From 97fdedfbe393ef2ce2195960d72bd0b5fe339413 Mon Sep 17 00:00:00 2001 From: orignal Date: Wed, 16 Oct 2024 08:28:25 -0400 Subject: [PATCH] implement SSU2HolPunchSession --- libi2pd/SSU2.cpp | 11 +++++-- libi2pd/SSU2OutOfSession.cpp | 58 ++++++++++++++++++++++++++++++++++++ libi2pd/SSU2OutOfSession.h | 15 ++++++++++ libi2pd/SSU2Session.cpp | 48 +++-------------------------- libi2pd/SSU2Session.h | 5 ++-- 5 files changed, 88 insertions(+), 49 deletions(-) diff --git a/libi2pd/SSU2.cpp b/libi2pd/SSU2.cpp index 574aea55..e96a7233 100644 --- a/libi2pd/SSU2.cpp +++ b/libi2pd/SSU2.cpp @@ -479,9 +479,11 @@ namespace transport { if (session) { - m_Sessions.emplace (session->GetConnID (), session); - if (session->GetState () != eSSU2SessionStatePeerTest) - AddSessionByRouterHash (session); + if (m_Sessions.emplace (session->GetConnID (), session).second) + { + if (session->GetState () != eSSU2SessionStatePeerTest) + AddSessionByRouterHash (session); + } } } @@ -715,6 +717,9 @@ namespace transport m_LastSession->SetRemoteEndpoint (senderEndpoint); m_LastSession->ProcessPeerTest (buf, len); break; + case eSSU2SessionStateHolePunch: + m_LastSession->ProcessFirstIncomingMessage (connID, buf, len); // SessionRequest + break; case eSSU2SessionStateClosing: m_LastSession->ProcessData (buf, len, senderEndpoint); // we might receive termintaion block if (m_LastSession && m_LastSession->GetState () == eSSU2SessionStateClosing) diff --git a/libi2pd/SSU2OutOfSession.cpp b/libi2pd/SSU2OutOfSession.cpp index cf9f3f36..574ad75b 100644 --- a/libi2pd/SSU2OutOfSession.cpp +++ b/libi2pd/SSU2OutOfSession.cpp @@ -224,5 +224,63 @@ namespace transport m_NumResends++; } } + + SSU2HolePunchSession::SSU2HolePunchSession (SSU2Server& server, uint32_t nonce, + const boost::asio::ip::udp::endpoint& remoteEndpoint, + std::shared_ptr localAddr): + SSU2Session (server), // we create full incoming session + m_Nonce (nonce) + { + // we are Charlie + m_Token = GetServer ().GetIncomingToken (remoteEndpoint); + uint64_t destConnID = htobe64 (((uint64_t)nonce << 32) | nonce); // dest id + uint32_t sourceConnID = ~destConnID; + SetSourceConnID (sourceConnID); + SetDestConnID (destConnID); + SetState (eSSU2SessionStateHolePunch); + SetRemoteEndpoint (remoteEndpoint); + SetAddress (localAddr); + SetTerminationTimeout (SSU2_RELAY_NONCE_EXPIRATION_TIMEOUT); + } + + void SSU2HolePunchSession::SendHolePunch () + { + auto addr = GetAddress (); + if (!addr) return; + auto& ep = GetRemoteEndpoint (); + LogPrint (eLogDebug, "SSU2: Sending HolePunch to ", ep); + Header header; + uint8_t h[32], payload[SSU2_MAX_PACKET_SIZE]; + // fill packet + header.h.connID = GetDestConnID (); // dest id + RAND_bytes (header.buf + 8, 4); // random packet num + header.h.type = eSSU2HolePunch; + header.h.flags[0] = 2; // ver + header.h.flags[1] = (uint8_t)i2p::context.GetNetID (); // netID + header.h.flags[2] = 0; // flag + memcpy (h, header.buf, 16); + htobuf64 (h + 16, GetSourceConnID ()); // source id + RAND_bytes (h + 24, 8); // header token, to be ignored by Alice + // payload + payload[0] = eSSU2BlkDateTime; + htobe16buf (payload + 1, 4); + htobe32buf (payload + 3, (i2p::util::GetMillisecondsSinceEpoch () + 500)/1000); + size_t payloadSize = 7; + payloadSize += CreateAddressBlock (payload + payloadSize, GetMaxPayloadSize () - payloadSize, ep); + payloadSize += CreateRelayResponseBlock (payload + payloadSize, GetMaxPayloadSize () - payloadSize, + eSSU2RelayResponseCodeAccept, m_Nonce, m_Token, ep.address ().is_v4 ()); + payloadSize += CreatePaddingBlock (payload + payloadSize, GetMaxPayloadSize () - payloadSize); + // encrypt + uint8_t n[12]; + CreateNonce (be32toh (header.h.packetNum), n); + i2p::crypto::AEADChaCha20Poly1305 (payload, payloadSize, h, 32, addr->i, n, payload, payloadSize + 16, true); + payloadSize += 16; + header.ll[0] ^= CreateHeaderMask (addr->i, payload + (payloadSize - 24)); + header.ll[1] ^= CreateHeaderMask (addr->i, payload + (payloadSize - 12)); + memset (n, 0, 12); + i2p::crypto::ChaCha20 (h + 16, 16, addr->i, n, h + 16); + // send + GetServer ().Send (header.buf, 16, h + 16, 16, payload, payloadSize, ep); + } } } diff --git a/libi2pd/SSU2OutOfSession.h b/libi2pd/SSU2OutOfSession.h index 29a35d52..d0d944d1 100644 --- a/libi2pd/SSU2OutOfSession.h +++ b/libi2pd/SSU2OutOfSession.h @@ -51,6 +51,21 @@ namespace transport std::vector m_SignedData; // for resends boost::asio::deadline_timer m_PeerTestResendTimer; }; + + class SSU2HolePunchSession: public SSU2Session // Charlie + { + public: + + SSU2HolePunchSession (SSU2Server& server, uint32_t nonce, const boost::asio::ip::udp::endpoint& remoteEndpoint, + std::shared_ptr localAddr); + + void SendHolePunch (); + + private: + + uint32_t m_Nonce; + uint64_t m_Token; // for RelayResponse block + }; } } diff --git a/libi2pd/SSU2Session.cpp b/libi2pd/SSU2Session.cpp index 37d078ac..958f7536 100644 --- a/libi2pd/SSU2Session.cpp +++ b/libi2pd/SSU2Session.cpp @@ -1352,46 +1352,6 @@ namespace transport return true; } - void SSU2Session::SendHolePunch (uint32_t nonce, const boost::asio::ip::udp::endpoint& ep, - const uint8_t * introKey, uint64_t token) - { - // we are Charlie - LogPrint (eLogDebug, "SSU2: Sending HolePunch to ", ep); - Header header; - uint8_t h[32], payload[SSU2_MAX_PACKET_SIZE]; - // fill packet - header.h.connID = htobe64 (((uint64_t)nonce << 32) | nonce); // dest id - RAND_bytes (header.buf + 8, 4); // random packet num - header.h.type = eSSU2HolePunch; - header.h.flags[0] = 2; // ver - header.h.flags[1] = (uint8_t)i2p::context.GetNetID (); // netID - header.h.flags[2] = 0; // flag - memcpy (h, header.buf, 16); - uint64_t c = ~header.h.connID; - memcpy (h + 16, &c, 8); // source id - RAND_bytes (h + 24, 8); // token - // payload - payload[0] = eSSU2BlkDateTime; - htobe16buf (payload + 1, 4); - htobe32buf (payload + 3, (i2p::util::GetMillisecondsSinceEpoch () + 500)/1000); - size_t payloadSize = 7; - payloadSize += CreateAddressBlock (payload + payloadSize, m_MaxPayloadSize - payloadSize, ep); - payloadSize += CreateRelayResponseBlock (payload + payloadSize, m_MaxPayloadSize - payloadSize, - eSSU2RelayResponseCodeAccept, nonce, token, ep.address ().is_v4 ()); - payloadSize += CreatePaddingBlock (payload + payloadSize, m_MaxPayloadSize - payloadSize); - // encrypt - uint8_t n[12]; - CreateNonce (be32toh (header.h.packetNum), n); - i2p::crypto::AEADChaCha20Poly1305 (payload, payloadSize, h, 32, introKey, n, payload, payloadSize + 16, true); - payloadSize += 16; - header.ll[0] ^= CreateHeaderMask (introKey, payload + (payloadSize - 24)); - header.ll[1] ^= CreateHeaderMask (introKey, payload + (payloadSize - 12)); - memset (n, 0, 12); - i2p::crypto::ChaCha20 (h + 16, 16, introKey, n, h + 16); - // send - m_Server.Send (header.buf, 16, h + 16, 16, payload, payloadSize, ep); - } - bool SSU2Session::ProcessHolePunch (uint8_t * buf, size_t len) { // we are Alice @@ -1984,7 +1944,6 @@ namespace transport void SSU2Session::HandleRelayIntro (const uint8_t * buf, size_t len, int attempts) { // we are Charlie - auto mts = i2p::util::GetMillisecondsSinceEpoch (); SSU2RelayResponseCode code = eSSU2RelayResponseCodeAccept; uint64_t token = 0; bool isV4 = false; @@ -2011,10 +1970,11 @@ namespace transport { if (m_Server.IsSupported (ep.address ())) { - token = m_Server.GetIncomingToken (ep); isV4 = ep.address ().is_v4 (); - SendHolePunch (bufbe32toh (buf + 33), ep, addr->i, token); - m_Server.AddConnectedRecently (ep, mts/1000); + auto holePunchSession = std::make_shared( + m_Server, bufbe32toh (buf + 33), ep, addr); + m_Server.AddSession (holePunchSession); + holePunchSession->SendHolePunch (); } else { diff --git a/libi2pd/SSU2Session.h b/libi2pd/SSU2Session.h index f0b6d7e6..b3b81b4d 100644 --- a/libi2pd/SSU2Session.h +++ b/libi2pd/SSU2Session.h @@ -112,6 +112,7 @@ namespace transport eSSU2SessionStateTerminated, eSSU2SessionStateFailed, eSSU2SessionStateIntroduced, + eSSU2SessionStateHolePunch, eSSU2SessionStatePeerTest, eSSU2SessionStateTokenRequestReceived }; @@ -295,6 +296,8 @@ namespace transport size_t CreateAddressBlock (uint8_t * buf, size_t len, const boost::asio::ip::udp::endpoint& ep); size_t CreatePaddingBlock (uint8_t * buf, size_t len, size_t minSize = 0); size_t CreatePeerTestBlock (uint8_t * buf, size_t len, uint8_t msg, SSU2PeerTestCode code, const uint8_t * routerHash, const uint8_t * signedData, size_t signedDataLen); + + size_t CreateRelayResponseBlock (uint8_t * buf, size_t len, SSU2RelayResponseCode code, uint32_t nonce, uint64_t token, bool v4); private: @@ -320,7 +323,6 @@ namespace transport uint32_t SendData (const uint8_t * buf, size_t len, uint8_t flags = 0); // returns packet num void SendQuickAck (); void SendTermination (); - void SendHolePunch (uint32_t nonce, const boost::asio::ip::udp::endpoint& ep, const uint8_t * introKey, uint64_t token); void SendPathResponse (const uint8_t * data, size_t len); void SendPathChallenge (); @@ -352,7 +354,6 @@ namespace transport size_t CreateFirstFragmentBlock (uint8_t * buf, size_t len, std::shared_ptr msg); size_t CreateFollowOnFragmentBlock (uint8_t * buf, size_t len, std::shared_ptr msg, uint8_t& fragmentNum, uint32_t msgID); size_t CreateRelayIntroBlock (uint8_t * buf, size_t len, const uint8_t * introData, size_t introDataLen); - size_t CreateRelayResponseBlock (uint8_t * buf, size_t len, SSU2RelayResponseCode code, uint32_t nonce, uint64_t token, bool v4); size_t CreatePeerTestBlock (uint8_t * buf, size_t len, uint32_t nonce); // Alice size_t CreateTerminationBlock (uint8_t * buf, size_t len);