#include #include #include "I2PEndian.h" #include #include "ElGamal.h" #include "Timestamp.h" #include "RouterContext.h" #include "NetDb.h" #include "Tunnel.h" #include "base64.h" #include "Transports.h" #include "Garlic.h" #include "I2NPProtocol.h" using namespace i2p::transport; namespace i2p { I2NPMessage * NewI2NPMessage () { return new I2NPMessageBuffer(); } I2NPMessage * NewI2NPShortMessage () { return new I2NPMessageBuffer(); } I2NPMessage * NewI2NPMessage (size_t len) { return (len < I2NP_MAX_SHORT_MESSAGE_SIZE/2) ? NewI2NPShortMessage () : NewI2NPMessage (); } void DeleteI2NPMessage (I2NPMessage * msg) { delete msg; } static std::atomic I2NPmsgID(0); // TODO: create class void FillI2NPMessageHeader (I2NPMessage * msg, I2NPMessageType msgType, uint32_t replyMsgID) { msg->SetTypeID (msgType); if (replyMsgID) // for tunnel creation msg->SetMsgID (replyMsgID); else { msg->SetMsgID (I2NPmsgID); I2NPmsgID++; } msg->SetExpiration (i2p::util::GetMillisecondsSinceEpoch () + 5000); // TODO: 5 secs is a magic number msg->UpdateSize (); msg->UpdateChks (); } void RenewI2NPMessageHeader (I2NPMessage * msg) { if (msg) { msg->SetMsgID (I2NPmsgID); I2NPmsgID++; msg->SetExpiration (i2p::util::GetMillisecondsSinceEpoch () + 5000); } } I2NPMessage * CreateI2NPMessage (I2NPMessageType msgType, const uint8_t * buf, int len, uint32_t replyMsgID) { I2NPMessage * msg = NewI2NPMessage (len); memcpy (msg->GetPayload (), buf, len); msg->len += len; FillI2NPMessageHeader (msg, msgType, replyMsgID); return msg; } I2NPMessage * CreateI2NPMessage (const uint8_t * buf, int len, i2p::tunnel::InboundTunnel * from) { I2NPMessage * msg = NewI2NPMessage (); memcpy (msg->GetBuffer (), buf, len); msg->len = msg->offset + len; msg->from = from; return msg; } I2NPMessage * CreateDeliveryStatusMsg (uint32_t msgID) { I2NPMessage * m = NewI2NPMessage (); uint8_t * buf = m->GetPayload (); if (msgID) { htobe32buf (buf + DELIVERY_STATUS_MSGID_OFFSET, msgID); htobe64buf (buf + DELIVERY_STATUS_TIMESTAMP_OFFSET, i2p::util::GetMillisecondsSinceEpoch ()); } else // for SSU establishment { htobe32buf (buf + DELIVERY_STATUS_MSGID_OFFSET, i2p::context.GetRandomNumberGenerator ().GenerateWord32 ()); htobe64buf (buf + DELIVERY_STATUS_TIMESTAMP_OFFSET, 2); // netID = 2 } m->len += DELIVERY_STATUS_SIZE; FillI2NPMessageHeader (m, eI2NPDeliveryStatus); return m; } I2NPMessage * CreateRouterInfoDatabaseLookupMsg (const uint8_t * key, const uint8_t * from, uint32_t replyTunnelID, bool exploratory, std::set * excludedPeers) { I2NPMessage * m = NewI2NPMessage (); uint8_t * buf = m->GetPayload (); memcpy (buf, key, 32); // key buf += 32; memcpy (buf, from, 32); // from buf += 32; uint8_t flag = exploratory ? 