public override void ResizeTerminal(int width, int height, int pixel_width, int pixel_height)
{
SSH2DataWriter wr = new SSH2DataWriter();
wr.WritePacketType(PacketType.SSH_MSG_CHANNEL_REQUEST);
wr.Write(_remoteID);
wr.Write("window-change");
wr.Write(false);
wr.Write(width);
wr.Write(height);
wr.Write(pixel_width); //no graphics
wr.Write(pixel_height);
TransmitPacket(wr.ToByteArray());
}
public override void Close()
{
if(_connection.IsClosed) return;
SSH2DataWriter wr = new SSH2DataWriter();
wr.WritePacketType(PacketType.SSH_MSG_CHANNEL_CLOSE);
wr.Write(_remoteID);
TransmitPacket(wr.ToByteArray());
}
public byte[] GetPublicKeyBlob()
{
SSH2DataWriter w = new SSH2DataWriter();
w.Write(SSH2Util.PublicKeyAlgorithmName(_keypair.Algorithm));
_keypair.PublicKey.WriteTo(w);
return(w.ToByteArray());
}
public override string DumpHostKeyInKnownHostsStyle()
{
StringBuilder bld = new StringBuilder();
bld.Append(SSH2Util.PublicKeyAlgorithmName(_hostkey.Algorithm));
bld.Append(' ');
SSH2DataWriter wr = new SSH2DataWriter();
wr.Write(SSH2Util.PublicKeyAlgorithmName(_hostkey.Algorithm));
if (_hostkey.Algorithm == PublicKeyAlgorithm.RSA)
{
RSAPublicKey rsa = (RSAPublicKey)_hostkey;
wr.Write(rsa.Exponent);
wr.Write(rsa.Modulus);
}
else if (_hostkey.Algorithm == PublicKeyAlgorithm.DSA)
{
DSAPublicKey dsa = (DSAPublicKey)_hostkey;
wr.Write(dsa.P);
wr.Write(dsa.Q);
wr.Write(dsa.G);
wr.Write(dsa.Y);
}
else
{
throw new SSHException("Host key algorithm is unsupported");
}
bld.Append(Encoding.ASCII.GetString(Base64.Encode(wr.ToByteArray())));
return(bld.ToString());
}
private string FormatBase64EncodedPublicKeyBody()
{
SSH2DataWriter wr = new SSH2DataWriter();
wr.Write(SSH2Util.PublicKeyAlgorithmName(_keypair.Algorithm));
_keypair.PublicKey.WriteTo(wr);
return(Encoding.ASCII.GetString(Base64.Encode(wr.ToByteArray())));
}
public static SSH2Packet FromDecryptedHead(byte[] head, byte[] buffer, int offset, Cipher cipher, int sequence, MAC mac)
{
SSH2Packet p = new SSH2Packet();
p._packetLength = SSHUtil.ReadInt32(head, 0);
if (p._packetLength <= 0 || p._packetLength >= MAX_PACKET_LENGTH)
{
throw new SSHException(String.Format("packet size {0} is invalid", p._packetLength));
}
SSH2DataWriter buf = new SSH2DataWriter();
buf.Write(sequence);
buf.Write(head);
if (p._packetLength > (cipher.BlockSize - 4))
{
byte[] tmp = new byte[p._packetLength - (cipher.BlockSize - 4)];
cipher.Decrypt(buffer, offset, tmp.Length, tmp, 0);
offset += tmp.Length;
buf.Write(tmp);
}
byte[] result = buf.ToByteArray();
int padding_len = (int)result[8];
if (padding_len < 4)
{
throw new SSHException("padding length is invalid");
}
byte[] payload = new byte[result.Length - 9 - padding_len];
Array.Copy(result, 9, payload, 0, payload.Length);
p._payload = payload;
if (mac != null)
{
p._mac = mac.Calc(result);
if (SSHUtil.memcmp(p._mac, 0, buffer, offset, mac.Size) != 0)
{
throw new SSHException("MAC Error");
}
}
return(p);
}
public void SendBreak(int time)
{
SSH2DataWriter wr = new SSH2DataWriter();
wr.WritePacketType(PacketType.SSH_MSG_CHANNEL_REQUEST);
wr.Write(_remoteID);
wr.Write("break");
wr.Write(true);
wr.Write(time);
TransmitPacket(wr.ToByteArray());
}
public override string DumpHostKeyInKnownHostsStyle()
{
StringBuilder bld = new StringBuilder();
bld.Append(SSH2Util.PublicKeyAlgorithmName(_hostkey.Algorithm));
bld.Append(' ');
SSH2DataWriter wr = new SSH2DataWriter();
wr.Write(SSH2Util.PublicKeyAlgorithmName(_hostkey.Algorithm));
if(_hostkey.Algorithm==PublicKeyAlgorithm.RSA) {
RSAPublicKey rsa = (RSAPublicKey)_hostkey;
wr.Write(rsa.Exponent);
wr.Write(rsa.Modulus);
}
else if(_hostkey.Algorithm==PublicKeyAlgorithm.DSA) {
DSAPublicKey dsa = (DSAPublicKey)_hostkey;
wr.Write(dsa.P);
wr.Write(dsa.Q);
wr.Write(dsa.G);
wr.Write(dsa.Y);
}
else
