mirror of
https://github.com/PurpleI2P/i2pd.git
synced 2024-11-17 21:26:04 +00:00
376 lines
15 KiB
C++
376 lines
15 KiB
C++
/*
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* Copyright (c) 2022-2023, 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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#ifndef SSU2_SESSION_H__
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#define SSU2_SESSION_H__
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#include <memory>
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#include <functional>
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#include <map>
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#include <set>
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#include <list>
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#include <boost/asio.hpp>
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#include "Crypto.h"
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#include "RouterInfo.h"
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#include "RouterContext.h"
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#include "TransportSession.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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const int SSU2_CONNECT_TIMEOUT = 5; // 5 seconds
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const int SSU2_TERMINATION_TIMEOUT = 330; // 5.5 minutes
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const int SSU2_CLOCK_SKEW = 60; // in seconds
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const int SSU2_CLOCK_THRESHOLD = 15; // in seconds, if more we should adjust
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const int SSU2_TOKEN_EXPIRATION_TIMEOUT = 9; // for Retry message, in seconds
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const int SSU2_NEXT_TOKEN_EXPIRATION_TIMEOUT = 52*60; // for next token block, in seconds
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const int SSU2_TOKEN_EXPIRATION_THRESHOLD = 2; // in seconds
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const int SSU2_RELAY_NONCE_EXPIRATION_TIMEOUT = 10; // in seconds
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const int SSU2_PEER_TEST_EXPIRATION_TIMEOUT = 60; // 60 seconds
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const size_t SSU2_MAX_PACKET_SIZE = 1500;
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const size_t SSU2_MIN_PACKET_SIZE = 1280;
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const int SSU2_HANDSHAKE_RESEND_INTERVAL = 1000; // in milliseconds
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const int SSU2_RESEND_INTERVAL = 300; // in milliseconds
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const int SSU2_MAX_NUM_RESENDS = 5;
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const int SSU2_INCOMPLETE_MESSAGES_CLEANUP_TIMEOUT = 30; // in seconds
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const int SSU2_MAX_NUM_RECEIVED_I2NP_MSGIDS = 5000; // how many msgID we store for duplicates check
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const int SSU2_RECEIVED_I2NP_MSGIDS_CLEANUP_TIMEOUT = 10; // in seconds
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const int SSU2_DECAY_INTERVAL = 20; // in seconds
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const size_t SSU2_MIN_WINDOW_SIZE = 16; // in packets
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const size_t SSU2_MAX_WINDOW_SIZE = 256; // in packets
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const size_t SSU2_MIN_RTO = 100; // in milliseconds
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const size_t SSU2_MAX_RTO = 2500; // in milliseconds
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const float SSU2_kAPPA = 1.8;
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const size_t SSU2_MAX_OUTGOING_QUEUE_SIZE = 500; // in messages
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const int SSU2_MAX_NUM_ACNT = 255; // acnt, acks or nacks
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const int SSU2_MAX_NUM_ACK_PACKETS = 510; // 2*255 ack + nack
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const int SSU2_MAX_NUM_ACK_RANGES = 32; // to send
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const uint8_t SSU2_MAX_NUM_FRAGMENTS = 64;
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// flags
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const uint8_t SSU2_FLAG_IMMEDIATE_ACK_REQUESTED = 0x01;
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enum SSU2MessageType
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{
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eSSU2SessionRequest = 0,
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eSSU2SessionCreated = 1,
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eSSU2SessionConfirmed = 2,
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eSSU2Data = 6,
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eSSU2PeerTest = 7,
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eSSU2Retry = 9,
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eSSU2TokenRequest = 10,
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eSSU2HolePunch = 11
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};
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enum SSU2BlockType
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{
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eSSU2BlkDateTime = 0,
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eSSU2BlkOptions, // 1
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eSSU2BlkRouterInfo, // 2
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eSSU2BlkI2NPMessage, // 3
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eSSU2BlkFirstFragment, // 4
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eSSU2BlkFollowOnFragment, // 5
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eSSU2BlkTermination, // 6
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eSSU2BlkRelayRequest, // 7
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eSSU2BlkRelayResponse, // 8
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eSSU2BlkRelayIntro, // 9
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eSSU2BlkPeerTest, // 10
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eSSU2BlkNextNonce, // 11
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eSSU2BlkAck, // 12
