i2pd/libi2pd/I2NPProtocol.h
Anatolii Cherednichenko 55534ea002 Reformat code
2022-08-30 02:11:28 +03:00

368 lines
16 KiB
C++

/*
* Copyright (c) 2013-2021, The PurpleI2P Project
*
* This file is part of Purple i2pd project and licensed under BSD3
*
* See full license text in LICENSE file at top of project tree
*/
#ifndef I2NP_PROTOCOL_H__
#define I2NP_PROTOCOL_H__
#include <inttypes.h>
#include <string.h>
#include <set>
#include <memory>
#include "Crypto.h"
#include "I2PEndian.h"
#include "Identity.h"
#include "RouterInfo.h"
#include "LeaseSet.h"
namespace i2p {
// I2NP header
const size_t I2NP_HEADER_TYPEID_OFFSET = 0;
const size_t I2NP_HEADER_MSGID_OFFSET = I2NP_HEADER_TYPEID_OFFSET + 1;
const size_t I2NP_HEADER_EXPIRATION_OFFSET = I2NP_HEADER_MSGID_OFFSET + 4;
const size_t I2NP_HEADER_SIZE_OFFSET = I2NP_HEADER_EXPIRATION_OFFSET + 8;
const size_t I2NP_HEADER_CHKS_OFFSET = I2NP_HEADER_SIZE_OFFSET + 2;
const size_t I2NP_HEADER_SIZE = I2NP_HEADER_CHKS_OFFSET + 1;
// I2NP short header
const size_t I2NP_SHORT_HEADER_TYPEID_OFFSET = 0;
const size_t I2NP_SHORT_HEADER_EXPIRATION_OFFSET = I2NP_SHORT_HEADER_TYPEID_OFFSET + 1;
const size_t I2NP_SHORT_HEADER_SIZE = I2NP_SHORT_HEADER_EXPIRATION_OFFSET + 4;
// I2NP NTCP2 header
const size_t I2NP_NTCP2_HEADER_SIZE = I2NP_HEADER_EXPIRATION_OFFSET + 4;
// Tunnel Gateway header
const size_t TUNNEL_GATEWAY_HEADER_TUNNELID_OFFSET = 0;
const size_t TUNNEL_GATEWAY_HEADER_LENGTH_OFFSET = TUNNEL_GATEWAY_HEADER_TUNNELID_OFFSET + 4;
const size_t TUNNEL_GATEWAY_HEADER_SIZE = TUNNEL_GATEWAY_HEADER_LENGTH_OFFSET + 2;
// DeliveryStatus
const size_t DELIVERY_STATUS_MSGID_OFFSET = 0;
const size_t DELIVERY_STATUS_TIMESTAMP_OFFSET = DELIVERY_STATUS_MSGID_OFFSET + 4;
const size_t DELIVERY_STATUS_SIZE = DELIVERY_STATUS_TIMESTAMP_OFFSET + 8;
// DatabaseStore
const size_t DATABASE_STORE_KEY_OFFSET = 0;
const size_t DATABASE_STORE_TYPE_OFFSET = DATABASE_STORE_KEY_OFFSET + 32;
const size_t DATABASE_STORE_REPLY_TOKEN_OFFSET = DATABASE_STORE_TYPE_OFFSET + 1;
const size_t DATABASE_STORE_HEADER_SIZE = DATABASE_STORE_REPLY_TOKEN_OFFSET + 4;
// TunnelBuild
const size_t TUNNEL_BUILD_RECORD_SIZE = 528;
const size_t SHORT_TUNNEL_BUILD_RECORD_SIZE = 218;
// BuildRequestRecordEncrypted
const size_t BUILD_REQUEST_RECORD_TO_PEER_OFFSET = 0;
const size_t BUILD_REQUEST_RECORD_ENCRYPTED_OFFSET = BUILD_REQUEST_RECORD_TO_PEER_OFFSET + 16;
// ECIES BuildRequestRecordClearText
const size_t ECIES_BUILD_REQUEST_RECORD_RECEIVE_TUNNEL_OFFSET = 0;
const size_t ECIES_BUILD_REQUEST_RECORD_NEXT_TUNNEL_OFFSET = ECIES_BUILD_REQUEST_RECORD_RECEIVE_TUNNEL_OFFSET + 4;
const size_t ECIES_BUILD_REQUEST_RECORD_NEXT_IDENT_OFFSET = ECIES_BUILD_REQUEST_RECORD_NEXT_TUNNEL_OFFSET + 4;
