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i2pd
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decrypt message first

pull/64/head
orignal 11 years ago
parent
a510e7c2c6
commit
8694ed16fd
2 changed files with 89 additions and 156 deletions
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  1. 237
      SSU.cpp
  2. 8
      SSU.h

237
SSU.cpp
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@ -19,7 +19,7 @@ namespace ssu
const i2p::data::RouterInfo * router, bool peerTest ): const i2p::data::RouterInfo * router, bool peerTest ):
m_Server (server), m_RemoteEndpoint (remoteEndpoint), m_RemoteRouter (router), m_Server (server), m_RemoteEndpoint (remoteEndpoint), m_RemoteRouter (router),
m_Timer (m_Server.GetService ()), m_PeerTest (peerTest), m_State (eSessionStateUnknown), m_Timer (m_Server.GetService ()), m_PeerTest (peerTest), m_State (eSessionStateUnknown),
m_RelayTag (0) m_IsSessionKey (false), m_RelayTag (0)
{ {
m_DHKeysPair = i2p::transports.GetNextDHKeysPair (); m_DHKeysPair = i2p::transports.GetNextDHKeysPair ();
} }
@ -35,7 +35,7 @@ namespace ssu
} }
} }
void SSUSession::CreateAESandMacKey (uint8_t * pubKey, uint8_t * aesKey, uint8_t * macKey) void SSUSession::CreateAESandMacKey (const uint8_t * pubKey, uint8_t * aesKey, uint8_t * macKey)
{ {
CryptoPP::DH dh (i2p::crypto::elgp, i2p::crypto::elgg); CryptoPP::DH dh (i2p::crypto::elgp, i2p::crypto::elgg);
CryptoPP::SecByteBlock secretKey(dh.AgreedValueLength()); CryptoPP::SecByteBlock secretKey(dh.AgreedValueLength());
@ -56,128 +56,92 @@ namespace ssu
memcpy (aesKey, secretKey, 32); memcpy (aesKey, secretKey, 32);
memcpy (macKey, secretKey + 32, 32); memcpy (macKey, secretKey + 32, 32);
} }
m_IsSessionKey = true;
} }
void SSUSession::ProcessNextMessage (uint8_t * buf, size_t len, const boost::asio::ip::udp::endpoint& senderEndpoint) void SSUSession::ProcessNextMessage (uint8_t * buf, size_t len, const boost::asio::ip::udp::endpoint& senderEndpoint)
{ {
switch (m_State) if (m_State == eSessionStateIntroduced)
{ {
case eSessionStateConfirmedSent: // HolePunch received
case eSessionStateEstablished: LogPrint ("SSU HolePuch of ", len, " bytes received");
// most common case m_State = eSessionStateUnknown;
ScheduleTermination (); Connect ();
ProcessMessage (buf, len, senderEndpoint);
break;
// establishing or testing
case eSessionStateUnknown:
case eSessionStateRequestSent:
// we must use intro key
ProcessIntroKeyMessage (buf, len, senderEndpoint);
break;
case eSessionStateCreatedSent:
// session confirmed
ProcessSessionConfirmed (buf, len);
break;
case eSessionStateRelayRequestSent:
// relay response
ProcessRelayResponse (buf, len);
m_Server.DeleteSession (this);
break;
case eSessionStateIntroduced:
// HolePunch received
LogPrint ("SSU HolePuch of ", len, " bytes received");
m_State = eSessionStateUnknown;
Connect ();
break;
default:
LogPrint ("SSU state not implemented yet");
}
}
void SSUSession::ProcessMessage (uint8_t * buf, size_t len, const boost::asio::ip::udp::endpoint& senderEndpoint)
{
if (Validate (buf, len, m_MacKey))
{
Decrypt (buf, len, m_SessionKey);
SSUHeader * header = (SSUHeader *)buf;
switch (header->GetPayloadType ())
{
case PAYLOAD_TYPE_DATA:
LogPrint ("SSU data received");
ProcessData (buf + sizeof (SSUHeader), len - sizeof (SSUHeader));
break;
case PAYLOAD_TYPE_PEER_TEST:
LogPrint ("SSU peer test received");
ProcessPeerTest (buf + sizeof (SSUHeader), len - sizeof (SSUHeader), senderEndpoint);
break;
case PAYLOAD_TYPE_SESSION_DESTROYED:
{
LogPrint ("SSU session destroy received");
m_Server.DeleteSession (this); // delete this