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eSSU2BlkAddress, // 13
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eSSU2BlkIntroKey, // 14
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eSSU2BlkRelayTagRequest, // 15
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eSSU2BlkRelayTag, // 16
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eSSU2BlkNewToken, // 17
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eSSU2BlkPathChallenge, // 18
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eSSU2BlkPathResponse, // 19
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eSSU2BlkFirstPacketNumber, // 20
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eSSU2BlkPadding = 254
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};
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enum SSU2SessionState
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{
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eSSU2SessionStateUnknown,
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eSSU2SessionStateTokenReceived,
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eSSU2SessionStateSessionRequestSent,
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eSSU2SessionStateSessionRequestReceived,
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eSSU2SessionStateSessionCreatedSent,
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eSSU2SessionStateSessionCreatedReceived,
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eSSU2SessionStateSessionConfirmedSent,
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eSSU2SessionStateEstablished,
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eSSU2SessionStateClosing,
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eSSU2SessionStateClosingConfirmed,
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eSSU2SessionStateTerminated,
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eSSU2SessionStateFailed,
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eSSU2SessionStateIntroduced,
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eSSU2SessionStatePeerTest,
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eSSU2SessionStatePeerTestReceived, // 5 before 4
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eSSU2SessionStateTokenRequestReceived
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};
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enum SSU2PeerTestCode
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{
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eSSU2PeerTestCodeAccept = 0,
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eSSU2PeerTestCodeBobReasonUnspecified = 1,
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eSSU2PeerTestCodeBobNoCharlieAvailable = 2,
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eSSU2PeerTestCodeBobLimitExceeded = 3,
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eSSU2PeerTestCodeBobSignatureFailure = 4,
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eSSU2PeerTestCodeCharlieReasonUnspecified = 64,
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eSSU2PeerTestCodeCharlieUnsupportedAddress = 65,
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eSSU2PeerTestCodeCharlieLimitExceeded = 66,
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eSSU2PeerTestCodeCharlieSignatureFailure = 67,
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eSSU2PeerTestCodeCharlieAliceIsAlreadyConnected = 68,
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eSSU2PeerTestCodeCharlieAliceIsBanned = 69,
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eSSU2PeerTestCodeCharlieAliceIsUnknown = 70,
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eSSU2PeerTestCodeUnspecified = 128
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};
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enum SSU2RelayResponseCode
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{
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eSSU2RelayResponseCodeAccept = 0,
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eSSU2RelayResponseCodeBobRelayTagNotFound = 5,
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eSSU2RelayResponseCodeCharlieUnsupportedAddress = 65,
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eSSU2RelayResponseCodeCharlieSignatureFailure = 67,
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eSSU2RelayResponseCodeCharlieAliceIsUnknown = 70
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};
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enum SSU2TerminationReason
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{
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eSSU2TerminationReasonNormalClose = 0,
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eSSU2TerminationReasonTerminationReceived = 1,
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eSSU2TerminationReasonIdleTimeout = 2,
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eSSU2TerminationReasonRouterShutdown = 3,
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eSSU2TerminationReasonDataPhaseAEADFailure= 4,
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eSSU2TerminationReasonIncompatibleOptions = 5,
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eSSU2TerminationReasonTncompatibleSignatureType = 6,
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eSSU2TerminationReasonClockSkew = 7,
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eSSU2TerminationPaddingViolation = 8,
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eSSU2TerminationReasonAEADFramingError = 9,
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eSSU2TerminationReasonPayloadFormatError = 10,
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eSSU2TerminationReasonSessionRequestError = 11,
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eSSU2TerminationReasonSessionCreatedError = 12,
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eSSU2TerminationReasonSessionConfirmedError = 13,
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eSSU2TerminationReasonTimeout = 14,
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eSSU2TerminationReasonRouterInfoSignatureVerificationFail = 15,
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eSSU2TerminationReasonInvalidS = 16,
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eSSU2TerminationReasonBanned = 17,
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eSSU2TerminationReasonBadToken = 18,