const size_t ECIES_BUILD_REQUEST_RECORD_LAYER_KEY_OFFSET = ECIES_BUILD_REQUEST_RECORD_NEXT_IDENT_OFFSET + 32;
const size_t ECIES_BUILD_REQUEST_RECORD_IV_KEY_OFFSET = ECIES_BUILD_REQUEST_RECORD_LAYER_KEY_OFFSET + 32;
const size_t ECIES_BUILD_REQUEST_RECORD_REPLY_KEY_OFFSET = ECIES_BUILD_REQUEST_RECORD_IV_KEY_OFFSET + 32;
const size_t ECIES_BUILD_REQUEST_RECORD_REPLY_IV_OFFSET = ECIES_BUILD_REQUEST_RECORD_REPLY_KEY_OFFSET + 32;
const size_t ECIES_BUILD_REQUEST_RECORD_FLAG_OFFSET = ECIES_BUILD_REQUEST_RECORD_REPLY_IV_OFFSET + 16;
const size_t ECIES_BUILD_REQUEST_RECORD_MORE_FLAGS_OFFSET = ECIES_BUILD_REQUEST_RECORD_FLAG_OFFSET + 1;
const size_t ECIES_BUILD_REQUEST_RECORD_REQUEST_TIME_OFFSET = ECIES_BUILD_REQUEST_RECORD_MORE_FLAGS_OFFSET + 3;
const size_t ECIES_BUILD_REQUEST_RECORD_REQUEST_EXPIRATION_OFFSET =
ECIES_BUILD_REQUEST_RECORD_REQUEST_TIME_OFFSET + 4;
const size_t ECIES_BUILD_REQUEST_RECORD_SEND_MSG_ID_OFFSET =
ECIES_BUILD_REQUEST_RECORD_REQUEST_EXPIRATION_OFFSET + 4;
const size_t ECIES_BUILD_REQUEST_RECORD_PADDING_OFFSET = ECIES_BUILD_REQUEST_RECORD_SEND_MSG_ID_OFFSET + 4;
const size_t ECIES_BUILD_REQUEST_RECORD_CLEAR_TEXT_SIZE = 464;
// ECIES BuildResponseRecord
const size_t ECIES_BUILD_RESPONSE_RECORD_OPTIONS_OFFSET = 0;
const size_t ECIES_BUILD_RESPONSE_RECORD_RET_OFFSET = 511;
// ShortRequestRecordClearText
const size_t SHORT_REQUEST_RECORD_ENCRYPTED_OFFSET = 16;
const size_t SHORT_REQUEST_RECORD_RECEIVE_TUNNEL_OFFSET = 0;
const size_t SHORT_REQUEST_RECORD_NEXT_TUNNEL_OFFSET = SHORT_REQUEST_RECORD_RECEIVE_TUNNEL_OFFSET + 4;
const size_t SHORT_REQUEST_RECORD_NEXT_IDENT_OFFSET = SHORT_REQUEST_RECORD_NEXT_TUNNEL_OFFSET + 4;
const size_t SHORT_REQUEST_RECORD_FLAG_OFFSET = SHORT_REQUEST_RECORD_NEXT_IDENT_OFFSET + 32;
const size_t SHORT_REQUEST_RECORD_MORE_FLAGS_OFFSET = SHORT_REQUEST_RECORD_FLAG_OFFSET + 1;
const size_t SHORT_REQUEST_RECORD_LAYER_ENCRYPTION_TYPE = SHORT_REQUEST_RECORD_MORE_FLAGS_OFFSET + 2;
const size_t SHORT_REQUEST_RECORD_REQUEST_TIME_OFFSET = SHORT_REQUEST_RECORD_LAYER_ENCRYPTION_TYPE + 1;
const size_t SHORT_REQUEST_RECORD_REQUEST_EXPIRATION_OFFSET = SHORT_REQUEST_RECORD_REQUEST_TIME_OFFSET + 4;
const size_t SHORT_REQUEST_RECORD_SEND_MSG_ID_OFFSET = SHORT_REQUEST_RECORD_REQUEST_EXPIRATION_OFFSET + 4;
const size_t SHORT_REQUEST_RECORD_PADDING_OFFSET = SHORT_REQUEST_RECORD_SEND_MSG_ID_OFFSET + 4;
const size_t SHORT_REQUEST_RECORD_CLEAR_TEXT_SIZE = 154;
// ShortResponseRecord
const size_t SHORT_RESPONSE_RECORD_OPTIONS_OFFSET = 0;
const size_t SHORT_RESPONSE_RECORD_RET_OFFSET = 201;
enum I2NPMessageType {
eI2NPDummyMsg = 0,
eI2NPDatabaseStore = 1,
eI2NPDatabaseLookup = 2,
eI2NPDatabaseSearchReply = 3,
eI2NPDeliveryStatus = 10,
eI2NPGarlic = 11,
eI2NPTunnelData = 18,
eI2NPTunnelGateway = 19,
eI2NPData = 20,
eI2NPTunnelBuild = 21,
