// Session to introducer
internal SSUSession(SSUHost owner, IPEndPoint remoteep, IntroducerInfo ii, IMTUProvider mtup, RouterContext rc)
{
Host = owner;
RemoteEP = remoteep;
MTUProvider = mtup;
MyRouterContext = rc;
RemoteAddr = new I2PRouterAddress(ii.Host, ii.Port, 0, "SSU");
// TODO: This is what PurpleI2P does. Seems strange... But there is no RouterInfo available for introducer sessions.
RemoteRouter = MyRouterContext.MyRouterIdentity;
TransportInstance = Interlocked.Increment(ref NTCPClient.TransportInstanceCounter);
#if LOG_ALL_TRANSPORT
DebugUtils.LogDebug("SSUSession: " + DebugId + " Introducer instance created.");
#endif
Fragmenter = new DataFragmenter();
if (RemoteAddr == null)
{
throw new NullReferenceException("SSUSession needs an address");
}
IntroKey = ii.IntroKey;
MTU = MTUProvider.GetMTU(remoteep);
}
// We are client
public SSUSession(SSUHost owner, IPEndPoint remoteep, I2PRouterAddress remoteaddr, I2PKeysAndCert rri, IMTUProvider mtup, RouterContext rc)
{
Host = owner;
RemoteEP = remoteep;
RemoteAddr = remoteaddr;
RemoteRouter = rri;
MTUProvider = mtup;
MyRouterContext = rc;
TransportInstance = Interlocked.Increment(ref NTCPClient.TransportInstanceCounter);
#if LOG_ALL_TRANSPORT
DebugUtils.LogDebug("SSUSession: " + DebugId + " Client instance created.");
#endif
Fragmenter = new DataFragmenter();
if (RemoteAddr == null)
{
throw new NullReferenceException("SSUSession needs an address");
}
IntroKey = new BufLen(FreenetBase64.Decode(RemoteAddr.Options["key"]));
MTU = MTUProvider.GetMTU(remoteep);
}
private PeerTestState(SSUHost host, I2PRouterAddress addr, I2PKeysAndCert dest)
{
Host = host;
Addr = addr;
Dest = dest;
Session = (SSUSession)Host.AddSession(addr, dest);
//Session.StartPeerTest( this );
}
public SSUHeader(BufRef writer, MessageTypes msgtype)
{
MAC = writer.ReadBufLen(16);
IV = writer.ReadBufLen(16);
IV.Randomize();
FlagBuf = writer.ReadBufLen(1);
MessageType = msgtype;
TimeStampBuf = writer.ReadBufLen(4);
TimeStamp = SSUHost.SSUTime(DateTime.UtcNow);
}
private void SendUnfragmentedSessionConfirmed()
{
var ri = new BufLen(Session.MyRouterContext.MyRouterInfo.ToByteArray());
SendMessage(
SSUHeader.MessageTypes.SessionConfirmed,
Session.MACKey,
Session.SharedKey,
(start, writer) =>
{
writer.Write8((byte)((0 << 4) + 1));
writer.WriteFlip16((ushort)ri.Length);
writer.Write(ri);
Session.SignOnTimeA = BufUtils.Flip32(SSUHost.SSUTime(DateTime.UtcNow));
writer.Write32(Session.SignOnTimeA);
var padding = BufUtils.Get16BytePadding(Session.MyRouterContext.Certificate.SignatureLength + (writer - start));
writer.Write(BufUtils.Random(padding));
var baddr = new BufLen(Session.RemoteEP.Address.GetAddressBytes());
var bport = BufUtils.Flip16BL((ushort)Session.RemoteEP.Port);
#if LOG_ALL_TRANSPORT
Logging.LogTransport(string.Format("SSU SessionConfirmedState {0}: X for signature {1}.",
Session.DebugId, Request.X.Key));
Logging.LogTransport(string.Format("SSU SessionConfirmedState {0}: Y for signature {1}.",
Session.DebugId, Request.Y.Key));
Logging.LogTransport(string.Format("SSU SessionConfirmedState {0}: Alice address for signature {1}. Port {2}.",
Session.DebugId, Request.SCMessage.Address, Request.SCMessage.Port));
Logging.LogTransport(string.Format("SSU SessionConfirmedState {0}: Bob address for signature {1}. Port {2}.",
Session.DebugId, baddr, bport));
