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send SessionCreated

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pull/1742/head
orignal 2 years ago
parent 11f9eeabf1
commit 7faa732f38
2 changed files with 65 additions and 29 deletions
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75
libi2pd/SSU2.cpp
Unescape Escape View File

@ -30,10 +30,11 @@ namespace transport
m_Server (server), m_Address (addr), m_DestConnID (0), m_SourceConnID (0)
{
m_NoiseState.reset (new i2p::crypto::NoiseSymmetricState);
if (in_RemoteRouter && addr)
if (in_RemoteRouter && m_Address)
{
// outgoing
InitNoiseXKState1 (*m_NoiseState, addr->s);
InitNoiseXKState1 (*m_NoiseState, m_Address->s);
m_RemoteEndpoint = boost::asio::ip::udp::endpoint (m_Address->host, m_Address->port);
}
else
{
@ -48,6 +49,7 @@ namespace transport
void SSU2Session::SendSessionRequest ()
{
// we are Alice
m_EphemeralKeys = i2p::transport::transports.GetNextX25519KeysPair ();
Header header;
@ -56,11 +58,11 @@ namespace transport
// fill packet
RAND_bytes ((uint8_t *)&m_DestConnID, 8);
header.h.connID = m_DestConnID; // dest id
memset (header.h.h2.h.packetNum, 0, 4);
header.h.h2.h.type = eSSU2SessionRequest;
header.h.h2.h.flags[0] = 2; // ver
header.h.h2.h.flags[1] = (uint8_t)i2p::context.GetNetID (); // netID
header.h.h2.h.flags[2] = 0; // flag
memset (header.h.packetNum, 0, 4);
header.h.type = eSSU2SessionRequest;
header.h.flags[0] = 2; // ver
header.h.flags[1] = (uint8_t)i2p::context.GetNetID (); // netID
header.h.flags[2] = 0; // flag
RAND_bytes ((uint8_t *)&m_SourceConnID, 8);
memcpy (headerX, &m_SourceConnID, 8); // source id
RAND_bytes (headerX + 8, 8); // token
@ -75,13 +77,13 @@ namespace transport
// encrypt
const uint8_t nonce[12] = {0};
i2p::crypto::AEADChaCha20Poly1305 (payload, payloadSize, m_NoiseState->m_H, 32, m_NoiseState->m_CK + 32, 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 (headerX, 48, m_Address->i, nonce, headerX);
payloadSize += 16;
m_NoiseState->MixHash (payload, 32); // h = SHA256(h || 32 byte encrypted payload from Session Request) for SessionCreated
// send
m_Server.Send (header.buf, 16, headerX, 48, payload, payloadSize, boost::asio::ip::udp::endpoint (m_Address->host, m_Address->port));
m_Server.Send (header.buf, 16, headerX, 48, payload, payloadSize, m_RemoteEndpoint);
}
void SSU2Session::ProcessSessionRequest (uint64_t connID, uint8_t * buf, size_t len)
@ -90,11 +92,11 @@ namespace transport
m_SourceConnID = connID;
Header header;
header.h.connID = connID;
memcpy (header.h.h2.buf, buf, 8);
header.h.h2.ll ^= CreateHeaderMask (i2p::context.GetSSU2IntroKey (), buf + (len - 12));
if (header.h.h2.h.type != eSSU2SessionRequest)
memcpy (header.buf + 8, buf + 8, 8);
header.ll[1] ^= CreateHeaderMask (i2p::context.GetSSU2IntroKey (), buf + (len - 12));
if (header.h.type != eSSU2SessionRequest)
{
LogPrint (eLogWarning, "SSU2: Unexpected message type ", (int)header.h.h2.h.type);
LogPrint (eLogWarning, "SSU2: Unexpected message type ", (int)header.h.type);
return;
}
const uint8_t nonce[12] = {0};
@ -117,6 +119,44 @@ namespace transport
// process payload
m_Server.AddSession (m_SourceConnID, shared_from_this ());
SendSessionCreated (headerX + 16);
}
void SSU2Session::SendSessionCreated (const uint8_t * X)
{
// we are Bob
m_EphemeralKeys = i2p::transport::transports.GetNextX25519KeysPair ();
// fill packet
Header header;
uint8_t headerX[48], payload[1200]; // TODO: correct payload size
size_t payloadSize = 8;
header.h.connID = m_DestConnID; // dest id
memset (header.h.packetNum, 0, 4);
header.h.type = eSSU2SessionCreated;
header.h.flags[0] = 2; // ver
header.h.flags[1] = (uint8_t)i2p::context.GetNetID (); // netID
header.h.flags[2] = 0; // flag
memcpy (headerX, &m_SourceConnID, 8); // source id
RAND_bytes (headerX + 8, 8); // token
memcpy (headerX + 16, m_EphemeralKeys->GetPublicKey (), 32); // Y
// KDF for SessionCreated
m_NoiseState->MixHash ( { {header.buf, 16}, {headerX, 16} } ); // h = SHA256(h || header)
m_NoiseState->MixHash (headerX + 16, 32); // h = SHA256(h || bepk);
uint8_t sharedSecret[32];
m_EphemeralKeys->Agree (X, sharedSecret);
m_NoiseState->MixKey (sharedSecret);
// encrypt
const uint8_t nonce[12] = {0};
i2p::crypto::AEADChaCha20Poly1305 (payload, payloadSize, m_NoiseState->m_H, 32, m_NoiseState->m_CK + 32, nonce, payload, payloadSize + 16, true);
payloadSize += 16;
header.ll[0] ^= CreateHeaderMask (i2p::context.GetSSU2IntroKey (), payload + (payloadSize - 24));
uint8_t kh2[32];
i2p::crypto::HKDF (m_NoiseState->m_CK, nullptr, 0, "SessCreateHeader", kh2, 32); // k_header_2 = HKDF(chainKey, ZEROLEN, "SessCreateHeader", 32)
header.ll[1] ^= CreateHeaderMask (kh2, payload + (payloadSize - 12));
i2p::crypto::ChaCha20 (headerX, 48, kh2, nonce, headerX);
// send
m_Server.Send (header.buf, 16, headerX, 48, payload, payloadSize, m_RemoteEndpoint);
}
bool SSU2Session::ProcessSessionCreated (uint8_t * buf, size_t len)
@ -124,13 +164,13 @@ namespace transport
// we are Alice
Header header;
header.h.connID = m_SourceConnID;
memcpy (header.h.h2.buf, buf, 8);
memcpy (header.buf + 8, buf + 8, 8);
uint8_t kh2[32];
i2p::crypto::HKDF (m_NoiseState->m_CK, nullptr, 0, "SessCreateHeader", kh2, 32); // k_header_2 = HKDF(chainKey, ZEROLEN, "SessCreateHeader", 32)
header.h.h2.ll ^= CreateHeaderMask (kh2, buf + (len - 12));
if (header.h.h2.h.type != eSSU2SessionCreated)
header.ll[1] ^= CreateHeaderMask (kh2, buf + (len - 12));
if (header.h.type != eSSU2SessionCreated)
{
LogPrint (eLogWarning, "SSU2: Unexpected message type ", (int)header.h.h2.h.type);
LogPrint (eLogWarning, "SSU2: Unexpected message type ", (int)header.h.type);
return false;
}
const uint8_t nonce[12] = {0};
@ -210,6 +250,7 @@ namespace transport
{
// assume new incoming session
auto session = std::make_shared<SSU2Session> (*this);
session->SetRemoteEndpoint (senderEndpoint);
session->ProcessSessionRequest (connID, buf, len);
}
}