0x0C : 0x08; // 1000 - RI, 1100 -exporatory if (replyTunnelID) { *buf = flag | 0x01; // set delivery flag htobe32buf (buf+1, replyTunnelID); buf += 5; } else { *buf = flag; // flag buf++; } if (excludedPeers) { int cnt = excludedPeers->size (); htobe16buf (buf, cnt); buf += 2; for (auto& it: *excludedPeers) { memcpy (buf, it, 32); buf += 32; } } else { // nothing to exclude htobuf16 (buf, 0); buf += 2; } m->len += (buf - m->GetPayload ()); FillI2NPMessageHeader (m, eI2NPDatabaseLookup); return m; } I2NPMessage * CreateLeaseSetDatabaseLookupMsg (const i2p::data::IdentHash& dest, const std::set& excludedFloodfills, const i2p::tunnel::InboundTunnel * replyTunnel, const uint8_t * replyKey, const uint8_t * replyTag) { I2NPMessage * m = NewI2NPMessage (); uint8_t * buf = m->GetPayload (); memcpy (buf, dest, 32); // key buf += 32; memcpy (buf, replyTunnel->GetNextIdentHash (), 32); // reply tunnel GW buf += 32; *buf = 7; // flags (01 - tunnel, 10 - encrypted, 0100 - LS lookup htobe32buf (buf + 1, replyTunnel->GetNextTunnelID ()); // reply tunnel ID buf += 5; // excluded int cnt = excludedFloodfills.size (); htobe16buf (buf, cnt); buf += 2; if (cnt > 0) { for (auto& it: excludedFloodfills) { memcpy (buf, it, 32); buf += 32; } } // encryption memcpy (buf, replyKey, 32); buf[32] = 1; // 1 tag memcpy (buf + 33, replyTag, 32); buf += 65; m->len += (buf - m->GetPayload ()); FillI2NPMessageHeader (m, eI2NPDatabaseLookup); return m; } I2NPMessage * CreateDatabaseSearchReply (const i2p::data::IdentHash& ident, const i2p::data::RouterInfo * floodfill) { I2NPMessage * m = NewI2NPShortMessage (); uint8_t * buf = m->GetPayload (); size_t len = 0; memcpy (buf, ident, 32); len += 32; buf[len] = floodfill ? 1 : 0; // 1 router for now len++; if (floodfill) { memcpy (buf + len, floodfill->GetIdentHash (), 32); len += 32; } memcpy (buf + len, i2p::context.GetRouterInfo ().GetIdentHash (), 32); len += 32; m->len += len; FillI2NPMessageHeader (m, eI2NPDatabaseSearchReply); return m; } I2NPMessage * CreateDatabaseStoreMsg (const i2p::data::RouterInfo * router) { if (!router) // we send own RouterInfo router = &context.GetRouterInfo (); I2NPMessage * m = NewI2NPShortMessage (); uint8_t * payload = m->GetPayload (); memcpy (payload + DATABASE_STORE_KEY_OFFSET, router->GetIdentHash (), 32); payload[DATABASE_STORE_TYPE_OFFSET] = 0; htobe32buf (payload + DATABASE_STORE_REPLY_TOKEN_OFFSET, 0); CryptoPP::Gzip compressor; compressor.Put (router->GetBuffer (), router->GetBufferLen ()); compressor.MessageEnd(); auto size = compressor.MaxRetrievable (); uint8_t * buf = payload + DATABASE_STORE_HEADER_SIZE; htobe16buf (buf, size); // size buf += 2; // TODO: check if size doesn't exceed buffer compressor.Get (buf, size); m->len += DATABASE_STORE_HEADER_SIZE + 2 + size; // payload size FillI2NPMessageHeader (m, eI2NPDatabaseStore); return m; } I2NPMessage * CreateDatabaseStoreMsg (const i2p::data::LeaseSet * leaseSet, uint32_t replyToken) { if (!leaseSet) return