eI2NPTunnelBuildReply = 22,
eI2NPVariableTunnelBuild = 23,
eI2NPVariableTunnelBuildReply = 24,
eI2NPShortTunnelBuild = 25,
eI2NPShortTunnelBuildReply = 26
};
const uint8_t TUNNEL_BUILD_RECORD_GATEWAY_FLAG = 0x80;
const uint8_t TUNNEL_BUILD_RECORD_ENDPOINT_FLAG = 0x40;
const int NUM_TUNNEL_BUILD_RECORDS = 8;
// DatabaseLookup flags
const uint8_t DATABASE_LOOKUP_DELIVERY_FLAG = 0x01;
const uint8_t DATABASE_LOOKUP_ENCRYPTION_FLAG = 0x02;
const uint8_t DATABASE_LOOKUP_ECIES_FLAG = 0x10;
const uint8_t DATABASE_LOOKUP_TYPE_FLAGS_MASK = 0x0C;
const uint8_t DATABASE_LOOKUP_TYPE_NORMAL_LOOKUP = 0;
const uint8_t DATABASE_LOOKUP_TYPE_LEASESET_LOOKUP = 0x04; // 0100
const uint8_t DATABASE_LOOKUP_TYPE_ROUTERINFO_LOOKUP = 0x08; // 1000
const uint8_t DATABASE_LOOKUP_TYPE_EXPLORATORY_LOOKUP = 0x0C; // 1100
namespace tunnel {
class InboundTunnel;
class TunnelPool;
}
const size_t I2NP_MAX_MESSAGE_SIZE = 62708;
const size_t I2NP_MAX_SHORT_MESSAGE_SIZE = 4096;
const unsigned int I2NP_MESSAGE_EXPIRATION_TIMEOUT = 8000; // in milliseconds (as initial RTT)
const unsigned int I2NP_MESSAGE_CLOCK_SKEW = 60 * 1000; // 1 minute in milliseconds
struct I2NPMessage {
uint8_t *buf;
size_t len, offset, maxLen;
std::shared_ptr<i2p::tunnel::InboundTunnel> from;
I2NPMessage() : buf(nullptr), len(I2NP_HEADER_SIZE + 2),
offset(2), maxLen(0), from(nullptr) {}; // reserve 2 bytes for NTCP header
// header accessors
uint8_t *GetHeader() { return GetBuffer(); };
const uint8_t *GetHeader() const { return GetBuffer(); };
void SetTypeID(uint8_t typeID) { GetHeader()[I2NP_HEADER_TYPEID_OFFSET] = typeID; };
uint8_t GetTypeID() const { return GetHeader()[I2NP_HEADER_TYPEID_OFFSET]; };
void SetMsgID(uint32_t msgID) { htobe32buf(GetHeader() + I2NP_HEADER_MSGID_OFFSET, msgID); };
uint32_t GetMsgID() const { return bufbe32toh(GetHeader() + I2NP_HEADER_MSGID_OFFSET); };
void SetExpiration(uint64_t expiration) {
htobe64buf(GetHeader() + I2NP_HEADER_EXPIRATION_OFFSET, expiration);
};
uint64_t GetExpiration() const { return bufbe64toh(GetHeader() + I2NP_HEADER_EXPIRATION_OFFSET); };
void SetSize(uint16_t size) { htobe16buf(GetHeader() + I2NP_HEADER_SIZE_OFFSET, size); };
uint16_t GetSize() const { return bufbe16toh(GetHeader() + I2NP_HEADER_SIZE_OFFSET); };
void UpdateSize() { SetSize(GetPayloadLength()); };
void SetChks(uint8_t chks) { GetHeader()[I2NP_HEADER_CHKS_OFFSET] = chks; };
void UpdateChks() {
uint8_t hash[32];
SHA256(GetPayload(), GetPayloadLength(), hash);
GetHeader()[I2NP_HEADER_CHKS_OFFSET] = hash[0];
}
// payload
uint8_t *GetPayload() { return GetBuffer() + I2NP_HEADER_SIZE; };
const uint8_t *GetPayload() const { return GetBuffer() + I2NP_HEADER_SIZE; };
uint8_t *GetBuffer() { return buf + offset; };
const uint8_t *GetBuffer() const { return buf + offset; };
