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I2P: End-to-End encrypted and anonymous Internet
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315 lines
14 KiB
315 lines
14 KiB
/* |
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* Copyright (c) 2013-2023, 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 I2NP_PROTOCOL_H__ |
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#define I2NP_PROTOCOL_H__ |
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#include <inttypes.h> |
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#include <string.h> |
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#include <set> |
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#include <memory> |
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#include "Crypto.h" |
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#include "I2PEndian.h" |
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#include "Identity.h" |
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#include "RouterInfo.h" |
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#include "LeaseSet.h" |
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namespace i2p |
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{ |
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// I2NP header |
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const size_t I2NP_HEADER_TYPEID_OFFSET = 0; |
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const size_t I2NP_HEADER_MSGID_OFFSET = I2NP_HEADER_TYPEID_OFFSET + 1; |
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const size_t I2NP_HEADER_EXPIRATION_OFFSET = I2NP_HEADER_MSGID_OFFSET + 4; |
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const size_t I2NP_HEADER_SIZE_OFFSET = I2NP_HEADER_EXPIRATION_OFFSET + 8; |
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const size_t I2NP_HEADER_CHKS_OFFSET = I2NP_HEADER_SIZE_OFFSET + 2; |
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const size_t I2NP_HEADER_SIZE = I2NP_HEADER_CHKS_OFFSET + 1; |
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// I2NP short header |
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const size_t I2NP_SHORT_HEADER_TYPEID_OFFSET = 0; |
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const size_t I2NP_SHORT_HEADER_EXPIRATION_OFFSET = I2NP_SHORT_HEADER_TYPEID_OFFSET + 1; |
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const size_t I2NP_SHORT_HEADER_SIZE = I2NP_SHORT_HEADER_EXPIRATION_OFFSET + 4; |
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// I2NP NTCP2 header |
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const size_t I2NP_NTCP2_HEADER_SIZE = I2NP_HEADER_EXPIRATION_OFFSET + 4; |
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// Tunnel Gateway header |
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const size_t TUNNEL_GATEWAY_HEADER_TUNNELID_OFFSET = 0; |
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const size_t TUNNEL_GATEWAY_HEADER_LENGTH_OFFSET = TUNNEL_GATEWAY_HEADER_TUNNELID_OFFSET + 4; |
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const size_t TUNNEL_GATEWAY_HEADER_SIZE = TUNNEL_GATEWAY_HEADER_LENGTH_OFFSET + 2; |
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// DeliveryStatus |
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const size_t DELIVERY_STATUS_MSGID_OFFSET = 0; |
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const size_t DELIVERY_STATUS_TIMESTAMP_OFFSET = DELIVERY_STATUS_MSGID_OFFSET + 4; |
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const size_t DELIVERY_STATUS_SIZE = DELIVERY_STATUS_TIMESTAMP_OFFSET + 8; |
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// DatabaseStore |
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const size_t DATABASE_STORE_KEY_OFFSET = 0; |
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const size_t DATABASE_STORE_TYPE_OFFSET = DATABASE_STORE_KEY_OFFSET + 32; |
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const size_t DATABASE_STORE_REPLY_TOKEN_OFFSET = DATABASE_STORE_TYPE_OFFSET + 1; |
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const size_t DATABASE_STORE_HEADER_SIZE = DATABASE_STORE_REPLY_TOKEN_OFFSET + 4; |
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// TunnelBuild |
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const size_t TUNNEL_BUILD_RECORD_SIZE = 528; |
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const size_t SHORT_TUNNEL_BUILD_RECORD_SIZE = 218; |
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// BuildRequestRecordEncrypted |
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const size_t BUILD_REQUEST_RECORD_TO_PEER_OFFSET = 0; |
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const size_t BUILD_REQUEST_RECORD_ENCRYPTED_OFFSET = BUILD_REQUEST_RECORD_TO_PEER_OFFSET + 16; |
