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I2P: End-to-End encrypted and anonymous Internet
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943 lines
31 KiB
943 lines
31 KiB
/* |
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* Copyright (c) 2013-2024, 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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#include <string.h> |
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#include <atomic> |
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#include "Base.h" |
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#include "Log.h" |
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#include "Crypto.h" |
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#include "I2PEndian.h" |
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#include "Timestamp.h" |
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#include "RouterContext.h" |
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#include "NetDb.hpp" |
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#include "Tunnel.h" |
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#include "Transports.h" |
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#include "Garlic.h" |
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#include "ECIESX25519AEADRatchetSession.h" |
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#include "I2NPProtocol.h" |
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#include "version.h" |
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using namespace i2p::transport; |
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namespace i2p |
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{ |
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std::shared_ptr<I2NPMessage> NewI2NPMessage () |
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{ |
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return std::make_shared<I2NPMessageBuffer<I2NP_MAX_MESSAGE_SIZE> >(); |
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} |
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std::shared_ptr<I2NPMessage> NewI2NPShortMessage () |
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{ |
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return std::make_shared<I2NPMessageBuffer<I2NP_MAX_SHORT_MESSAGE_SIZE> >(); |
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} |
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std::shared_ptr<I2NPMessage> NewI2NPMediumMessage () |
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{ |
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return std::make_shared<I2NPMessageBuffer<I2NP_MAX_MEDIUM_MESSAGE_SIZE> >(); |
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} |
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std::shared_ptr<I2NPMessage> NewI2NPTunnelMessage (bool endpoint) |
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{ |
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return i2p::tunnel::tunnels.NewI2NPTunnelMessage (endpoint); |
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} |
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std::shared_ptr<I2NPMessage> NewI2NPMessage (size_t len) |
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{ |
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len += I2NP_HEADER_SIZE + 2; |
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if (len <= I2NP_MAX_SHORT_MESSAGE_SIZE) return NewI2NPShortMessage (); |
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if (len <= I2NP_MAX_MEDIUM_MESSAGE_SIZE) return NewI2NPMediumMessage (); |
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return NewI2NPMessage (); |
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} |
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void I2NPMessage::FillI2NPMessageHeader (I2NPMessageType msgType, uint32_t replyMsgID, bool checksum) |
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{ |
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SetTypeID (msgType); |
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if (!replyMsgID) RAND_bytes ((uint8_t *)&replyMsgID, 4); |
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SetMsgID (replyMsgID); |
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SetExpiration (i2p::util::GetMillisecondsSinceEpoch () + I2NP_MESSAGE_EXPIRATION_TIMEOUT); |
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UpdateSize (); |
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if (checksum) UpdateChks (); |
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} |
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void I2NPMessage::RenewI2NPMessageHeader () |
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{ |
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uint32_t msgID; |
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RAND_bytes ((uint8_t *)&msgID, 4); |
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SetMsgID (msgID); |
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SetExpiration (i2p::util::GetMillisecondsSinceEpoch () + I2NP_MESSAGE_EXPIRATION_TIMEOUT); |
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} |
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bool I2NPMessage::IsExpired (uint64_t ts) const |
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{ |
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auto exp = GetExpiration (); |
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return (ts > exp + I2NP_MESSAGE_CLOCK_SKEW) || (ts < exp - 3*I2NP_MESSAGE_CLOCK_SKEW); // check if expired or too far in future |
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} |
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bool I2NPMessage::IsExpired () const |
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{ |
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return IsExpired (i2p::util::GetMillisecondsSinceEpoch ()); |
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} |
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std::shared_ptr<I2NPMessage> CreateI2NPMessage (I2NPMessageType msgType, const uint8_t * buf, size_t len, uint32_t replyMsgID) |
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{ |
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auto msg = NewI2NPMessage (len); |
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if (msg->Concat (buf, len) < len) |
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LogPrint (eLogError, "I2NP: Message length ", len, " exceeds max length ", msg->maxLen); |
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msg->FillI2NPMessageHeader (msgType, replyMsgID); |
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return msg; |
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} |
