1 /* 2 * Copyright (c) 2013-2021, The PurpleI2P Project 3 * 4 * This file is part of Purple i2pd project and licensed under BSD3 5 * 6 * See full license text in LICENSE file at top of project tree 7 * 8 */ 9 #ifndef NTCP2_H__ 10 #define NTCP2_H__ 11 12 #include <inttypes.h> 13 #include <memory> 14 #include <list> 15 #include <map> 16 #include <array> 17 #include <openssl/bn.h> 18 #include <openssl/evp.h> 19 #include <boost/asio.hpp> 20 #include "Crypto.h" 21 #include "util.h" 22 #include "RouterInfo.h" 23 #include "TransportSession.h" 24 25 namespace i2p 26 { 27 namespace transport 28 { 29 30 const size_t NTCP2_UNENCRYPTED_FRAME_MAX_SIZE = 65519; 31 const size_t NTCP2_SESSION_REQUEST_MAX_SIZE = 287; 32 const size_t NTCP2_SESSION_CREATED_MAX_SIZE = 287; 33 const int NTCP2_MAX_PADDING_RATIO = 6; // in % 34 35 const int NTCP2_CONNECT_TIMEOUT = 5; // 5 seconds 36 const int NTCP2_ESTABLISH_TIMEOUT = 10; // 10 seconds 37 const int NTCP2_TERMINATION_TIMEOUT = 120; // 2 minutes 38 const int NTCP2_TERMINATION_CHECK_TIMEOUT = 30; // 30 seconds 39 const int NTCP2_RECEIVE_BUFFER_DELETION_TIMEOUT = 3; // 3 seconds 40 const int NTCP2_ROUTERINFO_RESEND_INTERVAL = 25*60; // 25 minuntes in seconds 41 const int NTCP2_ROUTERINFO_RESEND_INTERVAL_THRESHOLD = 25*60; // 25 minuntes 42 43 const int NTCP2_CLOCK_SKEW = 60; // in seconds 44 const int NTCP2_MAX_OUTGOING_QUEUE_SIZE = 500; // how many messages we can queue up 45 46 enum NTCP2BlockType 47 { 48 eNTCP2BlkDateTime = 0, 49 eNTCP2BlkOptions, // 1 50 eNTCP2BlkRouterInfo, // 2 51 eNTCP2BlkI2NPMessage, // 3 52 eNTCP2BlkTermination, // 4 53 eNTCP2BlkPadding = 254 54 }; 55 56 enum NTCP2TerminationReason 57 { 58 eNTCP2NormalClose = 0, 59 eNTCP2TerminationReceived, // 1 60 eNTCP2IdleTimeout, // 2 61 eNTCP2RouterShutdown, // 3 62 eNTCP2DataPhaseAEADFailure, // 4 63 eNTCP2IncompatibleOptions, // 5 64 eNTCP2IncompatibleSignatureType, // 6 65 eNTCP2ClockSkew, // 7 66 eNTCP2PaddingViolation, // 8 67 eNTCP2AEADFramingError, // 9 68 eNTCP2PayloadFormatError, // 10 69 eNTCP2Message1Error, // 11 70 eNTCP2Message2Error, // 12 71 eNTCP2Message3Error, // 13 72 eNTCP2IntraFrameReadTimeout, // 14 73 eNTCP2RouterInfoSignatureVerificationFail, // 15 74 eNTCP2IncorrectSParameter, // 16 75 eNTCP2Banned, // 17 76 }; 77 78 // RouterInfo flags 79 const uint8_t NTCP2_ROUTER_INFO_FLAG_REQUEST_FLOOD = 0x01; 80 81 struct NTCP2Establisher: private i2p::crypto::NoiseSymmetricState 82 { 83 NTCP2Establisher (); 84 ~NTCP2Establisher (); 85 GetPubNTCP2Establisher86 const uint8_t * GetPub () const { return m_EphemeralKeys->GetPublicKey (); }; GetRemotePubNTCP2Establisher87 const uint8_t * GetRemotePub () const { return m_RemoteEphemeralPublicKey; }; // Y for Alice and X for Bob GetRemotePubNTCP2Establisher88 uint8_t * GetRemotePub () { return m_RemoteEphemeralPublicKey; }; // to set 89 GetKNTCP2Establisher90 const uint8_t * GetK () const { return m_CK + 32; }; GetCKNTCP2Establisher91 const uint8_t * GetCK () const { return