private void SendSign(SSH2DataReader r)
{
byte[] blob = r.ReadByteString();
byte[] data = r.ReadByteString();
//Debug.WriteLine(String.Format("SignRequest blobsize={0} datasize={1}", blob.Length, data.Length));
SSH2UserAuthKey[] keys = _client.GetAvailableSSH2UserAuthKeys();
SSH2UserAuthKey key = FindKey(keys, blob);
if (key == null) {
TransmitWriter(OpenWriter(AgentForwadPacketType.SSH_AGENT_FAILURE));
_client.NotifyPublicKeyDidNotMatch();
}
else {
SSH2DataWriter signpack = new SSH2DataWriter();
signpack.WriteString(SSH2Util.PublicKeyAlgorithmName(key.Algorithm));
signpack.WriteAsString(key.Sign(data));
SSH2DataWriter wr = OpenWriter(AgentForwadPacketType.SSH2_AGENT_SIGN_RESPONSE);
wr.WriteAsString(signpack.ToByteArray());
TransmitWriter(wr);
}
}
public SSH2TransmissionPacket()
{
_writer = new SSH2DataWriter();
_dataFragment = new DataFragment(null, 0, 0);
_isOpen = false;
}
private string FormatBase64EncodedPublicKeyBody() {
SSH2DataWriter wr = new SSH2DataWriter();
wr.WriteString(SSH2Util.PublicKeyAlgorithmName(_keypair.Algorithm));
_keypair.PublicKey.WriteTo(wr);
return Encoding.ASCII.GetString(Base64.Encode(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();
}
else {
_remoteID = reader.ReadInt32();
_allowedDataSize = reader.ReadInt32();
_serverMaxPacketSize = reader.ReadInt32();
//open pty
SSH2DataWriter wr = new SSH2DataWriter();
SSHConnectionParameter param = _connection.Param;
wr.WritePacketType(PacketType.SSH_MSG_CHANNEL_REQUEST);
wr.Write(_remoteID);
wr.Write("pty-req");
wr.Write(true);
wr.Write(param.TerminalName);
wr.Write(param.TerminalWidth);
wr.Write(param.TerminalHeight);
wr.Write(param.TerminalPixelWidth);
wr.Write(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.Write(_remoteID);
wr.Write("*****@*****.**");
wr.Write(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!
}
}
}
// 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.Write(_remoteID);
wr.Write("exec"); // "exec"
wr.Write(false); // want confirm is disabled. (*)
wr.Write(_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 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.Write(r.ReadInt32());
wr.Write(0);
wr.Write("unknown method");
wr.Write(""); //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 {
_eventReceiver.OnUnknownMessage((byte)pt, r.Image);
return false;
}
}
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.Write(_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 DataFragment SendKEXDHINIT(Mode mode) {
//Round1 computes and sends [e]
byte[] sx = new byte[16];
_param.Random.NextBytes(sx);
_x = new BigInteger(sx);
_e = new BigInteger(2).modPow(_x, DH_PRIME);
SSH2DataWriter wr = new SSH2DataWriter();
wr.WritePacketType(PacketType.SSH_MSG_KEXDH_INIT);
wr.WriteBigInteger(_e);
_status = Status.WAIT_KEXDH_REPLY;
TraceTransmissionNegotiation(PacketType.SSH_MSG_KEXDH_INIT, "");
if (mode == Mode.Synchronized)
return SynchronizedTransmitRawPayload(wr.ToByteArray());
else {
TransmitRawPayload(wr.ToByteArray());
return null;
}
}
public byte[] ToByteArray(string passphrase)
{
//step1 key body
SSH2DataWriter wr = new SSH2DataWriter();
wr.Write(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.Write(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)
{
Cipher c = CipherFactory.CreateCipher(SSHProtocol.SSH2, CipherAlgorithm.TripleDES, PassphraseToKey(passphrase, 24));
Debug.Assert(encrypted_body.Length % 8 == 0);
byte[] 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.Write(MAGIC_VAL);
wr.Write(0); //for total size
wr.Write(_keypair.Algorithm == PublicKeyAlgorithm.RSA ?