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std::shared_ptr<I2NPMessage> CreateI2NPMessage (const uint8_t * buf, size_t len, std::shared_ptr<i2p::tunnel::InboundTunnel> from) |
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{ |
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auto msg = NewI2NPMessage (); |
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if (msg->offset + len < msg->maxLen) |
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{ |
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memcpy (msg->GetBuffer (), buf, len); |
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msg->len = msg->offset + len; |
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msg->from = from; |
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} |
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else |
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LogPrint (eLogError, "I2NP: Message length ", len, " exceeds max length"); |
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return msg; |
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} |
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std::shared_ptr<I2NPMessage> CopyI2NPMessage (std::shared_ptr<I2NPMessage> msg) |
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{ |
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if (!msg) return nullptr; |
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auto newMsg = NewI2NPMessage (msg->len); |
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newMsg->offset = msg->offset; |
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*newMsg = *msg; |
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return newMsg; |
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} |
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std::shared_ptr<I2NPMessage> CreateTunnelTestMsg (uint32_t msgID) |
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{ |
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auto m = NewI2NPShortMessage (); |
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uint8_t * buf = m->GetPayload (); |
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htobe32buf (buf + TUNNEL_TEST_MSGID_OFFSET, msgID); |
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htobe64buf (buf + TUNNEL_TEST_TIMESTAMP_OFFSET, i2p::util::GetMonotonicMicroseconds ()); |
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m->len += TUNNEL_TEST_SIZE; |
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m->FillI2NPMessageHeader (eI2NPTunnelTest); |
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return m; |
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} |
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std::shared_ptr<I2NPMessage> CreateDeliveryStatusMsg (uint32_t msgID) |
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{ |
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auto m = NewI2NPShortMessage (); |
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uint8_t * buf = m->GetPayload (); |
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if (msgID) |
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{ |
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htobe32buf (buf + DELIVERY_STATUS_MSGID_OFFSET, msgID); |
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htobe64buf (buf + DELIVERY_STATUS_TIMESTAMP_OFFSET, i2p::util::GetMillisecondsSinceEpoch ()); |
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} |
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else // for SSU establishment |
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{ |
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RAND_bytes ((uint8_t *)&msgID, 4); |
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htobe32buf (buf + DELIVERY_STATUS_MSGID_OFFSET, msgID); |
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htobe64buf (buf + DELIVERY_STATUS_TIMESTAMP_OFFSET, i2p::context.GetNetID ()); |
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} |
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m->len += DELIVERY_STATUS_SIZE; |
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m->FillI2NPMessageHeader (eI2NPDeliveryStatus); |
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return m; |
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} |
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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, std::set<i2p::data::IdentHash> * excludedPeers) |
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{ |
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int cnt = excludedPeers ? excludedPeers->size () : 0; |
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auto m = cnt > 7 ? NewI2NPMessage () : NewI2NPShortMessage (); |
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uint8_t * buf = m->GetPayload (); |
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memcpy (buf, key, 32); // key |
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buf += 32; |
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memcpy (buf, from, 32); // from |
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buf += 32; |
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uint8_t flag = exploratory ? DATABASE_LOOKUP_TYPE_EXPLORATORY_LOOKUP : DATABASE_LOOKUP_TYPE_ROUTERINFO_LOOKUP; |
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if (replyTunnelID) |
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{ |
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*buf = flag | DATABASE_LOOKUP_DELIVERY_FLAG; // set delivery flag |
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htobe32buf (buf+1, replyTunnelID); |
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buf += 5; |
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} |
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else |
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{ |
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*buf = flag; // flag |
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buf++; |
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} |
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if (excludedPeers) |
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{ |
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htobe16buf (buf, cnt); |
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buf += 2; |
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for (auto& it: *excludedPeers) |
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{ |
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memcpy (buf, it, 32); |
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buf += 32; |
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} |
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} |
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else |
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{ |
