diff --git a/libi2pd/SSU2.cpp b/libi2pd/SSU2.cpp
index daa9244f..fdaa5889 100644
--- a/libi2pd/SSU2.cpp
+++ b/libi2pd/SSU2.cpp
@@ -54,7 +54,11 @@ namespace transport
void SSU2Session::Connect ()
{
- SendSessionRequest ();
+ auto token = m_Server.FindOutgoingToken (m_RemoteEndpoint);
+ if (token)
+ SendSessionRequest (token);
+ else
+ SendTokenRequest ();
}
void SSU2Session::SendSessionRequest (uint64_t token)
@@ -242,9 +246,7 @@ namespace transport
header.h.connID = m_DestConnID; // dest id
header.h.packetNum = 0;
header.h.type = eSSU2SessionConfirmed;
- header.h.flags[0] = 2; // ver
- header.h.flags[1] = (uint8_t)i2p::context.GetNetID (); // netID
- header.h.flags[2] = 0; // flag
+ memset (header.h.flags, 0, 3);
// payload
uint8_t payload[SSU2_MTU];
size_t payloadSize = i2p::context.GetRouterInfo ().GetBufferLen ();
@@ -367,6 +369,42 @@ namespace transport
return true;
}
+
+ void SSU2Session::SendTokenRequest ()
+ {
+ // we are Alice
+ Header header;
+ uint8_t h[32], payload[40];
+ // fill packet
+ header.h.connID = m_DestConnID; // dest id
+ header.h.packetNum = 0;
+ header.h.type = eSSU2TokenRequest;
+ 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);
+ memcpy (h + 16, &m_SourceConnID, 8); // source id
+ memset (h + 24, 0, 8); // zero token
+ // payload
+ payload[0] = eSSU2BlkDateTime;
+ htobe16buf (payload + 1, 4);
+ htobe32buf (payload + 3, i2p::util::GetSecondsSinceEpoch ());
+ size_t payloadSize = 7;
+ uint8_t paddingSize = (rand () & 0x0F) + 1; // 1 - 16
+ payload[payloadSize] = eSSU2BlkPadding;
+ htobe16buf (payload + payloadSize + 1, paddingSize);
+ payloadSize += paddingSize + 3;
+ // encrypt
+ const uint8_t nonce[12] = {0};
+ i2p::crypto::AEADChaCha20Poly1305 (payload, payloadSize, h, 32, m_Address->i, nonce, payload, payloadSize + 16, true);
+ payloadSize += 16;
+ header.ll[0] ^= CreateHeaderMask (m_Address->i, payload + (payloadSize - 24));
+ header.ll[1] ^= CreateHeaderMask (m_Address->i, payload + (payloadSize - 12));
+ i2p::crypto::ChaCha20 (h + 16, 16, m_Address->i, nonce, h + 16);
+ // send
+ m_Server.AddPendingOutgoingSession (m_RemoteEndpoint, shared_from_this ());
+ m_Server.Send (header.buf, 16, h + 16, 16, payload, payloadSize, m_RemoteEndpoint);
+ }
bool SSU2Session::ProcessRetry (uint8_t * buf, size_t len)
{
@@ -383,8 +421,9 @@ namespace transport
const uint8_t nonce[12] = {0};
uint64_t headerX[2]; // sourceConnID, token
i2p::crypto::ChaCha20 (buf + 16, 16, m_Address->i, nonce, (uint8_t *)headerX);
+ m_Server.UpdateOutgoingToken (m_RemoteEndpoint, headerX[1], i2p::util::GetSecondsSinceEpoch () + SSU2_TOKEN_EXPIRATION_TIMEOUT);
// TODO: decrypt and handle payload
- InitNoiseXKState1 (*m_NoiseState, m_Address->s); // reset Noise
+ InitNoiseXKState1 (*m_NoiseState, m_Address->s); // reset Noise TODO: check state
SendSessionRequest (headerX[1]);
return true;
}
@@ -457,7 +496,9 @@ namespace transport
case eSSU2BlkNewToken:
{
LogPrint (eLogDebug, "SSU2: New token");
