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SessionConfirmed message

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orignal 2014-02-04 14:20:58 -05:00
parent e24795dd41
commit 670508016b
2 changed files with 80 additions and 5 deletions
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81
SSU.cpp
View File

@ -55,6 +55,10 @@ namespace ssu
// session created
ProcessSessionCreated (buf, len);
break;
case eSessionStateCreatedSent:
// session confirmed
ProcessSessionConfirmed (buf, len);
break;
default:
LogPrint ("SSU state not implemented yet");
}
@ -88,12 +92,35 @@ namespace ssu
{
m_State = eSessionStateCreatedReceived;
LogPrint ("Session created received");
boost::asio::ip::address_v4 ourAddress (be32toh (*(uint32_t* )(buf + sizeof (SSUHeader) + 257)));
uint16_t ourPort = be16toh (*(uint16_t *)(buf + sizeof (SSUHeader) + 261));
LogPrint ("Our external address is ", ourAddress.to_string (), ":", ourPort);
uint8_t * ourAddress = buf + sizeof (SSUHeader) + 257;
boost::asio::ip::address_v4 ourIP (be32toh (*(uint32_t* )(ourAddress)));
uint16_t ourPort = be16toh (*(uint16_t *)(ourAddress + 4));
LogPrint ("Our external address is ", ourIP.to_string (), ":", ourPort);
uint32_t relayTag = be32toh (*(uint32_t *)(buf + sizeof (SSUHeader) + 263));
SendSessionConfirmed (buf + sizeof (SSUHeader), ourAddress, relayTag);
}
}
void SSUSession::ProcessSessionConfirmed (uint8_t * buf, size_t len)
{
LogPrint ("Process session confirmed");
if (Validate (buf, len, m_MacKey))
{
Decrypt (buf, len, m_SessionKey);
SSUHeader * header = (SSUHeader *)buf;
if ((header->flag >> 4) == PAYLOAD_TYPE_SESSION_CONFIRMED)
{
m_State = eSessionStateConfirmedReceived;
LogPrint ("Session confirmed received");
// TODO:
}
else
LogPrint ("Unexpected payload type ", (int)(header->flag >> 4));
}
else
LogPrint ("MAC verifcation failed");
}
void SSUSession::SendSessionRequest ()
{
auto address = m_RemoteRouter ? m_RemoteRouter->GetSSUAddress () : nullptr;
@ -141,7 +168,7 @@ namespace ssu
*(uint16_t *)(payload) = htobe16 (m_RemoteEndpoint.port ());
payload += 2;
memcpy (signedData + 512, payload - 6, 6); // remote endpoint IP and port
*(uint32_t *)(signedData + 518) = m_Server->GetEndpoint ().address ().to_v4 ().to_ulong (); // our IP
*(uint32_t *)(signedData + 518) = htobe32 (m_Server->GetEndpoint ().address ().to_v4 ().to_ulong ()); // our IP
*(uint16_t *)(signedData + 522) = htobe16 (m_Server->GetEndpoint ().port ()); // our port
*(uint32_t *)(payload) = 0; // relay tag, always 0 for now
payload += 4;
@ -164,6 +191,52 @@ namespace ssu
m_Server->Send (buf, 368, m_RemoteEndpoint);
}
void SSUSession::SendSessionConfirmed (const uint8_t * y, const uint8_t * ourAddress, uint32_t relayTag)
{
auto address = m_RemoteRouter ? m_RemoteRouter->GetSSUAddress () : nullptr;
if (!address)
{
LogPrint ("Missing remote SSU address");
return;
}
uint8_t buf[480 + 18];
uint8_t * payload = buf + sizeof (SSUHeader);
*payload = 1; // 1 fragment
payload++; // info
size_t identLen = sizeof (i2p::context.GetRouterIdentity ()); // 387 bytes
*(uint16_t *)(payload) = htobe16 (identLen);
payload += 2; // cursize
memcpy (payload, (uint8_t *)&i2p::context.GetRouterIdentity (), identLen);
payload += identLen;
uint32_t signedOnTime = i2p::util::GetSecondsSinceEpoch ();
*(uint32_t *)(payload) = htobe32 (signedOnTime); // signed on time
payload += 4;
size_t paddingSize = ((payload - buf) + 40)%16;
if (paddingSize > 0) paddingSize = 16 - paddingSize;
// TODO: fill padding
payload += paddingSize; // padding size
// signature
uint8_t signedData[532]; // x,y, our IP, our port, remote IP, remote port, relayTag, our signed on time
memcpy (signedData, i2p::context.GetRouterIdentity ().publicKey, 256); // x
memcpy (signedData + 256, y, 256); // y
memcpy (signedData + 512, ourAddress, 6); // our address/port as seem by party
*(uint32_t *)(signedData + 518) = htobe32 (m_RemoteEndpoint.address ().to_v4 ().to_ulong ()); // remote IP
*(uint16_t *)(signedData + 522) = htobe16 (m_RemoteEndpoint.port ()); // remote port
*(uint32_t *)(signedData + 524) = htobe32 (relayTag); // relay tag
*(uint32_t *)(signedData + 528) = htobe32 (signedOnTime); // signed on time
i2p::context.Sign (signedData, 532, payload); // DSA signature
uint8_t iv[16];
CryptoPP::RandomNumberGenerator& rnd = i2p::context.GetRandomNumberGenerator ();
rnd.GenerateBlock (iv, 16); // random iv
// encrypt message with session key
FillHeaderAndEncrypt (PAYLOAD_TYPE_SESSION_CONFIRMED, buf, 480, m_SessionKey, iv, m_MacKey);
m_State = eSessionStateConfirmedSent;
m_Server->Send (buf, 480, m_RemoteEndpoint);
}
bool SSUSession::ProcessIntroKeyEncryptedMessage (uint8_t expectedPayloadType, i2p::data::RouterInfo& r, uint8_t * buf, size_t len)
{
auto address = r.GetSSUAddress ();

4
SSU.h
View File

@ -30,12 +30,12 @@ namespace ssu
const uint8_t PAYLOAD_TYPE_SESSION_REQUEST = 0;
const uint8_t PAYLOAD_TYPE_SESSION_CREATED = 1;
const uint8_t PAYLOAD_TYPE_SESSION_CONFIRMED = 2;
const uint8_t PAYLOAD_TYPE_SESSION_DESTROY = 8;
const uint8_t PAYLOAD_TYPE_RELAY_REQUEST = 3;
const uint8_t PAYLOAD_TYPE_RELAY_RESPONSE = 4;
const uint8_t PAYLOAD_TYPE_RELAY_INTRO = 5;
const uint8_t PAYLOAD_TYPE_DATA = 6;
const uint8_t PAYLOAD_TYPE_TEST = 7;
const uint8_t PAYLOAD_TYPE_SESSION_DESTROY = 8;
enum SessionState
{
@ -69,6 +69,8 @@ namespace ssu
void SendSessionRequest ();
void ProcessSessionCreated (uint8_t * buf, size_t len);
void SendSessionCreated (const uint8_t * x);
void ProcessSessionConfirmed (uint8_t * buf, size_t len);
void SendSessionConfirmed (const uint8_t * y, const uint8_t * ourAddress, uint32_t relayTag);
bool ProcessIntroKeyEncryptedMessage (uint8_t expectedPayloadType, i2p::data::RouterInfo& r, uint8_t * buf, size_t len);
void FillHeaderAndEncrypt (uint8_t payloadType, uint8_t * buf, size_t len, uint8_t * aesKey, uint8_t * iv, uint8_t * macKey);