19
libi2pd/SSU2.h
Unescape Escape View File

@ -34,17 +34,6 @@ namespace transport
class SSU2Server;
class SSU2Session: public TransportSession, public std::enable_shared_from_this<SSU2Session>
{
union Header2
{
uint64_t ll;
uint8_t buf[8];
struct
{
uint8_t packetNum[4];
uint8_t type;
uint8_t flags[3];
} h;
};
union Header
{
uint64_t ll[2];
@ -52,7 +41,9 @@ namespace transport
struct
{
uint64_t connID;
Header2 h2;
uint8_t packetNum[4];
uint8_t type;
uint8_t flags[3];
} h;
};
@ -62,6 +53,8 @@ namespace transport
std::shared_ptr<const i2p::data::RouterInfo::Address> addr = nullptr, bool peerTest = false);
~SSU2Session ();
void SetRemoteEndpoint (const boost::asio::ip::udp::endpoint& ep) { m_RemoteEndpoint = ep; };
void Done () override {};
void SendI2NPMessages (const std::vector<std::shared_ptr<I2NPMessage> >& msgs) override {};
@ -71,6 +64,7 @@ namespace transport
private:
void SendSessionRequest ();
void SendSessionCreated (const uint8_t * X);
private:
@ -78,6 +72,7 @@ namespace transport
std::shared_ptr<i2p::crypto::X25519Keys> m_EphemeralKeys;
std::unique_ptr<i2p::crypto::NoiseSymmetricState> m_NoiseState;
std::shared_ptr<const i2p::data::RouterInfo::Address> m_Address;
boost::asio::ip::udp::endpoint m_RemoteEndpoint;
uint64_t m_DestConnID, m_SourceConnID;
};

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