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KDF and process Data message

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orignal 2022-03-25 15:34:43 -04:00
parent ee1c4f4fdc
commit 44735681af
2 changed files with 60 additions and 6 deletions
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47
libi2pd/SSU2.cpp
View File

@ -30,7 +30,8 @@ namespace transport
SSU2Session::SSU2Session (SSU2Server& server, std::shared_ptr<const i2p::data::RouterInfo> in_RemoteRouter,
std::shared_ptr<const i2p::data::RouterInfo::Address> addr, bool peerTest):
TransportSession (in_RemoteRouter, SSU2_CONNECT_TIMEOUT),
m_Server (server), m_Address (addr), m_DestConnID (0), m_SourceConnID (0)
m_Server (server), m_Address (addr), m_DestConnID (0), m_SourceConnID (0),
m_State (eSSU2SessionStateUnknown)
{
m_NoiseState.reset (new i2p::crypto::NoiseSymmetricState);
if (in_RemoteRouter && m_Address)
@ -242,7 +243,9 @@ namespace transport
HandlePayload (decryptedPayload.data (), decryptedPayload.size ());
m_Server.AddSession (m_SourceConnID, shared_from_this ());
m_State = eSSU2SessionStateEstablished;
SendSessionConfirmed (headerX + 16);
KDFDataPhase (m_KeyDataSend, m_KeyDataReceive);
return true;
}
@ -377,10 +380,21 @@ namespace transport
i2p::data::netdb.PostI2NPMsg (CreateI2NPMessage (eI2NPDummyMsg, ri->GetBuffer (), ri->GetBufferLen ())); // TODO: should insert ri
// handle other blocks
HandlePayload (decryptedPayload.data () + riSize + 3, decryptedPayload.size () - riSize - 3);
m_State = eSSU2SessionStateEstablished;
KDFDataPhase (m_KeyDataReceive, m_KeyDataSend);
return true;
}
void SSU2Session::KDFDataPhase (uint8_t * keydata_ab, uint8_t * keydata_ba)
{
uint8_t keydata[64];
i2p::crypto::HKDF (m_NoiseState->m_CK, nullptr, 0, "", keydata); // keydata = HKDF(chainKey, ZEROLEN, "", 64)
// ab
i2p::crypto::HKDF (keydata, nullptr, 0, "HKDFSSU2DataKeys", keydata_ab); // keydata_ab = HKDF(keydata, ZEROLEN, "HKDFSSU2DataKeys", 64)
// ba
i2p::crypto::HKDF (keydata + 32, nullptr, 0, "HKDFSSU2DataKeys", keydata_ba); // keydata_ba = HKDF(keydata + 32, ZEROLEN, "HKDFSSU2DataKeys", 64)
}
void SSU2Session::SendTokenRequest ()
{
// we are Alice
@ -512,6 +526,29 @@ namespace transport
SendSessionRequest (headerX[1]);
return true;
}
void SSU2Session::ProcessData (uint8_t * buf, size_t len)
{
Header header;
memcpy (header.buf, buf, 16);
header.ll[1] ^= CreateHeaderMask (m_KeyDataReceive + 32, buf + (len - 12));
if (header.h.type != eSSU2Data)
{
LogPrint (eLogWarning, "SSU2: Unexpected message type ", (int)header.h.type);
return;
}
uint8_t payload[SSU2_MTU];
size_t payloadSize = len - 32;
uint8_t nonce[12];
CreateNonce (be32toh (header.h.packetNum), nonce);
if (!i2p::crypto::AEADChaCha20Poly1305 (buf + 16, payloadSize, header.buf, 16,
m_KeyDataReceive, nonce, payload, payloadSize, false))
{
LogPrint (eLogWarning, "SSU2: Data AEAD verification failed ");
return;
}
HandlePayload (payload, payloadSize);
}
void SSU2Session::HandlePayload (const uint8_t * buf, size_t len)
{
@ -799,8 +836,10 @@ namespace transport
auto it = m_Sessions.find (connID);
if (it != m_Sessions.end ())
{
// TODO: check state
it->second->ProcessSessionConfirmed (buf, len);
if (it->second->IsEstablished ())
it->second->ProcessData (buf, len);
else
it->second->ProcessSessionConfirmed (buf, len);
}
else
{

19
libi2pd/SSU2.h
View File

@ -34,6 +34,7 @@ namespace transport
eSSU2SessionRequest = 0,
eSSU2SessionCreated = 1,
eSSU2SessionConfirmed = 2,
eSSU2Data = 6,
eSSU2Retry = 9,
eSSU2TokenRequest = 10
};
@ -64,6 +65,15 @@ namespace transport
eSSU2BlkPadding = 254
};
enum SSU2SessionState
{
eSSU2SessionStateUnknown,
eSSU2SessionStateEstablished,
eSSU2SessionStateClosed,
eSSU2SessionStateFailed
};
// RouterInfo flags
const uint8_t SSU2_ROUTER_INFO_FLAG_REQUEST_FLOOD = 0x01;
const uint8_t SSU2_ROUTER_INFO_FLAG_GZIP = 0x02;
@ -95,11 +105,13 @@ namespace transport
void Connect ();
void Done () override {};
void SendI2NPMessages (const std::vector<std::shared_ptr<I2NPMessage> >& msgs) override {};
bool IsEstablished () const { return m_State == eSSU2SessionStateEstablished; };
void ProcessFirstIncomingMessage (uint64_t connID, uint8_t * buf, size_t len);
bool ProcessSessionCreated (uint8_t * buf, size_t len);
bool ProcessSessionConfirmed (uint8_t * buf, size_t len);
bool ProcessRetry (uint8_t * buf, size_t len);
void ProcessData (uint8_t * buf, size_t len);
private:
@ -109,9 +121,10 @@ namespace transport
void SendSessionRequest (uint64_t token = 0);
void SendSessionCreated (const uint8_t * X);
void SendSessionConfirmed (const uint8_t * Y);
void KDFDataPhase (uint8_t * keydata_ab, uint8_t * keydata_ba);
void SendTokenRequest ();
void SendRetry ();
void HandlePayload (const uint8_t * buf, size_t len);
bool ExtractEndpoint (const uint8_t * buf, size_t size, boost::asio::ip::udp::endpoint& ep);
size_t CreateAddressBlock (const boost::asio::ip::udp::endpoint& ep, uint8_t * buf, size_t len);
@ -126,6 +139,8 @@ namespace transport
std::shared_ptr<const i2p::data::RouterInfo::Address> m_Address;
boost::asio::ip::udp::endpoint m_RemoteEndpoint;
uint64_t m_DestConnID, m_SourceConnID;
SSU2SessionState m_State;
uint8_t m_KeyDataSend[64], m_KeyDataReceive[64];
};
class SSU2Server: private i2p::util::RunnableServiceWithWork