throw new SSHException("Host key algorithm is unsupported");
bld.Append(Encoding.ASCII.GetString(Base64.Encode(wr.ToByteArray())));
return bld.ToString();
}
public override void SendIgnorableData(string msg)
{
SSH2DataWriter w = new SSH2DataWriter();
w.WritePacketType(PacketType.SSH_MSG_IGNORE);
w.Write(msg);
TransmitPacket(w.ToByteArray());
}
public override void ListenForwardedPort(string allowed_host, int bind_port)
{
SSH2DataWriter wr = new SSH2DataWriter();
wr.WritePacketType(PacketType.SSH_MSG_GLOBAL_REQUEST);
wr.Write("tcpip-forward");
wr.Write(true);
wr.Write(allowed_host);
wr.Write(bind_port);
_waitingForPortForwardingResponse = true;
TransmitPacket(wr.ToByteArray());
}
public AuthenticationResult DoKeyboardInteractiveAuth(string[] input)
{
if(_param.AuthenticationType!=AuthenticationType.KeyboardInteractive)
throw new SSHException("DoKeyboardInteractiveAuth() must be called with keyboard-interactive authentication");
SSH2DataWriter re = new SSH2DataWriter();
re.WritePacketType(PacketType.SSH_MSG_USERAUTH_INFO_RESPONSE);
re.Write(input.Length);
foreach(string t in input)
re.Write(t);
TransmitPacket(re.ToByteArray());
_authenticationResult = ProcessAuthenticationResponse();
//try again on failure
if(_authenticationResult==AuthenticationResult.Failure) {
SSH2DataWriter wr = new SSH2DataWriter();
wr.WritePacketType(PacketType.SSH_MSG_USERAUTH_REQUEST);
wr.Write(_param.UserName);
wr.Write("ssh-connection");
wr.Write("keyboard-interactive");
wr.Write(""); //lang
wr.Write(""); //submethod
TransmitPacket(wr.ToByteArray());
_authenticationResult = ProcessAuthenticationResponse();
}
return _authenticationResult;
}
public override void CancelForwardedPort(string host, int port)
{
SSH2DataWriter wr = new SSH2DataWriter();
wr.WritePacketType(PacketType.SSH_MSG_GLOBAL_REQUEST);
wr.Write("cancel-tcpip-forward");
wr.Write(true);
wr.Write(host);
wr.Write(port);
TransmitPacket(wr.ToByteArray());
}
public void WritePrivatePartInSECSHStyleFile(Stream dest, string comment, 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
//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 string FormatBase64EncodedPublicKeyBody()
{
SSH2DataWriter wr = new SSH2DataWriter();
wr.Write(SSH2Util.PublicKeyAlgorithmName(_keypair.Algorithm));
_keypair.PublicKey.WriteTo(wr);
return Encoding.ASCII.GetString(Base64.Encode(wr.ToByteArray()));
}
public void WritePrivatePartInSECSHStyleFile(Stream dest, string comment, 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
//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();
}
public byte[] GetPublicKeyBlob()
{
SSH2DataWriter w = new SSH2DataWriter();
w.Write(SSH2Util.PublicKeyAlgorithmName(_keypair.Algorithm));
_keypair.PublicKey.WriteTo(w);
return w.ToByteArray();
}
internal void ProcessPacket(ISSHChannelEventReceiver receiver, PacketType pt, int data_length, SSH2DataReader re)
{
//NOTE: the offset of 're' is next to 'receipiant channel' field
_leftWindowSize -= data_length;
while(_leftWindowSize <= _windowSize) {
SSH2DataWriter adj = new SSH2DataWriter();
adj.WritePacketType(PacketType.SSH_MSG_CHANNEL_WINDOW_ADJUST);
adj.Write(_remoteID);
adj.Write(_windowSize);
TransmitPacket(adj.ToByteArray());
_leftWindowSize += _windowSize;
//Debug.WriteLine("Window size is adjusted to " + _leftWindowSize);
}
if(pt==PacketType.SSH_MSG_CHANNEL_WINDOW_ADJUST) {
int w = re.ReadInt32();
//Debug.WriteLine(String.Format("Window Adjust +={0}",w));
}
else if(_negotiationStatus!=0) { //when the negotiation is not completed
if(_type==ChannelType.Shell)
OpenShell(receiver, pt, re);
else if(_type==ChannelType.ForwardedLocalToRemote)
ReceivePortForwardingResponse(receiver, pt, re);
else if(_type==ChannelType.Session)
EstablishSession(receiver, pt, re);
}
else {
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.Write((byte)PacketType.SSH_MSG_CHANNEL_FAILURE);