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// nothing to exclude |
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htobuf16 (buf, 0); |
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buf += 2; |
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} |
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m->len += (buf - m->GetPayload ()); |
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m->FillI2NPMessageHeader (eI2NPDatabaseLookup); |
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return m; |
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} |
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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, const uint8_t * replyKey, |
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const uint8_t * replyTag, bool replyECIES) |
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{ |
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int cnt = excludedFloodfills.size (); |
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auto m = cnt > 7 ? NewI2NPMessage () : NewI2NPShortMessage (); |
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uint8_t * buf = m->GetPayload (); |
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memcpy (buf, dest, 32); // key |
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buf += 32; |
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memcpy (buf, replyTunnel->GetNextIdentHash (), 32); // reply tunnel GW |
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buf += 32; |
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*buf = DATABASE_LOOKUP_DELIVERY_FLAG | DATABASE_LOOKUP_TYPE_LEASESET_LOOKUP; // flags |
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*buf |= (replyECIES ? DATABASE_LOOKUP_ECIES_FLAG : DATABASE_LOOKUP_ENCRYPTION_FLAG); |
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buf ++; |
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htobe32buf (buf, replyTunnel->GetNextTunnelID ()); // reply tunnel ID |
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buf += 4; |
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// excluded |
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if (cnt > 512) |
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{ |
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LogPrint (eLogWarning, "I2NP: Too many peers to exclude ", cnt, " for DatabaseLookup"); |
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cnt = 0; |
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} |
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htobe16buf (buf, cnt); |
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buf += 2; |
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if (cnt > 0) |
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{ |
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for (auto& it: excludedFloodfills) |
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{ |
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memcpy (buf, it, 32); |
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buf += 32; |
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} |
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} |
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// encryption |
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memcpy (buf, replyKey, 32); |
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buf[32] = 1; // 1 tag |
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if (replyECIES) |
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{ |
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memcpy (buf + 33, replyTag, 8); // 8 bytes tag |
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buf += 41; |
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} |
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else |
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{ |
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memcpy (buf + 33, replyTag, 32); // 32 bytes tag |
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buf += 65; |
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} |
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m->len += (buf - m->GetPayload ()); |
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m->FillI2NPMessageHeader (eI2NPDatabaseLookup); |
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return m; |
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} |
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std::shared_ptr<I2NPMessage> CreateDatabaseSearchReply (const i2p::data::IdentHash& ident, |
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std::vector<i2p::data::IdentHash> routers) |
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{ |
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auto m = NewI2NPShortMessage (); |
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uint8_t * buf = m->GetPayload (); |
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size_t len = 0; |
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memcpy (buf, ident, 32); |
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len += 32; |
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buf[len] = routers.size (); |
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len++; |
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for (const auto& it: routers) |
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{ |
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memcpy (buf + len, it, 32); |
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len += 32; |
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} |
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memcpy (buf + len, i2p::context.GetRouterInfo ().GetIdentHash (), 32); |
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len += 32; |
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m->len += len; |
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m->FillI2NPMessageHeader (eI2NPDatabaseSearchReply); |
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return m; |
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} |
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std::shared_ptr<I2NPMessage> CreateDatabaseStoreMsg (std::shared_ptr<const i2p::data::RouterInfo> router, |
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uint32_t replyToken, std::shared_ptr<const i2p::tunnel::InboundTunnel> replyTunnel) |
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{ |
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if (!router) // we send own RouterInfo |
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router = context.GetSharedRouterInfo (); |
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if (!router->GetBuffer ()) |
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{ |
