// sending "exec" service for SCP protocol.
private void ExecCommand(ISSHChannelEventReceiver receiver, PacketType pt, SSH2DataReader reader) {
if (_negotiationStatus == NegotiationStatus.WaitingChannelConfirmation) {
if (pt != PacketType.SSH_MSG_CHANNEL_OPEN_CONFIRMATION) {
if (pt != PacketType.SSH_MSG_CHANNEL_OPEN_FAILURE)
receiver.OnChannelError(new SSHException("opening channel failed; packet type=" + pt));
else {
int errcode = reader.ReadInt32();
string msg = Encoding.ASCII.GetString(reader.ReadString());
receiver.OnChannelError(new SSHException(msg));
}
Close();
}
else {
_remoteID = reader.ReadInt32();
_allowedDataSize = reader.ReadInt32();
_serverMaxPacketSize = reader.ReadInt32();
// exec command
SSH2DataWriter wr = new SSH2DataWriter();
SSHConnectionParameter param = _connection.Param;
wr.WritePacketType(PacketType.SSH_MSG_CHANNEL_REQUEST);
wr.WriteInt32(_remoteID);
wr.WriteString("exec"); // "exec"
wr.WriteBool(false); // want confirm is disabled. (*)
wr.WriteString(_command);
if (_connection.IsEventTracerAvailable)
_connection.TraceTransmissionEvent("exec command", "cmd={0}", _command);
TransmitPayload(wr.ToByteArray());
//confirmation is omitted
receiver.OnChannelReady();
_negotiationStatus = NegotiationStatus.Ready; //goal!
}
}
else if (_negotiationStatus == NegotiationStatus.WaitingExecCmdConfirmation) {
if (pt != PacketType.SSH_MSG_CHANNEL_DATA) {
receiver.OnChannelError(new SSHException("exec command failed"));
Close();
}
else {
receiver.OnChannelReady();
_negotiationStatus = NegotiationStatus.Ready; //goal!
}
}
else
throw new SSHException("internal state error");
}
private void OpenScheme(string scheme) {
//open shell / subsystem
SSH2DataWriter wr = new SSH2DataWriter();
wr.WritePacketType(PacketType.SSH_MSG_CHANNEL_REQUEST);
wr.WriteInt32(_remoteID);
wr.WriteString(scheme);
wr.WriteBool(true);
if (_command != null)
wr.WriteString(_command);
TransmitPayload(wr.ToByteArray());
}
private void OpenShellOrSubsystem(ISSHChannelEventReceiver receiver, PacketType pt, SSH2DataReader reader, string scheme) {
if (_negotiationStatus == NegotiationStatus.WaitingChannelConfirmation) {
if (pt != PacketType.SSH_MSG_CHANNEL_OPEN_CONFIRMATION) {
if (pt != PacketType.SSH_MSG_CHANNEL_OPEN_FAILURE)
receiver.OnChannelError(new SSHException("opening channel failed; packet type=" + pt));
else {
int errcode = reader.ReadInt32();
string msg = Encoding.ASCII.GetString(reader.ReadString());
receiver.OnChannelError(new SSHException(msg));
}
// Close() shouldn't be called because remote channel number is not given yet.
// We just remove an event receiver from the collection of channels.
// FIXME: _negotiationStatus sould be set an error status ?
_connection.ChannelCollection.UnregisterChannelEventReceiver(_localID);
}
else {
_remoteID = reader.ReadInt32();
_allowedDataSize = reader.ReadInt32();
_serverMaxPacketSize = reader.ReadInt32();
if (_type == ChannelType.Subsystem) {
OpenScheme(scheme);
_negotiationStatus = NegotiationStatus.WaitingSubsystemConfirmation;
}
else {
//open pty
SSH2DataWriter wr = new SSH2DataWriter();
SSHConnectionParameter param = _connection.Param;
wr.WritePacketType(PacketType.SSH_MSG_CHANNEL_REQUEST);
wr.WriteInt32(_remoteID);
wr.WriteString("pty-req");
wr.WriteBool(true);
wr.WriteString(param.TerminalName);
wr.WriteInt32(param.TerminalWidth);
wr.WriteInt32(param.TerminalHeight);
wr.WriteInt32(param.TerminalPixelWidth);
wr.WriteInt32(param.TerminalPixelHeight);
wr.WriteAsString(new byte[0]);
if (_connection.IsEventTracerAvailable)
_connection.TraceTransmissionEvent(PacketType.SSH_MSG_CHANNEL_REQUEST, "pty-req", "terminal={0} width={1} height={2}", param.TerminalName, param.TerminalWidth, param.TerminalHeight);
TransmitPayload(wr.ToByteArray());
_negotiationStatus = NegotiationStatus.WaitingPtyReqConfirmation;
}
}
}
else if (_negotiationStatus == NegotiationStatus.WaitingPtyReqConfirmation) {