"if-modn{sign{rsa-pkcs1-sha1},encrypt{rsa-pkcs1v2-oaep}}" :
"dl-modp{sign{dsa-nist-sha1},dh{plain}}");
wr.Write(passphrase == null ? "none" : "3des-cbc");
wr.WriteAsString(encrypted_body);
byte[] rawdata = wr.ToByteArray();
SSHUtil.WriteIntToByteArray(rawdata, 4, rawdata.Length); //fix total length
return rawdata;
}
/// <summary>
/// Signing
/// </summary>
/// <param name="data">data to sign</param>
/// <returns>signature blob</returns>
public byte[] Sign(byte[] data) {
BigInteger order = _curve.Order;
byte[] hash = _publicKey.HashForSigning(data, _curve);
BigInteger e = new BigInteger(hash);
using (var rng = new RNGCryptoServiceProvider()) {
BigInteger.ModulusRing nring = new BigInteger.ModulusRing(order);
for (int tries = 0; tries < 10; ++tries) {
try {
ECDSAKeyPair tempKeyPair = _curve.GenerateKeyPair(rng);
BigInteger r = tempKeyPair.PublicKeyPoint.X % order;
if (r == 0) {
continue;
}
BigInteger k = tempKeyPair.PrivateKey;
BigInteger s = nring.Multiply(k.ModInverse(order), e + nring.Multiply(r, _privateKey));
if (s == 0) {
continue;
}
SSH2DataWriter writer = new SSH2DataWriter();
writer.WriteBigInteger(r);
writer.WriteBigInteger(s);
return writer.ToByteArray();
}
catch (Exception ex) {
Debug.WriteLine(ex);
}
}
}
throw new SSHException(Strings.GetString("FailedSigning"));
}
// Tests signature verification using test vectors from NIST CAVP.
// http://csrc.nist.gov/groups/STM/cavp/digital-signatures.html
internal static void TestSignatureVerification() {
using (var reader = new System.IO.StreamReader(@"186-3ecdsatestvectors\SigVer.rsp")) {
EllipticCurve curve = null;
byte[] msg = null;
BigInteger qx = null;
BigInteger qy = null;
BigInteger r = null;
BigInteger s = null;
string result = null;
int testCount = 0;
while (true) {
string line = reader.ReadLine();
if (line == null) {
break;
}
var match = System.Text.RegularExpressions.Regex.Match(line, @"\[([-\w]+),(SHA-\d+)\]");
if (match.Success) {
string curveName = "nist" + match.Groups[1].Value.ToLowerInvariant().Replace("-", "");
curve = FindByName(curveName);
if (curve != null) {
using (var hashFunc = ECDSAHashAlgorithmChooser.Choose(curve)) {
var hashName = "SHA-" + hashFunc.HashSize.ToString();
if (hashName == match.Groups[2].Value) {
Debug.WriteLine("Test " + curve.CurveName);
}
else {
// hash function doesn't match
curve = null;
}
}
}
msg = null;
qx = qy = r = s = null;
result = null;
testCount = 0;
continue;
}
if (line.StartsWith("Msg = ") && curve != null) {
msg = BigIntegerConverter.ParseHex(line.Substring(6).Trim());
continue;
}
if (line.StartsWith("Qx = ") && curve != null) {
qx = new BigInteger(BigIntegerConverter.ParseHex(line.Substring(5).Trim()));
continue;
}
if (line.StartsWith("Qy = ") && curve != null) {
qy = new BigInteger(BigIntegerConverter.ParseHex(line.Substring(5).Trim()));
continue;
}
if (line.StartsWith("R = ") && curve != null) {
r = new BigInteger(BigIntegerConverter.ParseHex(line.Substring(4).Trim()));
continue;
}
if (line.StartsWith("S = ") && curve != null) {
s = new BigInteger(BigIntegerConverter.ParseHex(line.Substring(4).Trim()));
continue;
}
if (line.StartsWith("Result = ") && curve != null) {
result = line.Substring(9, 1);
if (msg != null && qx != null && qy != null && r != null && s != null) {
var pk = new ECDSAPublicKey(curve, new ECPoint(qx, qy));
var buf = new SSH2DataWriter();
buf.WriteBigInteger(r);
buf.WriteBigInteger(s);
var sig = buf.ToByteArray();
string verRes;
try {
pk.Verify(sig, msg);
verRes = "P";
}
catch (VerifyException) {
verRes = "F";
}
if (verRes != result) {
throw new Exception("verification result doesn't match");
}
++testCount;
Debug.WriteLine("Pass #{0}", testCount);
}
msg = null;
qx = qy = r = s = null;
result = null;
}
}
}
}
public SSH2TransmissionPacket()
{
_padding = new byte[32];
_writer = new SSH2DataWriter();
_is_open = false;
}
private DataFragment SendKEXDHINIT(Mode mode)
{
//Round1 computes and sends [e]
byte[] sx = new byte[32];
RngManager.GetSecureRng().GetBytes(sx);
_x = new BigInteger(sx);
_e = new BigInteger(2).modPow(_x, GetDiffieHellmanPrime(_cInfo._kexAlgorithm));