break;
}
case PAYLOAD_TYPE_RELAY_RESPONSE:
LogPrint ("SSU relay response received though established session");
// Ignore it for now
break;
case PAYLOAD_TYPE_RELAY_INTRO:
LogPrint ("SSU relay intro received");
ProcessRelayIntro (buf + sizeof (SSUHeader), len - sizeof (SSUHeader));
break;
default:
LogPrint ("Unexpected SSU payload type ", (int)header->GetPayloadType ());
}
} }
else else
{ {
LogPrint ("MAC key failed. Trying intro key"); ScheduleTermination ();
auto introKey = GetIntroKey (); if (m_IsSessionKey && Validate (buf, len, m_MacKey)) // try session key first
if (introKey && Validate (buf, len, introKey)) Decrypt (buf, len, m_SessionKey);
else
{ {
Decrypt (buf, len, introKey); // try intro key depending on side
SSUHeader * header = (SSUHeader *)buf; auto introKey = GetIntroKey ();
LogPrint ("Unexpected SSU payload type ", (int)(header->flag >> 4)); if (introKey && Validate (buf, len, introKey))
// TODO: Decrypt (buf, len, introKey);
else
{
// try own intro key
auto address = i2p::context.GetRouterInfo ().GetSSUAddress ();
if (!address)
{
LogPrint ("SSU is not supported");
return;
}
if (Validate (buf, len, address->key))
Decrypt (buf, len, address->key);
else
{
LogPrint ("MAC verifcation failed");
m_Server.DeleteSession (this);
return;
}
}
} }
else // successfully decrypted
LogPrint ("MAC verifcation failed"); ProcessMessage (buf, len, senderEndpoint);
m_State = eSessionStateUnknown; }
}
} }
void SSUSession::ProcessIntroKeyMessage (uint8_t * buf, size_t len, const boost::asio::ip::udp::endpoint& senderEndpoint) void SSUSession::ProcessMessage (uint8_t * buf, size_t len, const boost::asio::ip::udp::endpoint& senderEndpoint)
{ {
auto introKey = GetIntroKey ();
if (!introKey)
{
LogPrint ("SSU is not supported");
return;
}
// use intro key for verification and decryption
if (!Validate (buf, len, introKey))
{
LogPrint ("MAC verification intro key failed");
m_Server.DeleteSession (this);
return;
}
Decrypt (buf, len, introKey);
CreateAESandMacKey (buf + sizeof (SSUHeader), m_SessionKey, m_MacKey);
SSUHeader * header = (SSUHeader *)buf; SSUHeader * header = (SSUHeader *)buf;
switch (header->GetPayloadType ()) switch (header->GetPayloadType ())
{ {
case PAYLOAD_TYPE_DATA:
LogPrint ("SSU data received");
ProcessData (buf + sizeof (SSUHeader), len - sizeof (SSUHeader));
break;
case PAYLOAD_TYPE_SESSION_REQUEST: case PAYLOAD_TYPE_SESSION_REQUEST:
ProcessSessionRequest (buf, len, senderEndpoint); ProcessSessionRequest (buf, len, senderEndpoint);
break; break;
case PAYLOAD_TYPE_SESSION_CREATED: case PAYLOAD_TYPE_SESSION_CREATED:
ProcessSessionCreated (buf, len); ProcessSessionCreated (buf, len);
break; break;
case PAYLOAD_TYPE_SESSION_CONFIRMED:
ProcessSessionConfirmed (buf, len);
break;
case PAYLOAD_TYPE_PEER_TEST: case PAYLOAD_TYPE_PEER_TEST:
LogPrint ("SSU peer test received"); LogPrint ("SSU peer test received");
// TODO: ProcessPeerTest (buf + sizeof (SSUHeader), len - sizeof (SSUHeader), senderEndpoint);
break; break;
default: ; case PAYLOAD_TYPE_SESSION_DESTROYED:
} {
LogPrint ("SSU session destroy received");
m_Server.DeleteSession (this); // delete this
break;
}
case PAYLOAD_TYPE_RELAY_RESPONSE:
ProcessRelayResponse (buf, len);
m_Server.DeleteSession (this);
break;
case PAYLOAD_TYPE_RELAY_INTRO:
LogPrint ("SSU relay intro received");
ProcessRelayIntro (buf + sizeof (SSUHeader), len - sizeof (SSUHeader));
break;
default:
LogPrint ("Unexpected SSU payload type ", (int)header->GetPayloadType ());
}
} }