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eSSU2TerminationReasonConnectionLimits = 19,
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eSSU2TerminationReasonIncompatibleVersion = 20,
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eSSU2TerminationReasonWrongNetID = 21,
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eSSU2TerminationReasonReplacedByNewSession = 22
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};
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struct SSU2IncompleteMessage
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{
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struct Fragment
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{
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uint8_t buf[SSU2_MAX_PACKET_SIZE];
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size_t len;
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int fragmentNum;
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bool isLast;
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std::shared_ptr<Fragment> next;
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};
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std::shared_ptr<I2NPMessage> msg;
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int nextFragmentNum;
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uint32_t lastFragmentInsertTime; // in seconds
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std::shared_ptr<Fragment> outOfSequenceFragments; // #1 and more
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void AttachNextFragment (const uint8_t * fragment, size_t fragmentSize);
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bool ConcatOutOfSequenceFragments (); // true if message complete
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void AddOutOfSequenceFragment (std::shared_ptr<Fragment> fragment);
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};
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struct SSU2SentPacket
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{
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uint8_t payload[SSU2_MAX_PACKET_SIZE];
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size_t payloadSize = 0;
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uint64_t sendTime; // in milliseconds
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int numResends = 0;
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};
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// RouterInfo flags
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const uint8_t SSU2_ROUTER_INFO_FLAG_REQUEST_FLOOD = 0x01;
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const uint8_t SSU2_ROUTER_INFO_FLAG_GZIP = 0x02;
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class SSU2Server;
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class SSU2Session: public TransportSession, public std::enable_shared_from_this<SSU2Session>
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{
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union Header
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{
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uint64_t ll[2];
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uint8_t buf[16];
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struct
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{
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uint64_t connID;
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uint32_t packetNum;
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uint8_t type;
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uint8_t flags[3];
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} h;
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};
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struct HandshakePacket
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{
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Header header;
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uint8_t headerX[48]; // part1 for SessionConfirmed
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uint8_t payload[SSU2_MAX_PACKET_SIZE*2];
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size_t payloadSize = 0;
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uint64_t sendTime = 0; // in milliseconds
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bool isSecondFragment = false; // for SessionConfirmed
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};
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typedef std::function<void ()> OnEstablished;
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public:
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SSU2Session (SSU2Server& server, std::shared_ptr<const i2p::data::RouterInfo> in_RemoteRouter = nullptr,
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std::shared_ptr<const i2p::data::RouterInfo::Address> addr = nullptr);
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~SSU2Session ();
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void SetRemoteEndpoint (const boost::asio::ip::udp::endpoint& ep) { m_RemoteEndpoint = ep; };
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const boost::asio::ip::udp::endpoint& GetRemoteEndpoint () const { return m_RemoteEndpoint; };
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i2p::data::RouterInfo::CompatibleTransports GetRemoteTransports () const { return m_RemoteTransports; };
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std::shared_ptr<const i2p::data::RouterInfo::Address> GetAddress () const { return m_Address; };
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void SetOnEstablished (OnEstablished e) { m_OnEstablished = e; };
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OnEstablished GetOnEstablished () const { return m_OnEstablished; };
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void Connect ();
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bool Introduce (std::shared_ptr<SSU2Session> session, uint32_t relayTag);
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void WaitForIntroduction ();
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void SendPeerTest (); // Alice, Data message
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void SendKeepAlive ();
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void RequestTermination (SSU2TerminationReason reason);
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void CleanUp (uint64_t ts);
