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implement SSU2HolPunchSession

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orignal 2024-10-16 08:28:25 -04:00
parent ec1f41b13c
commit 97fdedfbe3
5 changed files with 88 additions and 49 deletions
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48
libi2pd/SSU2Session.cpp
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@ -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<SSU2HolePunchSession>(
m_Server, bufbe32toh (buf + 33), ep, addr);
m_Server.AddSession (holePunchSession);
holePunchSession->SendHolePunch ();
}
else
{