SSH2DataWriter wr = new SSH2DataWriter();
wr.WritePacketType(PacketType.SSH_MSG_KEXDH_INIT);
wr.WriteBigInteger(_e);
_status = Status.WAIT_KEXDH_REPLY;
TraceTransmissionNegotiation(PacketType.SSH_MSG_KEXDH_INIT, "");
if (mode == Mode.Synchronized)
return SynchronizedTransmitRawPayload(wr.ToByteArray());
else {
TransmitRawPayload(wr.ToByteArray());
return null;
}
}
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);
}
internal void TransmitPacket(SSH2DataWriter payload) {
lock(this) {
Debug.Assert(payload==_transmissionPacket.UnderlyingWriter);
_transmissionPacket.Close(_tCipher, _param.Random, _tMAC, _tSequence++, _transmissionImage);
_stream.Write(_transmissionImage.Data, _transmissionImage.Offset, _transmissionImage.Length);
}
}
private DataFragment SynchronizedTransmitPacket(SSH2DataWriter wr) {
return _connection.SynchronizedTransmitPacket(wr);
}
internal DataFragment SynchronizedTransmitPacket(SSH2DataWriter payload) {
lock(this) {
Debug.Assert(payload==_transmissionPacket.UnderlyingWriter);
_transmissionPacket.Close(_tCipher, _param.Random, _tMAC, _tSequence++, _transmissionImage);
return _packetReceiver.SendAndWaitResponse(_transmissionImage);
}
}
private void SendKEXINIT(Mode mode) {
const string kex_algorithm = "diffie-hellman-group1-sha1";
const string mac_algorithm = "hmac-sha1";
SSH2DataWriter wr = new SSH2DataWriter();
wr.WritePacketType(PacketType.SSH_MSG_KEXINIT);
byte[] cookie = new byte[16];
_param.Random.NextBytes(cookie);
wr.Write(cookie);
wr.Write(kex_algorithm); // kex_algorithms
wr.Write(FormatHostKeyAlgorithmDescription()); // server_host_key_algorithms
wr.Write(FormatCipherAlgorithmDescription()); // encryption_algorithms_client_to_server
wr.Write(FormatCipherAlgorithmDescription()); // encryption_algorithms_server_to_client
wr.Write(mac_algorithm); // mac_algorithms_client_to_server
wr.Write(mac_algorithm); // mac_algorithms_server_to_client
wr.Write("none"); // compression_algorithms_client_to_server
wr.Write("none"); // compression_algorithms_server_to_client
wr.Write(""); // languages_client_to_server
wr.Write(""); // languages_server_to_client
wr.Write(false); //Indicates whether a guessed key exchange packet follows
wr.Write(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(kex_algorithm);
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 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.Write(_remoteID);
adj.Write(_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 AuthenticationResult UserAuth() {
const string sn = "ssh-connection";
if(_param.AuthenticationType==AuthenticationType.KeyboardInteractive) {
SSH2DataWriter wr = OpenTransmissionPacket();
wr.WritePacketType(PacketType.SSH_MSG_USERAUTH_REQUEST);
wr.Write(_param.UserName);
wr.Write(sn);
wr.Write("keyboard-interactive");
wr.Write(""); //lang
wr.Write(""); //submethod
TraceTransmissionEvent(PacketType.SSH_MSG_USERAUTH_REQUEST, "starting keyboard-interactive authentication");
TransmitPacket(wr);
_authenticationResult = ProcessAuthenticationResponse();
}
else {
SSH2DataWriter wr = OpenTransmissionPacket();
wr.WritePacketType(PacketType.SSH_MSG_USERAUTH_REQUEST);
wr.Write(_param.UserName);
if(_param.AuthenticationType==AuthenticationType.Password) {
//Password authentication
wr.Write(sn);
wr.Write("password");
wr.Write(false);
wr.Write(_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.Write(_param.UserName);
signsource.Write(sn);
signsource.Write("publickey");
signsource.Write(true);
signsource.Write(SSH2Util.PublicKeyAlgorithmName(kp.Algorithm));
signsource.WriteAsString(kp.GetPublicKeyBlob());
SSH2DataWriter signpack = new SSH2DataWriter();
signpack.Write(SSH2Util.PublicKeyAlgorithmName(kp.Algorithm));
signpack.WriteAsString(kp.Sign(signsource.ToByteArray()));
wr.Write(sn);
wr.Write("publickey");
wr.Write(true);
wr.Write(SSH2Util.PublicKeyAlgorithmName(kp.Algorithm));
wr.WriteAsString(kp.GetPublicKeyBlob());
wr.WriteAsString(signpack.ToByteArray());
TraceTransmissionEvent(PacketType.SSH_MSG_USERAUTH_REQUEST, "starting public key authentication");