void SSUSession::ProcessSessionRequest (uint8_t * buf, size_t len, const boost::asio::ip::udp::endpoint& senderEndpoint) void SSUSession::ProcessSessionRequest (uint8_t * buf, size_t len, const boost::asio::ip::udp::endpoint& senderEndpoint)
@ -185,6 +149,7 @@ namespace ssu
m_State = eSessionStateRequestReceived; m_State = eSessionStateRequestReceived;
LogPrint ("Session request received"); LogPrint ("Session request received");
m_RemoteEndpoint = senderEndpoint; m_RemoteEndpoint = senderEndpoint;
CreateAESandMacKey (buf + sizeof (SSUHeader), m_SessionKey, m_MacKey);
SendSessionCreated (buf + sizeof (SSUHeader)); SendSessionCreated (buf + sizeof (SSUHeader));
} }
@ -202,6 +167,7 @@ namespace ssu
uint8_t signedData[532]; // x,y, our IP, our port, remote IP, remote port, relayTag, signed on time uint8_t signedData[532]; // x,y, our IP, our port, remote IP, remote port, relayTag, signed on time
uint8_t * payload = buf + sizeof (SSUHeader); uint8_t * payload = buf + sizeof (SSUHeader);
uint8_t * y = payload; uint8_t * y = payload;
CreateAESandMacKey (y, m_SessionKey, m_MacKey);
memcpy (signedData, m_DHKeysPair->publicKey, 256); // x memcpy (signedData, m_DHKeysPair->publicKey, 256); // x
memcpy (signedData + 256, y, 256); // y memcpy (signedData + 256, y, 256); // y
payload += 256; payload += 256;
@ -235,24 +201,11 @@ namespace ssu
void SSUSession::ProcessSessionConfirmed (uint8_t * buf, size_t len) void SSUSession::ProcessSessionConfirmed (uint8_t * buf, size_t len)
{ {
LogPrint ("Process session confirmed"); m_State = eSessionStateConfirmedReceived;
if (Validate (buf, len, m_MacKey)) LogPrint ("Session confirmed received");
{ m_State = eSessionStateEstablished;
Decrypt (buf, len, m_SessionKey); SendI2NPMessage (CreateDeliveryStatusMsg (0));
SSUHeader * header = (SSUHeader *)buf; Established ();
if (header->GetPayloadType () == PAYLOAD_TYPE_SESSION_CONFIRMED)
{
m_State = eSessionStateConfirmedReceived;
LogPrint ("Session confirmed received");
m_State = eSessionStateEstablished;
SendI2NPMessage (CreateDeliveryStatusMsg (0));
Established ();
}
else
LogPrint ("Unexpected payload type ", (int)(header->flag >> 4));
}
else
LogPrint ("MAC verifcation failed");
} }
void SSUSession::SendSessionRequest () void SSUSession::SendSessionRequest ()
@ -403,38 +356,20 @@ namespace ssu
void SSUSession::ProcessRelayResponse (uint8_t * buf, size_t len) void SSUSession::ProcessRelayResponse (uint8_t * buf, size_t len)
{ {
LogPrint ("Process relay response"); LogPrint ("Relay response received");
auto address = i2p::context.GetRouterInfo ().GetSSUAddress (); uint8_t * payload = buf + sizeof (SSUHeader);
if (!address) payload++; // remote size
{ //boost::asio::ip::address_v4 remoteIP (be32toh (*(uint32_t* )(payload)));
LogPrint ("SSU is not supported"); payload += 4; // remote address
return; //uint16_t remotePort = be16toh (*(uint16_t *)(payload));
} payload += 2; // remote port
payload++; // our size
if (Validate (buf, len, address->key)) boost::asio::ip::address_v4 ourIP (be32toh (*(uint32_t* )(payload)));
{ payload += 4; // our address
Decrypt (buf, len, address->key); uint16_t ourPort = be16toh (*(uint16_t *)(payload));
SSUHeader * header = (SSUHeader *)buf; payload += 2; // our port
if (header->GetPayloadType () == PAYLOAD_TYPE_RELAY_RESPONSE) LogPrint ("Our external address is ", ourIP.to_string (), ":", ourPort);
{ i2p::context.UpdateAddress (ourIP.to_string ().c_str ());
LogPrint ("Relay response received");
uint8_t * payload = buf + sizeof (SSUHeader);
payload++; // remote size
//boost::asio::ip::address_v4 remoteIP (be32toh (*(uint32_t* )(payload)));
payload += 4; // remote address
