData (payload, payloadSize); |
|
break; |
|
} |
|
case 3: // Bob from Charlie |
|
{ |
|
auto it = m_PeerTests.find (nonce); |
|
if (it != m_PeerTests.end () && it->second.first) |
|
{ |
|
uint8_t payload[SSU2_MAX_PACKET_SIZE]; |
|
// Charlie's RouterInfo |
|
auto r = i2p::data::netdb.FindRouter (GetRemoteIdentity ()->GetIdentHash ()); |
|
if (r) i2p::data::netdb.PopulateRouterInfoBuffer (r); |
|
size_t payloadSize = r ? CreateRouterInfoBlock (payload, m_MaxPayloadSize - len - 32, r) : 0; |
|
if (!payloadSize && r) |
|
it->second.first->SendFragmentedMessage (CreateDatabaseStoreMsg (r)); |
|
if (payloadSize + len + 16 > m_MaxPayloadSize) |
|
{ |
|
// doesn't fit one message, send RouterInfo in separate message |
|
it->second.first->SendData (payload, payloadSize); |
|
payloadSize = 0; |
|
} |
|
// PeerTest to Alice |
|
payloadSize += CreatePeerTestBlock (payload + payloadSize, m_MaxPayloadSize, 4, |
|
(SSU2PeerTestCode)buf[1], GetRemoteIdentity ()->GetIdentHash (), buf + offset, len - offset); |
|
if (payloadSize < m_MaxPayloadSize) |
|
payloadSize += CreatePaddingBlock (payload + payloadSize, m_MaxPayloadSize - payloadSize); |
|
it->second.first->SendData (payload, payloadSize); |
|
m_PeerTests.erase (it); |
|
} |
|
else |
|
LogPrint (eLogWarning, "SSU2: Unknown peer test 3 nonce ", nonce); |
|
break; |
|
} |
|
case 4: // Alice from Bob |
|
{ |
|
auto it = m_PeerTests.find (nonce); |
|
if (it != m_PeerTests.end ()) |
|
{ |
|
if (buf[1] == eSSU2PeerTestCodeAccept) |
|
{ |
|
if (GetRouterStatus () == eRouterStatusUnknown) |
|
SetRouterStatus (eRouterStatusTesting); |
|
auto r = i2p::data::netdb.FindRouter (buf + 3); // find Charlie |
|
if (r && it->second.first) |
|
{ |
|
uint8_t asz = buf[offset + 9]; |
|
SignedData s; |
|
s.Insert ((const uint8_t *)"PeerTestValidate", 16); // prologue |
|
s.Insert (GetRemoteIdentity ()->GetIdentHash (), 32); // bhash |
|
s.Insert (i2p::context.GetIdentity ()->GetIdentHash (), 32); // ahash |
|
s.Insert (buf + offset, asz + 10); // ver, nonce, ts, asz, Alice's endpoint |
|
if (s.Verify (r->GetIdentity (), buf + offset + asz + 10)) |
|
{ |
|
it->second.first->SetRemoteIdentity (r->GetIdentity ()); |
|
auto addr = r->GetSSU2Address (m_Address->IsV4 ()); |
|
if (addr) |
|
{ |
|
it->second.first->m_Address = addr; |
|
if (it->second.first->m_State == eSSU2SessionStatePeerTestReceived) |
|
{ |
|
// msg 5 already received. send msg 6 |
|
SetRouterStatus (eRouterStatusOK); |
|
it->second.first->m_State = eSSU2SessionStatePeerTest; |
|
it->second.first->SendPeerTest (6, buf + offset, len - offset, addr->i); |
|
} |
|
else |
|
{ |
|
if (GetRouterStatus () == eRouterStatusTesting) |
|
{ |
|
SetRouterStatus (eRouterStatusFirewalled); |
|
if (m_Address->IsV4 ()) |
|
m_Server.RescheduleIntroducersUpdateTimer (); |
|
else |
|
m_Server.RescheduleIntroducersUpdateTimerV6 (); |
|
} |
|
} |
|
LogPrint (eLogDebug, "SSU2: Peer test 4 received from ", i2p::data::GetIdentHashAbbreviation (GetRemoteIdentity ()->GetIdentHash ()), |