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// ECIES BuildRequestRecordClearText |
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const size_t ECIES_BUILD_REQUEST_RECORD_RECEIVE_TUNNEL_OFFSET = 0; |
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const size_t ECIES_BUILD_REQUEST_RECORD_NEXT_TUNNEL_OFFSET = ECIES_BUILD_REQUEST_RECORD_RECEIVE_TUNNEL_OFFSET + 4; |
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const size_t ECIES_BUILD_REQUEST_RECORD_NEXT_IDENT_OFFSET = ECIES_BUILD_REQUEST_RECORD_NEXT_TUNNEL_OFFSET + 4; |
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const size_t ECIES_BUILD_REQUEST_RECORD_LAYER_KEY_OFFSET = ECIES_BUILD_REQUEST_RECORD_NEXT_IDENT_OFFSET + 32; |
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const size_t ECIES_BUILD_REQUEST_RECORD_IV_KEY_OFFSET = ECIES_BUILD_REQUEST_RECORD_LAYER_KEY_OFFSET + 32; |
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const size_t ECIES_BUILD_REQUEST_RECORD_REPLY_KEY_OFFSET = ECIES_BUILD_REQUEST_RECORD_IV_KEY_OFFSET + 32; |
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const size_t ECIES_BUILD_REQUEST_RECORD_REPLY_IV_OFFSET = ECIES_BUILD_REQUEST_RECORD_REPLY_KEY_OFFSET + 32; |
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const size_t ECIES_BUILD_REQUEST_RECORD_FLAG_OFFSET = ECIES_BUILD_REQUEST_RECORD_REPLY_IV_OFFSET + 16; |
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const size_t ECIES_BUILD_REQUEST_RECORD_MORE_FLAGS_OFFSET = ECIES_BUILD_REQUEST_RECORD_FLAG_OFFSET + 1; |
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const size_t ECIES_BUILD_REQUEST_RECORD_REQUEST_TIME_OFFSET = ECIES_BUILD_REQUEST_RECORD_MORE_FLAGS_OFFSET + 3; |
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const size_t ECIES_BUILD_REQUEST_RECORD_REQUEST_EXPIRATION_OFFSET = ECIES_BUILD_REQUEST_RECORD_REQUEST_TIME_OFFSET + 4; |
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const size_t ECIES_BUILD_REQUEST_RECORD_SEND_MSG_ID_OFFSET = ECIES_BUILD_REQUEST_RECORD_REQUEST_EXPIRATION_OFFSET + 4; |
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const size_t ECIES_BUILD_REQUEST_RECORD_PADDING_OFFSET = ECIES_BUILD_REQUEST_RECORD_SEND_MSG_ID_OFFSET + 4; |
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const size_t ECIES_BUILD_REQUEST_RECORD_CLEAR_TEXT_SIZE = 464; |
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// ECIES BuildResponseRecord |
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const size_t ECIES_BUILD_RESPONSE_RECORD_OPTIONS_OFFSET = 0; |
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const size_t ECIES_BUILD_RESPONSE_RECORD_RET_OFFSET = 511; |
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// ShortRequestRecordClearText |
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const size_t SHORT_REQUEST_RECORD_ENCRYPTED_OFFSET = 16; |
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const size_t SHORT_REQUEST_RECORD_RECEIVE_TUNNEL_OFFSET = 0; |
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const size_t SHORT_REQUEST_RECORD_NEXT_TUNNEL_OFFSET = SHORT_REQUEST_RECORD_RECEIVE_TUNNEL_OFFSET + 4; |
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const size_t SHORT_REQUEST_RECORD_NEXT_IDENT_OFFSET = SHORT_REQUEST_RECORD_NEXT_TUNNEL_OFFSET + 4; |
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const size_t SHORT_REQUEST_RECORD_FLAG_OFFSET = SHORT_REQUEST_RECORD_NEXT_IDENT_OFFSET + 32; |
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const size_t SHORT_REQUEST_RECORD_MORE_FLAGS_OFFSET = SHORT_REQUEST_RECORD_FLAG_OFFSET + 1; |
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const size_t SHORT_REQUEST_RECORD_LAYER_ENCRYPTION_TYPE = SHORT_REQUEST_RECORD_MORE_FLAGS_OFFSET + 2; |
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const size_t SHORT_REQUEST_RECORD_REQUEST_TIME_OFFSET = SHORT_REQUEST_RECORD_LAYER_ENCRYPTION_TYPE + 1; |
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const size_t SHORT_REQUEST_RECORD_REQUEST_EXPIRATION_OFFSET = SHORT_REQUEST_RECORD_REQUEST_TIME_OFFSET + 4; |
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const size_t SHORT_REQUEST_RECORD_SEND_MSG_ID_OFFSET = SHORT_REQUEST_RECORD_REQUEST_EXPIRATION_OFFSET + 4; |
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const size_t SHORT_REQUEST_RECORD_PADDING_OFFSET = SHORT_REQUEST_RECORD_SEND_MSG_ID_OFFSET + 4; |
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const size_t SHORT_REQUEST_RECORD_CLEAR_TEXT_SIZE = 154; |
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// ShortResponseRecord |
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const size_t SHORT_RESPONSE_RECORD_OPTIONS_OFFSET = 0; |
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const size_t SHORT_RESPONSE_RECORD_RET_OFFSET = 201; |
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enum I2NPMessageType |
