#ifndef SSU_SESSION_H__ #define SSU_SESSION_H__ #include <inttypes.h> #include <set> #include <memory> #include "Crypto.h" #include "I2NPProtocol.h" #include "TransportSession.h" #include "SSUData.h" namespace i2p { namespace transport { const uint8_t SSU_HEADER_EXTENDED_OPTIONS_INCLUDED = 0x04; struct SSUHeader { uint8_t mac[16]; uint8_t iv[16]; uint8_t flag; uint8_t time[4]; uint8_t GetPayloadType () const { return flag >> 4; }; bool IsExtendedOptions () const { return flag & SSU_HEADER_EXTENDED_OPTIONS_INCLUDED; }; }; const int SSU_CONNECT_TIMEOUT = 5; // 5 seconds const int SSU_TERMINATION_TIMEOUT = 330; // 5.5 minutes // payload types (4 bits) const uint8_t PAYLOAD_TYPE_SESSION_REQUEST = 0; const uint8_t PAYLOAD_TYPE_SESSION_CREATED = 1; const uint8_t PAYLOAD_TYPE_SESSION_CONFIRMED = 2; const uint8_t PAYLOAD_TYPE_RELAY_REQUEST = 3; const uint8_t PAYLOAD_TYPE_RELAY_RESPONSE = 4; const uint8_t PAYLOAD_TYPE_RELAY_INTRO = 5; const uint8_t PAYLOAD_TYPE_DATA = 6; const uint8_t PAYLOAD_TYPE_PEER_TEST = 7; const uint8_t PAYLOAD_TYPE_SESSION_DESTROYED = 8; // extended options const uint16_t EXTENDED_OPTIONS_FLAG_REQUEST_RELAY_TAG = 0x0001; enum SessionState { eSessionStateUnknown, eSessionStateIntroduced, eSessionStateEstablished, eSessionStateClosed, eSessionStateFailed }; enum PeerTestParticipant { ePeerTestParticipantUnknown = 0, ePeerTestParticipantAlice1, ePeerTestParticipantAlice2, ePeerTestParticipantBob, ePeerTestParticipantCharlie }; class SSUServer; class SSUSession: public TransportSession, public std::enable_shared_from_this<SSUSession> { public: SSUSession (SSUServer& server, boost::asio::ip::udp::endpoint& remoteEndpoint, std::shared_ptr<const i2p::data::RouterInfo> router = nullptr, bool peerTest = false); void ProcessNextMessage (uint8_t * buf, size_t len, const boost::asio::ip::udp::endpoint& senderEndpoint); ~SSUSession (); void Connect (); void WaitForConnect (); void Introduce (const i2p::data::RouterInfo::Introducer& introducer, std::shared_ptr<const i2p::data::RouterInfo> to); // Alice to Charlie void WaitForIntroduction (); void Close (); void Done (); boost::asio::ip::udp::endpoint& GetRemoteEndpoint () { return m_RemoteEndpoint; }; bool IsV6 () const { return m_RemoteEndpoint.address ().is_v6 (); }; void SendI2NPMessages (const std::vector<std::shared_ptr<I2NPMessage> >& msgs); void SendPeerTest (); // Alice SessionState GetState () const { return m_State; }; size_t GetNumSentBytes () const { return m_NumSentBytes; }; size_t GetNumReceivedBytes () const { return m_NumReceivedBytes; }; void SendKeepAlive (); uint32_t GetRelayTag () const { return m_RelayTag; }; const i2p::data::RouterInfo::IntroKey& GetIntroKey () const { return m_IntroKey; }; uint32_t GetCreationTime () const { return m_CreationTime; }; void FlushData (); private: boost::asio::io_service& GetService (); void CreateAESandMacKey (const uint8_t * pubKey); size_t GetSSUHeaderSize (const uint8_t * buf) const; void PostI2NPMessages (std::vector<std::shared_ptr<I2NPMessage> > msgs); void ProcessMessage (uint8_t * buf, size_t len, const boost::asio::ip::udp::endpoint& senderEndpoint); // call for established session void ProcessSessionRequest (const uint8_t * buf, size_t len, const boost::asio::ip::udp::endpoint& senderEndpoint); void SendSessionRequest (); void SendRelayRequest (const i2p::data::RouterInfo::Introducer& introducer, uint32_t nonce); void ProcessSessionCreated (uint8_t * buf, size_t len); void SendSessionCreated (const uint8_t * x, bool sendRelayTag = true); void ProcessSessionConfirmed (const uint8_t * buf, size_t len); void SendSessionConfirmed (const uint8_t * y, const uint8_t * ourAddress, size_t ourAddressLen); void ProcessRelayRequest (const uint8_t * buf, size_t len, const boost::asio::ip::udp::endpoint& from); void SendRelayResponse (uint32_t nonce, const boost::asio::ip::udp::endpoint& from, const uint8_t * introKey, const boost::asio::ip::udp::endpoint& to); void SendRelayIntro (std::shared_ptr<SSUSession> session, const boost::asio::ip::udp::endpoint& from); void ProcessRelayResponse (const uint8_t * buf, size_t len); void ProcessRelayIntro (const uint8_t * buf, size_t len); void Established (); void Failed (); void ScheduleConnectTimer (); void HandleConnectTimer (const boost::system::error_code& ecode); void ProcessPeerTest (const uint8_t * buf, size_t len, const boost::asio::ip::udp::endpoint& senderEndpoint); void SendPeerTest (uint32_t nonce, const boost::asio::ip::address& address, uint16_t port, const uint8_t * introKey, bool toAddress = true, bool sendAddress = true); void ProcessData (uint8_t * buf, size_t len); void SendSesionDestroyed (); void Send (uint8_t type, const uint8_t * payload, size_t len); // with session key void Send (const uint8_t * buf, size_t size); void FillHeaderAndEncrypt (uint8_t payloadType, uint8_t * buf, size_t len, const i2p::crypto::AESKey& aesKey, const uint8_t * iv, const i2p::crypto::MACKey& macKey, uint8_t flag = 0); void FillHeaderAndEncrypt (uint8_t payloadType, uint8_t * buf, size_t len); // with session key void Decrypt (uint8_t * buf, size_t len, const i2p::crypto::AESKey& aesKey); void DecryptSessionKey (uint8_t * buf, size_t len); bool Validate (uint8_t * buf, size_t len, const i2p::crypto::MACKey& macKey); void ScheduleTermination (); void HandleTerminationTimer (const boost::system::error_code& ecode); private: friend class SSUData; // TODO: change in later SSUServer& m_Server; boost::asio::ip::udp::endpoint m_RemoteEndpoint; boost::asio::deadline_timer m_Timer; bool m_IsPeerTest; SessionState m_State; bool m_IsSessionKey; uint32_t m_RelayTag; i2p::crypto::CBCEncryption m_SessionKeyEncryption; i2p::crypto::CBCDecryption m_SessionKeyDecryption; i2p::crypto::AESKey m_SessionKey; i2p::crypto::MACKey m_MacKey; i2p::data::RouterInfo::IntroKey m_IntroKey; uint32_t m_CreationTime; // seconds since epoch SSUData m_Data; bool m_IsDataReceived; std::unique_ptr<SignedData> m_SignedData; // we need it for SessionConfirmed only std::map<uint32_t, std::shared_ptr<const i2p::data::RouterInfo> > m_RelayRequests; // nonce->Charlie }; } } #endif