|
" with information about ", i2p::data::GetIdentHashAbbreviation (i2p::data::IdentHash (buf + 3))); |
|
} |
|
else |
|
{ |
|
LogPrint (eLogWarning, "SSU2: Peer test 4 address not found"); |
|
it->second.first->Done (); |
|
} |
|
} |
|
else |
|
{ |
|
LogPrint (eLogWarning, "SSU2: Peer test 4 signature verification failed"); |
|
it->second.first->Done (); |
|
} |
|
} |
|
else |
|
{ |
|
LogPrint (eLogWarning, "SSU2: Peer test 4 router not found"); |
|
if (it->second.first) |
|
it->second.first->Done (); |
|
} |
|
} |
|
else |
|
{ |
|
LogPrint (eLogInfo, "SSU2: Peer test 4 error code ", (int)buf[1], " from ", |
|
i2p::data::GetIdentHashAbbreviation (buf[1] < 64 ? GetRemoteIdentity ()->GetIdentHash () : i2p::data::IdentHash (buf + 3))); |
|
if (GetRouterStatus () == eRouterStatusTesting) |
|
SetRouterStatus (eRouterStatusUnknown); |
|
it->second.first->Done (); |
|
} |
|
m_PeerTests.erase (it); |
|
} |
|
else |
|
LogPrint (eLogWarning, "SSU2: Unknown peer test 4 nonce ", nonce); |
|
break; |
|
} |
|
case 5: // Alice from Charlie 1 |
|
if (htobe64 (((uint64_t)nonce << 32) | nonce) == m_SourceConnID) |
|
{ |
|
if (m_Address) |
|
{ |
|
SetRouterStatus (eRouterStatusOK); |
|
SendPeerTest (6, buf + offset, len - offset, m_Address->i); |
|
} |
|
else |
|
// we received msg 5 before msg 4 |
|
m_State = eSSU2SessionStatePeerTestReceived; |
|
} |
|
else |
|
LogPrint (eLogWarning, "SSU2: Peer test 5 nonce mismatch ", nonce, " connID=", m_SourceConnID); |
|
break; |
|
case 6: // Charlie from Alice |
|
if (m_Address) |
|
SendPeerTest (7, buf + offset, len - offset, m_Address->i); |
|
else |
|
LogPrint (eLogWarning, "SSU2: Unknown address for peer test 6"); |
|
m_Server.RemoveSession (~htobe64 (((uint64_t)nonce << 32) | nonce)); |
|
break; |
|
case 7: // Alice from Charlie 2 |
|
m_Server.RemoveSession (htobe64 (((uint64_t)nonce << 32) | nonce)); |
|
if (m_Address->IsV6 ()) |
|
i2p::context.SetStatusV6 (eRouterStatusOK); // set status OK for ipv6 even if from SSU2 |
|
break; |
|
default: |
|
LogPrint (eLogWarning, "SSU2: PeerTest unexpected msg num ", buf[0]); |
|
} |
|
} |
|
|
|
bool SSU2Session::ExtractEndpoint (const uint8_t * buf, size_t size, boost::asio::ip::udp::endpoint& ep) |
|
{ |
|
if (size < 2) return false; |
|
int port = bufbe16toh (buf); |
|
if (size == 6) |
|
{ |
|
boost::asio::ip::address_v4::bytes_type bytes; |
|
memcpy (bytes.data (), buf + 2, 4); |
|
ep = boost::asio::ip::udp::endpoint (boost::asio::ip::address_v4 (bytes), port); |
|
} |
|
else if (size == 18) |
|
{ |
|
boost::asio::ip::address_v6::bytes_type bytes; |
|
memcpy (bytes.data (), buf + 2, 16); |
|
ep = boost::asio::ip::udp::endpoint (boost::asio::ip::address_v6 (bytes), port); |
|
} |
|
else |
|
{ |
|
LogPrint (eLogWarning, "SSU2: Address size ", int(size), " is not supported"); |
|
return false; |
|
} |
|
return true; |
|
} |
|
|
|
size_t SSU2Session::CreateEndpoint (uint8_t * buf, size_t len, const boost::asio::ip::udp::endpoint& ep) |