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{ |
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eI2NPDummyMsg = 0, |
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eI2NPDatabaseStore = 1, |
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eI2NPDatabaseLookup = 2, |
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eI2NPDatabaseSearchReply = 3, |
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eI2NPDeliveryStatus = 10, |
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eI2NPGarlic = 11, |
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eI2NPTunnelData = 18, |
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eI2NPTunnelGateway = 19, |
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eI2NPData = 20, |
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eI2NPTunnelBuild = 21, |
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eI2NPTunnelBuildReply = 22, |
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eI2NPVariableTunnelBuild = 23, |
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eI2NPVariableTunnelBuildReply = 24, |
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eI2NPShortTunnelBuild = 25, |
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eI2NPShortTunnelBuildReply = 26 |
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}; |
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const uint8_t TUNNEL_BUILD_RECORD_GATEWAY_FLAG = 0x80; |
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const uint8_t TUNNEL_BUILD_RECORD_ENDPOINT_FLAG = 0x40; |
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const int NUM_TUNNEL_BUILD_RECORDS = 8; |
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// DatabaseLookup flags |
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const uint8_t DATABASE_LOOKUP_DELIVERY_FLAG = 0x01; |
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const uint8_t DATABASE_LOOKUP_ENCRYPTION_FLAG = 0x02; |
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const uint8_t DATABASE_LOOKUP_ECIES_FLAG = 0x10; |
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const uint8_t DATABASE_LOOKUP_TYPE_FLAGS_MASK = 0x0C; |
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const uint8_t DATABASE_LOOKUP_TYPE_NORMAL_LOOKUP = 0; |
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const uint8_t DATABASE_LOOKUP_TYPE_LEASESET_LOOKUP = 0x04; // 0100 |
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const uint8_t DATABASE_LOOKUP_TYPE_ROUTERINFO_LOOKUP = 0x08; // 1000 |
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const uint8_t DATABASE_LOOKUP_TYPE_EXPLORATORY_LOOKUP = 0x0C; // 1100 |
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namespace tunnel |
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{ |
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class InboundTunnel; |
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class TunnelPool; |
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} |
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const size_t I2NP_MAX_MESSAGE_SIZE = 62708; |
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const size_t I2NP_MAX_SHORT_MESSAGE_SIZE = 4096; |
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const size_t I2NP_MAX_MEDIUM_MESSAGE_SIZE = 16384; |
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const unsigned int I2NP_MESSAGE_EXPIRATION_TIMEOUT = 8000; // in milliseconds (as initial RTT) |
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const unsigned int I2NP_MESSAGE_CLOCK_SKEW = 60*1000; // 1 minute in milliseconds |
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struct I2NPMessage |
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{ |
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uint8_t * buf; |
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size_t len, offset, maxLen; |
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std::shared_ptr<i2p::tunnel::InboundTunnel> from; |
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I2NPMessage (): buf (nullptr),len (I2NP_HEADER_SIZE + 2), |
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offset(2), maxLen (0), from (nullptr) {}; // reserve 2 bytes for NTCP header |
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// header accessors |
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uint8_t * GetHeader () { return GetBuffer (); }; |
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const uint8_t * GetHeader () const { return GetBuffer (); }; |
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void SetTypeID (uint8_t typeID) { GetHeader ()[I2NP_HEADER_TYPEID_OFFSET] = typeID; }; |
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uint8_t GetTypeID () const { return GetHeader ()[I2NP_HEADER_TYPEID_OFFSET]; }; |
