#include #include #include "I2PEndian.h" #include #include #include #include "base64.h" #include "Log.h" #include "Timestamp.h" #include "CryptoConst.h" #include "I2NPProtocol.h" #include "RouterContext.h" #include "Transports.h" #include "NTCPSession.h" using namespace i2p::crypto; namespace i2p { namespace transport { NTCPSession::NTCPSession (boost::asio::io_service& service, i2p::data::RouterInfo& in_RemoteRouterInfo): m_Socket (service), m_TerminationTimer (service), m_IsEstablished (false), m_RemoteRouterInfo (in_RemoteRouterInfo), m_ReceiveBufferOffset (0), m_NextMessage (nullptr), m_NumSentBytes (0), m_NumReceivedBytes (0) { m_DHKeysPair = transports.GetNextDHKeysPair (); m_Establisher = new Establisher; } NTCPSession::~NTCPSession () { delete m_Establisher; if (m_NextMessage) i2p::DeleteI2NPMessage (m_NextMessage); for (auto it :m_DelayedMessages) i2p::DeleteI2NPMessage (it); m_DelayedMessages.clear (); } void NTCPSession::CreateAESKey (uint8_t * pubKey, uint8_t * aesKey) { CryptoPP::DH dh (elgp, elgg); uint8_t sharedKey[256]; if (!dh.Agree (sharedKey, m_DHKeysPair->privateKey, pubKey)) { LogPrint ("Couldn't create shared key"); Terminate (); return; }; if (sharedKey[0] & 0x80) { aesKey[0] = 0; memcpy (aesKey + 1, sharedKey, 31); } else if (sharedKey[0]) memcpy (aesKey, sharedKey, 32); else { // find first non-zero byte uint8_t * nonZero = sharedKey + 1; while (!*nonZero) { nonZero++; if (nonZero - sharedKey > 32) { LogPrint ("First 32 bytes of shared key is all zeros. Ignored"); return; } } memcpy (aesKey, nonZero, 32); } } void NTCPSession::Terminate () { m_IsEstablished = false; m_Socket.close (); transports.RemoveNTCPSession (this); int numDelayed = 0; for (auto it :m_DelayedMessages) { // try to send them again transports.SendMessage (m_RemoteRouterInfo.GetIdentHash (), it); numDelayed++; } m_DelayedMessages.clear (); if (numDelayed > 0) LogPrint ("NTCP session ", numDelayed, " not sent"); // TODO: notify tunnels delete this; LogPrint ("NTCP session terminated"); } void NTCPSession::Connected () { LogPrint ("NTCP session connected"); m_IsEstablished = true; delete m_Establisher; m_Establisher = nullptr; delete m_DHKeysPair; m_DHKeysPair = nullptr; SendTimeSyncMessage (); SendI2NPMessage (CreateDatabaseStoreMsg ()); // we tell immediately who we are if (!m_DelayedMessages.empty ()) { for (auto it :m_DelayedMessages) SendI2NPMessage (it); m_DelayedMessages.clear (); } } void NTCPSession::ClientLogin () { if (!m_DHKeysPair) m_DHKeysPair = transports.GetNextDHKeysPair (); // send Phase1 const uint8_t * x = m_DHKeysPair->publicKey; memcpy (m_Establisher->phase1.pubKey, x, 256); CryptoPP::SHA256().CalculateDigest(m_Establisher->phase1.HXxorHI, x, 256); const uint8_t * ident = m_RemoteRouterInfo.GetIdentHash (); for (int i = 0; i < 32; i++) m_Establisher->phase1.HXxorHI[i] ^= ident[i]; boost::asio::async_write (m_Socket, boost::asio::buffer (&m_Establisher->phase1, sizeof (NTCPPhase1)), boost::asio::transfer_all (), boost::bind(&NTCPSession::HandlePhase1Sent, this, boost::asio::placeholders::error, boost::asio::placeholders::bytes_transferred)); } void NTCPSession::ServerLogin () { // receive Phase1 boost::asio::async_read (m_Socket, boost::asio::buffer(&m_Establisher->phase1, sizeof (NTCPPhase1)), boost::asio::transfer_all (), boost::bind(&NTCPSession::HandlePhase1Received, this, boost::asio::placeholders::error, boost::asio::placeholders::bytes_transferred)); } void NTCPSession::HandlePhase1Sent (const boost::system::error_code& ecode, std::size_t bytes_transferred) { if (ecode) { LogPrint ("Couldn't send Phase 1 message: ", ecode.message ()); if (ecode != boost::asio::error::operation_aborted) Terminate (); } else { LogPrint ("Phase 1 sent: ", bytes_transferred); boost::asio::async_read (m_Socket, boost::asio::buffer(&m_Establisher->phase2, sizeof (NTCPPhase2)), boost::asio::transfer_all (), boost::bind(&NTCPSession::HandlePhase2Received, this, boost::asio::placeholders::error, boost::asio::placeholders::bytes_transferred)); } } void NTCPSession::HandlePhase1Received (const boost::system::error_code& ecode, std::size_t bytes_transferred) { if (ecode) { LogPrint ("Phase 1 read error: ", ecode.message ()); if (ecode != boost::asio::error::operation_aborted) Terminate (); } else { LogPrint ("Phase 1 received: ", bytes_transferred); // verify ident uint8_t digest[32]; CryptoPP::SHA256().CalculateDigest(digest, m_Establisher->phase1.pubKey, 256); const uint8_t * ident = i2p::context.GetRouterInfo ().GetIdentHash (); for (int i = 0; i < 32; i++) { if ((m_Establisher->phase1.HXxorHI[i] ^ ident[i]) != digest[i]) { LogPrint ("Wrong ident"); Terminate (); return; } } SendPhase2 (); } } void NTCPSession::SendPhase2 () { if (!m_DHKeysPair) m_DHKeysPair = transports.GetNextDHKeysPair (); const uint8_t * y = m_DHKeysPair->publicKey; memcpy (m_Establisher->phase2.pubKey, y, 256); uint8_t xy[512]; memcpy (xy, m_Establisher->phase1.pubKey, 256); memcpy (xy + 256, y, 256); CryptoPP::SHA256().CalculateDigest(m_Establisher->phase2.encrypted.hxy, xy, 512); uint32_t tsB = htobe32 (i2p::util::GetSecondsSinceEpoch ()); m_Establisher->phase2.encrypted.timestamp = tsB; // TODO: fill filler uint8_t aesKey[32]; CreateAESKey (m_Establisher->phase1.pubKey, aesKey); m_Encryption.SetKey (aesKey); m_Encryption.SetIV (y + 240); m_Decryption.SetKey (aesKey); m_Decryption.SetIV (m_Establisher->phase1.HXxorHI + 16); m_Encryption.Encrypt ((uint8_t *)&m_Establisher->phase2.encrypted, sizeof(m_Establisher->phase2.encrypted), (uint8_t *)&m_Establisher->phase2.encrypted); boost::asio::async_write (m_Socket, boost::asio::buffer (&m_Establisher->phase2, sizeof (NTCPPhase2)), boost::asio::transfer_all (), boost::bind(&NTCPSession::HandlePhase2Sent, this, boost::asio::placeholders::error, boost::asio::placeholders::bytes_transferred, tsB)); } void NTCPSession::HandlePhase2Sent (const boost::system::error_code& ecode, std::size_t bytes_transferred, uint32_t tsB) { if (ecode) { LogPrint ("Couldn't send Phase 2 message: ", ecode.message ()); if (ecode != boost::asio::error::operation_aborted) Terminate (); } else { LogPrint ("Phase 2 sent: ", bytes_transferred); boost::asio::async_read (m_Socket, boost::asio::buffer(&m_Establisher->phase3, sizeof (NTCPPhase3)), boost::asio::transfer_all (), boost::bind(&NTCPSession::HandlePhase3Received, this, boost::asio::placeholders::error, boost::asio::placeholders::bytes_transferred, tsB)); } } void NTCPSession::HandlePhase2Received (const boost::system::error_code& ecode, std::size_t bytes_transferred) { if (ecode) { LogPrint ("Phase 2 read error: ", ecode.message (), ". Wrong ident assumed"); if (ecode != boost::asio::error::operation_aborted) { GetRemoteRouterInfo ().SetUnreachable (true); // this RouterInfo is not valid transports.ReuseDHKeysPair (m_DHKeysPair); m_DHKeysPair = nullptr; Terminate (); } } else { LogPrint ("Phase 2 received: ", bytes_transferred); uint8_t aesKey[32]; CreateAESKey (m_Establisher->phase2.pubKey, aesKey); m_Decryption.SetKey (aesKey); m_Decryption.SetIV (m_Establisher->phase2.pubKey + 240); m_Encryption.SetKey (aesKey); m_Encryption.SetIV (m_Establisher->phase1.HXxorHI + 16); m_Decryption.Decrypt((uint8_t *)&m_Establisher->phase2.encrypted, sizeof(m_Establisher->phase2.encrypted), (uint8_t *)&m_Establisher->phase2.encrypted); // verify uint8_t xy[512], hxy[32]; memcpy (xy, m_DHKeysPair->publicKey, 256); memcpy (xy + 256, m_Establisher->phase2.pubKey, 256); CryptoPP::SHA256().CalculateDigest(hxy, xy, 512); if (memcmp (hxy, m_Establisher->phase2.encrypted.hxy, 32)) { LogPrint ("Incorrect hash"); transports.ReuseDHKeysPair (m_DHKeysPair); m_DHKeysPair = nullptr; Terminate (); return ; } SendPhase3 (); } } void NTCPSession::SendPhase3 () { m_Establisher->phase3.size = htons (i2p::data::DEFAULT_IDENTITY_SIZE); memcpy (&m_Establisher->phase3.ident, &i2p::context.GetRouterIdentity (), i2p::data::DEFAULT_IDENTITY_SIZE); uint32_t tsA = htobe32 (i2p::util::GetSecondsSinceEpoch ()); m_Establisher->phase3.timestamp = tsA; SignedData s; memcpy (s.x, m_Establisher->phase1.pubKey, 256); memcpy (s.y, m_Establisher->phase2.pubKey, 256); memcpy (s.ident, m_RemoteRouterInfo.GetIdentHash (), 32); s.tsA = tsA; s.tsB = m_Establisher->phase2.encrypted.timestamp; i2p::context.Sign ((uint8_t *)&s, sizeof (s), m_Establisher->phase3.signature); m_Encryption.Encrypt((uint8_t *)&m_Establisher->phase3, sizeof(NTCPPhase3), (uint8_t *)&m_Establisher->phase3); boost::asio::async_write (m_Socket, boost::asio::buffer (&m_Establisher->phase3, sizeof (NTCPPhase3)), boost::asio::transfer_all (), boost::bind(&NTCPSession::HandlePhase3Sent, this, boost::asio::placeholders::error, boost::asio::placeholders::bytes_transferred, tsA)); } void NTCPSession::HandlePhase3Sent (const boost::system::error_code& ecode, std::size_t bytes_transferred, uint32_t tsA) { if (ecode) { LogPrint ("Couldn't send Phase 3 message: ", ecode.message ()); if (ecode != boost::asio::error::operation_aborted) Terminate (); } else { LogPrint ("Phase 3 sent: ", bytes_transferred); boost::asio::async_read (m_Socket, boost::asio::buffer(&m_Establisher->phase4, sizeof (NTCPPhase4)), boost::asio::transfer_all (), boost::bind(&NTCPSession::HandlePhase4Received, this, boost::asio::placeholders::error, boost::asio::placeholders::bytes_transferred, tsA)); } } void NTCPSession::HandlePhase3Received (const boost::system::error_code& ecode, std::size_t bytes_transferred, uint32_t tsB) { if (ecode) { LogPrint ("Phase 3 read error: ", ecode.message ()); if (ecode != boost::asio::error::operation_aborted) Terminate (); } else { LogPrint ("Phase 3 received: ", bytes_transferred); m_Decryption.Decrypt ((uint8_t *)&m_Establisher->phase3, sizeof(NTCPPhase3), (uint8_t *)&m_Establisher->phase3); m_RemoteRouterInfo.SetRouterIdentity (m_Establisher->phase3.ident); SignedData s; memcpy (s.x, m_Establisher->phase1.pubKey, 256); memcpy (s.y, m_Establisher->phase2.pubKey, 256); memcpy (s.ident, i2p::context.GetRouterInfo ().GetIdentHash (), 32); s.tsA = m_Establisher->phase3.timestamp; s.tsB = tsB; CryptoPP::DSA::PublicKey pubKey; pubKey.Initialize (dsap, dsaq, dsag, CryptoPP::Integer (m_RemoteRouterInfo.GetRouterIdentity ().signingKey, 128)); CryptoPP::DSA::Verifier verifier (pubKey); if (!verifier.VerifyMessage ((uint8_t *)&s, sizeof(s), m_Establisher->phase3.signature, 40)) { LogPrint ("signature verification failed"); Terminate (); return; } SendPhase4 (tsB); } } void NTCPSession::SendPhase4 (uint32_t tsB) { SignedData s; memcpy (s.x, m_Establisher->phase1.pubKey, 256); memcpy (s.y, m_Establisher->phase2.pubKey, 256); memcpy (s.ident, m_RemoteRouterInfo.GetIdentHash (), 32); s.tsA = m_Establisher->phase3.timestamp; s.tsB = tsB; i2p::context.Sign ((uint8_t *)&s, sizeof (s), m_Establisher->phase4.signature); m_Encryption.Encrypt ((uint8_t *)&m_Establisher->phase4, sizeof(NTCPPhase4), (uint8_t *)&m_Establisher->phase4); boost::asio::async_write (m_Socket, boost::asio::buffer (&m_Establisher->phase4, sizeof (NTCPPhase4)), boost::asio::transfer_all (), boost::bind(&NTCPSession::HandlePhase4Sent, this, boost::asio::placeholders::error, boost::asio::placeholders::bytes_transferred)); } void NTCPSession::HandlePhase4Sent (const boost::system::error_code& ecode, std::size_t bytes_transferred) { if (ecode) { LogPrint ("Couldn't send Phase 4 message: ", ecode.message ()); if (ecode != boost::asio::error::operation_aborted) Terminate (); } else { LogPrint ("Phase 4 sent: ", bytes_transferred); Connected (); m_ReceiveBufferOffset = 0; m_NextMessage = nullptr; Receive (); } } void NTCPSession::HandlePhase4Received (const boost::system::error_code& ecode, std::size_t bytes_transferred, uint32_t tsA) { if (ecode) { LogPrint ("Phase 4 read error: ", ecode.message ()); if (ecode != boost::asio::error::operation_aborted) { GetRemoteRouterInfo ().SetUnreachable (true); // this router doesn't like us Terminate (); } } else { LogPrint ("Phase 4 received: ", bytes_transferred); m_Decryption.Decrypt((uint8_t *)&m_Establisher->phase4, sizeof(NTCPPhase4), (uint8_t *)&m_Establisher->phase4); // verify signature SignedData s; memcpy (s.x, m_Establisher->phase1.pubKey, 256); memcpy (s.y, m_Establisher->phase2.pubKey, 256); memcpy (s.ident, i2p::context.GetRouterInfo ().GetIdentHash (), 32); s.tsA = tsA; s.tsB = m_Establisher->phase2.encrypted.timestamp; CryptoPP::DSA::PublicKey pubKey; pubKey.Initialize (dsap, dsaq, dsag, CryptoPP::Integer (m_RemoteRouterInfo.GetRouterIdentity ().signingKey, 128)); CryptoPP::DSA::Verifier verifier (pubKey); if (!verifier.VerifyMessage ((uint8_t *)&s, sizeof(s), m_Establisher->phase4.signature, 40)) { LogPrint ("signature verification failed"); Terminate (); return; } Connected (); m_ReceiveBufferOffset = 0; m_NextMessage = nullptr; Receive (); } } void NTCPSession::Receive () { m_Socket.async_read_some (boost::asio::buffer(m_ReceiveBuffer + m_ReceiveBufferOffset, NTCP_BUFFER_SIZE - m_ReceiveBufferOffset), boost::bind(&NTCPSession::HandleReceived, this, boost::asio::placeholders::error, boost::asio::placeholders::bytes_transferred)); } void NTCPSession::HandleReceived (const boost::system::error_code& ecode, std::size_t bytes_transferred) { if (ecode) { LogPrint ("Read error: ", ecode.message ()); if (ecode != boost::asio::error::operation_aborted) Terminate (); } else { m_NumReceivedBytes += bytes_transferred; m_ReceiveBufferOffset += bytes_transferred; if (m_ReceiveBufferOffset >= 16) { uint8_t * nextBlock = m_ReceiveBuffer; while (m_ReceiveBufferOffset >= 16) { if (!DecryptNextBlock (nextBlock)) // 16 bytes { Terminate (); return; } nextBlock += 16; m_ReceiveBufferOffset -= 16; } if (m_ReceiveBufferOffset > 0) memcpy (m_ReceiveBuffer, nextBlock, m_ReceiveBufferOffset); } ScheduleTermination (); // reset termination timer Receive (); } } bool NTCPSession::DecryptNextBlock (const uint8_t * encrypted) // 16 bytes { if (!m_NextMessage) // new message, header expected { m_NextMessage = i2p::NewI2NPMessage (); m_NextMessageOffset = 0; m_Decryption.Decrypt (encrypted, m_NextMessage->buf); uint16_t dataSize = be16toh (*(uint16_t *)m_NextMessage->buf); if (dataSize) { // new message if (dataSize > NTCP_MAX_MESSAGE_SIZE) { LogPrint ("NTCP data size ", dataSize, " exceeds max size"); i2p::DeleteI2NPMessage (m_NextMessage); m_NextMessage = nullptr; return false; } m_NextMessageOffset += 16; m_NextMessage->offset = 2; // size field m_NextMessage->len = dataSize + 2; } else { // timestamp LogPrint ("Timestamp"); i2p::DeleteI2NPMessage (m_NextMessage); m_NextMessage = nullptr; return true; } } else // message continues { m_Decryption.Decrypt (encrypted, m_NextMessage->buf + m_NextMessageOffset); m_NextMessageOffset += 16; } if (m_NextMessageOffset >= m_NextMessage->len + 4) // +checksum { // we have a complete I2NP message i2p::HandleI2NPMessage (m_NextMessage); m_NextMessage = nullptr; } return true; } void NTCPSession::Send (i2p::I2NPMessage * msg) { uint8_t * sendBuffer; int len; if (msg) { // regular I2NP if (msg->offset < 2) { LogPrint ("Malformed I2NP message"); i2p::DeleteI2NPMessage (msg); } sendBuffer = msg->GetBuffer () - 2; len = msg->GetLength (); *((uint16_t *)sendBuffer) = htobe16 (len); } else { // prepare timestamp sendBuffer = m_TimeSyncBuffer; len = 4; *((uint16_t *)sendBuffer) = 0; *((uint32_t *)(sendBuffer + 2)) = htobe32 (time (0)); } int rem = (len + 6) & 0x0F; // %16 int padding = 0; if (rem > 0) padding = 16 - rem; // TODO: fill padding m_Adler.CalculateDigest (sendBuffer + len + 2 + padding, sendBuffer, len + 2+ padding); int l = len + padding + 6; m_Encryption.Encrypt(sendBuffer, l, sendBuffer); boost::asio::async_write (m_Socket, boost::asio::buffer (sendBuffer, l), boost::asio::transfer_all (), boost::bind(&NTCPSession::HandleSent, this, boost::asio::placeholders::error, boost::asio::placeholders::bytes_transferred, msg)); } void NTCPSession::HandleSent (const boost::system::error_code& ecode, std::size_t bytes_transferred, i2p::I2NPMessage * msg) { if (msg) i2p::DeleteI2NPMessage (msg); if (ecode) { LogPrint ("Couldn't send msg: ", ecode.message ()); // we shouldn't call Terminate () here, because HandleReceive takes care // TODO: 'delete this' statement in Terminate () must be eliminated later // Terminate (); } else { m_NumSentBytes += bytes_transferred; ScheduleTermination (); // reset termination timer } } void NTCPSession::SendTimeSyncMessage () { Send (nullptr); } void NTCPSession::SendI2NPMessage (I2NPMessage * msg) { if (msg) { if (m_IsEstablished) Send (msg); else m_DelayedMessages.push_back (msg); } } void NTCPSession::ScheduleTermination () { m_TerminationTimer.cancel (); m_TerminationTimer.expires_from_now (boost::posix_time::seconds(NTCP_TERMINATION_TIMEOUT)); m_TerminationTimer.async_wait (boost::bind (&NTCPSession::HandleTerminationTimer, this, boost::asio::placeholders::error)); } void NTCPSession::HandleTerminationTimer (const boost::system::error_code& ecode) { if (ecode != boost::asio::error::operation_aborted) { LogPrint ("No activity fo ", NTCP_TERMINATION_TIMEOUT, " seconds"); Terminate (); } } NTCPClient::NTCPClient (boost::asio::io_service& service, const boost::asio::ip::address& address, int port, i2p::data::RouterInfo& in_RouterInfo): NTCPSession (service, in_RouterInfo), m_Endpoint (address, port) { Connect (); } void NTCPClient::Connect () { LogPrint ("Connecting to ", m_Endpoint.address ().to_string (),":", m_Endpoint.port ()); GetSocket ().async_connect (m_Endpoint, boost::bind (&NTCPClient::HandleConnect, this, boost::asio::placeholders::error)); } void NTCPClient::HandleConnect (const boost::system::error_code& ecode) { if (ecode) { LogPrint ("Connect error: ", ecode.message ()); if (ecode != boost::asio::error::operation_aborted) { GetRemoteRouterInfo ().SetUnreachable (true); Terminate (); } } else { LogPrint ("Connected"); ClientLogin (); } } void NTCPServerConnection::Connected () { LogPrint ("NTCP server session connected"); SetIsEstablished (true); transports.AddNTCPSession (this); SendTimeSyncMessage (); SendI2NPMessage (CreateDatabaseStoreMsg ()); // we tell immediately who we are } } }