|
{ |
|
if (len < 6) return 0; |
|
htobe16buf (buf, ep.port ()); |
|
size_t size = 0; |
|
if (ep.address ().is_v4 ()) |
|
{ |
|
memcpy (buf + 2, ep.address ().to_v4 ().to_bytes ().data (), 4); |
|
size = 6; |
|
} |
|
else if (ep.address ().is_v6 ()) |
|
{ |
|
if (len < 18) return 0; |
|
memcpy (buf + 2, ep.address ().to_v6 ().to_bytes ().data (), 16); |
|
size = 18; |
|
} |
|
else |
|
{ |
|
LogPrint (eLogWarning, "SSU2: Wrong address type ", ep.address ().to_string ()); |
|
return 0; |
|
} |
|
return size; |
|
} |
|
|
|
std::shared_ptr<const i2p::data::RouterInfo::Address> SSU2Session::FindLocalAddress () const |
|
{ |
|
if (m_Address) |
|
return i2p::context.GetRouterInfo ().GetSSU2Address (m_Address->IsV4 ()); |
|
return nullptr; |
|
} |
|
|
|
void SSU2Session::AdjustMaxPayloadSize () |
|
{ |
|
auto addr = FindLocalAddress (); |
|
if (addr && addr->ssu) |
|
{ |
|
int mtu = addr->ssu->mtu; |
|
if (!mtu && addr->IsV4 ()) mtu = SSU2_MAX_PACKET_SIZE; |
|
if (m_Address && m_Address->ssu && (!mtu || m_Address->ssu->mtu < mtu)) |
|
mtu = m_Address->ssu->mtu; |
|
if (mtu) |
|
{ |
|
if (mtu < (int)SSU2_MIN_PACKET_SIZE) mtu = SSU2_MIN_PACKET_SIZE; |
|
m_MaxPayloadSize = mtu - (addr->IsV6 () ? IPV6_HEADER_SIZE: IPV4_HEADER_SIZE) - UDP_HEADER_SIZE - 32; |
|
LogPrint (eLogDebug, "SSU2: Session MTU=", mtu, ", max payload size=", m_MaxPayloadSize); |
|
} |
|
} |
|
} |
|
|
|
RouterStatus SSU2Session::GetRouterStatus () const |
|
{ |
|
if (m_Address) |
|
{ |
|
if (m_Address->IsV4 ()) |
|
return i2p::context.GetStatus (); |
|
if (m_Address->IsV6 ()) |
|
return i2p::context.GetStatusV6 (); |
|
} |
|
return eRouterStatusUnknown; |
|
} |
|
|
|
void SSU2Session::SetRouterStatus (RouterStatus status) const |
|
{ |
|
if (m_Address) |
|
{ |
|
if (m_Address->IsV4 ()) |
|
i2p::context.SetStatus (status); |
|
else if (m_Address->IsV6 ()) |
|
i2p::context.SetStatusV6 (status); |
|
} |
|
} |
|
|
|
size_t SSU2Session::CreateAddressBlock (uint8_t * buf, size_t len, const boost::asio::ip::udp::endpoint& ep) |
|
{ |
|
if (len < 9) return 0; |
|
buf[0] = eSSU2BlkAddress; |
|
size_t size = CreateEndpoint (buf + 3, len - 3, ep); |
|
if (!size) return 0; |
|
htobe16buf (buf + 1, size); |
|
return size + 3; |
|
} |
|
|
|
size_t SSU2Session::CreateRouterInfoBlock (uint8_t * buf, size_t len, std::shared_ptr<const i2p::data::RouterInfo> r) |
|
{ |
|
if (!r || !r->GetBuffer () || len < 5) return 0; |
|
buf[0] = eSSU2BlkRouterInfo; |
|
size_t size = r->GetBufferLen (); |
|
if (size + 5 < len) |
|
{ |
|
memcpy (buf + 5, r->GetBuffer (), size); |
|
buf[3] = 0; // flag |
|
} |
|
else |
|
{ |
|
i2p::data::GzipDeflator deflator; |
|
deflator.SetCompressionLevel (9); |
|
size = deflator.Deflate (r->GetBuffer (), r->GetBufferLen (), buf + 5, len - 5); |
|
if (!size) return 0; // doesn't fit |
|
buf[3] = SSU2_ROUTER_INFO_FLAG_GZIP; // flag |
|
} |
|
htobe16buf (buf + 1, size + 2); // size |
|
buf[4] = 1; // frag |
