private void TransmitWriter(SSH2DataWriter wr) { int o = wr.Length; wr.SetOffset(0); wr.WriteInt32(o - 4); //length of int32 _channel.Transmit(wr.UnderlyingBuffer, 0, o); }
// 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"); }
//writer util private SSH2DataWriter OpenWriter(AgentForwadPacketType pt) { SSH2DataWriter wr = new SSH2DataWriter(); wr.WriteInt32(0); //length field wr.WriteByte((byte)pt); return wr; }
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 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 AdjustWindowSize(PacketType pt, int data_length) { _leftWindowSize -= data_length; if (pt == PacketType.SSH_MSG_CHANNEL_EOF || pt == PacketType.SSH_MSG_CHANNEL_CLOSE) return; //window adjust is not necessary if the channel is being closed // need not send window size to server when the channel is not opened. if (_negotiationStatus != NegotiationStatus.Ready) return; while (_leftWindowSize <= _windowSize) { SSH2DataWriter adj = new SSH2DataWriter(); adj.WritePacketType(PacketType.SSH_MSG_CHANNEL_WINDOW_ADJUST); adj.WriteInt32(_remoteID); adj.WriteInt32(_windowSize); TransmitPayload(adj.ToByteArray()); _leftWindowSize += _windowSize; if (_connection.IsEventTracerAvailable) _connection.TraceTransmissionEvent("SSH_MSG_CHANNEL_WINDOW_ADJUST", "adjusted to {0} by increasing {1}", _leftWindowSize, _windowSize); } }
private void ProcessChannelLocalData(ISSHChannelEventReceiver receiver, PacketType pt, SSH2DataReader re) { switch (pt) { case PacketType.SSH_MSG_CHANNEL_DATA: { int len = re.ReadInt32(); receiver.OnData(re.Image, re.Offset, len); } break; case PacketType.SSH_MSG_CHANNEL_EXTENDED_DATA: { int t = re.ReadInt32(); byte[] data = re.ReadString(); receiver.OnExtendedData(t, data); } break; case PacketType.SSH_MSG_CHANNEL_REQUEST: { string request = Encoding.ASCII.GetString(re.ReadString()); bool reply = re.ReadBool(); if (request == "exit-status") { int status = re.ReadInt32(); } else if (reply) { //we reject unknown requests including keep-alive check SSH2DataWriter wr = new SSH2DataWriter(); wr.WritePacketType(PacketType.SSH_MSG_CHANNEL_FAILURE); wr.WriteInt32(_remoteID); TransmitPayload(wr.ToByteArray()); } } break; case PacketType.SSH_MSG_CHANNEL_EOF: receiver.OnChannelEOF(); break; case PacketType.SSH_MSG_CHANNEL_CLOSE: _connection.ChannelCollection.UnregisterChannelEventReceiver(_localID); receiver.OnChannelClosed(); break; case PacketType.SSH_MSG_CHANNEL_FAILURE: receiver.OnMiscPacket((byte)pt, re.Image, re.Offset, re.Rest); break; default: receiver.OnMiscPacket((byte)pt, re.Image, re.Offset, re.Rest); //Debug.WriteLine("Unknown Packet " + pt); break; } }
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 ProcessAgentForwardRequest(ISSHConnectionEventReceiver receiver, SSH2DataReader reader) { int remote_channel = reader.ReadInt32(); int window_size = reader.ReadInt32(); //skip initial window size int servermaxpacketsize = reader.ReadInt32(); TraceReceptionEvent("agent forward request", ""); SSH2DataWriter wr = new SSH2DataWriter(); IAgentForward af = _param.AgentForward; if (_agentForwardConfirmed && af != null && af.CanAcceptForwarding()) { //send OPEN_CONFIRMATION AgentForwardingChannel ch = new AgentForwardingChannel(af); SSH2Channel channel = new SSH2Channel(this, ChannelType.AgentForward, this.ChannelCollection.RegisterChannelEventReceiver(null, ch).LocalID, remote_channel, servermaxpacketsize); ch.SetChannel(channel); wr.WritePacketType(PacketType.SSH_MSG_CHANNEL_OPEN_CONFIRMATION); wr.WriteInt32(remote_channel); wr.WriteInt32(channel.LocalChannelID); wr.WriteInt32(_param.WindowSize); //initial window size wr.WriteInt32(_param.MaxPacketSize); //max packet size TraceTransmissionEvent("granados confirmed agent-forwarding request", ""); } else { wr.WritePacketType(PacketType.SSH_MSG_CHANNEL_OPEN_FAILURE); wr.WriteInt32(remote_channel); wr.WriteInt32(0); wr.WriteString("reject"); wr.WriteString(""); //lang tag TraceTransmissionEvent("granados rejected agent-forwarding request", ""); } TransmitRawPayload(wr.ToByteArray()); }