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LogPrint (eLogError, "I2NP: Invalid RouterInfo buffer for DatabaseStore"); |
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return nullptr; |
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} |
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auto m = NewI2NPShortMessage (); |
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uint8_t * payload = m->GetPayload (); |
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memcpy (payload + DATABASE_STORE_KEY_OFFSET, router->GetIdentHash (), 32); |
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payload[DATABASE_STORE_TYPE_OFFSET] = 0; // RouterInfo |
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htobe32buf (payload + DATABASE_STORE_REPLY_TOKEN_OFFSET, replyToken); |
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uint8_t * buf = payload + DATABASE_STORE_HEADER_SIZE; |
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if (replyToken) |
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{ |
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if (replyTunnel) |
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{ |
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htobe32buf (buf, replyTunnel->GetNextTunnelID ()); |
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buf += 4; // reply tunnelID |
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memcpy (buf, replyTunnel->GetNextIdentHash (), 32); |
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buf += 32; // reply tunnel gateway |
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} |
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else |
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{ |
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memset (buf, 0, 4); // zero tunnelID means direct reply |
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buf += 4; |
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memcpy (buf, context.GetIdentHash (), 32); |
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buf += 32; |
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} |
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} |
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uint8_t * sizePtr = buf; |
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buf += 2; |
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m->len += (buf - payload); // payload size |
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size_t size = 0; |
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if (router->GetBufferLen () + (buf - payload) <= 940) // fits one tunnel message |
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size = i2p::data::GzipNoCompression (router->GetBuffer (), router->GetBufferLen (), buf, m->maxLen -m->len); |
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else |
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{ |
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i2p::data::GzipDeflator deflator; |
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size = deflator.Deflate (router->GetBuffer (), router->GetBufferLen (), buf, m->maxLen -m->len); |
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} |
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if (size) |
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{ |
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htobe16buf (sizePtr, size); // size |
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m->len += size; |
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} |
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else |
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m = nullptr; |
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if (m) |
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m->FillI2NPMessageHeader (eI2NPDatabaseStore); |
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return m; |
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} |
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std::shared_ptr<I2NPMessage> CreateDatabaseStoreMsg (const i2p::data::IdentHash& storeHash, std::shared_ptr<const i2p::data::LeaseSet> leaseSet) |
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{ |
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if (!leaseSet) return nullptr; |
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auto m = NewI2NPShortMessage (); |
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uint8_t * payload = m->GetPayload (); |
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memcpy (payload + DATABASE_STORE_KEY_OFFSET, storeHash, 32); |
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payload[DATABASE_STORE_TYPE_OFFSET] = leaseSet->GetStoreType (); // 1 for LeaseSet |
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htobe32buf (payload + DATABASE_STORE_REPLY_TOKEN_OFFSET, 0); |
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size_t size = DATABASE_STORE_HEADER_SIZE; |
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memcpy (payload + size, leaseSet->GetBuffer (), leaseSet->GetBufferLen ()); |
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size += leaseSet->GetBufferLen (); |
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m->len += size; |
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m->FillI2NPMessageHeader (eI2NPDatabaseStore); |
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return m; |
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} |
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std::shared_ptr<I2NPMessage> CreateDatabaseStoreMsg (std::shared_ptr<const i2p::data::LocalLeaseSet> leaseSet, uint32_t replyToken, std::shared_ptr<const i2p::tunnel::InboundTunnel> replyTunnel) |
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{ |
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if (!leaseSet) return nullptr; |
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auto m = NewI2NPShortMessage (); |
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uint8_t * payload = m->GetPayload (); |
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memcpy (payload + DATABASE_STORE_KEY_OFFSET, leaseSet->GetStoreHash (), 32); |
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payload[DATABASE_STORE_TYPE_OFFSET] = leaseSet->GetStoreType (); // LeaseSet or LeaseSet2 |
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htobe32buf (payload + DATABASE_STORE_REPLY_TOKEN_OFFSET, replyToken); |
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size_t size = DATABASE_STORE_HEADER_SIZE; |
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if (replyToken && replyTunnel) |
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{ |
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if (replyTunnel) |
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{ |
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htobe32buf (payload + size, replyTunnel->GetNextTunnelID ()); |