|
return size + 5; |
|
} |
|
|
|
size_t SSU2Session::CreateAckBlock (uint8_t * buf, size_t len) |
|
{ |
|
if (len < 8) return 0; |
|
int maxNumRanges = (len - 8) >> 1; |
|
if (maxNumRanges > SSU2_MAX_NUM_ACK_RANGES) maxNumRanges = SSU2_MAX_NUM_ACK_RANGES; |
|
buf[0] = eSSU2BlkAck; |
|
uint32_t ackThrough = m_OutOfSequencePackets.empty () ? m_ReceivePacketNum : *m_OutOfSequencePackets.rbegin (); |
|
htobe32buf (buf + 3, ackThrough); // Ack Through |
|
uint16_t acnt = 0; |
|
int numRanges = 0; |
|
if (ackThrough) |
|
{ |
|
if (m_OutOfSequencePackets.empty ()) |
|
acnt = std::min ((int)ackThrough, 255); // no gaps |
|
else |
|
{ |
|
auto it = m_OutOfSequencePackets.rbegin (); it++; // prev packet num |
|
while (it != m_OutOfSequencePackets.rend () && *it == ackThrough - acnt - 1) |
|
{ |
|
acnt++; |
|
it++; |
|
} |
|
// ranges |
|
uint32_t lastNum = ackThrough - acnt; |
|
if (acnt > 255) |
|
{ |
|
auto d = std::div (acnt - 255, 255); |
|
acnt = 255; |
|
if (d.quot > maxNumRanges) |
|
{ |
|
d.quot = maxNumRanges; |
|
d.rem = 0; |
|
} |
|
// Acks only ranges for acnt |
|
for (int i = 0; i < d.quot; i++) |
|
{ |
|
buf[8 + numRanges*2] = 0; buf[8 + numRanges*2 + 1] = 255; // NACKs 0, Acks 255 |
|
numRanges++; |
|
} |
|
if (d.rem > 0) |
|
{ |
|
buf[8 + numRanges*2] = 0; buf[8 + numRanges*2 + 1] = d.rem; |
|
numRanges++; |
|
} |
|
} |
|
while (it != m_OutOfSequencePackets.rend () && numRanges < maxNumRanges) |
|
{ |
|
if (lastNum - (*it) > 255) |
|
{ |
|
// NACKs only ranges |
|
if (lastNum > (*it) + 255*(maxNumRanges - numRanges)) break; // too many NACKs |
|
while (lastNum - (*it) > 255) |
|
{ |
|
buf[8 + numRanges*2] = 255; buf[8 + numRanges*2 + 1] = 0; // NACKs 255, Acks 0 |
|
lastNum -= 255; |
|
numRanges++; |
|
} |
|
} |
|
// NACKs and Acks ranges |
|
buf[8 + numRanges*2] = lastNum - (*it) - 1; // NACKs |
|
lastNum = *it; it++; |
|
int numAcks = 1; |
|
while (it != m_OutOfSequencePackets.rend () && lastNum > 0 && *it == lastNum - 1) |
|
{ |
|
numAcks++; lastNum--; |
|
it++; |
|
} |
|
while (numAcks > 255) |
|
{ |
|
// Acks only ranges |
|
buf[8 + numRanges*2 + 1] = 255; // Acks 255 |
|
numAcks -= 255; |
|
numRanges++; |
|
buf[8 + numRanges*2] = 0; // NACKs 0 |
|
if (numRanges >= maxNumRanges) break; |
|
} |
|
if (numAcks > 255) numAcks = 255; |
|
buf[8 + numRanges*2 + 1] = (uint8_t)numAcks; // Acks |
|
numRanges++; |
|
} |
|
if (numRanges < maxNumRanges && it == m_OutOfSequencePackets.rend ()) |
|
{ |
|
// add range between out-of-sequence and received |
|
int nacks = *m_OutOfSequencePackets.begin () - m_ReceivePacketNum - 1; |
|
if (nacks > 0) |
|
{ |
|
if (nacks > 255) nacks = 255; |
|
buf[8 + numRanges*2] = nacks; |
|
buf[8 + numRanges*2 + 1] = std::min ((int)m_ReceivePacketNum + 1, 255); |
|
numRanges++; |
|
} |
|
} |
|
} |
|
} |
|
buf[7] = (uint8_t)acnt; // acnt |
|
htobe16buf (buf + 1, 5 + numRanges*2); |
|
return 8 + numRanges*2; |
|
} |
|
|
|
size_t SSU2Session::CreatePaddingBlock (uint8_t * buf, size_t len, size_t minSize) |