wr.Write(_remoteID);
TransmitPacket(wr.ToByteArray());
}
}
break;
case PacketType.SSH_MSG_CHANNEL_EOF:
receiver.OnChannelEOF();
break;
case PacketType.SSH_MSG_CHANNEL_CLOSE:
_connection.UnregisterChannelEventReceiver(_localID);
receiver.OnChannelClosed();
break;
case PacketType.SSH_MSG_CHANNEL_FAILURE:
case PacketType.SSH_MSG_CHANNEL_SUCCESS:
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 void OpenShell(ISSHChannelEventReceiver receiver, PacketType pt, SSH2DataReader reader)
{
if(_negotiationStatus==3) {
if(pt!=PacketType.SSH_MSG_CHANNEL_OPEN_CONFIRMATION) {
if(pt!=PacketType.SSH_MSG_CHANNEL_OPEN_FAILURE)
receiver.OnChannelError(null, "opening channel failed; packet type="+pt);
else {
int errcode = reader.ReadInt32();
string msg = Encoding.ASCII.GetString(reader.ReadString());
receiver.OnChannelError(null, msg);
}
Close();
}
else {
_remoteID = reader.ReadInt32();
_serverMaxPacketSize = reader.ReadInt32();
//open pty
SSH2DataWriter wr = new SSH2DataWriter();
wr.WritePacketType(PacketType.SSH_MSG_CHANNEL_REQUEST);
wr.Write(_remoteID);
wr.Write("pty-req");
wr.Write(true);
wr.Write(_connection.Param.TerminalName);
wr.Write(_connection.Param.TerminalWidth);
wr.Write(_connection.Param.TerminalHeight);
wr.Write(_connection.Param.TerminalPixelWidth);
wr.Write(_connection.Param.TerminalPixelHeight);
wr.WriteAsString(new byte[0]);
TransmitPacket(wr.ToByteArray());
_negotiationStatus = 2;
}
}
else if(_negotiationStatus==2) {
if(pt!=PacketType.SSH_MSG_CHANNEL_SUCCESS) {
receiver.OnChannelError(null, "opening pty failed");
Close();
}
else {
//open shell
SSH2DataWriter wr = new SSH2DataWriter();
wr.Write((byte)PacketType.SSH_MSG_CHANNEL_REQUEST);
wr.Write(_remoteID);
wr.Write("shell");
wr.Write(true);
TransmitPacket(wr.ToByteArray());
_negotiationStatus = 1;
}
}
else if(_negotiationStatus==1) {
if(pt!=PacketType.SSH_MSG_CHANNEL_SUCCESS) {
receiver.OnChannelError(null, "Opening shell failed: packet type="+pt.ToString());
Close();
}
else {
receiver.OnChannelReady();
_negotiationStatus = 0; //goal!
}
}
else
Debug.Assert(false);
}
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;
}
public override void Disconnect(string msg)
{
if(_closed) return;
SSH2DataWriter wr = new SSH2DataWriter();
wr.WritePacketType(PacketType.SSH_MSG_DISCONNECT);
wr.Write(0);
wr.Write(msg);
wr.Write(""); //language
TransmitPacket(wr.ToByteArray());
_stream.Flush();
_closed = true;
_stream.Close();
}
private void SendKEXDHINIT()
{
//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.Write(_e);
_status = Status.WAIT_KEXDH_REPLY;
TransmitPacket(wr.ToByteArray());
}
public override SSHChannel ForwardPort(ISSHChannelEventReceiver receiver, string remote_host, int remote_port, string originator_host, int originator_port)
{
SSH2DataWriter wr = new SSH2DataWriter();
wr.WritePacketType(PacketType.SSH_MSG_CHANNEL_OPEN);
wr.Write("direct-tcpip");
int local_id = RegisterChannelEventReceiver(null, receiver)._localID;
wr.Write(local_id);
wr.Write(_param.WindowSize); //initial window size
int windowsize = _param.WindowSize;
wr.Write(_param.MaxPacketSize); //max packet size
wr.Write(remote_host);
wr.Write(remote_port);
wr.Write(originator_host);
wr.Write(originator_port);
SSH2Channel channel = new SSH2Channel(this, ChannelType.ForwardedLocalToRemote, local_id);
TransmitPacket(wr.ToByteArray());
return channel;
}
private void ProcessPortforwardingRequest(ISSHConnectionEventReceiver receiver, SSH2DataReader reader)
{
string method = Encoding.ASCII.GetString(reader.ReadString());
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();
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, 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);
}
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
}
TransmitPacket(wr.ToByteArray());
}