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void FlushData ();
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void Done () override;
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void SendLocalRouterInfo (bool update) override;
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void SendI2NPMessages (const std::vector<std::shared_ptr<I2NPMessage> >& msgs) override;
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uint32_t GetRelayTag () const override { return m_RelayTag; };
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size_t Resend (uint64_t ts); // return number or resent packets
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bool IsEstablished () const override { return m_State == eSSU2SessionStateEstablished; };
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uint64_t GetConnID () const { return m_SourceConnID; };
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SSU2SessionState GetState () const { return m_State; };
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void SetState (SSU2SessionState state) { m_State = state; };
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bool ProcessFirstIncomingMessage (uint64_t connID, uint8_t * buf, size_t len);
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bool ProcessSessionCreated (uint8_t * buf, size_t len);
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bool ProcessSessionConfirmed (uint8_t * buf, size_t len);
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bool ProcessRetry (uint8_t * buf, size_t len);
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bool ProcessHolePunch (uint8_t * buf, size_t len);
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bool ProcessPeerTest (uint8_t * buf, size_t len);
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void ProcessData (uint8_t * buf, size_t len, const boost::asio::ip::udp::endpoint& from);
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private:
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void Terminate ();
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void Established ();
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void ScheduleConnectTimer ();
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void HandleConnectTimer (const boost::system::error_code& ecode);
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void PostI2NPMessages (std::vector<std::shared_ptr<I2NPMessage> > msgs);
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bool SendQueue (); // returns true if ack block was sent
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bool SendFragmentedMessage (std::shared_ptr<I2NPMessage> msg);
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void ResendHandshakePacket ();
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void ConnectAfterIntroduction ();
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void ProcessSessionRequest (Header& header, uint8_t * buf, size_t len);
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void ProcessTokenRequest (Header& header, uint8_t * buf, size_t len);
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void SendSessionRequest (uint64_t token = 0);
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void SendSessionCreated (const uint8_t * X);
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void SendSessionConfirmed (const uint8_t * Y);
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void KDFDataPhase (uint8_t * keydata_ab, uint8_t * keydata_ba);
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void SendTokenRequest ();
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void SendRetry ();
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uint32_t SendData (const uint8_t * buf, size_t len, uint8_t flags = 0); // returns packet num
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void SendQuickAck ();
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void SendTermination ();
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void SendHolePunch (uint32_t nonce, const boost::asio::ip::udp::endpoint& ep, const uint8_t * introKey, uint64_t token);
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void SendPeerTest (uint8_t msg, const uint8_t * signedData, size_t signedDataLen, const uint8_t * introKey); // PeerTest message
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void SendPathResponse (const uint8_t * data, size_t len);
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void SendPathChallenge ();
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void HandlePayload (const uint8_t * buf, size_t len);
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void HandleDateTime (const uint8_t * buf, size_t len);
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void HandleAck (const uint8_t * buf, size_t len);
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void HandleAckRange (uint32_t firstPacketNum, uint32_t lastPacketNum, uint64_t ts);
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void HandleAddress (const uint8_t * buf, size_t len);
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bool ExtractEndpoint (const uint8_t * buf, size_t size, boost::asio::ip::udp::endpoint& ep);
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size_t CreateEndpoint (uint8_t * buf, size_t len, const boost::asio::ip::udp::endpoint& ep);
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std::shared_ptr<const i2p::data::RouterInfo::Address> FindLocalAddress () const;
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void AdjustMaxPayloadSize ();
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RouterStatus GetRouterStatus () const;
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void SetRouterStatus (RouterStatus status) const;
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std::shared_ptr<const i2p::data::RouterInfo> ExtractRouterInfo (const uint8_t * buf, size_t size);
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void CreateNonce (uint64_t seqn, uint8_t * nonce);
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bool UpdateReceivePacketNum (uint32_t packetNum); // for Ack, returns false if duplicate
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void HandleFirstFragment (const uint8_t * buf, size_t len);
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void HandleFollowOnFragment (const uint8_t * buf, size_t len);
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void HandleRelayRequest (const uint8_t * buf, size_t len);