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void SetMsgID (uint32_t msgID) { htobe32buf (GetHeader () + I2NP_HEADER_MSGID_OFFSET, msgID); }; |
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uint32_t GetMsgID () const { return bufbe32toh (GetHeader () + I2NP_HEADER_MSGID_OFFSET); }; |
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void SetExpiration (uint64_t expiration) { htobe64buf (GetHeader () + I2NP_HEADER_EXPIRATION_OFFSET, expiration); }; |
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uint64_t GetExpiration () const { return bufbe64toh (GetHeader () + I2NP_HEADER_EXPIRATION_OFFSET); }; |
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void SetSize (uint16_t size) { htobe16buf (GetHeader () + I2NP_HEADER_SIZE_OFFSET, size); }; |
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uint16_t GetSize () const { return bufbe16toh (GetHeader () + I2NP_HEADER_SIZE_OFFSET); }; |
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void UpdateSize () { SetSize (GetPayloadLength ()); }; |
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void SetChks (uint8_t chks) { GetHeader ()[I2NP_HEADER_CHKS_OFFSET] = chks; }; |
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void UpdateChks () |
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{ |
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uint8_t hash[32]; |
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SHA256(GetPayload (), GetPayloadLength (), hash); |
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GetHeader ()[I2NP_HEADER_CHKS_OFFSET] = hash[0]; |
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} |
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// payload |
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uint8_t * GetPayload () { return GetBuffer () + I2NP_HEADER_SIZE; }; |
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const uint8_t * GetPayload () const { return GetBuffer () + I2NP_HEADER_SIZE; }; |
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uint8_t * GetBuffer () { return buf + offset; }; |
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const uint8_t * GetBuffer () const { return buf + offset; }; |
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size_t GetLength () const { return len - offset; }; |
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size_t GetPayloadLength () const { return GetLength () - I2NP_HEADER_SIZE; }; |
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void Align (size_t alignment) |
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{ |
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if (len + alignment > maxLen) return; |
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size_t rem = ((size_t)GetBuffer ()) % alignment; |
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if (rem) |
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{ |
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offset += (alignment - rem); |
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len += (alignment - rem); |
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} |
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} |
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size_t Concat (const uint8_t * buf1, size_t len1) |
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{ |
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// make sure with don't write beyond maxLen |
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if (len + len1 > maxLen) len1 = maxLen - len; |
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memcpy (buf + len, buf1, len1); |
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len += len1; |
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return len1; |
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} |
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I2NPMessage& operator=(const I2NPMessage& other) |
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{ |
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memcpy (buf + offset, other.buf + other.offset, other.GetLength ()); |
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len = offset + other.GetLength (); |
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from = other.from; |
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return *this; |
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} |
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// for SSU only |
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uint8_t * GetSSUHeader () { return buf + offset + I2NP_HEADER_SIZE - I2NP_SHORT_HEADER_SIZE; }; |
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void FromSSU (uint32_t msgID) // we have received SSU message and convert it to regular |
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{ |
