private void ServiceRequest(string servicename)
{
SSH2DataWriter wr = new SSH2DataWriter();
wr.WritePacketType(PacketType.SSH_MSG_SERVICE_REQUEST);
wr.Write(servicename);
TransmitPacket(wr.ToByteArray());
byte[] response = ReceivePacket().Data;
SSH2DataReader re = new SSH2DataReader(response);
PacketType t = re.ReadPacketType();
if(t!=PacketType.SSH_MSG_SERVICE_ACCEPT) {
throw new SSHException("service establishment failed "+t);
}
string s = Encoding.ASCII.GetString(re.ReadString());
if(servicename!=s)
throw new SSHException("protocol error");
}
private bool ProcessPacket(SSH2Packet packet)
{
SSH2DataReader r = new SSH2DataReader(packet.Data);
PacketType pt = r.ReadPacketType();
//Debug.WriteLine("ProcessPacket pt="+pt);
if(pt==PacketType.SSH_MSG_DISCONNECT) {
int errorcode = r.ReadInt32();
//string description = Encoding.ASCII.GetString(r.ReadString());
_eventReceiver.OnConnectionClosed();
return false;
}
else if(_waitingForPortForwardingResponse) {
if(pt!=PacketType.SSH_MSG_REQUEST_SUCCESS)
_eventReceiver.OnUnknownMessage((byte)pt, r.Image);
_waitingForPortForwardingResponse = false;
return true;
}
else if(pt==PacketType.SSH_MSG_CHANNEL_OPEN) {
ProcessPortforwardingRequest(_eventReceiver, r);
return true;
}
else if(pt>=PacketType.SSH_MSG_CHANNEL_OPEN_CONFIRMATION && pt<=PacketType.SSH_MSG_CHANNEL_FAILURE) {
int local_channel = r.ReadInt32();
ChannelEntry e = FindChannelEntry(local_channel);
if(e!=null) //throw new SSHException("Unknown channel "+local_channel);
((SSH2Channel)e._channel).ProcessPacket(e._receiver, pt, 5+r.Rest, r);
else
Debug.WriteLine("unexpected channel pt="+pt+" local_channel="+local_channel.ToString());
return true;
}
else if(pt==PacketType.SSH_MSG_IGNORE) {
_eventReceiver.OnIgnoreMessage(r.ReadString());
return true;
}
else if(_asyncKeyExchanger!=null) {
_asyncKeyExchanger.AsyncProcessPacket(packet);
return true;
}
else if(pt==PacketType.SSH_MSG_KEXINIT) {
Debug.WriteLine("Host sent KEXINIT");
_asyncKeyExchanger = new KeyExchanger(this, _sessionID);
_asyncKeyExchanger.AsyncProcessPacket(packet);
return true;
}
else {
_eventReceiver.OnUnknownMessage((byte)pt, r.Image);
return false;
}
}
//synchronous reception
internal SSH2Packet ReceivePacket()
{
while(true) {
SSH2Packet p = null;
SynchronizedSSH2PacketHandler handler = (SynchronizedSSH2PacketHandler)_packetBuilder.Handler;
if(!handler.HasPacket) {
handler.Wait();
if(handler.State==ReceiverState.Error)
throw new SSHException(handler.ErrorMessage);
else if(handler.State==ReceiverState.Closed)
throw new SSHException("socket closed");
}
p = handler.PopPacket();
SSH2DataReader r = new SSH2DataReader(p.Data);
PacketType pt = r.ReadPacketType();
if(pt==PacketType.SSH_MSG_IGNORE) {
if(_eventReceiver!=null) _eventReceiver.OnIgnoreMessage(r.ReadString());
}
else if(pt==PacketType.SSH_MSG_DEBUG) {
bool f = r.ReadBool();
if(_eventReceiver!=null) _eventReceiver.OnDebugMessage(f, r.ReadString());
}
else
return p;
}
}
private AuthenticationResult ProcessAuthenticationResponse()
{
do {
SSH2DataReader response = new SSH2DataReader(ReceivePacket().Data);
PacketType h = response.ReadPacketType();
if(h==PacketType.SSH_MSG_USERAUTH_FAILURE) {
string msg = Encoding.ASCII.GetString(response.ReadString());
return AuthenticationResult.Failure;
}
else if(h==PacketType.SSH_MSG_USERAUTH_BANNER) {
Debug.WriteLine("USERAUTH_BANNER");
}
else if(h==PacketType.SSH_MSG_USERAUTH_SUCCESS) {
_packetBuilder.Handler = new CallbackSSH2PacketHandler(this);
return AuthenticationResult.Success; //successfully exit
}
else if(h==PacketType.SSH_MSG_USERAUTH_INFO_REQUEST) {
string name = Encoding.ASCII.GetString(response.ReadString());
string inst = Encoding.ASCII.GetString(response.ReadString());
string lang = Encoding.ASCII.GetString(response.ReadString());
int num = response.ReadInt32();
string[] prompts = new string[num];
for(int i=0; i<num; i++) {
prompts[i] = Encoding.ASCII.GetString(response.ReadString());
bool echo = response.ReadBool();
}
_eventReceiver.OnAuthenticationPrompt(prompts);
return AuthenticationResult.Prompt;
}
else
throw new SSHException("protocol error: unexpected packet type "+h);
} while(true);
}
private bool ProcessKEXDHREPLY(SSH2Packet packet)
{
//Round2 receives response
SSH2DataReader re = new SSH2DataReader(packet.Data);
PacketType h = re.ReadPacketType();
if(h!=PacketType.SSH_MSG_KEXDH_REPLY) throw new SSHException(String.Format("KeyExchange response is not KEXDH_REPLY but {0}", h));
byte[] key_and_cert = re.ReadString();
BigInteger f = re.ReadMPInt();
byte[] signature = re.ReadString();
Debug.Assert(re.Rest==0);
//Round3 calc hash H
SSH2DataWriter wr = new SSH2DataWriter();
_k = f.modPow(_x, DH_PRIME);
wr = new SSH2DataWriter();
wr.Write(_cInfo._clientVersionString);
wr.Write(_cInfo._serverVersionString);
wr.WriteAsString(_clientKEXINITPayload);
wr.WriteAsString(_serverKEXINITPayload);
wr.WriteAsString(key_and_cert);
wr.Write(_e);
wr.Write(f);
wr.Write(_k);
_hash = new SHA1CryptoServiceProvider().ComputeHash(wr.ToByteArray());
if(!VerifyHostKey(key_and_cert, signature, _hash)) return false;
//Debug.WriteLine("hash="+DebugUtil.DumpByteArray(hash));
if(_sessionID==null) _sessionID = _hash;
return true;
}