|
{ |
|
if (len < 3 || len < minSize) return 0; |
|
size_t paddingSize = rand () & 0x0F; // 0 - 15 |
|
if (paddingSize + 3 > len) paddingSize = len - 3; |
|
else if (paddingSize + 3 < minSize) paddingSize = minSize - 3; |
|
buf[0] = eSSU2BlkPadding; |
|
htobe16buf (buf + 1, paddingSize); |
|
memset (buf + 3, 0, paddingSize); |
|
return paddingSize + 3; |
|
} |
|
|
|
size_t SSU2Session::CreateI2NPBlock (uint8_t * buf, size_t len, std::shared_ptr<I2NPMessage>&& msg) |
|
{ |
|
msg->ToNTCP2 (); |
|
auto msgBuf = msg->GetNTCP2Header (); |
|
auto msgLen = msg->GetNTCP2Length (); |
|
if (msgLen + 3 > len) msgLen = len - 3; |
|
buf[0] = eSSU2BlkI2NPMessage; |
|
htobe16buf (buf + 1, msgLen); // size |
|
memcpy (buf + 3, msgBuf, msgLen); |
|
return msgLen + 3; |
|
} |
|
|
|
size_t SSU2Session::CreateFirstFragmentBlock (uint8_t * buf, size_t len, std::shared_ptr<I2NPMessage> msg) |
|
{ |
|
if (len < 12) return 0; |
|
msg->ToNTCP2 (); |
|
auto msgBuf = msg->GetNTCP2Header (); |
|
auto msgLen = msg->GetNTCP2Length (); |
|
if (msgLen + 3 <= len) return 0; |
|
msgLen = len - 3; |
|
buf[0] = eSSU2BlkFirstFragment; |
|
htobe16buf (buf + 1, msgLen); // size |
|
memcpy (buf + 3, msgBuf, msgLen); |
|
msg->offset = (msgBuf - msg->buf) + msgLen; |
|
return msgLen + 3; |
|
} |
|
|
|
size_t SSU2Session::CreateFollowOnFragmentBlock (uint8_t * buf, size_t len, std::shared_ptr<I2NPMessage> msg, uint8_t& fragmentNum, uint32_t msgID) |
|
{ |
|
if (len < 8) return 0; |
|
bool isLast = true; |
|
auto msgLen = msg->len - msg->offset; |
|
if (msgLen + 8 > len) |
|
{ |
|
msgLen = len - 8; |
|
isLast = false; |
|
} |
|
buf[0] = eSSU2BlkFollowOnFragment; |
|
htobe16buf (buf + 1, msgLen + 5); // size |
|
fragmentNum++; |
|
buf[3] = fragmentNum << 1; |
|
if (isLast) buf[3] |= 0x01; |
|
memcpy (buf + 4, &msgID, 4); |
|
memcpy (buf + 8, msg->buf + msg->offset, msgLen); |
|
msg->offset += msgLen; |
|
return msgLen + 8; |
|
} |
|
|
|
size_t SSU2Session::CreateRelayIntroBlock (uint8_t * buf, size_t len, const uint8_t * introData, size_t introDataLen) |
|
{ |
|
buf[0] = eSSU2BlkRelayIntro; |
|
size_t payloadSize = 1/* flag */ + 32/* Alice router hash */ + introDataLen; |
|
if (payloadSize + 3 > len) return 0; |
|
htobe16buf (buf + 1, payloadSize); // size |
|
buf[3] = 0; // flag |
|
memcpy (buf + 4, GetRemoteIdentity ()->GetIdentHash (), 32); // Alice router hash |
|
memcpy (buf + 36, introData, introDataLen); |
|
return payloadSize + 3; |
|
} |
|
|
|
size_t SSU2Session::CreateRelayResponseBlock (uint8_t * buf, size_t len, |
|
SSU2RelayResponseCode code, uint32_t nonce, uint64_t token, bool v4) |
|
{ |
|
buf[0] = eSSU2BlkRelayResponse; |
|
buf[3] = 0; // flag |
|
buf[4] = code; // code |
|
htobe32buf (buf + 5, nonce); // nonce |
|
htobe32buf (buf + 9, i2p::util::GetSecondsSinceEpoch ()); // timestamp |
|
buf[13] = 2; // ver |
|
size_t csz = 0; |
|
if (code == eSSU2RelayResponseCodeAccept) |
|
{ |
|
