diff --git a/libi2pd/SSU2.cpp b/libi2pd/SSU2.cpp index daa9244f..fdaa5889 100644 --- a/libi2pd/SSU2.cpp +++ b/libi2pd/SSU2.cpp @@ -54,7 +54,11 @@ namespace transport void SSU2Session::Connect () { - SendSessionRequest (); + auto token = m_Server.FindOutgoingToken (m_RemoteEndpoint); + if (token) + SendSessionRequest (token); + else + SendTokenRequest (); } void SSU2Session::SendSessionRequest (uint64_t token) @@ -242,9 +246,7 @@ namespace transport header.h.connID = m_DestConnID; // dest id header.h.packetNum = 0; header.h.type = eSSU2SessionConfirmed; - header.h.flags[0] = 2; // ver - header.h.flags[1] = (uint8_t)i2p::context.GetNetID (); // netID - header.h.flags[2] = 0; // flag + memset (header.h.flags, 0, 3); // payload uint8_t payload[SSU2_MTU]; size_t payloadSize = i2p::context.GetRouterInfo ().GetBufferLen (); @@ -367,6 +369,42 @@ namespace transport return true; } + + void SSU2Session::SendTokenRequest () + { + // we are Alice + Header header; + uint8_t h[32], payload[40]; + // fill packet + header.h.connID = m_DestConnID; // dest id + header.h.packetNum = 0; + 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::GetSecondsSinceEpoch ()); + size_t payloadSize = 7; + uint8_t paddingSize = (rand () & 0x0F) + 1; // 1 - 16 + payload[payloadSize] = eSSU2BlkPadding; + htobe16buf (payload + payloadSize + 1, paddingSize); + payloadSize += paddingSize + 3; + // encrypt + const uint8_t nonce[12] = {0}; + 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)); + i2p::crypto::ChaCha20 (h + 16, 16, m_Address->i, nonce, h + 16); + // send + m_Server.AddPendingOutgoingSession (m_RemoteEndpoint, shared_from_this ()); + m_Server.Send (header.buf, 16, h + 16, 16, payload, payloadSize, m_RemoteEndpoint); + } bool SSU2Session::ProcessRetry (uint8_t * buf, size_t len) { @@ -383,8 +421,9 @@ namespace transport const uint8_t nonce[12] = {0}; uint64_t headerX[2]; // sourceConnID, token i2p::crypto::ChaCha20 (buf + 16, 16, m_Address->i, nonce, (uint8_t *)headerX); + m_Server.UpdateOutgoingToken (m_RemoteEndpoint, headerX[1], i2p::util::GetSecondsSinceEpoch () + SSU2_TOKEN_EXPIRATION_TIMEOUT); // TODO: decrypt and handle payload - InitNoiseXKState1 (*m_NoiseState, m_Address->s); // reset Noise + InitNoiseXKState1 (*m_NoiseState, m_Address->s); // reset Noise TODO: check state SendSessionRequest (headerX[1]); return true; } @@ -457,7 +496,9 @@ namespace transport case eSSU2BlkNewToken: { LogPrint (eLogDebug, "SSU2: New token"); - // TODO: + uint64_t token; + memcpy (&token, buf + offset + 4, 8); + m_Server.UpdateOutgoingToken (m_RemoteEndpoint, token, bufbe32toh (buf + offset)); break; } case eSSU2BlkPathChallenge: @@ -761,9 +802,38 @@ namespace transport else it++; } + + for (auto it = m_IncomingTokens.begin (); it != m_IncomingTokens.end (); ) + { + if (ts > it->second.second) + it = m_IncomingTokens.erase (it); + else + it++; + } + + for (auto it = m_OutgoingTokens.begin (); it != m_OutgoingTokens.end (); ) + { + if (ts > it->second.second) + it = m_OutgoingTokens.erase (it); + else + it++; + } ScheduleTermination (); } + } + + void SSU2Server::UpdateOutgoingToken (const boost::asio::ip::udp::endpoint& ep, uint64_t token, uint32_t exp) + { + m_OutgoingTokens[ep] = {token, exp}; + } + + uint64_t SSU2Server::FindOutgoingToken (const boost::asio::ip::udp::endpoint& ep) + { + auto it = m_OutgoingTokens.find (ep); + if (it != m_OutgoingTokens.end ()) + return it->second.first; + return 0; } } } diff --git a/libi2pd/SSU2.h b/libi2pd/SSU2.h index 0e3fb449..99cd23ff 100644 --- a/libi2pd/SSU2.h +++ b/libi2pd/SSU2.h @@ -24,6 +24,7 @@ namespace transport const int SSU2_CONNECT_TIMEOUT = 5; // 5 seconds const int SSU2_TERMINATION_TIMEOUT = 330; // 5.5 minutes const int SSU2_TERMINATION_CHECK_TIMEOUT = 30; // 30 seconds + const int SSU2_TOKEN_EXPIRATION_TIMEOUT = 9; // in second const size_t SSU2_SOCKET_RECEIVE_BUFFER_SIZE = 0x1FFFF; // 128K const size_t SSU2_SOCKET_SEND_BUFFER_SIZE = 0x1FFFF; // 128K const size_t SSU2_MTU = 1488; @@ -33,7 +34,8 @@ namespace transport eSSU2SessionRequest = 0, eSSU2SessionCreated = 1, eSSU2SessionConfirmed = 2, - eSSU2Retry = 9 + eSSU2Retry = 9, + eSSU2TokenRequest = 10 }; enum SSU2BlockType @@ -104,6 +106,7 @@ namespace transport void SendSessionRequest (uint64_t token = 0); void SendSessionCreated (const uint8_t * X); void SendSessionConfirmed (const uint8_t * Y); + void SendTokenRequest (); void HandlePayload (const uint8_t * buf, size_t len); bool ExtractEndpoint (const uint8_t * buf, size_t size, boost::asio::ip::udp::endpoint& ep); @@ -147,6 +150,9 @@ namespace transport bool CreateSession (std::shared_ptr router, std::shared_ptr address); + + void UpdateOutgoingToken (const boost::asio::ip::udp::endpoint& ep, uint64_t token, uint32_t exp); + uint64_t FindOutgoingToken (const boost::asio::ip::udp::endpoint& ep); private: @@ -164,6 +170,7 @@ namespace transport boost::asio::ip::udp::socket m_Socket, m_SocketV6; std::unordered_map > m_Sessions; std::map > m_PendingOutgoingSessions; + std::map > m_IncomingTokens, m_OutgoingTokens; // remote endpoint -> (token, expires in seconds) i2p::util::MemoryPoolMt m_PacketsPool; boost::asio::deadline_timer m_TerminationTimer; };