Logging.LogTransport(string.Format("SSU SessionConfirmedState {0}: Relay tag {1}. Signon time {2}.",
Session.DebugId, Request.SCMessage.RelayTag, (BufLen)Session.SignOnTimeA));
#endif
var sign = I2PSignature.DoSign(Session.MyRouterContext.PrivateSigningKey,
Request.X.Key, Request.Y.Key,
Request.SCMessage.Address, Request.SCMessage.Port,
baddr, bport,
Request.SCMessage.RelayTag, (BufLen)Session.SignOnTimeA
);
writer.Write(sign);
#if LOG_ALL_TRANSPORT
Logging.LogTransport(string.Format("SessionConfirmedState {0}: sending unfragmented SessionConfirmed. {1} bytes [0x{1:X}].",
Session.DebugId,
writer - start - SSUHeader.FIXED_HEADER_SIZE));
#endif
return(true);
});
}
// We are host
public SSUSession(SSUHost owner, IPEndPoint remoteep, IMTUProvider mtup, RouterContext rc)
{
Host = owner;
RemoteEP = remoteep;
MTUProvider = mtup;
MyRouterContext = rc;
TransportInstance = Interlocked.Increment(ref NTCPClient.TransportInstanceCounter) + 10000;
#if LOG_ALL_TRANSPORT
DebugUtils.LogDebug("SSUSession: " + DebugId + " Host instance created.");
#endif
Fragmenter = new DataFragmenter();
MTU = MTUProvider.GetMTU(remoteep);
SendQueue.AddLast((new DeliveryStatusMessage((ulong)I2PConstants.I2P_NETWORK_ID)).Header5);
SendQueue.AddLast((new DatabaseStoreMessage(MyRouterContext.MyRouterInfo)).Header5);
CurrentState = new SessionCreatedState(this);
}
private void SendSessionCreated()
{
SendMessage(
SSUHeader.MessageTypes.SessionCreated,
Session.MyRouterContext.IntroKey,
Session.MyRouterContext.IntroKey,
(start, writer) =>
{
writer.Write(Y.Key);
AAddr = Session.RemoteEP.Address.GetAddressBytes();
writer.Write8((byte)AAddr.Length);
writer.Write(AAddr);
APort = BufUtils.Flip16((ushort)Session.RemoteEP.Port);
writer.Write16(APort);
writer.WriteFlip32(RelayTag);
Session.SignOnTimeB = BufUtils.Flip32(SSUHost.SSUTime(DateTime.UtcNow));
writer.Write32(Session.SignOnTimeB);
var sign = I2PSignature.DoSign(Session.MyRouterContext.PrivateSigningKey,
Request.X, Y.Key,
new BufLen(AAddr), (BufLen)APort,
Request.Address, (BufLen)BufUtils.Flip16((ushort)Session.MyRouterContext.UDPPort),
(BufLen)RelayTag, (BufLen)Session.SignOnTimeB);
var signstart = new BufLen(writer);
writer.Write(sign);
var padding = BufUtils.Get16BytePadding(writer - signstart);
writer.Write(BufUtils.Random(padding));
var cipher = new CbcBlockCipher(new AesEngine());
var signcryptbuf = new BufLen(signstart, 0, writer - signstart);
cipher.Init(true, Session.SharedKey.ToParametersWithIV(new BufLen(start, 16, 16)));
cipher.ProcessBytes(signcryptbuf);
return(true);
});
}
private void SendFragmentedSessionConfirmed()
{
var ri = new BufLen(Session.MyRouterContext.MyRouterInfo.ToByteArray());
var rireader = new BufRefLen(ri);
var datafragments = new List <BufLen>();
while (rireader.Length > 0)
{
datafragments.Add(rireader.ReadBufLen(Math.Min(rireader.Length, 472)));
}
for (int i = 0; i < datafragments.Count; ++i)
{
#if LOG_ALL_TRANSPORT
Logging.LogTransport(string.Format("SessionConfirmedState {0}: sending fragment {1} of {2}, {3} bytes [0x{3:X}].",
Session.DebugId,
i + 1,
datafragments.Count + 1,
datafragments[i].Length));
#endif
SendMessage(
SSUHeader.MessageTypes.SessionConfirmed,
Session.MACKey,
Session.SharedKey,
(start, writer) =>
{
writer.Write8((byte)((i << 4) + datafragments.Count + 1));
writer.WriteFlip16((ushort)datafragments[i].Length);
writer.Write(datafragments[i]);
return(true);
});
}
SendMessage(