public override SSHChannel OpenShell(ISSHChannelEventReceiver receiver)
{
//open channel
SSH2DataWriter wr = new SSH2DataWriter();
wr.WritePacketType(PacketType.SSH_MSG_CHANNEL_OPEN);
wr.Write("session");
int local_channel = this.RegisterChannelEventReceiver(null, receiver)._localID;
wr.Write(local_channel);
wr.Write(_param.WindowSize); //initial window size
int windowsize = _param.WindowSize;
wr.Write(_param.MaxPacketSize); //max packet size
SSH2Channel channel = new SSH2Channel(this, ChannelType.Shell, local_channel);
TransmitPacket(wr.ToByteArray());
return channel;
}
private AuthenticationResult UserAuth()
{
string sn = "ssh-connection";
SSH2DataWriter wr = new SSH2DataWriter();
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);
}
else if(_param.AuthenticationType==AuthenticationType.KeyboardInteractive) {
wr.Write(sn);
wr.Write("keyboard-interactive");
wr.Write(""); //lang
wr.Write(""); //submethod
}
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());
}
TransmitPacket(wr.ToByteArray());
_authenticationResult = ProcessAuthenticationResponse();
if(_authenticationResult==AuthenticationResult.Failure)
throw new SSHException(Strings.GetString("AuthenticationFailed"));
return _authenticationResult;
}
private void SendKEXINIT()
{
SSH2DataWriter wr = new SSH2DataWriter();
wr.WritePacketType(PacketType.SSH_MSG_KEXINIT);
byte[] cookie = new byte[16];
_param.Random.NextBytes(cookie);
wr.Write(cookie);
wr.Write("diffie-hellman-group1-sha1"); // 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("hmac-sha1"); // mac_algorithms_client_to_server
wr.Write("hmac-sha1"); // 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;
TransmitPacket(_clientKEXINITPayload);
}
public static SSH2Packet FromDecryptedHead(byte[] head, byte[] buffer, int offset, Cipher cipher, int sequence, MAC mac)
{
SSH2Packet p = new SSH2Packet();
p._packetLength = SSHUtil.ReadInt32(head, 0);
if(p._packetLength<=0 || p._packetLength>=MAX_PACKET_LENGTH) throw new SSHException(String.Format("packet size {0} is invalid", p._packetLength));
SSH2DataWriter buf = new SSH2DataWriter();
buf.Write(sequence);
buf.Write(head);
if(p._packetLength > (cipher.BlockSize - 4)) {
byte[] tmp = new byte[p._packetLength-(cipher.BlockSize - 4)];
cipher.Decrypt(buffer, offset, tmp.Length, tmp, 0);
offset += tmp.Length;
buf.Write(tmp);
}
byte[] result = buf.ToByteArray();
int padding_len = (int)result[8];
if(padding_len<4) throw new SSHException("padding length is invalid");
byte[] payload = new byte[result.Length-9-padding_len];
Array.Copy(result, 9, payload, 0, payload.Length);
p._payload = payload;
if(mac!=null) {
p._mac = mac.Calc(result);
if(SSHUtil.memcmp(p._mac, 0, buffer, offset, mac.Size)!=0)
throw new SSHException("MAC Error");
}
return p;
}
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");
}
//maybe this is SSH2 only feature
public void SetEnvironmentVariable(string name, string value)
{
SSH2DataWriter wr = new SSH2DataWriter();
wr.WritePacketType(PacketType.SSH_MSG_CHANNEL_REQUEST);
wr.Write(_remoteID);
wr.Write("env");
wr.Write(false);
wr.Write(name);
wr.Write(value);
TransmitPacket(wr.ToByteArray());
}
public override void Transmit(byte[] data)
{
//!!it is better idea that we wait a WINDOW_ADJUST if the left size is lack
SSH2DataWriter wr = new SSH2DataWriter();
wr.WritePacketType(PacketType.SSH_MSG_CHANNEL_DATA);
wr.Write(_remoteID);
wr.WriteAsString(data);
TransmitPacket(wr.ToByteArray());
}
public override void Transmit(byte[] data, int offset, int length)
{
SSH2DataWriter wr = new SSH2DataWriter();
wr.WritePacketType(PacketType.SSH_MSG_CHANNEL_DATA);
wr.Write(_remoteID);
wr.WriteAsString(data, offset, length);
TransmitPacket(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
}
}
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);
}