if (pt != PacketType.SSH_MSG_CHANNEL_SUCCESS) {
receiver.OnChannelError(new SSHException("opening pty failed"));
Close();
}
else {
//agent request (optional)
if (_connection.Param.AgentForward != null) {
SSH2DataWriter wr = new SSH2DataWriter();
wr.WritePacketType(PacketType.SSH_MSG_CHANNEL_REQUEST);
wr.WriteInt32(_remoteID);
wr.WriteString("*****@*****.**");
wr.WriteBool(true);
_connection.TraceTransmissionEvent(PacketType.SSH_MSG_CHANNEL_REQUEST, "auth-agent-req", "");
TransmitPayload(wr.ToByteArray());
_negotiationStatus = NegotiationStatus.WaitingAuthAgentReqConfirmation;
}
else {
OpenScheme(scheme);
_negotiationStatus = NegotiationStatus.WaitingShellConfirmation;
}
}
}
else if (_negotiationStatus == NegotiationStatus.WaitingAuthAgentReqConfirmation) {
if (pt != PacketType.SSH_MSG_CHANNEL_SUCCESS && pt != PacketType.SSH_MSG_CHANNEL_FAILURE) {
receiver.OnChannelError(new SSHException("auth-agent-req error"));
Close();
}
else { //auth-agent-req is optional
_connection.SetAgentForwardConfirmed(pt == PacketType.SSH_MSG_CHANNEL_SUCCESS);
_connection.TraceReceptionEvent(pt, "auth-agent-req");
OpenScheme(scheme);
_negotiationStatus = NegotiationStatus.WaitingShellConfirmation;
}
}
else if (_negotiationStatus == NegotiationStatus.WaitingShellConfirmation) {
if (pt != PacketType.SSH_MSG_CHANNEL_SUCCESS) {
receiver.OnChannelError(new SSHException("Opening shell failed: packet type=" + pt.ToString()));
Close();
}
else {
receiver.OnChannelReady();
_negotiationStatus = NegotiationStatus.Ready; //goal!
}
}
else if (_negotiationStatus == NegotiationStatus.WaitingSubsystemConfirmation) {
if (pt != PacketType.SSH_MSG_CHANNEL_SUCCESS) {
receiver.OnChannelError(new SSHException("Opening subsystem failed: packet type=" + pt.ToString()));
Close();
}
else {
receiver.OnChannelReady();
_negotiationStatus = NegotiationStatus.Ready; //goal!
}
}
}
private bool ProcessPacket(DataFragment packet) {
if (_readerForProcessPacket == null)
_readerForProcessPacket = new SSH2DataReader(packet);
else
_readerForProcessPacket.Recycle(packet); //avoid 'new'
SSH2DataReader r = _readerForProcessPacket; //rename for frequently use
PacketType pt = r.ReadPacketType();
if (pt == PacketType.SSH_MSG_DISCONNECT) {
int errorcode = r.ReadInt32();
_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) {
string method = Encoding.ASCII.GetString(r.ReadString());
if (method == "forwarded-tcpip")
ProcessPortforwardingRequest(_eventReceiver, r);
else if (method.StartsWith("auth-agent")) //in most cases, method is "*****@*****.**"
ProcessAgentForwardRequest(_eventReceiver, r);
else {
SSH2DataWriter wr = new SSH2DataWriter();
wr.WritePacketType(PacketType.SSH_MSG_CHANNEL_OPEN_FAILURE);
wr.WriteInt32(r.ReadInt32());
wr.WriteInt32(0);
wr.WriteString("unknown method");
wr.WriteString(""); //lang tag
TraceReceptionEvent("SSH_MSG_CHANNEL_OPEN rejected", "method={0}", method);
}
return true;
}
else if (pt >= PacketType.SSH_MSG_CHANNEL_OPEN_CONFIRMATION && pt <= PacketType.SSH_MSG_CHANNEL_FAILURE) {
int local_channel = r.ReadInt32();
ChannelCollection.Entry e = this.ChannelCollection.FindChannelEntry(local_channel);
if (e != null)
((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 if (pt == PacketType.SSH_MSG_GLOBAL_REQUEST)
{
SSH2DataWriter wr = new SSH2DataWriter();
wr.WritePacketType(PacketType.SSH_MSG_REQUEST_SUCCESS);
wr.WriteBool(true);
TransmitRawPayload(wr.ToByteArray());
return true;
}
else {
_eventReceiver.OnUnknownMessage((byte)pt, r.Image);
return false;
}
}
private void SendKEXINIT(Mode mode) {
const string mac_algorithm = "hmac-sha1";
SSH2DataWriter wr = new SSH2DataWriter();
wr.WritePacketType(PacketType.SSH_MSG_KEXINIT);
byte[] cookie = new byte[16];
RngManager.GetSecureRng().GetBytes(cookie);
wr.Write(cookie);
wr.WriteString(GetSupportedKexAlgorithms()); // kex_algorithms
wr.WriteString(FormatHostKeyAlgorithmDescription()); // server_host_key_algorithms