SSUHeader.MessageTypes.SessionConfirmed,
Session.MACKey,
Session.SharedKey,
(start, writer) =>
{
var frag = datafragments.Count;
writer.Write8((byte)((frag << 4) + frag + 1));
writer.WriteFlip16(0);
Session.SignOnTimeA = BufUtils.Flip32(SSUHost.SSUTime(DateTime.UtcNow));
writer.Write32(Session.SignOnTimeA);
var padding = BufUtils.Get16BytePadding(Session.MyRouterContext.Certificate.SignatureLength + (writer - start));
writer.Write(BufUtils.Random(padding));
var baddr = new BufLen(Session.RemoteEP.Address.GetAddressBytes());
var sign = I2PSignature.DoSign(Session.MyRouterContext.PrivateSigningKey,
Request.X.Key, Request.Y.Key,
Request.SCMessage.Address, Request.SCMessage.Port,
baddr, BufUtils.Flip16BL((ushort)Session.RemoteEP.Port),
Request.SCMessage.RelayTag, (BufLen)Session.SignOnTimeA
);
writer.Write(sign);
#if LOG_ALL_TRANSPORT
Logging.LogTransport(string.Format("SessionConfirmedState {0}: sending fragment {1} of {2}, {3} bytes [0x{3:X}].",
Session.DebugId,
frag + 1,
datafragments.Count + 1,
writer - start - SSUHeader.FIXED_HEADER_SIZE));
#endif
return(true);
});
}
public override SSUState HandleMessage(SSUHeader header, BufRefLen reader)
{
var tstime = SSUHost.SSUDateTime(header.TimeStamp);
if (header.MessageType != SSUHeader.MessageTypes.SessionCreated)
{
#if LOG_ALL_TRANSPORT
Logging.LogTransport("SSU SessionRequestState: Received unexpected message " + tstime.ToString() + " : " + header.Flag.ToString());
#endif
return(this);
}
SCMessage = new SessionCreated(reader, Session.RemoteRouter.Certificate);
Session.RelayTag = SCMessage.RelayTag;
Y = new I2PPublicKey((BufRefLen)SCMessage.Y, Session.RemoteRouter.Certificate);
BufUtils.DHI2PToSessionAndMAC(out Session.SharedKey, out Session.MACKey,
Y.ToBigInteger().ModPow(PrivateKey.ToBigInteger(), I2PConstants.ElGamalP));
var ipaddr = new IPAddress(SCMessage.Address.ToByteArray());
ushort port = SCMessage.Port.PeekFlip16(0);
Session.SignOnTimeB = SCMessage.SignOnTime.Peek32(0);
var btime = SSUHost.SSUDateTime(BufUtils.Flip32(Session.SignOnTimeB));
#if LOG_ALL_TRANSPORT
Logging.LogTransport("SSU SessionRequestState " + Session.DebugId + " : Received SessionCreated. " + tstime.ToString() + " : " + btime.ToString());
#endif
Session.Host.ReportedAddress(ipaddr);
if (!I2PSignature.SupportedSignatureType(Session.RemoteRouter.Certificate.SignatureType))
{
throw new SignatureCheckFailureException("SSU SessionRequestState " + Session.DebugId + " : " +
"Received non supported signature type: " +
Session.RemoteRouter.Certificate.SignatureType.ToString());
}
var cipher = new CbcBlockCipher(new AesEngine());
cipher.Init(false, Session.SharedKey.ToParametersWithIV(header.IV));
cipher.ProcessBytes(SCMessage.SignatureEncrBuf);
var baddr = new BufLen(Session.RemoteEP.Address.GetAddressBytes());
var sign = new I2PSignature((BufRefLen)SCMessage.Signature, Session.RemoteRouter.Certificate);
var sok = I2PSignature.DoVerify(
Session.RemoteRouter.SigningPublicKey, sign,
X.Key, Y.Key,
SCMessage.Address, SCMessage.Port,
baddr, BufUtils.Flip16BL((ushort)Session.RemoteEP.Port),
SCMessage.RelayTag, SCMessage.SignOnTime);
#if LOG_ALL_TRANSPORT
Logging.LogTransport("SSU SessionRequestState: Signature check: " + sok.ToString() + ". " + Session.RemoteRouter.Certificate.SignatureType.ToString());
#endif
if (!sok)
{
throw new SignatureCheckFailureException("SSU SessionRequestState " + Session.DebugId + ": Received SessionCreated signature check failed." +