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size += 4; // reply tunnelID |
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memcpy (payload + size, replyTunnel->GetNextIdentHash (), 32); |
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size += 32; // reply tunnel gateway |
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} |
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else |
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htobe32buf (payload + DATABASE_STORE_REPLY_TOKEN_OFFSET, 0); |
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} |
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memcpy (payload + size, leaseSet->GetBuffer (), leaseSet->GetBufferLen ()); |
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size += leaseSet->GetBufferLen (); |
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m->len += size; |
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m->FillI2NPMessageHeader (eI2NPDatabaseStore); |
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return m; |
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} |
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bool IsRouterInfoMsg (std::shared_ptr<I2NPMessage> msg) |
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{ |
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if (!msg || msg->GetTypeID () != eI2NPDatabaseStore) return false; |
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return !msg->GetPayload ()[DATABASE_STORE_TYPE_OFFSET]; // 0- RouterInfo |
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} |
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static bool HandleBuildRequestRecords (int num, uint8_t * records, uint8_t * clearText) |
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{ |
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for (int i = 0; i < num; i++) |
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{ |
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uint8_t * record = records + i*TUNNEL_BUILD_RECORD_SIZE; |
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if (!memcmp (record + BUILD_REQUEST_RECORD_TO_PEER_OFFSET, (const uint8_t *)i2p::context.GetRouterInfo ().GetIdentHash (), 16)) |
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{ |
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LogPrint (eLogDebug, "I2NP: Build request record ", i, " is ours"); |
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if (!i2p::context.DecryptTunnelBuildRecord (record + BUILD_REQUEST_RECORD_ENCRYPTED_OFFSET, clearText)) |
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{ |
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LogPrint (eLogWarning, "I2NP: Failed to decrypt tunnel build record"); |
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return false; |
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} |
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if (!memcmp ((const uint8_t *)i2p::context.GetIdentHash (), clearText + ECIES_BUILD_REQUEST_RECORD_NEXT_IDENT_OFFSET, 32) && // if next ident is now ours |
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!(clearText[ECIES_BUILD_REQUEST_RECORD_FLAG_OFFSET] & TUNNEL_BUILD_RECORD_ENDPOINT_FLAG)) // and not endpoint |
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{ |
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LogPrint (eLogWarning, "I2NP: Next ident is ours in tunnel build record"); |
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return false; |
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} |
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uint8_t retCode = 0; |
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// replace record to reply |
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if (i2p::context.AcceptsTunnels () && i2p::context.GetCongestionLevel (false) < CONGESTION_LEVEL_FULL) |
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{ |
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auto transitTunnel = i2p::tunnel::CreateTransitTunnel ( |
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bufbe32toh (clearText + ECIES_BUILD_REQUEST_RECORD_RECEIVE_TUNNEL_OFFSET), |
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clearText + ECIES_BUILD_REQUEST_RECORD_NEXT_IDENT_OFFSET, |
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bufbe32toh (clearText + ECIES_BUILD_REQUEST_RECORD_NEXT_TUNNEL_OFFSET), |
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clearText + ECIES_BUILD_REQUEST_RECORD_LAYER_KEY_OFFSET, |
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clearText + ECIES_BUILD_REQUEST_RECORD_IV_KEY_OFFSET, |
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clearText[ECIES_BUILD_REQUEST_RECORD_FLAG_OFFSET] & TUNNEL_BUILD_RECORD_GATEWAY_FLAG, |
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clearText[ECIES_BUILD_REQUEST_RECORD_FLAG_OFFSET] & TUNNEL_BUILD_RECORD_ENDPOINT_FLAG); |
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if (!i2p::tunnel::tunnels.AddTransitTunnel (transitTunnel)) |
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retCode = 30; |
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} |
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else |
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retCode = 30; // always reject with bandwidth reason (30) |
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memset (record + ECIES_BUILD_RESPONSE_RECORD_OPTIONS_OFFSET, 0, 2); // no options |
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record[ECIES_BUILD_RESPONSE_RECORD_RET_OFFSET] = retCode; |
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// encrypt reply |
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i2p::crypto::CBCEncryption encryption; |
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for (int j = 0; j < num; j++) |
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{ |
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uint8_t * reply = records + j*TUNNEL_BUILD_RECORD_SIZE; |
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if (j == i) |
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{ |
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uint8_t nonce[12]; |
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memset (nonce, 0, 12); |
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auto& noiseState = i2p::context.GetCurrentNoiseState (); |
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if (!i2p::crypto::AEADChaCha20Poly1305 (reply, TUNNEL_BUILD_RECORD_SIZE - 16, |
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noiseState.m_H, 32, noiseState.m_CK, nonce, reply, TUNNEL_BUILD_RECORD_SIZE, true)) // encrypt |
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{ |
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LogPrint (eLogWarning, "I2NP: Reply AEAD encryption failed"); |