m_CK; }; GetHNTCP2Establisher92 const uint8_t * GetH () const { return m_H; }; 93 94 void KDF1Alice (); 95 void KDF1Bob (); 96 void KDF2Alice (); 97 void KDF2Bob (); 98 void KDF3Alice (); // for SessionConfirmed part 2 99 void KDF3Bob (); 100 101 void KeyDerivationFunction1 (const uint8_t * pub, i2p::crypto::X25519Keys& priv, const uint8_t * rs, const uint8_t * epub); // for SessionRequest, (pub, priv) for DH 102 void KeyDerivationFunction2 (const uint8_t * sessionRequest, size_t sessionRequestLen, const uint8_t * epub); // for SessionCreate 103 void CreateEphemeralKey (); 104 105 void CreateSessionRequestMessage (); 106 void CreateSessionCreatedMessage (); 107 void CreateSessionConfirmedMessagePart1 (const uint8_t * nonce); 108 void CreateSessionConfirmedMessagePart2 (const uint8_t * nonce); 109 110 bool ProcessSessionRequestMessage (uint16_t& paddingLen); 111 bool ProcessSessionCreatedMessage (uint16_t& paddingLen); 112 bool ProcessSessionConfirmedMessagePart1 (const uint8_t * nonce); 113 bool ProcessSessionConfirmedMessagePart2 (const uint8_t * nonce, uint8_t * m3p2Buf); 114 115 std::shared_ptr<i2p::crypto::X25519Keys> m_EphemeralKeys; 116 uint8_t m_RemoteEphemeralPublicKey[32]; // x25519 117 uint8_t m_RemoteStaticKey[32], m_IV[16]; 118 i2p::data::IdentHash m_RemoteIdentHash; 119 uint16_t m3p2Len; 120 121 uint8_t m_SessionRequestBuffer[NTCP2_SESSION_REQUEST_MAX_SIZE], 122 m_SessionCreatedBuffer[NTCP2_SESSION_CREATED_MAX_SIZE], * m_SessionConfirmedBuffer; 123 size_t m_SessionRequestBufferLen, m_SessionCreatedBufferLen; 124 125 }; 126 127 class NTCP2Server; 128 class NTCP2Session: public TransportSession, public std::enable_shared_from_this<NTCP2Session> 129 { 130 public: 131 132 NTCP2Session (NTCP2Server& server, std::shared_ptr<const i2p::data::RouterInfo> in_RemoteRouter = nullptr, 133 std::shared_ptr<const i2p::data::RouterInfo::Address> addr = nullptr); 134 ~NTCP2Session (); 135 void Terminate (); 136 void TerminateByTimeout (); 137 void Done (); Close()138 void Close () { m_Socket.close (); }; // for accept 139 void DeleteNextReceiveBuffer (uint64_t ts); 140 GetSocket()141 boost::asio::ip::tcp::socket& GetSocket () { return m_Socket; }; GetRemoteEndpoint()142 const boost::asio::ip::tcp::endpoint& GetRemoteEndpoint () { return m_RemoteEndpoint; }; SetRemoteEndpoint(const boost::asio::ip::tcp::endpoint & ep)143 void SetRemoteEndpoint (const boost::asio::ip::tcp::endpoint& ep) { m_RemoteEndpoint = ep; }; 144 IsEstablished()145 bool IsEstablished () const { return m_IsEstablished; }; IsTerminated()146 bool IsTerminated () const { return m_IsTerminated; }; 147 148 void ClientLogin (); // Alice 149 void ServerLogin (); // Bob 150 151 void SendLocalRouterInfo (); // after handshake 152 void SendI2NPMessages (const std::vector<std::shared_ptr<I2NPMessage> >& msgs); 153 154 private: 155 156 void Established (); 157 158 void CreateNonce (uint64_t seqn, uint8_t * nonce); 159 void CreateNextReceivedBuffer (size_t size); 