//uint16_t remotePort = be16toh (*(uint16_t *)(payload));
payload += 2; // remote port
payload++; // our size
boost::asio::ip::address_v4 ourIP (be32toh (*(uint32_t* )(payload)));
payload += 4; // our address
uint16_t ourPort = be16toh (*(uint16_t *)(payload));
payload += 2; // our port
LogPrint ("Our external address is ", ourIP.to_string (), ":", ourPort);
i2p::context.UpdateAddress (ourIP.to_string ().c_str ());
}
else
LogPrint ("Unexpected payload type ", (int)(header->flag >> 4));
}
} }
void SSUSession::ProcessRelayIntro (uint8_t * buf, size_t len) void SSUSession::ProcessRelayIntro (uint8_t * buf, size_t len)
@ -874,7 +809,7 @@ namespace ssu
void SSUSession::SendSesionDestroyed () void SSUSession::SendSesionDestroyed ()
{ {
if (HasSessionKey ()) if (m_IsSessionKey)
{ {
uint8_t buf[48 + 18], iv[16]; uint8_t buf[48 + 18], iv[16];
CryptoPP::RandomNumberGenerator& rnd = i2p::context.GetRandomNumberGenerator (); CryptoPP::RandomNumberGenerator& rnd = i2p::context.GetRandomNumberGenerator ();

8
SSU.h
Unescape View File

@ -66,7 +66,7 @@ namespace ssu
eSessionStateIntroduced, eSessionStateIntroduced,
eSessionStateEstablished, eSessionStateEstablished,
eSessionStateFailed eSessionStateFailed
}; };
class SSUServer; class SSUServer;
class SSUSession class SSUSession
@ -89,11 +89,9 @@ namespace ssu
private: private:
void CreateAESandMacKey (uint8_t * pubKey, uint8_t * aesKey, uint8_t * macKey); void CreateAESandMacKey (const uint8_t * pubKey, uint8_t * aesKey, uint8_t * macKey);
void ProcessMessage (uint8_t * buf, size_t len, const boost::asio::ip::udp::endpoint& senderEndpoint); // call for established session void ProcessMessage (uint8_t * buf, size_t len, const boost::asio::ip::udp::endpoint& senderEndpoint); // call for established session
void ProcessIntroKeyMessage (uint8_t * buf, size_t len, const boost::asio::ip::udp::endpoint& senderEndpoint); // call for non-established session
void ProcessSessionRequest (uint8_t * buf, size_t len, const boost::asio::ip::udp::endpoint& senderEndpoint); void ProcessSessionRequest (uint8_t * buf, size_t len, const boost::asio::ip::udp::endpoint& senderEndpoint);
void SendSessionRequest (); void SendSessionRequest ();
void SendRelayRequest (uint32_t iTag, const uint8_t * iKey); void SendRelayRequest (uint32_t iTag, const uint8_t * iKey);
@ -118,7 +116,6 @@ namespace ssu
void Decrypt (uint8_t * buf, size_t len, const uint8_t * aesKey); void Decrypt (uint8_t * buf, size_t len, const uint8_t * aesKey);
bool Validate (uint8_t * buf, size_t len, const uint8_t * macKey); bool Validate (uint8_t * buf, size_t len, const uint8_t * macKey);
const uint8_t * GetIntroKey () const; const uint8_t * GetIntroKey () const;
bool HasSessionKey () const { return m_State == eSessionStateCreatedReceived || m_State == eSessionStateRequestReceived; };
void ScheduleTermination (); void ScheduleTermination ();
void HandleTerminationTimer (const boost::system::error_code& ecode); void HandleTerminationTimer (const boost::system::error_code& ecode);
@ -140,6 +137,7 @@ namespace ssu
i2p::data::DHKeysPair * m_DHKeysPair; // X - for client and Y - for server i2p::data::DHKeysPair * m_DHKeysPair; // X - for client and Y - for server
bool m_PeerTest; bool m_PeerTest;
SessionState m_State; SessionState m_State;
bool m_IsSessionKey;
uint32_t m_RelayTag; uint32_t m_RelayTag;
std::set<uint32_t> m_PeerTestNonces; std::set<uint32_t> m_PeerTestNonces;
CryptoPP::CBC_Mode<CryptoPP::AES>::Encryption m_Encryption; CryptoPP::CBC_Mode<CryptoPP::AES>::Encryption m_Encryption;

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