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return false; |
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} |
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} |
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else |
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{ |
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encryption.SetKey (clearText + ECIES_BUILD_REQUEST_RECORD_REPLY_KEY_OFFSET); |
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encryption.SetIV (clearText + ECIES_BUILD_REQUEST_RECORD_REPLY_IV_OFFSET); |
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encryption.Encrypt(reply, TUNNEL_BUILD_RECORD_SIZE, reply); |
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} |
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} |
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return true; |
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} |
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} |
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return false; |
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} |
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static void HandleVariableTunnelBuildMsg (uint32_t replyMsgID, uint8_t * buf, size_t len) |
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{ |
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int num = buf[0]; |
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LogPrint (eLogDebug, "I2NP: VariableTunnelBuild ", num, " records"); |
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if (num > i2p::tunnel::MAX_NUM_RECORDS) |
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{ |
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LogPrint (eLogError, "I2NP: Too many records in VaribleTunnelBuild message ", num); |
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return; |
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} |
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if (len < num*TUNNEL_BUILD_RECORD_SIZE + 1) |
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{ |
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LogPrint (eLogError, "I2NP: VaribleTunnelBuild message of ", num, " records is too short ", len); |
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return; |
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} |
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auto tunnel = i2p::tunnel::tunnels.GetPendingInboundTunnel (replyMsgID); |
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if (tunnel) |
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{ |
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// endpoint of inbound tunnel |
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LogPrint (eLogDebug, "I2NP: VariableTunnelBuild reply for tunnel ", tunnel->GetTunnelID ()); |
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if (tunnel->HandleTunnelBuildResponse (buf, len)) |
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{ |
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LogPrint (eLogInfo, "I2NP: Inbound tunnel ", tunnel->GetTunnelID (), " has been created"); |
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tunnel->SetState (i2p::tunnel::eTunnelStateEstablished); |
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i2p::tunnel::tunnels.AddInboundTunnel (tunnel); |
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} |
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else |
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{ |
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LogPrint (eLogInfo, "I2NP: Inbound tunnel ", tunnel->GetTunnelID (), " has been declined"); |
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tunnel->SetState (i2p::tunnel::eTunnelStateBuildFailed); |
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} |
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} |
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else |
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{ |
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uint8_t clearText[ECIES_BUILD_REQUEST_RECORD_CLEAR_TEXT_SIZE]; |
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if (HandleBuildRequestRecords (num, buf + 1, clearText)) |
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{ |
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if (clearText[ECIES_BUILD_REQUEST_RECORD_FLAG_OFFSET] & TUNNEL_BUILD_RECORD_ENDPOINT_FLAG) // we are endpoint of outboud tunnel |
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{ |
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// so we send it to reply tunnel |
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transports.SendMessage (clearText + ECIES_BUILD_REQUEST_RECORD_NEXT_IDENT_OFFSET, |
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CreateTunnelGatewayMsg (bufbe32toh (clearText + ECIES_BUILD_REQUEST_RECORD_NEXT_TUNNEL_OFFSET), |
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eI2NPVariableTunnelBuildReply, buf, len, |
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bufbe32toh (clearText + ECIES_BUILD_REQUEST_RECORD_SEND_MSG_ID_OFFSET))); |
|
} |
|
else |
|
transports.SendMessage (clearText + ECIES_BUILD_REQUEST_RECORD_NEXT_IDENT_OFFSET, |
|
CreateI2NPMessage (eI2NPVariableTunnelBuild, buf, len, |
|
bufbe32toh (clearText + ECIES_BUILD_REQUEST_RECORD_SEND_MSG_ID_OFFSET))); |
|
} |
|
} |
|
} |
|
|
|
static void HandleTunnelBuildMsg (uint8_t * buf, size_t len) |
|
{ |
|
LogPrint (eLogWarning, "I2NP: TunnelBuild is too old for ECIES router"); |
|
} |
|
|
|
static void HandleTunnelBuildReplyMsg (uint32_t replyMsgID, uint8_t * buf, size_t len, bool isShort) |
|
{ |
|
int num = buf[0]; |
|
LogPrint (eLogDebug, "I2NP: TunnelBuildReplyMsg of ", num, " records replyMsgID=", replyMsgID); |
|
if (num > i2p::tunnel::MAX_NUM_RECORDS) |
|
{ |
|
LogPrint (eLogError, "I2NP: Too many records in TunnelBuildReply message ", num); |
|
return; |
|
} |
|
size_t recordSize = isShort ? SHORT_TUNNEL_BUILD_RECORD_SIZE : TUNNEL_BUILD_RECORD_SIZE; |
|
if (len < num*recordSize + 1) |
|
{ |
|
LogPrint (eLogError, "I2NP: TunnelBuildReply message of ", num, " records is too short ", len); |
|
return; |
|
} |
|
|
|
auto tunnel = i2p::tunnel::tunnels.GetPendingOutboundTunnel (replyMsgID); |
|
if (tunnel) |
|
{ |
|
// reply for outbound tunnel |
|
if (tunnel->HandleTunnelBuildResponse (buf, len)) |
|
{ |
|
LogPrint (eLogInfo, "I2NP: Outbound tunnel ", tunnel->GetTunnelID (), " has been created"); |
|
tunnel->SetState (i2p::tunnel::eTunnelStateEstablished); |
|
i2p::tunnel::tunnels.AddOutboundTunnel (tunnel); |
|
} |
|
else |
|
{ |
|
LogPrint (eLogInfo, "I2NP: Outbound tunnel ", tunnel->GetTunnelID (), " has been declined"); |
|
tunnel->SetState (i2p::tunnel::eTunnelStateBuildFailed); |
|
} |
|
} |
