//Progress the state of this channel establishment negotiation
private void ProgressChannelNegotiation(ISSHChannelEventReceiver receiver, PacketType pt, SSH2DataReader re) {
if (_type == ChannelType.Shell)
OpenShellOrSubsystem(receiver, pt, re, "shell");
else if (_type == ChannelType.ForwardedLocalToRemote)
ReceivePortForwardingResponse(receiver, pt, re);
else if (_type == ChannelType.Session)
EstablishSession(receiver, pt, re);
else if (_type == ChannelType.ExecCommand) // for SCP
ExecCommand(receiver, pt, re);
else if (_type == ChannelType.Subsystem)
OpenShellOrSubsystem(receiver, pt, re, "subsystem");
}
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;
}
}
internal void ProcessPacket(ISSHChannelEventReceiver receiver, PacketType pt, int data_length, SSH2DataReader re) {
//NOTE: the offset of 're' is next to 'receipiant channel' field
AdjustWindowSize(pt, data_length);
//SSH_MSG_CHANNEL_WINDOW_ADJUST comes before the complete of channel establishment
if (pt == PacketType.SSH_MSG_CHANNEL_WINDOW_ADJUST) {
int w = re.ReadInt32();
//some servers may not send SSH_MSG_CHANNEL_WINDOW_ADJUST.
//it is dangerous to wait this message in send procedure
_allowedDataSize += w;
if (_connection.IsEventTracerAvailable)
_connection.TraceReceptionEvent("SSH_MSG_CHANNEL_WINDOW_ADJUST", "adjusted to {0} by increasing {1}", _allowedDataSize, w);
return;
}
// check closing sequence
if (_waitingChannelClose && pt == PacketType.SSH_MSG_CHANNEL_CLOSE) {
_waitingChannelClose = false;
return; // ignore it
}
if (_negotiationStatus != NegotiationStatus.Ready) //when the negotiation is not completed
ProgressChannelNegotiation(receiver, pt, re);
else
ProcessChannelLocalData(receiver, pt, re);
}
/// <summary>
/// Read SSH.com SSH2 private key parameters.
/// </summary>
/// <param name="passphrase">passphrase for decrypt the key file</param>
/// <param name="keyPair">key pair</param>
/// <param name="comment">comment or empty if it didn't exist</param>
/// <exception cref="SSHException">failed to parse</exception>
public void Load(SecureString passphrase, out KeyPair keyPair, out string comment) {
if (keyFile == null)
throw new SSHException("A key file is not loaded yet");
string base64Text;
using (StreamReader sreader = GetStreamReader()) {
var line = sreader.ReadLine();
if (line == null || line != PrivateKeyFileHeader.SSH2_SSHCOM_HEADER)
throw new SSHException(Strings.GetString("NotValidPrivateKeyFile") + " (missing header)");
var buf = new StringBuilder();
comment = string.Empty;
while (true) {
line = sreader.ReadLine();
if (line == null)
throw new SSHException(Strings.GetString("NotValidPrivateKeyFile") + " (unexpected eof)");
if (line == PrivateKeyFileHeader.SSH2_SSHCOM_FOOTER)
break;
if (line.IndexOf(':') >= 0) {
if (line.StartsWith("Comment: "))
comment = line.Substring("Comment: ".Length);
}
else if (line[line.Length - 1] == '\\')
buf.Append(line, 0, line.Length - 1);
else
buf.Append(line);
}
base64Text = buf.ToString();
}
var keydata = Base64.Decode(Encoding.ASCII.GetBytes(base64Text));
//Debug.WriteLine(DebugUtil.DumpByteArray(keydata));
var reader = new SSH2DataReader(keydata);
int magic = reader.ReadInt32();
if (magic != MAGIC)
throw new SSHException(Strings.GetString("NotValidPrivateKeyFile") + " (magic code unmatched)");
int privateKeyLen = reader.ReadInt32();
string type = Encoding.ASCII.GetString(reader.ReadString());
string ciphername = Encoding.ASCII.GetString(reader.ReadString());
int bufLen = reader.ReadInt32();
if (ciphername != "none") {
var algo = CipherFactory.SSH2NameToAlgorithm(ciphername);
var key = SSH2UserAuthKey.PassphraseToKey(passphrase, CipherFactory.GetKeySize(algo));
var c = CipherFactory.CreateCipher(SSHProtocol.SSH2, algo, key);
var tmp = new Byte[reader.Image.Length - reader.Offset];
c.Decrypt(reader.Image, reader.Offset, reader.Image.Length - reader.Offset, tmp, 0);
reader = new SSH2DataReader(tmp);
}
int parmLen = reader.ReadInt32();
if (parmLen < 0 || parmLen > reader.Rest)
throw new SSHException(Strings.GetString("WrongPassphrase"));
if (type.IndexOf("if-modn") != -1) {
//mindterm mistaken this order of BigIntegers
BigInteger e = reader.ReadBigIntWithBits();
BigInteger d = reader.ReadBigIntWithBits();
BigInteger n = reader.ReadBigIntWithBits();
BigInteger u = reader.ReadBigIntWithBits();
BigInteger p = reader.ReadBigIntWithBits();
BigInteger q = reader.ReadBigIntWithBits();
keyPair = new RSAKeyPair(e, d, n, u, p, q);
}