wr.WriteString(FormatCipherAlgorithmDescription()); // encryption_algorithms_client_to_server
wr.WriteString(FormatCipherAlgorithmDescription()); // encryption_algorithms_server_to_client
wr.WriteString(mac_algorithm); // mac_algorithms_client_to_server
wr.WriteString(mac_algorithm); // mac_algorithms_server_to_client
wr.WriteString("none"); // compression_algorithms_client_to_server
wr.WriteString("none"); // compression_algorithms_server_to_client
wr.WriteString(""); // languages_client_to_server
wr.WriteString(""); // languages_server_to_client
wr.WriteBool(false); //Indicates whether a guessed key exchange packet follows
wr.WriteInt32(0); //reserved for future extension
_clientKEXINITPayload = wr.ToByteArray();
_status = Status.WAIT_KEXINIT;
if (_connection.IsEventTracerAvailable) {
StringBuilder bld = new StringBuilder();
bld.Append("kex_algorithm=");
bld.Append(GetSupportedKexAlgorithms());
bld.Append("; server_host_key_algorithms=");
bld.Append(FormatHostKeyAlgorithmDescription());
bld.Append("; encryption_algorithms_client_to_server=");
bld.Append(FormatCipherAlgorithmDescription());
bld.Append("; encryption_algorithms_server_to_client=");
bld.Append(FormatCipherAlgorithmDescription());
bld.Append("; mac_algorithms_client_to_server=");
bld.Append(mac_algorithm);
bld.Append("; mac_algorithms_server_to_client=");
bld.Append(mac_algorithm);
TraceTransmissionNegotiation(PacketType.SSH_MSG_KEXINIT, bld.ToString());
}
TransmitRawPayload(_clientKEXINITPayload);
}
private AuthenticationResult UserAuth() {
const string sn = "ssh-connection";
if (_param.AuthenticationType == AuthenticationType.KeyboardInteractive) {
SSH2TransmissionPacket packet = OpenPacket();
SSH2DataWriter wr = packet.DataWriter;
wr.WritePacketType(PacketType.SSH_MSG_USERAUTH_REQUEST);
wr.WriteString(_param.UserName);
wr.WriteString(sn);
wr.WriteString("keyboard-interactive");
wr.WriteString(""); //lang
wr.WriteString(""); //submethod
TraceTransmissionEvent(PacketType.SSH_MSG_USERAUTH_REQUEST, "starting keyboard-interactive authentication");
TransmitPacket(packet);
_authenticationResult = ProcessAuthenticationResponse();
}
else {
SSH2TransmissionPacket packet = OpenPacket();
SSH2DataWriter wr = packet.DataWriter;
wr.WritePacketType(PacketType.SSH_MSG_USERAUTH_REQUEST);
wr.WriteString(_param.UserName);
if (_param.AuthenticationType == AuthenticationType.Password) {
//Password authentication
wr.WriteString(sn);
wr.WriteString("password");
wr.WriteBool(false);
wr.WriteString(_param.Password);
TraceTransmissionEvent(PacketType.SSH_MSG_USERAUTH_REQUEST, "starting password authentication");
}
else {
//public key authentication
SSH2UserAuthKey kp = SSH2UserAuthKey.FromSECSHStyleFile(_param.IdentityFile, _param.Password);
SSH2DataWriter signsource = new SSH2DataWriter();
signsource.WriteAsString(_sessionID);
signsource.WritePacketType(PacketType.SSH_MSG_USERAUTH_REQUEST);
signsource.WriteString(_param.UserName);
signsource.WriteString(sn);
signsource.WriteString("publickey");
signsource.WriteBool(true);
signsource.WriteString(SSH2Util.PublicKeyAlgorithmName(kp.Algorithm));
signsource.WriteAsString(kp.GetPublicKeyBlob());
SSH2DataWriter signpack = new SSH2DataWriter();
signpack.WriteString(SSH2Util.PublicKeyAlgorithmName(kp.Algorithm));
signpack.WriteAsString(kp.Sign(signsource.ToByteArray()));
wr.WriteString(sn);
wr.WriteString("publickey");
wr.WriteBool(true);
wr.WriteString(SSH2Util.PublicKeyAlgorithmName(kp.Algorithm));
wr.WriteAsString(kp.GetPublicKeyBlob());
wr.WriteAsString(signpack.ToByteArray());
TraceTransmissionEvent(PacketType.SSH_MSG_USERAUTH_REQUEST, "starting public key authentication");
}
TransmitPacket(packet);
_authenticationResult = ProcessAuthenticationResponse();
if (_authenticationResult == AuthenticationResult.Failure)
throw new SSHException(Strings.GetString("AuthenticationFailed"));
}
return _authenticationResult;
}