|
else |
|
LogPrint (eLogWarning, "I2NP: Pending tunnel for message ", replyMsgID, " not found"); |
|
} |
|
|
|
static void HandleShortTunnelBuildMsg (uint32_t replyMsgID, uint8_t * buf, size_t len) |
|
{ |
|
int num = buf[0]; |
|
LogPrint (eLogDebug, "I2NP: ShortTunnelBuild ", num, " records"); |
|
if (num > i2p::tunnel::MAX_NUM_RECORDS) |
|
{ |
|
LogPrint (eLogError, "I2NP: Too many records in ShortTunnelBuild message ", num); |
|
return; |
|
} |
|
if (len < num*SHORT_TUNNEL_BUILD_RECORD_SIZE + 1) |
|
{ |
|
LogPrint (eLogError, "I2NP: ShortTunnelBuild message of ", num, " records is too short ", len); |
|
return; |
|
} |
|
auto tunnel = i2p::tunnel::tunnels.GetPendingInboundTunnel (replyMsgID); |
|
if (tunnel) |
|
{ |
|
// endpoint of inbound tunnel |
|
LogPrint (eLogDebug, "I2NP: ShortTunnelBuild reply for tunnel ", tunnel->GetTunnelID ()); |
|
if (tunnel->HandleTunnelBuildResponse (buf, len)) |
|
{ |
|
LogPrint (eLogInfo, "I2NP: Inbound tunnel ", tunnel->GetTunnelID (), " has been created"); |
|
tunnel->SetState (i2p::tunnel::eTunnelStateEstablished); |
|
i2p::tunnel::tunnels.AddInboundTunnel (tunnel); |
|
} |
|
else |
|
{ |
|
LogPrint (eLogInfo, "I2NP: Inbound tunnel ", tunnel->GetTunnelID (), " has been declined"); |
|
tunnel->SetState (i2p::tunnel::eTunnelStateBuildFailed); |
|
} |
|
return; |
|
} |
|
const uint8_t * record = buf + 1; |
|
for (int i = 0; i < num; i++) |
|
{ |
|
if (!memcmp (record, (const uint8_t *)i2p::context.GetRouterInfo ().GetIdentHash (), 16)) |
|
{ |
|
LogPrint (eLogDebug, "I2NP: Short request record ", i, " is ours"); |
|
uint8_t clearText[SHORT_REQUEST_RECORD_CLEAR_TEXT_SIZE]; |
|
if (!i2p::context.DecryptTunnelShortRequestRecord (record + SHORT_REQUEST_RECORD_ENCRYPTED_OFFSET, clearText)) |
|
{ |
|
LogPrint (eLogWarning, "I2NP: Can't decrypt short request record ", i); |
|
return; |
|
} |
|
if (clearText[SHORT_REQUEST_RECORD_LAYER_ENCRYPTION_TYPE]) // not AES |
|
{ |
|
LogPrint (eLogWarning, "I2NP: Unknown layer encryption type ", clearText[SHORT_REQUEST_RECORD_LAYER_ENCRYPTION_TYPE], " in short request record"); |
|
return; |
|
} |
|
auto& noiseState = i2p::context.GetCurrentNoiseState (); |
|
uint8_t replyKey[32]; // AEAD/Chacha20/Poly1305 |
|
i2p::crypto::AESKey layerKey, ivKey; // AES |
|
i2p::crypto::HKDF (noiseState.m_CK, nullptr, 0, "SMTunnelReplyKey", noiseState.m_CK); |
|
memcpy (replyKey, noiseState.m_CK + 32, 32); |
|
i2p::crypto::HKDF (noiseState.m_CK, nullptr, 0, "SMTunnelLayerKey", noiseState.m_CK); |
|
memcpy (layerKey, noiseState.m_CK + 32, 32); |
|
bool isEndpoint = clearText[SHORT_REQUEST_RECORD_FLAG_OFFSET] & TUNNEL_BUILD_RECORD_ENDPOINT_FLAG; |
|
if (isEndpoint) |
|
{ |
|
i2p::crypto::HKDF (noiseState.m_CK, nullptr, 0, "TunnelLayerIVKey", noiseState.m_CK); |
|
memcpy (ivKey, noiseState.m_CK + 32, 32); |
|
} |
|
else |
|
{ |
|
if (!memcmp ((const uint8_t *)i2p::context.GetIdentHash (), clearText + SHORT_REQUEST_RECORD_NEXT_IDENT_OFFSET, 32)) // if next ident is now ours |
|
{ |
|
LogPrint (eLogWarning, "I2NP: Next ident is ours in short request record"); |
|
return; |
|
} |
|
memcpy (ivKey, noiseState.m_CK , 32); |
|
} |
|
|
|
// check if we accept this tunnel |
|
std::shared_ptr<i2p::tunnel::TransitTunnel> transitTunnel; |
|
uint8_t retCode = 0; |
|
if (!i2p::context.AcceptsTunnels () || i2p::context.GetCongestionLevel (false) >= CONGESTION_LEVEL_FULL) |
|
retCode = 30; |
|
if (!retCode) |
|
{ |
|
// create new transit tunnel |
|
transitTunnel = i2p::tunnel::CreateTransitTunnel ( |
|
bufbe32toh (clearText + SHORT_REQUEST_RECORD_RECEIVE_TUNNEL_OFFSET), |
|
clearText + SHORT_REQUEST_RECORD_NEXT_IDENT_OFFSET, |
|
bufbe32toh (clearText + SHORT_REQUEST_RECORD_NEXT_TUNNEL_OFFSET), |
|
layerKey, ivKey, |
|
clearText[SHORT_REQUEST_RECORD_FLAG_OFFSET] & TUNNEL_BUILD_RECORD_GATEWAY_FLAG, |
|
clearText[SHORT_REQUEST_RECORD_FLAG_OFFSET] & TUNNEL_BUILD_RECORD_ENDPOINT_FLAG); |
|
if (!i2p::tunnel::tunnels.AddTransitTunnel (transitTunnel)) |
|
retCode = 30; |
|
} |
|
|
|
// encrypt reply |
|
uint8_t nonce[12]; |
|
memset (nonce, 0, 12); |
|
uint8_t * reply = buf + 1; |
|
for (int j = 0; j < num; j++) |
|
{ |
|
nonce[4] = j; // nonce is record # |
|
if (j == i) |
|
{ |
|
memset (reply + SHORT_RESPONSE_RECORD_OPTIONS_OFFSET, 0, 2); // no options |
|
reply[SHORT_RESPONSE_RECORD_RET_OFFSET] = retCode; |
|
if (!i2p::crypto::AEADChaCha20Poly1305 (reply, SHORT_TUNNEL_BUILD_RECORD_SIZE - 16, |
|
noiseState.m_H, 32, replyKey, nonce, reply, SHORT_TUNNEL_BUILD_RECORD_SIZE, true)) // encrypt |
|
{ |
|
LogPrint (eLogWarning, "I2NP: Short reply AEAD encryption failed"); |
|
return; |
|
} |
|
} |
|
else |
|
i2p::crypto::ChaCha20 (reply, SHORT_TUNNEL_BUILD_RECORD_SIZE, replyKey, nonce, reply); |
|
reply += SHORT_TUNNEL_BUILD_RECORD_SIZE; |
|
} |
|
// send reply |
|
auto onDrop = [transitTunnel]() |
|
{ |
|
if (transitTunnel) |
|
{ |
|
auto t = transitTunnel->GetCreationTime (); |
|
if (t > i2p::tunnel::TUNNEL_EXPIRATION_TIMEOUT) |
|
// make transit tunnel expired |
|
transitTunnel->SetCreationTime (t - i2p::tunnel::TUNNEL_EXPIRATION_TIMEOUT); |
|
} |
|
}; |
|
if (isEndpoint) |
|
{ |
|
auto replyMsg = NewI2NPShortMessage (); |
|
replyMsg->Concat (buf, len); |
|
replyMsg->FillI2NPMessageHeader (eI2NPShortTunnelBuildReply, bufbe32toh (clearText + SHORT_REQUEST_RECORD_SEND_MSG_ID_OFFSET)); |
|
if (transitTunnel) replyMsg->onDrop = onDrop; |
|
if (memcmp ((const uint8_t *)i2p::context.GetIdentHash (), |
|
clearText + SHORT_REQUEST_RECORD_NEXT_IDENT_OFFSET, 32)) // reply IBGW is not local? |
|
{ |
|
i2p::crypto::HKDF (noiseState.m_CK, nullptr, 0, "RGarlicKeyAndTag", noiseState.m_CK); |
|
uint64_t tag; |
|
memcpy (&tag, noiseState.m_CK, 8); |
|
// we send it to reply tunnel |
|
transports.SendMessage (clearText + SHORT_REQUEST_RECORD_NEXT_IDENT_OFFSET, |
|
CreateTunnelGatewayMsg (bufbe32toh (clearText + SHORT_REQUEST_RECORD_NEXT_TUNNEL_OFFSET), |
|
i2p::garlic::WrapECIESX25519Message (replyMsg, noiseState.m_CK + 32, tag))); |
|
} |
|
else |
|
{ |
|
// IBGW is local |
|
uint32_t tunnelID = bufbe32toh (clearText + SHORT_REQUEST_RECORD_NEXT_TUNNEL_OFFSET); |
|
auto tunnel = i2p::tunnel::tunnels.GetTunnel (tunnelID); |
|
if (tunnel) |
|
{ |
|
tunnel->SendTunnelDataMsg (replyMsg); |
|
tunnel->FlushTunnelDataMsgs (); |
|
} |
|
else |
|
LogPrint (eLogWarning, "I2NP: Tunnel ", tunnelID, " not found for short tunnel build reply"); |
|
} |
|
} |
|
else |
|
{ |
|
auto msg = CreateI2NPMessage (eI2NPShortTunnelBuild, buf, len, |
|
bufbe32toh (clearText + SHORT_REQUEST_RECORD_SEND_MSG_ID_OFFSET)); |
|
if (transitTunnel) msg->onDrop = onDrop; |
|
transports.SendMessage (clearText + SHORT_REQUEST_RECORD_NEXT_IDENT_OFFSET, msg); |
|
} |
|
return; |
|
} |
|
record += SHORT_TUNNEL_BUILD_RECORD_SIZE; |
|
} |
|
} |
|
|
|
std::shared_ptr<I2NPMessage> CreateTunnelDataMsg (const uint8_t * buf) |
|
{ |
|