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void HandleRelayIntro (const uint8_t * buf, size_t len, int attempts = 0);
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void HandleRelayResponse (const uint8_t * buf, size_t len);
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void HandlePeerTest (const uint8_t * buf, size_t len);
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void HandleI2NPMsg (std::shared_ptr<I2NPMessage>&& msg);
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size_t CreateAddressBlock (uint8_t * buf, size_t len, const boost::asio::ip::udp::endpoint& ep);
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size_t CreateRouterInfoBlock (uint8_t * buf, size_t len, std::shared_ptr<const i2p::data::RouterInfo> r);
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size_t CreateAckBlock (uint8_t * buf, size_t len);
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size_t CreatePaddingBlock (uint8_t * buf, size_t len, size_t minSize = 0);
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size_t CreateI2NPBlock (uint8_t * buf, size_t len, std::shared_ptr<I2NPMessage>&& msg);
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size_t CreateFirstFragmentBlock (uint8_t * buf, size_t len, std::shared_ptr<I2NPMessage> msg);
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size_t CreateFollowOnFragmentBlock (uint8_t * buf, size_t len, std::shared_ptr<I2NPMessage> msg, uint8_t& fragmentNum, uint32_t msgID);
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size_t CreateRelayIntroBlock (uint8_t * buf, size_t len, const uint8_t * introData, size_t introDataLen);
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size_t CreateRelayResponseBlock (uint8_t * buf, size_t len, SSU2RelayResponseCode code, uint32_t nonce, uint64_t token, bool v4);
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size_t CreatePeerTestBlock (uint8_t * buf, size_t len, uint8_t msg, SSU2PeerTestCode code, const uint8_t * routerHash, const uint8_t * signedData, size_t signedDataLen);
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size_t CreatePeerTestBlock (uint8_t * buf, size_t len, uint32_t nonce); // Alice
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size_t CreateTerminationBlock (uint8_t * buf, size_t len);
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private:
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SSU2Server& m_Server;
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std::shared_ptr<i2p::crypto::X25519Keys> m_EphemeralKeys;
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std::unique_ptr<i2p::crypto::NoiseSymmetricState> m_NoiseState;
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std::unique_ptr<HandshakePacket> m_SessionConfirmedFragment; // for Bob if applicable or second fragment for Alice
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std::unique_ptr<HandshakePacket> m_SentHandshakePacket; // SessionRequest, SessionCreated or SessionConfirmed
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std::shared_ptr<const i2p::data::RouterInfo::Address> m_Address;
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boost::asio::ip::udp::endpoint m_RemoteEndpoint;
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i2p::data::RouterInfo::CompatibleTransports m_RemoteTransports; // for peer tests
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uint64_t m_DestConnID, m_SourceConnID;
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SSU2SessionState m_State;
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uint8_t m_KeyDataSend[64], m_KeyDataReceive[64];
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uint32_t m_SendPacketNum, m_ReceivePacketNum;
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std::set<uint32_t> m_OutOfSequencePackets; // packet nums > receive packet num
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std::map<uint32_t, std::shared_ptr<SSU2SentPacket> > m_SentPackets; // packetNum -> packet
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std::unordered_map<uint32_t, std::shared_ptr<SSU2IncompleteMessage> > m_IncompleteMessages; // msgID -> I2NP
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std::map<uint32_t, std::pair <std::shared_ptr<SSU2Session>, uint64_t > > m_RelaySessions; // nonce->(Alice, timestamp) for Bob or nonce->(Charlie, timestamp) for Alice
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std::map<uint32_t, std::pair <std::shared_ptr<SSU2Session>, uint64_t > > m_PeerTests; // same as for relay sessions
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std::list<std::shared_ptr<I2NPMessage> > m_SendQueue;
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i2p::I2NPMessagesHandler m_Handler;
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bool m_IsDataReceived;
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size_t m_WindowSize, m_RTT, m_RTO;
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uint32_t m_RelayTag; // between Bob and Charlie
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OnEstablished m_OnEstablished; // callback from Established
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boost::asio::deadline_timer m_ConnectTimer;
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SSU2TerminationReason m_TerminationReason;
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size_t m_MaxPayloadSize;
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std::unique_ptr<i2p::data::IdentHash> m_PathChallenge;
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std::unordered_map<uint32_t, uint32_t> m_ReceivedI2NPMsgIDs; // msgID -> timestamp in seconds
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};
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inline uint64_t CreateHeaderMask (const uint8_t * kh, const uint8_t * nonce)
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{
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uint64_t data = 0;
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i2p::crypto::ChaCha20 ((uint8_t *)&data, 8, kh, nonce, (uint8_t *)&data);
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return data;
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}
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}
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}
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#endif
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