}
TransmitPacket(wr);
_authenticationResult = ProcessAuthenticationResponse();
if(_authenticationResult==AuthenticationResult.Failure)
throw new SSHException(Strings.GetString("AuthenticationFailed"));
}
return _authenticationResult;
}
private void TransmitPacket(SSH2DataWriter writer) {
_allowedDataSize -= writer.Length - SSH2TransmissionPacket.INITIAL_OFFSET;
_connection.TransmitPacket(writer);
}
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;
}
private void OpenScheme(string scheme) {
//open shell / subsystem
SSH2DataWriter wr = new SSH2DataWriter();
wr.WritePacketType(PacketType.SSH_MSG_CHANNEL_REQUEST);
wr.Write(_remoteID);
wr.Write(scheme);
wr.Write(true);
if(_command!=null)
wr.Write(_command);
TransmitPayload(wr.ToByteArray());
}
private byte[] DeriveKey(BigInteger key, byte[] hash, char ch, int length) {
byte[] result = new byte[length];
SSH2DataWriter wr = new SSH2DataWriter();
wr.Write(key);
wr.Write(hash);
wr.Write((byte)ch);
wr.Write(_sessionID);
byte[] h1 = new SHA1CryptoServiceProvider().ComputeHash(wr.ToByteArray());
if(h1.Length >= length) {
Array.Copy(h1, 0, result, 0, length);
return result;
}
else {
wr = new SSH2DataWriter();
wr.Write(key);
wr.Write(_sessionID);
wr.Write(h1);
byte[] h2 = new SHA1CryptoServiceProvider().ComputeHash(wr.ToByteArray());
if(h1.Length+h2.Length >= length) {
Array.Copy(h1, 0, result, 0, h1.Length);
Array.Copy(h2, 0, result, h1.Length, length-h1.Length);
return result;
}
else
throw new SSHException("necessary key length is too big"); //long key is not supported
}
}
private byte[] WriteToDataWriter() {
SSH2DataWriter wr = new SSH2DataWriter();
wr.WriteString(SSH2Util.PublicKeyAlgorithmName(_hostkey.Algorithm));
if (_hostkey.Algorithm == PublicKeyAlgorithm.RSA) {
RSAPublicKey rsa = (RSAPublicKey)_hostkey;
wr.WriteBigInteger(rsa.Exponent);
wr.WriteBigInteger(rsa.Modulus);
}
else if (_hostkey.Algorithm == PublicKeyAlgorithm.DSA) {
DSAPublicKey dsa = (DSAPublicKey)_hostkey;
wr.WriteBigInteger(dsa.P);
wr.WriteBigInteger(dsa.Q);
wr.WriteBigInteger(dsa.G);
wr.WriteBigInteger(dsa.Y);
}
else
throw new SSHException("Host key algorithm is unsupported");
return 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.Write(remote_channel);
wr.Write(channel.LocalChannelID);
wr.Write(_param.WindowSize); //initial window size
wr.Write(_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.Write(remote_channel);
wr.Write(r.reason_code);
wr.Write(r.reason_message);
wr.Write(""); //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());
}
public void WritePrivatePartInSECSHStyleFile(Stream dest, string comment, string 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) {
Cipher c = CipherFactory.CreateCipher(SSHProtocol.SSH2, CipherAlgorithm.TripleDES, PassphraseToKey(passphrase, 24));
Debug.Assert(encrypted_body.Length % 8 == 0);
byte[] 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);
byte[] rawdata = wr.ToByteArray();
SSHUtil.WriteIntToByteArray(rawdata, 4, rawdata.Length); //fix total length
//step3 write final data
StreamWriter 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();
}
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.Write(remote_channel);
wr.Write(channel.LocalChannelID);
wr.Write(_param.WindowSize); //initial window size
wr.Write(_param.MaxPacketSize); //max packet size
TraceTransmissionEvent("granados confirmed agent-forwarding request", "");
}
else {
wr.WritePacketType(PacketType.SSH_MSG_CHANNEL_OPEN_FAILURE);
wr.Write(remote_channel);
wr.Write(0);
wr.Write("reject");
wr.Write(""); //lang tag
TraceTransmissionEvent("granados rejected agent-forwarding request", "");
}
TransmitRawPayload(wr.ToByteArray());
}
public byte[] GetPublicKeyBlob() {
SSH2DataWriter w = new SSH2DataWriter();
w.WriteString(SSH2Util.PublicKeyAlgorithmName(_keypair.Algorithm));
_keypair.PublicKey.WriteTo(w);
return w.ToByteArray();
}
//writer util
private SSH2DataWriter OpenWriter(AgentForwadPacketType pt)
{
SSH2DataWriter wr = new SSH2DataWriter();
wr.WriteInt32(0); //length field
wr.WriteByte((byte)pt);
return wr;
}