auto addr = i2p::context.GetRouterInfo ().GetSSU2Address (v4); |
|
if (!addr) |
|
{ |
|
LogPrint (eLogError, "SSU2: Can't find local address for RelayResponse"); |
|
return 0; |
|
} |
|
csz = CreateEndpoint (buf + 15, len - 15, boost::asio::ip::udp::endpoint (addr->host, addr->port)); |
|
if (!csz) |
|
{ |
|
LogPrint (eLogError, "SSU2: Can't create local endpoint for RelayResponse"); |
|
return 0; |
|
} |
|
} |
|
buf[14] = csz; // csz |
|
// signature |
|
size_t signatureLen = i2p::context.GetIdentity ()->GetSignatureLen (); |
|
if (15 + csz + signatureLen > len) |
|
{ |
|
LogPrint (eLogError, "SSU2: Buffer for RelayResponse signature is too small ", len); |
|
return 0; |
|
} |
|
SignedData s; |
|
s.Insert ((const uint8_t *)"RelayAgreementOK", 16); // prologue |
|
if (code == eSSU2RelayResponseCodeAccept || code >= 64) // Charlie |
|
s.Insert (GetRemoteIdentity ()->GetIdentHash (), 32); // bhash |
|
else // Bob's reject |
|
s.Insert (i2p::context.GetIdentity ()->GetIdentHash (), 32); // bhash |
|
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 + signatureLen; |
|
if (!code) |
|
{ |
|
if (payloadSize + 11 > len) |
|
{ |
|
LogPrint (eLogError, "SSU2: Buffer for RelayResponse token is too small ", len); |
|
return 0; |
|
} |
|
memcpy (buf + 3 + payloadSize, &token, 8); |
|
payloadSize += 8; |
|
} |
|
htobe16buf (buf + 1, payloadSize); // size |
|
return payloadSize + 3; |
|
} |
|
|
|
size_t SSU2Session::CreatePeerTestBlock (uint8_t * buf, size_t len, uint8_t msg, SSU2PeerTestCode code, |
|
const uint8_t * routerHash, const uint8_t * signedData, size_t signedDataLen) |
|
{ |
|
buf[0] = eSSU2BlkPeerTest; |
|
size_t payloadSize = 3/* msg, code, flag */ + signedDataLen; |
|
if (routerHash) payloadSize += 32; // router hash |
|
if (payloadSize + 3 > len) return 0; |
|
htobe16buf (buf + 1, payloadSize); // size |
|
buf[3] = msg; // msg |
|
buf[4] = (uint8_t)code; // code |
|
buf[5] = 0; //flag |
|
size_t offset = 6; |
|
if (routerHash) |
|
{ |
|
memcpy (buf + offset, routerHash, 32); // router hash |
|
offset += 32; |
|
} |
|
memcpy (buf + offset, signedData, signedDataLen); |
|
return payloadSize + 3; |
|
} |
|
|
|
size_t SSU2Session::CreatePeerTestBlock (uint8_t * buf, size_t len, uint32_t nonce) |
|
{ |
|
auto localAddress = FindLocalAddress (); |
|
if (!localAddress || !localAddress->port || localAddress->host.is_unspecified () || |
|
localAddress->host.is_v4 () != m_RemoteEndpoint.address ().is_v4 ()) |
|
{ |
|
LogPrint (eLogWarning, "SSU2: Can't find local address for peer test"); |
|
return 0; |
|
} |
|
// signed data |
|
auto ts = i2p::util::GetSecondsSinceEpoch (); |
|
uint8_t signedData[96]; |
|
signedData[0] = 2; // ver |
|
htobe32buf (signedData + 1, nonce); |
|
htobe32buf (signedData + 5, ts); |
|
size_t asz = CreateEndpoint (signedData + 10, 86, boost::asio::ip::udp::endpoint (localAddress->host, localAddress->port)); |
|
signedData[9] = asz; |
|
// signature |
|
SignedData s; |
|