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const uint8_t * ssu = GetSSUHeader (); |
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GetHeader ()[I2NP_HEADER_TYPEID_OFFSET] = ssu[I2NP_SHORT_HEADER_TYPEID_OFFSET]; // typeid |
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SetMsgID (msgID); |
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SetExpiration (bufbe32toh (ssu + I2NP_SHORT_HEADER_EXPIRATION_OFFSET)*1000LL); |
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SetSize (len - offset - I2NP_HEADER_SIZE); |
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SetChks (0); |
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} |
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uint32_t ToSSU () // return msgID |
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{ |
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uint8_t header[I2NP_HEADER_SIZE]; |
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memcpy (header, GetHeader (), I2NP_HEADER_SIZE); |
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uint8_t * ssu = GetSSUHeader (); |
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ssu[I2NP_SHORT_HEADER_TYPEID_OFFSET] = header[I2NP_HEADER_TYPEID_OFFSET]; // typeid |
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htobe32buf (ssu + I2NP_SHORT_HEADER_EXPIRATION_OFFSET, bufbe64toh (header + I2NP_HEADER_EXPIRATION_OFFSET)/1000LL); |
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len = offset + I2NP_SHORT_HEADER_SIZE + bufbe16toh (header + I2NP_HEADER_SIZE_OFFSET); |
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return bufbe32toh (header + I2NP_HEADER_MSGID_OFFSET); |
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} |
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// for NTCP2 only |
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uint8_t * GetNTCP2Header () { return GetPayload () - I2NP_NTCP2_HEADER_SIZE; }; |
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size_t GetNTCP2Length () const { return GetPayloadLength () + I2NP_NTCP2_HEADER_SIZE; }; |
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void FromNTCP2 () |
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{ |
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const uint8_t * ntcp2 = GetNTCP2Header (); |
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memcpy (GetHeader () + I2NP_HEADER_TYPEID_OFFSET, ntcp2 + I2NP_HEADER_TYPEID_OFFSET, 5); // typeid + msgid |
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SetExpiration (bufbe32toh (ntcp2 + I2NP_HEADER_EXPIRATION_OFFSET)*1000LL); |
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SetSize (len - offset - I2NP_HEADER_SIZE); |
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SetChks (0); |
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} |
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void ToNTCP2 () |
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{ |
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uint8_t * ntcp2 = GetNTCP2Header (); |
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htobe32buf (ntcp2 + I2NP_HEADER_EXPIRATION_OFFSET, bufbe64toh (GetHeader () + I2NP_HEADER_EXPIRATION_OFFSET)/1000LL); |
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memcpy (ntcp2 + I2NP_HEADER_TYPEID_OFFSET, GetHeader () + I2NP_HEADER_TYPEID_OFFSET, 5); // typeid + msgid |
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} |
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void FillI2NPMessageHeader (I2NPMessageType msgType, uint32_t replyMsgID = 0, bool checksum = true); |
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void RenewI2NPMessageHeader (); |
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bool IsExpired () const; |
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}; |
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template<int sz> |
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struct I2NPMessageBuffer: public I2NPMessage |
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{ |
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I2NPMessageBuffer () { buf = m_Buffer; maxLen = sz; }; |
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uint8_t m_Buffer[sz + 32]; // 16 alignment + 16 padding |
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}; |
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std::shared_ptr<I2NPMessage> NewI2NPMessage (); |
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std::shared_ptr<I2NPMessage> NewI2NPShortMessage (); |
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std::shared_ptr<I2NPMessage> NewI2NPMediumMessage (); |
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std::shared_ptr<I2NPMessage> NewI2NPTunnelMessage (bool endpoint); |
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std::shared_ptr<I2NPMessage> NewI2NPMessage (size_t len); |