size_t GetLength() const { return len - offset; };
size_t GetPayloadLength() const { return GetLength() - I2NP_HEADER_SIZE; };
void Align(size_t alignment) {
if (len + alignment > maxLen) return;
size_t rem = ((size_t) GetBuffer()) % alignment;
if (rem) {
offset += (alignment - rem);
len += (alignment - rem);
}
}
size_t Concat(const uint8_t *buf1, size_t len1) {
// make sure with don't write beyond maxLen
if (len + len1 > maxLen) len1 = maxLen - len;
memcpy(buf + len, buf1, len1);
len += len1;
return len1;
}
I2NPMessage &operator=(const I2NPMessage &other) {
memcpy(buf + offset, other.buf + other.offset, other.GetLength());
len = offset + other.GetLength();
from = other.from;
return *this;
}
// for SSU only
uint8_t *GetSSUHeader() { return buf + offset + I2NP_HEADER_SIZE - I2NP_SHORT_HEADER_SIZE; };
void FromSSU(uint32_t msgID) // we have received SSU message and convert it to regular
{
const uint8_t *ssu = GetSSUHeader();
GetHeader()[I2NP_HEADER_TYPEID_OFFSET] = ssu[I2NP_SHORT_HEADER_TYPEID_OFFSET]; // typeid
SetMsgID(msgID);
SetExpiration(bufbe32toh(ssu + I2NP_SHORT_HEADER_EXPIRATION_OFFSET) * 1000LL);
SetSize(len - offset - I2NP_HEADER_SIZE);
SetChks(0);
}
uint32_t ToSSU() // return msgID
{
uint8_t header[I2NP_HEADER_SIZE];
memcpy(header, GetHeader(), I2NP_HEADER_SIZE);
uint8_t *ssu = GetSSUHeader();
ssu[I2NP_SHORT_HEADER_TYPEID_OFFSET] = header[I2NP_HEADER_TYPEID_OFFSET]; // typeid
htobe32buf(ssu + I2NP_SHORT_HEADER_EXPIRATION_OFFSET,
bufbe64toh(header + I2NP_HEADER_EXPIRATION_OFFSET) / 1000LL);
len = offset + I2NP_SHORT_HEADER_SIZE + bufbe16toh(header + I2NP_HEADER_SIZE_OFFSET);
return bufbe32toh(header + I2NP_HEADER_MSGID_OFFSET);
}
// for NTCP2 only
uint8_t *GetNTCP2Header() { return GetPayload() - I2NP_NTCP2_HEADER_SIZE; };
size_t GetNTCP2Length() const { return GetPayloadLength() + I2NP_NTCP2_HEADER_SIZE; };
void FromNTCP2() {
const uint8_t *ntcp2 = GetNTCP2Header();
memcpy(GetHeader() + I2NP_HEADER_TYPEID_OFFSET, ntcp2 + I2NP_HEADER_TYPEID_OFFSET, 5); // typeid + msgid
SetExpiration(bufbe32toh(ntcp2 + I2NP_HEADER_EXPIRATION_OFFSET) * 1000LL);
SetSize(len - offset - I2NP_HEADER_SIZE);
SetChks(0);
}
void ToNTCP2() {
uint8_t *ntcp2 = GetNTCP2Header();
htobe32buf(ntcp2 + I2NP_HEADER_EXPIRATION_OFFSET,
bufbe64toh(GetHeader() + I2NP_HEADER_EXPIRATION_OFFSET) / 1000LL);
memcpy(ntcp2 + I2NP_HEADER_TYPEID_OFFSET, GetHeader() + I2NP_HEADER_TYPEID_OFFSET, 5); // typeid + msgid
}
void FillI2NPMessageHeader(I2NPMessageType msgType, uint32_t replyMsgID = 0, bool checksum = true);
void RenewI2NPMessageHeader();
bool IsExpired() const;
};
template<int sz>
struct I2NPMessageBuffer : public I2NPMessage {
I2NPMessageBuffer() {
buf = m_Buffer;
maxLen = sz;
};
uint8_t m_Buffer[sz + 32]; // 16 alignment + 16 padding
};