- // TODO:
+ uint64_t token;
+ memcpy (&token, buf + offset + 4, 8);
+ m_Server.UpdateOutgoingToken (m_RemoteEndpoint, token, bufbe32toh (buf + offset));
break;
}
case eSSU2BlkPathChallenge:
@@ -761,9 +802,38 @@ namespace transport
else
it++;
}
+
+ for (auto it = m_IncomingTokens.begin (); it != m_IncomingTokens.end (); )
+ {
+ if (ts > it->second.second)
+ it = m_IncomingTokens.erase (it);
+ else
+ it++;
+ }
+
+ for (auto it = m_OutgoingTokens.begin (); it != m_OutgoingTokens.end (); )
+ {
+ if (ts > it->second.second)
+ it = m_OutgoingTokens.erase (it);
+ else
+ it++;
+ }
ScheduleTermination ();
}
+ }
+
+ void SSU2Server::UpdateOutgoingToken (const boost::asio::ip::udp::endpoint& ep, uint64_t token, uint32_t exp)
+ {
+ m_OutgoingTokens[ep] = {token, exp};
+ }
+
+ uint64_t SSU2Server::FindOutgoingToken (const boost::asio::ip::udp::endpoint& ep)
+ {
+ auto it = m_OutgoingTokens.find (ep);
+ if (it != m_OutgoingTokens.end ())
+ return it->second.first;
+ return 0;
}
}
}
diff --git a/libi2pd/SSU2.h b/libi2pd/SSU2.h
index 0e3fb449..99cd23ff 100644
--- a/libi2pd/SSU2.h
+++ b/libi2pd/SSU2.h
@@ -24,6 +24,7 @@ namespace transport
const int SSU2_CONNECT_TIMEOUT = 5; // 5 seconds
const int SSU2_TERMINATION_TIMEOUT = 330; // 5.5 minutes
const int SSU2_TERMINATION_CHECK_TIMEOUT = 30; // 30 seconds
+ const int SSU2_TOKEN_EXPIRATION_TIMEOUT = 9; // in second
const size_t SSU2_SOCKET_RECEIVE_BUFFER_SIZE = 0x1FFFF; // 128K
const size_t SSU2_SOCKET_SEND_BUFFER_SIZE = 0x1FFFF; // 128K
const size_t SSU2_MTU = 1488;
@@ -33,7 +34,8 @@ namespace transport
eSSU2SessionRequest = 0,
eSSU2SessionCreated = 1,
eSSU2SessionConfirmed = 2,
- eSSU2Retry = 9
+ eSSU2Retry = 9,
+ eSSU2TokenRequest = 10
};
enum SSU2BlockType
@@ -104,6 +106,7 @@ namespace transport
void SendSessionRequest (uint64_t token = 0);
void SendSessionCreated (const uint8_t * X);
void SendSessionConfirmed (const uint8_t * Y);
+ void SendTokenRequest ();
void HandlePayload (const uint8_t * buf, size_t len);
bool ExtractEndpoint (const uint8_t * buf, size_t size, boost::asio::ip::udp::endpoint& ep);
@@ -147,6 +150,9 @@ namespace transport
bool CreateSession (std::shared_ptr<const i2p::data::RouterInfo> router,
std::shared_ptr<const i2p::data::RouterInfo::Address> address);
+
+ void UpdateOutgoingToken (const boost::asio::ip::udp::endpoint& ep, uint64_t token, uint32_t exp);
+ uint64_t FindOutgoingToken (const boost::asio::ip::udp::endpoint& ep);
private:
@@ -164,6 +170,7 @@ namespace transport
boost::asio::ip::udp::socket m_Socket, m_SocketV6;
std::unordered_map<uint64_t, std::shared_ptr<SSU2Session> > m_Sessions;
std::map<boost::asio::ip::udp::endpoint, std::shared_ptr<SSU2Session> > m_PendingOutgoingSessions;
+ std::map<boost::asio::ip::udp::endpoint, std::pair<uint64_t, uint32_t> > m_IncomingTokens, m_OutgoingTokens; // remote endpoint -> (token, expires in seconds)
i2p::util::MemoryPoolMt<Packet> m_PacketsPool;
boost::asio::deadline_timer m_TerminationTimer;
};