s.Insert ((const uint8_t *)"PeerTestValidate", 16); // prologue |
|
s.Insert (GetRemoteIdentity ()->GetIdentHash (), 32); // bhash |
|
s.Insert (signedData, 10 + asz); // ver, nonce, ts, asz, Alice's endpoint |
|
s.Sign (i2p::context.GetPrivateKeys (), signedData + 10 + asz); |
|
return CreatePeerTestBlock (buf, len, 1, eSSU2PeerTestCodeAccept, nullptr, |
|
signedData, 10 + asz + i2p::context.GetIdentity ()->GetSignatureLen ()); |
|
} |
|
|
|
size_t SSU2Session::CreateTerminationBlock (uint8_t * buf, size_t len) |
|
{ |
|
buf[0] = eSSU2BlkTermination; |
|
htobe16buf (buf + 1, 9); |
|
htobe64buf (buf + 3, m_ReceivePacketNum); |
|
buf[11] = (uint8_t)m_TerminationReason; |
|
return 12; |
|
} |
|
|
|
std::shared_ptr<const i2p::data::RouterInfo> SSU2Session::ExtractRouterInfo (const uint8_t * buf, size_t size) |
|
{ |
|
if (size < 2) return nullptr; |
|
// TODO: handle frag |
|
std::shared_ptr<const i2p::data::RouterInfo> ri; |
|
if (buf[0] & SSU2_ROUTER_INFO_FLAG_GZIP) |
|
{ |
|
i2p::data::GzipInflator inflator; |
|
uint8_t uncompressed[i2p::data::MAX_RI_BUFFER_SIZE]; |
|
size_t uncompressedSize = inflator.Inflate (buf + 2, size - 2, uncompressed, i2p::data::MAX_RI_BUFFER_SIZE); |
|
if (uncompressedSize && uncompressedSize < i2p::data::MAX_RI_BUFFER_SIZE) |
|
ri = std::make_shared<i2p::data::RouterInfo>(uncompressed, uncompressedSize); |
|
else |
|
LogPrint (eLogInfo, "SSU2: RouterInfo decompression failed ", uncompressedSize); |
|
} |
|
else |
|
ri = std::make_shared<i2p::data::RouterInfo>(buf + 2, size - 2); |
|
return ri; |
|
} |
|
|
|
void SSU2Session::CreateNonce (uint64_t seqn, uint8_t * nonce) |
|
{ |
|
memset (nonce, 0, 4); |
|
htole64buf (nonce + 4, seqn); |
|
} |
|
|
|
bool SSU2Session::UpdateReceivePacketNum (uint32_t packetNum) |
|
{ |
|
if (packetNum <= m_ReceivePacketNum) return false; // duplicate |
|
if (packetNum == m_ReceivePacketNum + 1) |
|
{ |
|
for (auto it = m_OutOfSequencePackets.begin (); it != m_OutOfSequencePackets.end ();) |
|
{ |
|
if (*it == packetNum + 1) |
|
{ |
|
packetNum++; |
|
it = m_OutOfSequencePackets.erase (it); |
|
} |
|
else |
|
break; |
|
} |
|
m_ReceivePacketNum = packetNum; |
|
} |
|
else |
|
m_OutOfSequencePackets.insert (packetNum); |
|
return true; |
|
} |
|
|
|
void SSU2Session::SendQuickAck () |
|
{ |
|
uint8_t payload[SSU2_MAX_PACKET_SIZE]; |
|
size_t payloadSize = CreateAckBlock (payload, m_MaxPayloadSize); |
|
payloadSize += CreatePaddingBlock (payload + payloadSize, m_MaxPayloadSize - payloadSize); |
|
SendData (payload, payloadSize); |
|
} |
|
|
|
void SSU2Session::SendTermination () |
|
{ |
|
uint8_t payload[32]; |
|
size_t payloadSize = CreateTerminationBlock (payload, 32); |
|
payloadSize += CreatePaddingBlock (payload + payloadSize, 32 - payloadSize); |
|
SendData (payload, payloadSize); |
|
} |
|
|
|
void SSU2Session::SendPathResponse (const uint8_t * data, size_t len) |
|
{ |
|
if (len < 8 || len > m_MaxPayloadSize - 3) |
|
{ |
|
LogPrint (eLogWarning, "SSU2: Incorrect data size for path response ", len); |
