private void ServiceRequest(string servicename) {
SSH2DataWriter wr = OpenTransmissionPacket();
wr.WritePacketType(PacketType.SSH_MSG_SERVICE_REQUEST);
wr.Write(servicename);
TraceTransmissionEvent("SSH_MSG_SERVICE_REQUEST", servicename);
TransmitPacket(wr);
DataFragment response = ReceivePacket();
SSH2DataReader re = new SSH2DataReader(response);
PacketType t = re.ReadPacketType();
if(t!=PacketType.SSH_MSG_SERVICE_ACCEPT) {
TraceReceptionEvent(t.ToString(), "service request failed");
throw new SSHException("service establishment failed "+t);
}
string s = Encoding.ASCII.GetString(re.ReadString());
if(servicename!=s)
throw new SSHException("protocol error");
}
private AuthenticationResult ProcessAuthenticationResponse() {
do {
SSH2DataReader response = new SSH2DataReader(ReceivePacket());
PacketType h = response.ReadPacketType();
if(h==PacketType.SSH_MSG_USERAUTH_FAILURE) {
string msg = Encoding.ASCII.GetString(response.ReadString());
TraceReceptionEvent(h, "user authentication failed:" + msg);
return AuthenticationResult.Failure;
}
else if(h==PacketType.SSH_MSG_USERAUTH_BANNER) {
TraceReceptionEvent(h, "");
}
else if(h==PacketType.SSH_MSG_USERAUTH_SUCCESS) {
TraceReceptionEvent(h, "user authentication succeeded");
_packetBuilder.InnerHandler = 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);
_requiredResponseCount = num;
return AuthenticationResult.Prompt;
}
else
throw new SSHException("protocol error: unexpected packet type "+h);
} while(true);
}
//synchronous reception
internal DataFragment ReceivePacket() {
while(true) {
DataFragment data = _packetReceiver.WaitResponse();
PacketType pt = (PacketType)data.ByteAt(0); //sneak
//filter unnecessary packet
if(pt==PacketType.SSH_MSG_IGNORE) {
SSH2DataReader r = new SSH2DataReader(data);
r.ReadPacketType(); //skip
byte[] msg = r.ReadString();
if(_eventReceiver!=null) _eventReceiver.OnIgnoreMessage(msg);
TraceReceptionEvent(pt, msg);
}
else if(pt==PacketType.SSH_MSG_DEBUG) {
SSH2DataReader r = new SSH2DataReader(data);
r.ReadPacketType(); //skip
bool f = r.ReadBool();
byte[] msg = r.ReadString();
if(_eventReceiver!=null) _eventReceiver.OnDebugMessage(f, msg);
TraceReceptionEvent(pt, msg);
}
else {
return data;
}
}
}
private bool ProcessKEXDHREPLY(DataFragment packet) {
//Round2 receives response
SSH2DataReader re = null;
PacketType h;
do {
re = new SSH2DataReader(packet);
h = re.ReadPacketType();
if(h==PacketType.SSH_MSG_KEXDH_REPLY)
break; //successfully exit
else if(h==PacketType.SSH_MSG_IGNORE || h==PacketType.SSH_MSG_DEBUG) { //continue
packet = _connection.ReceivePacket();
}
else
throw new SSHException(String.Format("KeyExchange response is not KEXDH_REPLY but {0}", h));
} while(true);
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());
_connection.TraceReceptionEvent(h, "verifying host key");
if(!VerifyHostKey(key_and_cert, signature, _hash)) return false;
//Debug.WriteLine("hash="+DebugUtil.DumpByteArray(hash));
if(_sessionID==null) _sessionID = _hash;
return true;
}