Session.RemoteRouter.Certificate.ToString());
}
var relaytag = SCMessage.RelayTag.PeekFlip32(0);
if (relaytag != 0)
{
Session.Host.IntroductionRelayOffered(
new IntroducerInfo(
Session.RemoteEP.Address,
(ushort)Session.RemoteEP.Port,
Session.IntroKey, relaytag));
}
Logging.LogTransport("SSU SessionRequestState: Session " + Session.DebugId + " created. Moving to SessionConfirmedState.");
Session.ReportConnectionEstablished();
return(new SessionConfirmedState(Session, this));
}
public override SSUState HandleMessage(SSUHeader header, BufRefLen reader)
{
DataSent();
#if LOG_ALL_TRANSPORT
DebugUtils.Log("SSU EstablishedState +" + Session.TransportInstance.ToString() + "+ received: " +
header.MessageType.ToString() + ": " + SSUHost.SSUDateTime(header.TimeStamp).ToString());
#endif
switch (header.MessageType)
{
case SSUHeader.MessageTypes.Data:
try
{
var datamsg = new SSUDataMessage(reader, Session.Defragmenter);
if (datamsg.ExplicitAcks != null)
{
Session.Fragmenter.GotAck(datamsg.ExplicitAcks);
}
if (datamsg.AckBitfields != null)
{
Session.Fragmenter.GotAck(datamsg.AckBitfields);
}
if (datamsg.NewMessages != null)
{
foreach (var msg in datamsg.NewMessages)
{
var i2npmsg = I2NPMessage.ReadHeader5((BufRefLen)msg.GetPayload());
#if LOG_ALL_TRANSPORT
DebugUtils.Log("SSU EstablishedState +" + Session.TransportInstance.ToString() + "+ complete message " +
msg.MessageId.ToString() + ": " + i2npmsg.Expiration.ToString());
#endif
if (i2npmsg.MessageType == I2PCore.Tunnel.I2NP.Messages.I2NPMessage.MessageTypes.DeliveryStatus)
{
if (((DeliveryStatusMessage)i2npmsg.Message).IsNetworkId((ulong)I2PConstants.I2P_NETWORK_ID))
{
continue;
}
}
Session.MessageReceived(i2npmsg);
}
}
}
catch (Exception ex)
{
DebugUtils.Log("EstablishedState: SSUHost.SSUMessageTypes.Data", ex);
}
break;
case SSUHeader.MessageTypes.SessionDestroyed:
DebugUtils.LogDebug(() => string.Format("SSU EstablishedState {0}: SessionDestroyed received.", Session.DebugId));
SendSessionDestroyed();
return(null);
case SSUHeader.MessageTypes.PeerTest:
HandleIncomingPeerTestPackage(reader);
break;
case SSUHeader.MessageTypes.RelayResponse:
DebugUtils.LogDebug(() => string.Format("SSU EstablishedState {0}: RelayResponse received from {1}.",
Session.DebugId, Session.RemoteEP));
var response = new RelayResponse(reader);
Session.Host.ReportRelayResponse(header, response, Session.RemoteEP);
break;
case SSUHeader.MessageTypes.RelayIntro:
var intro = new RelayIntro(reader);
DebugUtils.LogDebug(() => $"SSU EstablishedState {Session.DebugId}: RelayIntro received from {Session.RemoteEP} for {intro.AliceEndpoint}.");
Session.Host.Send(intro.AliceEndpoint, new BufLen(new byte[0]));
break;
case SSUHeader.MessageTypes.RelayRequest:
// if ( !SSUHost.IntroductionSupported ) throw new Exception( "SSU relay introduction not supported" );
DebugUtils.LogDebug(() => string.Format("SSU EstablishedState {0}: Relay introduction not supported.", Session.DebugId));
break;
case SSUHeader.MessageTypes.SessionRequest:
DebugUtils.LogDebug(() => string.Format("SSU EstablishedState {0}: SessionRequest received. Ending session.", Session.DebugId));
SendSessionDestroyed();
return(null);
default:
DebugUtils.LogDebug(() => string.Format("SSU EstablishedState {0}: Unexpected message received: {1}.",
Session.DebugId, header.MessageType));
break;
}
return(this);
}