nullptr; I2NPMessage * m = NewI2NPShortMessage (); uint8_t * payload = m->GetPayload (); memcpy (payload + DATABASE_STORE_KEY_OFFSET, leaseSet->GetIdentHash (), 32); payload[DATABASE_STORE_TYPE_OFFSET] = 1; // LeaseSet htobe32buf (payload + DATABASE_STORE_REPLY_TOKEN_OFFSET, replyToken); size_t size = DATABASE_STORE_HEADER_SIZE; if (replyToken) { auto leases = leaseSet->GetNonExpiredLeases (); if (leases.size () > 0) { htobe32buf (payload + size, leases[0].tunnelID); size += 4; // reply tunnelID memcpy (payload + size, leases[0].tunnelGateway, 32); size += 32; // reply tunnel gateway } else htobe32buf (payload + DATABASE_STORE_REPLY_TOKEN_OFFSET, 0); } memcpy (payload + size, leaseSet->GetBuffer (), leaseSet->GetBufferLen ()); size += leaseSet->GetBufferLen (); m->len += size; FillI2NPMessageHeader (m, eI2NPDatabaseStore); return m; } bool HandleBuildRequestRecords (int num, uint8_t * records, uint8_t * clearText) { for (int i = 0; i < num; i++) { uint8_t * record = records + i*TUNNEL_BUILD_RECORD_SIZE; if (!memcmp (record + BUILD_REQUEST_RECORD_TO_PEER_OFFSET, (const uint8_t *)i2p::context.GetRouterInfo ().GetIdentHash (), 16)) { LogPrint ("Record ",i," is ours"); i2p::crypto::ElGamalDecrypt (i2p::context.GetEncryptionPrivateKey (), record + BUILD_REQUEST_RECORD_ENCRYPTED_OFFSET, clearText); // replace record to reply if (i2p::context.AcceptsTunnels ()) { i2p::tunnel::TransitTunnel * transitTunnel = i2p::tunnel::CreateTransitTunnel ( bufbe32toh (clearText + BUILD_REQUEST_RECORD_RECEIVE_TUNNEL_OFFSET), clearText + BUILD_REQUEST_RECORD_NEXT_IDENT_OFFSET, bufbe32toh (clearText + BUILD_REQUEST_RECORD_NEXT_TUNNEL_OFFSET), clearText + BUILD_REQUEST_RECORD_LAYER_KEY_OFFSET, clearText + BUILD_REQUEST_RECORD_IV_KEY_OFFSET, clearText[BUILD_REQUEST_RECORD_FLAG_OFFSET] & 0x80, clearText[BUILD_REQUEST_RECORD_FLAG_OFFSET ] & 0x40); i2p::tunnel::tunnels.AddTransitTunnel (transitTunnel); record[BUILD_RESPONSE_RECORD_RET_OFFSET] = 0; } else record[BUILD_RESPONSE_RECORD_RET_OFFSET] = 30; // always reject with bandwidth reason (30) //TODO: fill filler CryptoPP::SHA256().CalculateDigest(record + BUILD_RESPONSE_RECORD_HASH_OFFSET, record + BUILD_RESPONSE_RECORD_PADDING_OFFSET, BUILD_RESPONSE_RECORD_PADDING_SIZE + 1); // + 1 byte of ret // encrypt reply i2p::crypto::CBCEncryption encryption; for (int j = 0; j < num; j++) { encryption.SetKey (clearText + BUILD_REQUEST_RECORD_REPLY_KEY_OFFSET); encryption.SetIV (clearText + BUILD_REQUEST_RECORD_REPLY_IV_OFFSET); uint8_t * reply = records + j*TUNNEL_BUILD_RECORD_SIZE; encryption.Encrypt(reply, TUNNEL_BUILD_RECORD_SIZE, reply); } return true; } } return false; } void HandleVariableTunnelBuildMsg (uint32_t replyMsgID, uint8_t * buf, size_t len) { int num = buf[0]; LogPrint ("VariableTunnelBuild ", num, " records"); i2p::tunnel::Tunnel * tunnel = i2p::tunnel::tunnels.GetPendingTunnel (replyMsgID); if (tunnel) { // endpoint of inbound tunnel LogPrint ("VariableTunnelBuild reply for tunnel ", tunnel->GetTunnelID ()); if (tunnel->HandleTunnelBuildResponse (buf, len)) { LogPrint ("Inbound tunnel ", tunnel->GetTunnelID (), " has been created"); tunnel->SetState (i2p::tunnel::eTunnelStateEstablished); i2p::tunnel::tunnels.AddInboundTunnel (static_cast(tunnel)); } else { LogPrint ("Inbound tunnel ", tunnel->GetTunnelID (), " has been declined"); tunnel->SetState (i2p::tunnel::eTunnelStateBuildFailed); } } else { uint8_t clearText[BUILD_REQUEST_RECORD_CLEAR_TEXT_SIZE]; if (HandleBuildRequestRecords (num, buf + 1, clearText)) { if (clearText[BUILD_REQUEST_RECORD_FLAG_OFFSET] & 0x40) // we are endpoint of outboud tunnel { // so we send it to reply tunnel transports.SendMessage (clearText + BUILD_REQUEST_RECORD_NEXT_IDENT_OFFSET, CreateTunnelGatewayMsg (bufbe32toh (clearText + BUILD_REQUEST_RECORD_NEXT_TUNNEL_OFFSET), eI2NPVariableTunnelBuildReply, buf, len, bufbe32toh (clearText + BUILD_REQUEST_RECORD_SEND_MSG_ID_OFFSET))); } else transports.SendMessage (clearText + BUILD_REQUEST_RECORD_NEXT_IDENT_OFFSET, CreateI2NPMessage (eI2NPVariableTunnelBuild, buf, len, bufbe32toh (clearText + BUILD_REQUEST_RECORD_SEND_MSG_ID_OFFSET))); } } } void HandleTunnelBuildMsg (uint8_t * buf, size_t len) { uint8_t clearText[BUILD_REQUEST_RECORD_CLEAR_TEXT_SIZE]; if (HandleBuildRequestRecords (NUM_TUNNEL_BUILD_RECORDS, buf, clearText)) { if (clearText[BUILD_REQUEST_RECORD_FLAG_OFFSET] & 0x40) // we are endpoint of outbound tunnel { // so we send it to reply tunnel transports.SendMessage (clearText + BUILD_REQUEST_RECORD_NEXT_IDENT_OFFSET, CreateTunnelGatewayMsg (bufbe32toh (clearText + BUILD_REQUEST_RECORD_NEXT_TUNNEL_OFFSET), eI2NPTunnelBuildReply, buf, len, bufbe32toh (clearText + BUILD_REQUEST_RECORD_SEND_MSG_ID_OFFSET))); } else transports.SendMessage (clearText + BUILD_REQUEST_RECORD_NEXT_IDENT_OFFSET, CreateI2NPMessage (eI2NPTunnelBuild, buf, len, bufbe32toh (clearText + BUILD_REQUEST_RECORD_SEND_MSG_ID_OFFSET))); } } void HandleVariableTunnelBuildReplyMsg (uint32_t replyMsgID, uint8_t * buf, size_t len) { LogPrint ("VariableTunnelBuildReplyMsg replyMsgID=", replyMsgID); i2p::tunnel::Tunnel * tunnel = i2p::tunnel::tunnels.GetPendingTunnel (replyMsgID); if (tunnel) { // reply for outbound tunnel if (tunnel->HandleTunnelBuildResponse (buf, len)) { LogPrint ("Outbound tunnel ", tunnel->GetTunnelID (), " has been created"); tunnel->SetState (i2p::tunnel::eTunnelStateEstablished); i2p::tunnel::tunnels.AddOutboundTunnel (static_cast(tunnel)); } else { LogPrint ("Outbound tunnel ", tunnel->GetTunnelID (), " has been declined"); tunnel->SetState (i2p::tunnel::eTunnelStateBuildFailed); } } else LogPrint ("Pending tunnel for message ", replyMsgID, " not found"); } I2NPMessage * CreateTunnelDataMsg (const uint8_t * buf) { I2NPMessage * msg = NewI2NPMessage (); memcpy (msg->GetPayload (), buf, i2p::tunnel::TUNNEL_DATA_MSG_SIZE); msg->len += i2p::tunnel::TUNNEL_DATA_MSG_SIZE; FillI2NPMessageHeader (msg, eI2NPTunnelData); return msg; } I2NPMessage * CreateTunnelDataMsg (uint32_t tunnelID, const uint8_t * payload) { I2NPMessage * msg = NewI2NPMessage (); memcpy (msg->GetPayload () + 4, payload, i2p::tunnel::TUNNEL_DATA_MSG_SIZE - 4); htobe32buf (msg->GetPayload (), tunnelID); msg->len += i2p::tunnel::TUNNEL_DATA_MSG_SIZE; FillI2NPMessageHeader (msg, eI2NPTunnelData); return msg; } I2NPMessage * CreateTunnelGatewayMsg (uint32_t tunnelID, const uint8_t * buf, size_t len) { I2NPMessage * msg = NewI2NPMessage (len); uint8_t * payload = msg->GetPayload (); htobe32buf (payload + TUNNEL_GATEWAY_HEADER_TUNNELID_OFFSET, tunnelID); htobe16buf (payload + TUNNEL_GATEWAY_HEADER_LENGTH_OFFSET, len); memcpy (payload + TUNNEL_GATEWAY_HEADER_SIZE, buf, len); msg->len += TUNNEL_GATEWAY_HEADER_SIZE + len; FillI2NPMessageHeader (msg, eI2NPTunnelGateway); return msg; } I2NPMessage * CreateTunnelGatewayMsg (uint32_t tunnelID, I2NPMessage * msg) { if (msg->offset >= I2NP_HEADER_SIZE + TUNNEL_GATEWAY_HEADER_SIZE) { // message is capable to be used without copying uint8_t * payload = msg->GetBuffer () - TUNNEL_GATEWAY_HEADER_SIZE; htobe32buf (payload + TUNNEL_GATEWAY_HEADER_TUNNELID_OFFSET, tunnelID); int len = msg->GetLength (); htobe16buf (payload + TUNNEL_GATEWAY_HEADER_LENGTH_OFFSET, len); msg->offset -= (I2NP_HEADER_SIZE + TUNNEL_GATEWAY_HEADER_SIZE); msg->len = msg->offset + I2NP_HEADER_SIZE + TUNNEL_GATEWAY_HEADER_SIZE +len; FillI2NPMessageHeader (msg, eI2NPTunnelGateway); return msg; } else { I2NPMessage * msg1 = CreateTunnelGatewayMsg (tunnelID, msg->GetBuffer (), msg->GetLength ()); DeleteI2NPMessage (msg); return msg1; } } I2NPMessage * CreateTunnelGatewayMsg (uint32_t tunnelID, I2NPMessageType msgType, const uint8_t * buf, size_t len, uint32_t replyMsgID) { I2NPMessage * msg = NewI2NPMessage (len); size_t gatewayMsgOffset = I2NP_HEADER_SIZE + TUNNEL_GATEWAY_HEADER_SIZE; msg->offset += gatewayMsgOffset; msg->len += gatewayMsgOffset; memcpy (msg->GetPayload (), buf, len); msg->len += len; FillI2NPMessageHeader (msg, msgType, replyMsgID); // create content message len = msg->GetLength (); msg->offset -= gatewayMsgOffset; uint8_t * payload = msg->GetPayload (); htobe32buf (payload + TUNNEL_GATEWAY_HEADER_TUNNELID_OFFSET, tunnelID); htobe16buf (payload + TUNNEL_GATEWAY_HEADER_LENGTH_OFFSET, len); FillI2NPMessageHeader (msg, eI2NPTunnelGateway); // gateway message return msg; } void HandleTunnelGatewayMsg (I2NPMessage * msg) { const uint8_t * payload = msg->GetPayload (); uint32_t tunnelID = bufbe32toh(payload + TUNNEL_GATEWAY_HEADER_TUNNELID_OFFSET); uint16_t len = bufbe16toh(payload + TUNNEL_GATEWAY_HEADER_LENGTH_OFFSET); // we make payload as new I2NP message to send msg->offset += I2NP_HEADER_SIZE + TUNNEL_GATEWAY_HEADER_SIZE; msg->len = msg->offset + len; auto typeID = msg->GetTypeID (); LogPrint ("TunnelGateway of ", (int)len, " bytes for tunnel ", (unsigned int)tunnelID, ". Msg type ", (int)typeID); if (typeID == eI2NPDatabaseStore || typeID == eI2NPDatabaseSearchReply) { // transit DatabaseStore my contain new/updated RI // or DatabaseSearchReply with new routers auto ds = NewI2NPMessage (); *ds = *msg; i2p::data::netdb.PostI2NPMsg (ds); } i2p::tunnel::TransitTunnel * tunnel = i2p::tunnel::tunnels.GetTransitTunnel (tunnelID); if (tunnel) tunnel->SendTunnelDataMsg (msg); else { LogPrint ("Tunnel ", (unsigned int)tunnelID, " not found"); i2p::DeleteI2NPMessage (msg); } } size_t GetI2NPMessageLength (const uint8_t * msg) { return bufbe16toh (msg + I2NP_HEADER_SIZE_OFFSET) + I2NP_HEADER_SIZE; } void HandleI2NPMessage (uint8_t * msg, size_t len) { uint8_t typeID = msg[I2NP_HEADER_TYPEID_OFFSET]; uint32_t msgID = bufbe32toh (msg + I2NP_HEADER_MSGID_OFFSET); LogPrint ("I2NP msg received len=", len,", type=", (int)typeID, ", msgID=", (unsigned int)msgID); uint8_t * buf = msg + I2NP_HEADER_SIZE; int size = bufbe16toh (msg + I2NP_HEADER_SIZE_OFFSET); switch (typeID) { case eI2NPVariableTunnelBuild: LogPrint ("VariableTunnelBuild"); HandleVariableTunnelBuildMsg (msgID, buf, size); break; case eI2NPVariableTunnelBuildReply: LogPrint ("VariableTunnelBuildReply"); HandleVariableTunnelBuildReplyMsg (msgID, buf, size); break; case eI2NPTunnelBuild: LogPrint ("TunnelBuild"); HandleTunnelBuildMsg (buf, size); break; case eI2NPTunnelBuildReply: LogPrint ("TunnelBuildReply"); // TODO: break; default: LogPrint ("Unexpected message ", (int)typeID); } } void HandleI2NPMessage (I2NPMessage * msg) { if (msg) { switch (msg->GetTypeID ()) { case eI2NPTunnelData: LogPrint ("TunnelData"); i2p::tunnel::tunnels.PostTunnelData (msg); break; case eI2NPTunnelGateway: LogPrint ("TunnelGateway"); HandleTunnelGatewayMsg (msg); break; case eI2NPGarlic: LogPrint ("Garlic"); if (msg->from) { if (msg->from->GetTunnelPool ()) msg->from->GetTunnelPool ()->ProcessGarlicMessage (msg); else { LogPrint (eLogInfo, "Local destination for garlic doesn't exist anymore"); DeleteI2NPMessage (msg); } } else i2p::context.ProcessGarlicMessage (msg); break; case eI2NPDatabaseStore: case eI2NPDatabaseSearchReply: case eI2NPDatabaseLookup: // forward to netDb i2p::data::netdb.PostI2NPMsg (msg); break; case eI2NPDeliveryStatus: LogPrint ("DeliveryStatus"); if (msg->from && msg->from->GetTunnelPool ()) msg->from->GetTunnelPool ()->ProcessDeliveryStatus (msg); else i2p::context.ProcessDeliveryStatusMessage (msg); break; default: HandleI2NPMessage (msg->GetBuffer (), msg->GetLength ()); DeleteI2NPMessage (msg); } } } }