160 void KeyDerivationFunctionDataPhase (); 161 void SetSipKeys (const uint8_t * sendSipKey, const uint8_t * receiveSipKey); 162 163 // establish 164 void SendSessionRequest (); 165 void SendSessionCreated (); 166 void SendSessionConfirmed (); 167 168 void HandleSessionRequestSent (const boost::system::error_code& ecode, std::size_t bytes_transferred); 169 void HandleSessionRequestReceived (const boost::system::error_code& ecode, std::size_t bytes_transferred); 170 void HandleSessionRequestPaddingReceived (const boost::system::error_code& ecode, std::size_t bytes_transferred); 171 void HandleSessionCreatedSent (const boost::system::error_code& ecode, std::size_t bytes_transferred); 172 void HandleSessionCreatedReceived (const boost::system::error_code& ecode, std::size_t bytes_transferred); 173 void HandleSessionCreatedPaddingReceived (const boost::system::error_code& ecode, std::size_t bytes_transferred); 174 void HandleSessionConfirmedSent (const boost::system::error_code& ecode, std::size_t bytes_transferred); 175 void HandleSessionConfirmedReceived (const boost::system::error_code& ecode, std::size_t bytes_transferred); 176 177 // data 178 void ReceiveLength (); 179 void HandleReceivedLength (const boost::system::error_code& ecode, std::size_t bytes_transferred); 180 void Receive (); 181 void HandleReceived (const boost::system::error_code& ecode, std::size_t bytes_transferred); 182 void ProcessNextFrame (const uint8_t * frame, size_t len); 183 184 void SetNextSentFrameLength (size_t frameLen, uint8_t * lengthBuf); 185 void SendI2NPMsgs (std::vector<std::shared_ptr<I2NPMessage> >& msgs); 186 void HandleI2NPMsgsSent (const boost::system::error_code& ecode, std::size_t bytes_transferred, std::vector<std::shared_ptr<I2NPMessage> > msgs); 187 void EncryptAndSendNextBuffer (size_t payloadLen); 188 void HandleNextFrameSent (const boost::system::error_code& ecode, std::size_t bytes_transferred); 189 size_t CreatePaddingBlock (size_t msgLen, uint8_t * buf, size_t len); 190 void SendQueue (); 191 void SendRouterInfo (); 192 void SendTermination (NTCP2TerminationReason reason); 193 void SendTerminationAndTerminate (NTCP2TerminationReason reason); 194 void PostI2NPMessages (std::vector<std::shared_ptr<I2NPMessage> > msgs); 195 196 private: 197 198 NTCP2Server& m_Server; 199 boost::asio::ip::tcp::socket m_Socket; 200 boost::asio::ip::tcp::endpoint m_RemoteEndpoint; 201 bool m_IsEstablished, m_IsTerminated; 202 203 std::unique_ptr<NTCP2Establisher> m_Establisher; 204 // data phase 205 uint8_t m_Kab[32], m_Kba[32], m_Sipkeysab[32], m_Sipkeysba[32]; 206 const uint8_t * m_SendKey, * m_ReceiveKey; 207 #if OPENSSL_SIPHASH 208 EVP_MD_CTX * m_SendMDCtx, * m_ReceiveMDCtx; 209 #else 210 const uint8_t * m_SendSipKey, * m_ReceiveSipKey; 211 #endif 212 uint16_t m_NextReceivedLen; 213 uint8_t * m_NextReceivedBuffer, * m_NextSendBuffer; 214 size_t m_NextReceivedBufferSize; 215 union 216 { 217 uint8_t buf[8]; 218 uint16_t key; 219 } m_ReceiveIV, m_SendIV; 220 uint64_t m_ReceiveSequenceNumber, m_SendSequenceNumber; 221 222 i2p::I2NPMessagesHandler m_Handler; 223 224 bool m_IsSending, m_IsReceiving; 225 std::list<std::shared_ptr<I2NPMessage> > m_SendQueue; 226 uint64_t m_NextRouterInfoResendTime; // seconds since epoch 227 228 uint16_t m_PaddingSizes[16]; 229 int m_NextPaddingSize; 230 }; 231 232 class NTCP2Server: private i2p::util::RunnableServiceWithWork 233 { 234 public: 235 236 enum ProxyType 237 { 238 eNoProxy, 239 eSocksProxy, 240 eHTTPProxy 241 }; 242 243 NTCP2Server (); 244 ~NTCP2Server (); 245 246 void Start (); 247 void Stop (); GetService()248 boost::asio::io_service& GetService () { return GetIOService (); }; 249 250 bool AddNTCP2Session (std::shared_ptr<NTCP2Session> session, bool incoming = false); 251 void RemoveNTCP2Session (std::shared_ptr<NTCP2Session> session); 252 std::shared_ptr<NTCP2Session> FindNTCP2Session (const i2p::data::IdentHash& ident); 253 254 void ConnectWithProxy (std::shared_ptr<NTCP2Session> conn); 255 void Connect(std::shared_ptr<NTCP2Session> conn); 256 UsingProxy()257 bool UsingProxy() const { return m_ProxyType != eNoProxy; }; 258 void UseProxy(ProxyType proxy, const std::string& address, uint16_t port, const std::string& user, const std::string& pass); 259 260 void SetLocalAddress (const boost::asio::ip::address& localAddress); 261 262 private: 263 264 void HandleAccept (std::shared_ptr<NTCP2Session> conn, const boost::system::error_code& error); 265 void HandleAcceptV6 (std::shared_ptr<NTCP2Session> conn, const boost::system::error_code& error); 266 267 void HandleConnect (const boost::system::error_code& ecode, std::shared_ptr<NTCP2Session> conn, std::shared_ptr<boost::asio::deadline_timer> timer); 268 void HandleProxyConnect(const boost::system::error_code& ecode, std::shared_ptr<NTCP2Session> conn, std::shared_ptr<boost::asio::deadline_timer> timer); 269 void AfterSocksHandshake(std::shared_ptr<NTCP2Session> conn, std::shared_ptr<boost::asio::deadline_timer> timer); 270 271 // timer 272 void ScheduleTermination (); 273 void HandleTerminationTimer (const boost::system::error_code& ecode); 274 275 private: 276 277 boost::asio::deadline_timer m_TerminationTimer; 278 std::unique_ptr<boost::asio::ip::tcp::acceptor> m_NTCP2Acceptor, m_NTCP2V6Acceptor; 279 std::map<i2p::data::IdentHash, std::shared_ptr<NTCP2Session> > m_NTCP2Sessions; 280 std::list<std::shared_ptr<NTCP2Session> > m_PendingIncomingSessions; 281 282 ProxyType m_ProxyType; 283 std::string m_ProxyAddress, m_ProxyAuthorization; 284 uint16_t m_ProxyPort; 285 boost::asio::ip::tcp::resolver m_Resolver; 286 std::unique_ptr<boost::asio::ip::tcp::endpoint> m_ProxyEndpoint; 287 std::shared_ptr<boost::asio::ip::tcp::endpoint> m_Address4, m_Address6, m_YggdrasilAddress; 288 289 public: 290 291 // for HTTP/I2PControl decltype(m_NTCP2Sessions)292 const decltype(m_NTCP2Sessions)& GetNTCP2Sessions () const { return m_NTCP2Sessions; }; 293 }; 294 } 295 } 296 297 #endif 298