I2P: End-to-End encrypted and anonymous Internet https://i2pd.website/
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#ifndef I2NP_PROTOCOL_H__
#define I2NP_PROTOCOL_H__
#include <inttypes.h>
#include <set>
#include <string.h>
#include "I2PEndian.h"
#include "Identity.h"
#include "RouterInfo.h"
#include "LeaseSet.h"
namespace i2p
{
#pragma pack (1)
struct I2NPHeader
{
uint8_t typeID;
uint32_t msgID;
uint64_t expiration;
uint16_t size;
uint8_t chks;
};
struct I2NPHeaderShort
{
uint8_t typeID;
uint32_t shortExpiration;
};
struct I2NPDatabaseStoreMsg
{
uint8_t key[32];
uint8_t type;
uint32_t replyToken;
};
struct I2NPDeliveryStatusMsg
{
uint32_t msgID;
uint64_t timestamp;
};
struct I2NPBuildRequestRecordClearText
{
uint32_t receiveTunnel;
uint8_t ourIdent[32];
uint32_t nextTunnel;
uint8_t nextIdent[32];
uint8_t layerKey[32];
uint8_t ivKey[32];
uint8_t replyKey[32];
uint8_t replyIV[16];
uint8_t flag;
uint32_t requestTime;
uint32_t nextMessageID;
uint8_t filler[29];
};
struct I2NPBuildResponseRecord
{
uint8_t hash[32];
uint8_t padding[495];
uint8_t ret;
};
struct I2NPBuildRequestRecordElGamalEncrypted
{
uint8_t toPeer[16];
uint8_t encrypted[512];
};
struct TunnelGatewayHeader
{
uint32_t tunnelID;
uint16_t length;
};
#pragma pack ()
enum I2NPMessageType
{
eI2NPDatabaseStore = 1,
eI2NPDatabaseLookup = 2,
eI2NPDatabaseSearchReply = 3,
eI2NPDeliveryStatus = 10,
eI2NPGarlic = 11,
eI2NPTunnelData = 18,
eI2NPTunnelGateway = 19,
eI2NPData = 20,
eI2NPTunnelBuild = 21,
eI2NPTunnelBuildReply = 22,
eI2NPVariableTunnelBuild = 23,
eI2NPVariableTunnelBuildReply = 24
};
const int NUM_TUNNEL_BUILD_RECORDS = 8;
namespace tunnel
{
class InboundTunnel;
class TunnelPool;
}
const size_t I2NP_MAX_MESSAGE_SIZE = 32768;
const size_t I2NP_MAX_SHORT_MESSAGE_SIZE = 2400;
struct I2NPMessage
{
uint8_t * buf;
size_t len, offset, maxLen;
i2p::tunnel::InboundTunnel * from;
I2NPMessage (): buf (nullptr),len (sizeof (I2NPHeader) + 2),
offset(2), maxLen (0), from (nullptr) {};
// reserve 2 bytes for NTCP header
I2NPHeader * GetHeader () { return (I2NPHeader *)GetBuffer (); };
uint8_t * GetPayload () { return GetBuffer () + sizeof(I2NPHeader); };
uint8_t * GetBuffer () { return buf + offset; };
const uint8_t * GetBuffer () const { return buf + offset; };
size_t GetLength () const { return len - offset; };
void Align (size_t alignment)
{
size_t rem = ((size_t)GetBuffer ()) % alignment;
if (rem)
{
offset += (alignment - rem);
len += (alignment - rem);
}
}
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 + sizeof(I2NPHeader) - sizeof(I2NPHeaderShort); };
void FromSSU (uint32_t msgID) // we have received SSU message and convert it to regular
{
I2NPHeaderShort ssu = *(I2NPHeaderShort *)GetSSUHeader ();
I2NPHeader * header = GetHeader ();
header->typeID = ssu.typeID;
header->msgID = htobe32 (msgID);
header->expiration = htobe64 (be32toh (ssu.shortExpiration)*1000LL);
header->size = htobe16 (len - offset - sizeof (I2NPHeader));
header->chks = 0;
}
uint32_t ToSSU () // return msgID
{
I2NPHeader header = *GetHeader ();
I2NPHeaderShort * ssu = (I2NPHeaderShort *)GetSSUHeader ();
ssu->typeID = header.typeID;
ssu->shortExpiration = htobe32 (be64toh (header.expiration)/1000LL);