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std::shared_ptr<I2NPMessage> CreateI2NPMessage (I2NPMessageType msgType, const uint8_t * buf, size_t len, uint32_t replyMsgID = 0); |
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std::shared_ptr<I2NPMessage> CreateI2NPMessage (const uint8_t * buf, size_t len, std::shared_ptr<i2p::tunnel::InboundTunnel> from = nullptr); |
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std::shared_ptr<I2NPMessage> CopyI2NPMessage (std::shared_ptr<I2NPMessage> msg); |
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std::shared_ptr<I2NPMessage> CreateDeliveryStatusMsg (uint32_t msgID); |
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std::shared_ptr<I2NPMessage> CreateRouterInfoDatabaseLookupMsg (const uint8_t * key, const uint8_t * from, |
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uint32_t replyTunnelID, bool exploratory = false, std::set<i2p::data::IdentHash> * excludedPeers = nullptr); |
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std::shared_ptr<I2NPMessage> CreateLeaseSetDatabaseLookupMsg (const i2p::data::IdentHash& dest, |
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const std::set<i2p::data::IdentHash>& excludedFloodfills, |
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std::shared_ptr<const i2p::tunnel::InboundTunnel> replyTunnel, |
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const uint8_t * replyKey, const uint8_t * replyTag, bool replyECIES = false); |
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std::shared_ptr<I2NPMessage> CreateDatabaseSearchReply (const i2p::data::IdentHash& ident, std::vector<i2p::data::IdentHash> routers); |
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std::shared_ptr<I2NPMessage> CreateDatabaseStoreMsg (std::shared_ptr<const i2p::data::RouterInfo> router = nullptr, uint32_t replyToken = 0, std::shared_ptr<const i2p::tunnel::InboundTunnel> replyTunnel = nullptr); |
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std::shared_ptr<I2NPMessage> CreateDatabaseStoreMsg (const i2p::data::IdentHash& storeHash, std::shared_ptr<const i2p::data::LeaseSet> leaseSet); // for floodfill only |
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std::shared_ptr<I2NPMessage> CreateDatabaseStoreMsg (std::shared_ptr<const i2p::data::LocalLeaseSet> leaseSet, uint32_t replyToken = 0, std::shared_ptr<const i2p::tunnel::InboundTunnel> replyTunnel = nullptr); |
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bool IsRouterInfoMsg (std::shared_ptr<I2NPMessage> msg); |
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std::shared_ptr<I2NPMessage> CreateTunnelDataMsg (const uint8_t * buf); |
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std::shared_ptr<I2NPMessage> CreateTunnelDataMsg (uint32_t tunnelID, const uint8_t * payload); |
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std::shared_ptr<I2NPMessage> CreateEmptyTunnelDataMsg (bool endpoint); |
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std::shared_ptr<I2NPMessage> CreateTunnelGatewayMsg (uint32_t tunnelID, const uint8_t * buf, size_t len); |
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std::shared_ptr<I2NPMessage> CreateTunnelGatewayMsg (uint32_t tunnelID, I2NPMessageType msgType, |
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const uint8_t * buf, size_t len, uint32_t replyMsgID = 0); |
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std::shared_ptr<I2NPMessage> CreateTunnelGatewayMsg (uint32_t tunnelID, std::shared_ptr<I2NPMessage> msg); |
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size_t GetI2NPMessageLength (const uint8_t * msg, size_t len); |
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void HandleTunnelBuildI2NPMessage (std::shared_ptr<I2NPMessage> msg); |
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void HandleI2NPMessage (std::shared_ptr<I2NPMessage> msg); |
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class I2NPMessagesHandler |
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{ |
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public: |
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~I2NPMessagesHandler (); |
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void PutNextMessage (std::shared_ptr<I2NPMessage>&& msg); |
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void Flush (); |
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private: |
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std::vector<std::shared_ptr<I2NPMessage> > m_TunnelMsgs, m_TunnelGatewayMsgs; |
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}; |
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} |
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#endif
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