|
return; |
|
} |
|
uint8_t payload[SSU2_MAX_PACKET_SIZE]; |
|
payload[0] = eSSU2BlkPathResponse; |
|
htobe16buf (payload + 1, len); |
|
memcpy (payload + 3, data, len); |
|
SendData (payload, len + 3); |
|
} |
|
|
|
void SSU2Session::SendPathChallenge () |
|
{ |
|
uint8_t payload[SSU2_MAX_PACKET_SIZE]; |
|
payload[0] = eSSU2BlkPathChallenge; |
|
size_t len = rand () % (m_MaxPayloadSize - 3); |
|
htobe16buf (payload + 1, len); |
|
if (len > 0) |
|
{ |
|
RAND_bytes (payload + 3, len); |
|
i2p::data::IdentHash * hash = new i2p::data::IdentHash (); |
|
SHA256 (payload + 3, len, *hash); |
|
m_PathChallenge.reset (hash); |
|
} |
|
len += 3; |
|
if (len < m_MaxPayloadSize) |
|
len += CreatePaddingBlock (payload + len, m_MaxPayloadSize - len); |
|
SendData (payload, len); |
|
} |
|
|
|
void SSU2Session::CleanUp (uint64_t ts) |
|
{ |
|
for (auto it = m_IncompleteMessages.begin (); it != m_IncompleteMessages.end ();) |
|
{ |
|
if (ts > it->second->lastFragmentInsertTime + SSU2_INCOMPLETE_MESSAGES_CLEANUP_TIMEOUT) |
|
{ |
|
LogPrint (eLogWarning, "SSU2: message ", it->first, " was not completed in ", SSU2_INCOMPLETE_MESSAGES_CLEANUP_TIMEOUT, " seconds, deleted"); |
|
it = m_IncompleteMessages.erase (it); |
|
} |
|
else |
|
++it; |
|
} |
|
if (!m_OutOfSequencePackets.empty ()) |
|
{ |
|
if (m_OutOfSequencePackets.size () > 2*SSU2_MAX_NUM_ACK_RANGES || |
|
*m_OutOfSequencePackets.rbegin () > m_ReceivePacketNum + 255*8) |
|
{ |
|
uint32_t packet = *m_OutOfSequencePackets.begin (); |
|
if (packet > m_ReceivePacketNum + 1) |
|
{ |
|
// like we've just received all packets before first |
|
packet--; |
|
m_ReceivePacketNum = packet - 1; |
|
UpdateReceivePacketNum (packet); |
|
} |
|
else |
|
LogPrint (eLogError, "SSU2: Out of sequence packet ", packet, " is less than last received ", m_ReceivePacketNum); |
|
} |
|
if (m_OutOfSequencePackets.size () > 255*4) |
|
{ |
|
// seems we have a serious network issue |
|
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: Relay nonce ", it->first, " was not responded in ", SSU2_RELAY_NONCE_EXPIRATION_TIMEOUT, " seconds, deleted"); |
|
it = m_RelaySessions.erase (it); |
|
} |
|
else |
|
++it; |
|
} |
|
for (auto it = m_PeerTests.begin (); it != m_PeerTests.end ();) |
|
{ |
|
if (ts > it->second.second + SSU2_PEER_TEST_EXPIRATION_TIMEOUT) |
|
{ |
|
LogPrint (eLogWarning, "SSU2: Peer test nonce ", it->first, " was not responded in ", SSU2_PEER_TEST_EXPIRATION_TIMEOUT, " seconds, deleted"); |
|
it = m_PeerTests.erase (it); |
|
} |
|
else |
|
++it; |
|
} |
|
if (m_PathChallenge) |
|
RequestTermination (eSSU2TerminationReasonNormalClose); |
|
} |
|
|
|
void SSU2Session::FlushData () |
|
{ |
|
bool sent = SendQueue (); // if we have something to send |
|
if (sent) |
|
m_SendQueueSize = m_SendQueue.size (); |
|
if (m_IsDataReceived) |
|
{ |
|
if (!sent) SendQuickAck (); |
|
m_Handler.Flush (); |
|
m_IsDataReceived = false; |
|
} |
|
} |
|
|
|
} |
|
}
|
|
|