std::shared_ptr<I2NPMessage> NewI2NPMessage();
std::shared_ptr<I2NPMessage> NewI2NPShortMessage();
std::shared_ptr<I2NPMessage> NewI2NPTunnelMessage(bool endpoint);
std::shared_ptr<I2NPMessage> NewI2NPMessage(size_t len);
std::shared_ptr<I2NPMessage>
CreateI2NPMessage(I2NPMessageType msgType, const uint8_t *buf, size_t len, uint32_t replyMsgID = 0);
std::shared_ptr<I2NPMessage>
CreateI2NPMessage(const uint8_t *buf, size_t len, std::shared_ptr<i2p::tunnel::InboundTunnel> from = nullptr);
std::shared_ptr<I2NPMessage> CopyI2NPMessage(std::shared_ptr<I2NPMessage> msg);
std::shared_ptr<I2NPMessage> CreateDeliveryStatusMsg(uint32_t msgID);
std::shared_ptr<I2NPMessage> CreateRouterInfoDatabaseLookupMsg(const uint8_t *key, const uint8_t *from,
uint32_t replyTunnelID, bool exploratory = false,
std::set<i2p::data::IdentHash> *excludedPeers = nullptr);
std::shared_ptr<I2NPMessage> CreateLeaseSetDatabaseLookupMsg(const i2p::data::IdentHash &dest,
const std::set<i2p::data::IdentHash> &excludedFloodfills,
std::shared_ptr<const i2p::tunnel::InboundTunnel> replyTunnel,
const uint8_t *replyKey, const uint8_t *replyTag,
bool replyECIES = false);
std::shared_ptr<I2NPMessage>
CreateDatabaseSearchReply(const i2p::data::IdentHash &ident, std::vector<i2p::data::IdentHash> routers);
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);
std::shared_ptr<I2NPMessage> CreateDatabaseStoreMsg(const i2p::data::IdentHash &storeHash,
std::shared_ptr<const i2p::data::LeaseSet> leaseSet); // for floodfill only
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);
bool IsRouterInfoMsg(std::shared_ptr<I2NPMessage> msg);
std::shared_ptr<I2NPMessage> CreateTunnelDataMsg(const uint8_t *buf);
std::shared_ptr<I2NPMessage> CreateTunnelDataMsg(uint32_t tunnelID, const uint8_t *payload);
std::shared_ptr<I2NPMessage> CreateEmptyTunnelDataMsg(bool endpoint);
std::shared_ptr<I2NPMessage> CreateTunnelGatewayMsg(uint32_t tunnelID, const uint8_t *buf, size_t len);
std::shared_ptr<I2NPMessage> CreateTunnelGatewayMsg(uint32_t tunnelID, I2NPMessageType msgType,
const uint8_t *buf, size_t len, uint32_t replyMsgID = 0);
std::shared_ptr<I2NPMessage> CreateTunnelGatewayMsg(uint32_t tunnelID, std::shared_ptr<I2NPMessage> msg);
size_t GetI2NPMessageLength(const uint8_t *msg, size_t len);
void HandleI2NPMessage(uint8_t *msg, size_t len);
void HandleI2NPMessage(std::shared_ptr<I2NPMessage> msg);
class I2NPMessagesHandler {
public:
~I2NPMessagesHandler();
void PutNextMessage(std::shared_ptr<I2NPMessage> &&msg);
void Flush();
private:
std::vector<std::shared_ptr<I2NPMessage> > m_TunnelMsgs, m_TunnelGatewayMsgs;
};
const uint16_t DEFAULT_MAX_NUM_TRANSIT_TUNNELS = 2500;
void SetMaxNumTransitTunnels(uint16_t maxNumTransitTunnels);
uint16_t GetMaxNumTransitTunnels();
}
#endif