auto msg = NewI2NPTunnelMessage (false); |
|
msg->Concat (buf, i2p::tunnel::TUNNEL_DATA_MSG_SIZE); |
|
msg->FillI2NPMessageHeader (eI2NPTunnelData); |
|
return msg; |
|
} |
|
|
|
std::shared_ptr<I2NPMessage> CreateTunnelDataMsg (uint32_t tunnelID, const uint8_t * payload) |
|
{ |
|
auto msg = NewI2NPTunnelMessage (false); |
|
htobe32buf (msg->GetPayload (), tunnelID); |
|
msg->len += 4; // tunnelID |
|
msg->Concat (payload, i2p::tunnel::TUNNEL_DATA_MSG_SIZE - 4); |
|
msg->FillI2NPMessageHeader (eI2NPTunnelData); |
|
return msg; |
|
} |
|
|
|
std::shared_ptr<I2NPMessage> CreateEmptyTunnelDataMsg (bool endpoint) |
|
{ |
|
auto msg = NewI2NPTunnelMessage (endpoint); |
|
msg->len += i2p::tunnel::TUNNEL_DATA_MSG_SIZE; |
|
return msg; |
|
} |
|
|
|
std::shared_ptr<I2NPMessage> CreateTunnelGatewayMsg (uint32_t tunnelID, const uint8_t * buf, size_t len) |
|
{ |
|
auto msg = NewI2NPMessage (len); |
|
uint8_t * payload = msg->GetPayload (); |
|
htobe32buf (payload + TUNNEL_GATEWAY_HEADER_TUNNELID_OFFSET, tunnelID); |
|
htobe16buf (payload + TUNNEL_GATEWAY_HEADER_LENGTH_OFFSET, len); |
|
msg->len += TUNNEL_GATEWAY_HEADER_SIZE; |
|
if (msg->Concat (buf, len) < len) |
|
LogPrint (eLogError, "I2NP: Tunnel gateway buffer overflow ", msg->maxLen); |
|
msg->FillI2NPMessageHeader (eI2NPTunnelGateway); |
|
return msg; |
|
} |
|
|
|
std::shared_ptr<I2NPMessage> CreateTunnelGatewayMsg (uint32_t tunnelID, std::shared_ptr<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; |
|
msg->FillI2NPMessageHeader (eI2NPTunnelGateway); |
|
return msg; |
|
} |
|
else |
|
{ |
|
auto newMsg = CreateTunnelGatewayMsg (tunnelID, msg->GetBuffer (), msg->GetLength ()); |
|
if (msg->onDrop) newMsg->onDrop = msg->onDrop; |
|
return newMsg; |
|
} |
|
} |
|
|
|
std::shared_ptr<I2NPMessage> CreateTunnelGatewayMsg (uint32_t tunnelID, I2NPMessageType msgType, |
|
const uint8_t * buf, size_t len, uint32_t replyMsgID) |
|
{ |
|
auto msg = NewI2NPMessage (len); |
|
size_t gatewayMsgOffset = I2NP_HEADER_SIZE + TUNNEL_GATEWAY_HEADER_SIZE; |
|
msg->offset += gatewayMsgOffset; |
|
msg->len += gatewayMsgOffset; |
|
if (msg->Concat (buf, len) < len) |
|
LogPrint (eLogError, "I2NP: Tunnel gateway buffer overflow ", msg->maxLen); |
|
msg->FillI2NPMessageHeader (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); |
|
msg->FillI2NPMessageHeader (eI2NPTunnelGateway); // gateway message |
|
return msg; |
|
} |
|
|
|
size_t GetI2NPMessageLength (const uint8_t * msg, size_t len) |
|
{ |
|
if (len < I2NP_HEADER_SIZE_OFFSET + 2) |
|
{ |
|
LogPrint (eLogError, "I2NP: Message length ", len, " is smaller than header"); |
|
return len; |
|
} |
|
auto l = bufbe16toh (msg + I2NP_HEADER_SIZE_OFFSET) + I2NP_HEADER_SIZE; |
|
if (l > len) |
|
{ |
|
LogPrint (eLogError, "I2NP: Message length ", l, " exceeds buffer length ", len); |
|
l = len; |
|
} |
|
return l; |
|
} |
|
|
|
void HandleTunnelBuildI2NPMessage (std::shared_ptr<I2NPMessage> msg) |
|
{ |
|
if (msg) |
|
{ |
|
uint8_t typeID = msg->GetTypeID(); |
|
uint32_t msgID = msg->GetMsgID(); |
|
LogPrint (eLogDebug, "I2NP: Handling tunnel build message with len=", msg->GetLength(),", type=", (int)typeID, ", msgID=", (unsigned int)msgID); |
|
uint8_t * payload = msg->GetPayload(); |
|
auto size = msg->GetPayloadLength(); |
|
switch (typeID) |
|
{ |
|
case eI2NPVariableTunnelBuild: |
|
HandleVariableTunnelBuildMsg (msgID, payload, size); |
|
break; |
|
case eI2NPShortTunnelBuild: |
|
HandleShortTunnelBuildMsg (msgID, payload, size); |
|
break; |
|
case eI2NPVariableTunnelBuildReply: |
|
HandleTunnelBuildReplyMsg (msgID, payload, size, false); |
|
break; |
|
case eI2NPShortTunnelBuildReply: |
|
HandleTunnelBuildReplyMsg (msgID, payload, size, true); |
|
break; |
|
case eI2NPTunnelBuild: |
|
HandleTunnelBuildMsg (payload, size); |
|
break; |
|
case eI2NPTunnelBuildReply: |
|
// TODO: |
|
break; |
|
default: |
|
LogPrint (eLogError, "I2NP: Unexpected message with type", (int)typeID, " during handling TBM; skipping"); |
|
} |
|
} |
|
} |
|
|
|
void HandleI2NPMessage (std::shared_ptr<I2NPMessage> msg) |
|
{ |
|
if (msg) |
|
{ |
|
uint8_t typeID = msg->GetTypeID (); |
|
LogPrint (eLogDebug, "I2NP: Handling message with type ", (int)typeID); |
|
switch (typeID) |
|
{ |
|
case eI2NPTunnelData: |
|
if (!msg->from) |
|
i2p::tunnel::tunnels.PostTunnelData (msg); |
|
break; |
|
case eI2NPTunnelGateway: |
|
if (!msg->from) |
|
i2p::tunnel::tunnels.PostTunnelData (msg); |
|
break; |
|
case eI2NPGarlic: |
|
{ |
|
if (msg->from && msg->from->GetTunnelPool ()) |
|
msg->from->GetTunnelPool ()->ProcessGarlicMessage (msg); |
|
else |
|
i2p::context.ProcessGarlicMessage (msg); |
|
break; |
|
} |
|
case eI2NPDatabaseStore: |
|
case eI2NPDatabaseSearchReply: |
|
// forward to netDb if came directly or through exploratory tunnel as response to our request |
|
if (!msg->from || !msg->from->GetTunnelPool () || msg->from->GetTunnelPool ()->IsExploratory ()) |
|
i2p::data::netdb.PostI2NPMsg (msg); |
|
break; |
|
|
|
case eI2NPDatabaseLookup: |
|
// forward to netDb if floodfill and came directly |
|
if (!msg->from && i2p::context.IsFloodfill ()) |
|
i2p::data::netdb.PostI2NPMsg (msg); |
|
break; |
|
case eI2NPDeliveryStatus: |
|
{ |
|
if (msg->from && msg->from->GetTunnelPool ()) |
|
msg->from->GetTunnelPool ()->ProcessDeliveryStatus (msg); |
|
else |
|
i2p::context.ProcessDeliveryStatusMessage (msg); |
|
break; |
|
} |
|
case eI2NPTunnelTest: |
|
if (msg->from && msg->from->GetTunnelPool ()) |
|
msg->from->GetTunnelPool ()->ProcessTunnelTest (msg); |
|
break; |
|
case eI2NPVariableTunnelBuild: |
|
case eI2NPTunnelBuild: |
|
case eI2NPShortTunnelBuild: |
|
// forward to tunnel thread |
|
if (!msg->from) |
|
i2p::tunnel::tunnels.PostTunnelData (msg); |
|
break; |
|
case eI2NPVariableTunnelBuildReply: |
|
case eI2NPTunnelBuildReply: |
|
case eI2NPShortTunnelBuildReply: |
|
// forward to tunnel thread |
|
i2p::tunnel::tunnels.PostTunnelData (msg); |
|
break; |
|
default: |
|
LogPrint(eLogError, "I2NP: Unexpected I2NP message with type ", int(typeID), " during handling; skipping"); |
|
} |
|
} |
|
} |
|
|
|
I2NPMessagesHandler::~I2NPMessagesHandler () |
|
{ |
|
Flush (); |
|
} |
|
|
|
void I2NPMessagesHandler::PutNextMessage (std::shared_ptr<I2NPMessage>&& msg) |
|
{ |
|
if (msg) |
|
{ |
|
switch (msg->GetTypeID ()) |
|
{ |
|
case eI2NPTunnelData: |
|
m_TunnelMsgs.push_back (msg); |
|
break; |
|
case eI2NPTunnelGateway: |
|
m_TunnelGatewayMsgs.push_back (msg); |
|
break; |
|
default: |
|
HandleI2NPMessage (msg); |
|
} |
|
} |
|
} |
|
|
|
void I2NPMessagesHandler::Flush () |
|
{ |
|
if (!m_TunnelMsgs.empty ()) |
|
{ |
|
i2p::tunnel::tunnels.PostTunnelData (m_TunnelMsgs); |
|
m_TunnelMsgs.clear (); |
|
} |
|
if (!m_TunnelGatewayMsgs.empty ()) |
|
{ |
|
i2p::tunnel::tunnels.PostTunnelData (m_TunnelGatewayMsgs); |
|
m_TunnelGatewayMsgs.clear (); |
|
} |
|
} |
|
}
|
|
|