len = offset + sizeof (I2NPHeaderShort) + be16toh (header.size);
return be32toh (header.msgID);
}
};
template<int sz>
struct I2NPMessageBuffer: public I2NPMessage
{
I2NPMessageBuffer () { buf = m_Buffer; maxLen = sz; };
uint8_t m_Buffer[sz];
};
I2NPMessage * NewI2NPMessage ();
I2NPMessage * NewI2NPShortMessage ();
I2NPMessage * NewI2NPMessage (size_t len);
void DeleteI2NPMessage (I2NPMessage * msg);
void FillI2NPMessageHeader (I2NPMessage * msg, I2NPMessageType msgType, uint32_t replyMsgID = 0);
void RenewI2NPMessageHeader (I2NPMessage * msg);
I2NPMessage * CreateI2NPMessage (I2NPMessageType msgType, const uint8_t * buf, int len, uint32_t replyMsgID = 0);
I2NPMessage * CreateI2NPMessage (const uint8_t * buf, int len, i2p::tunnel::InboundTunnel * from = nullptr);
I2NPMessage * CreateDeliveryStatusMsg (uint32_t msgID);
I2NPMessage * CreateDatabaseLookupMsg (const uint8_t * key, const uint8_t * from,
uint32_t replyTunnelID, bool exploratory = false,
std::set<i2p::data::IdentHash> * excludedPeers = nullptr, bool encryption = false,
i2p::tunnel::TunnelPool * pool = nullptr);
I2NPMessage * CreateLeaseSetDatabaseLookupMsg (const i2p::data::IdentHash& dest,
const std::set<i2p::data::IdentHash>& excludedFloodfills,
const i2p::tunnel::InboundTunnel * replyTunnel, const uint8_t * replyKey, const uint8_t * replyTag);
I2NPMessage * CreateDatabaseSearchReply (const i2p::data::IdentHash& ident, const i2p::data::RouterInfo * floodfill);
I2NPMessage * CreateDatabaseStoreMsg (const i2p::data::RouterInfo * router = nullptr);
I2NPMessage * CreateDatabaseStoreMsg (const i2p::data::LeaseSet * leaseSet, uint32_t replyToken = 0);
I2NPBuildRequestRecordClearText CreateBuildRequestRecord (
const uint8_t * ourIdent, uint32_t receiveTunnelID,
const uint8_t * nextIdent, uint32_t nextTunnelID,
const uint8_t * layerKey,const uint8_t * ivKey,
const uint8_t * replyKey, const uint8_t * replyIV, uint32_t nextMessageID,
bool isGateway, bool isEndpoint);
void EncryptBuildRequestRecord (const i2p::data::RouterInfo& router,
const I2NPBuildRequestRecordClearText& clearText,
I2NPBuildRequestRecordElGamalEncrypted& record);
bool HandleBuildRequestRecords (int num, I2NPBuildRequestRecordElGamalEncrypted * records, I2NPBuildRequestRecordClearText& clearText);
void HandleVariableTunnelBuildMsg (uint32_t replyMsgID, uint8_t * buf, size_t len);
void HandleVariableTunnelBuildReplyMsg (uint32_t replyMsgID, uint8_t * buf, size_t len);
void HandleTunnelBuildMsg (uint8_t * buf, size_t len);
I2NPMessage * CreateTunnelDataMsg (const uint8_t * buf);
I2NPMessage * CreateTunnelDataMsg (uint32_t tunnelID, const uint8_t * payload);
void HandleTunnelGatewayMsg (I2NPMessage * msg);
I2NPMessage * CreateTunnelGatewayMsg (uint32_t tunnelID, const uint8_t * buf, size_t len);
I2NPMessage * CreateTunnelGatewayMsg (uint32_t tunnelID, I2NPMessageType msgType,
const uint8_t * buf, size_t len, uint32_t replyMsgID = 0);
I2NPMessage * CreateTunnelGatewayMsg (uint32_t tunnelID, I2NPMessage * msg);
size_t GetI2NPMessageLength (const uint8_t * msg);
void HandleI2NPMessage (uint8_t * msg, size_t len);
void HandleI2NPMessage (I2NPMessage * msg);
}
#endif