private void ProcessPortforwardingRequest(ISSHConnectionEventReceiver receiver, SSH2DataReader reader) { int remote_channel = reader.ReadInt32(); int window_size = reader.ReadInt32(); //skip initial window size int servermaxpacketsize = reader.ReadInt32(); string host = Encoding.ASCII.GetString(reader.ReadString()); int port = reader.ReadInt32(); string originator_ip = Encoding.ASCII.GetString(reader.ReadString()); int originator_port = reader.ReadInt32(); TraceReceptionEvent("port forwarding request", String.Format("host={0} port={1} originator-ip={2} originator-port={3}", host, port, originator_ip, originator_port)); PortForwardingCheckResult r = receiver.CheckPortForwardingRequest(host, port, originator_ip, originator_port); SSH2DataWriter wr = new SSH2DataWriter(); if (r.allowed) { //send OPEN_CONFIRMATION SSH2Channel channel = new SSH2Channel(this, ChannelType.ForwardedRemoteToLocal, this.ChannelCollection.RegisterChannelEventReceiver(null, r.channel).LocalID, remote_channel, servermaxpacketsize); wr.WritePacketType(PacketType.SSH_MSG_CHANNEL_OPEN_CONFIRMATION); wr.WriteInt32(remote_channel); wr.WriteInt32(channel.LocalChannelID); wr.WriteInt32(_param.WindowSize); //initial window size wr.WriteInt32(_param.MaxPacketSize); //max packet size receiver.EstablishPortforwarding(r.channel, channel); TraceTransmissionEvent("port-forwarding request is confirmed", "host={0} port={1} originator-ip={2} originator-port={3}", host, port, originator_ip, originator_port); } else { wr.WritePacketType(PacketType.SSH_MSG_CHANNEL_OPEN_FAILURE); wr.WriteInt32(remote_channel); wr.WriteInt32(r.reason_code); wr.WriteString(r.reason_message); wr.WriteString(""); //lang tag TraceTransmissionEvent("port-forwarding request is rejected", "host={0} port={1} originator-ip={2} originator-port={3}", host, port, originator_ip, originator_port); } TransmitRawPayload(wr.ToByteArray()); }
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); }
public void WritePrivatePartInSECSHStyleFile(Stream dest, string comment, SecureString passphrase) { //step1 key body SSH2DataWriter wr = new SSH2DataWriter(); wr.WriteInt32(0); //this field is filled later if (_keypair.Algorithm == PublicKeyAlgorithm.RSA) { RSAKeyPair rsa = (RSAKeyPair)_keypair; RSAPublicKey pub = (RSAPublicKey)_keypair.PublicKey; wr.WriteBigIntWithBits(pub.Exponent); wr.WriteBigIntWithBits(rsa.D); wr.WriteBigIntWithBits(pub.Modulus); wr.WriteBigIntWithBits(rsa.U); wr.WriteBigIntWithBits(rsa.P); wr.WriteBigIntWithBits(rsa.Q); } else { DSAKeyPair dsa = (DSAKeyPair)_keypair; DSAPublicKey pub = (DSAPublicKey)_keypair.PublicKey; wr.WriteInt32(0); wr.WriteBigIntWithBits(pub.P); wr.WriteBigIntWithBits(pub.G); wr.WriteBigIntWithBits(pub.Q); wr.WriteBigIntWithBits(pub.Y); wr.WriteBigIntWithBits(dsa.X); } int padding_len = 0; if (passphrase != null) { padding_len = 8 - (int)wr.Length%8; wr.Write(new byte[padding_len]); } byte[] encrypted_body = wr.ToByteArray(); SSHUtil.WriteIntToByteArray(encrypted_body, 0, encrypted_body.Length - padding_len - 4); //encrypt if necessary if (passphrase != null) { var c = CipherFactory.CreateCipher(SSHProtocol.SSH2, CipherAlgorithm.TripleDES, PassphraseToKey(passphrase, 24)); Debug.Assert(encrypted_body.Length%8 == 0); var tmp = new byte[encrypted_body.Length]; c.Encrypt(encrypted_body, 0, encrypted_body.Length, tmp, 0); encrypted_body = tmp; } //step2 make binary key data wr = new SSH2DataWriter(); wr.WriteInt32(MAGIC_VAL); wr.WriteInt32(0); //for total size wr.WriteString(_keypair.Algorithm == PublicKeyAlgorithm.RSA ? "if-modn{sign{rsa-pkcs1-sha1},encrypt{rsa-pkcs1v2-oaep}}" : "dl-modp{sign{dsa-nist-sha1},dh{plain}}"); wr.WriteString(passphrase == null ? "none" : "3des-cbc"); wr.WriteAsString(encrypted_body); var rawdata = wr.ToByteArray(); SSHUtil.WriteIntToByteArray(rawdata, 4, rawdata.Length); //fix total length //step3 write final data var sw = new StreamWriter(dest, Encoding.ASCII); sw.WriteLine("---- BEGIN SSH2 ENCRYPTED PRIVATE KEY ----"); if (comment != null) WriteKeyFileBlock(sw, "Comment: " + comment, true); WriteKeyFileBlock(sw, Encoding.ASCII.GetString(Base64.Encode(rawdata)), false); sw.WriteLine("---- END SSH2 ENCRYPTED PRIVATE KEY ----"); sw.Close(); }