else if (type.IndexOf("dl-modp") != -1) {
if (reader.ReadInt32() != 0)
throw new SSHException(Strings.GetString("UnsupportedPrivateKeyFormat")
+ " (" + Strings.GetString("Reason_UnsupportedDSAKeyFormat") + ")");
BigInteger p = reader.ReadBigIntWithBits();
BigInteger g = reader.ReadBigIntWithBits();
BigInteger q = reader.ReadBigIntWithBits();
BigInteger y = reader.ReadBigIntWithBits();
BigInteger x = reader.ReadBigIntWithBits();
keyPair = new DSAKeyPair(p, g, q, y, x);
}
else
throw new SSHException(Strings.GetString("UnsupportedAuthenticationMethod"));
}
//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 void ServiceRequest(string servicename) {
SSH2TransmissionPacket packet = OpenPacket();
SSH2DataWriter wr = packet.DataWriter;
wr.WritePacketType(PacketType.SSH_MSG_SERVICE_REQUEST);
wr.WriteString(servicename);
TraceTransmissionEvent("SSH_MSG_SERVICE_REQUEST", servicename);
TransmitPacket(packet);
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 void SendSign(SSH2DataReader r) {
byte[] blob = r.ReadString();
byte[] data = r.ReadString();
//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);
}
}
private void VerifyHostKeyByRSA(SSH2DataReader pubkey, byte[] sigbody, byte[] hash) {
BigInteger exp = pubkey.ReadMPInt();
BigInteger mod = pubkey.ReadMPInt();
Debug.Assert(pubkey.Rest == 0);
RSAPublicKey pk = new RSAPublicKey(exp, mod);
pk.VerifyWithSHA1(sigbody, new SHA1CryptoServiceProvider().ComputeHash(hash));
_cInfo._hostkey = pk;
}
private void VerifyHostKeyByDSS(SSH2DataReader pubkey, byte[] sigbody, byte[] hash) {
BigInteger p = pubkey.ReadMPInt();
BigInteger q = pubkey.ReadMPInt();
BigInteger g = pubkey.ReadMPInt();
BigInteger y = pubkey.ReadMPInt();
Debug.Assert(pubkey.Rest == 0);
DSAPublicKey pk = new DSAPublicKey(p, g, q, y);
pk.Verify(sigbody, new SHA1CryptoServiceProvider().ComputeHash(hash));
_cInfo._hostkey = pk;
}
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, GetDiffieHellmanPrime(_cInfo._kexAlgorithm));
wr = new SSH2DataWriter();
wr.WriteString(_cInfo._clientVersionString);
wr.WriteString(_cInfo._serverVersionString);
wr.WriteAsString(_clientKEXINITPayload);
wr.WriteAsString(_serverKEXINITPayload);
wr.WriteAsString(key_and_cert);
wr.WriteBigInteger(_e);
wr.WriteBigInteger(f);
wr.WriteBigInteger(_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 bool VerifyHostKey(byte[] K_S, byte[] signature, byte[] hash) {
SSH2DataReader re1 = new SSH2DataReader(K_S);
string algorithm = Encoding.ASCII.GetString(re1.ReadString());
if (algorithm != SSH2Util.PublicKeyAlgorithmName(_cInfo._algorithmForHostKeyVerification))
throw new SSHException("Protocol Error: Host Key Algorithm Mismatch");
SSH2DataReader re2 = new SSH2DataReader(signature);
algorithm = Encoding.ASCII.GetString(re2.ReadString());
if (algorithm != SSH2Util.PublicKeyAlgorithmName(_cInfo._algorithmForHostKeyVerification))
throw new SSHException("Protocol Error: Host Key Algorithm Mismatch");
byte[] sigbody = re2.ReadString();
Debug.Assert(re2.Rest == 0);
if (_cInfo._algorithmForHostKeyVerification == PublicKeyAlgorithm.RSA)
VerifyHostKeyByRSA(re1, sigbody, hash);
else if (_cInfo._algorithmForHostKeyVerification == PublicKeyAlgorithm.DSA)
VerifyHostKeyByDSS(re1, sigbody, hash);
else
throw new SSHException("Bad host key algorithm " + _cInfo._algorithmForHostKeyVerification);
//ask the client whether he accepts the host key
if (!_startedByHost && _param.KeyCheck != null && !_param.KeyCheck(_cInfo))
return false;
else
return true;
}
private void ProcessKEXINIT(DataFragment packet) {
SSH2DataReader re = null;
do {
_serverKEXINITPayload = packet.ToNewArray();
re = new SSH2DataReader(_serverKEXINITPayload);
byte[] head = re.Read(17); //Type and cookie
PacketType pt = (PacketType)head[0];
if (pt == PacketType.SSH_MSG_KEXINIT)
break; //successfully exit
else if (pt == PacketType.SSH_MSG_IGNORE || pt == PacketType.SSH_MSG_DEBUG) { //continue
packet = _connection.ReceivePacket();
}
else
throw new SSHException(String.Format("Server response is not SSH_MSG_KEXINIT but {0}", head[0]));
} while (true);
Encoding enc = Encoding.ASCII;
string kex = enc.GetString(re.ReadString());
_cInfo._supportedKEXAlgorithms = kex;
_cInfo._kexAlgorithm = DecideKexAlgorithm(kex);
string host_key = enc.GetString(re.ReadString());
_cInfo._supportedHostKeyAlgorithms = host_key;
_cInfo._algorithmForHostKeyVerification = DecideHostKeyAlgorithm(host_key);
string enc_cs = enc.GetString(re.ReadString());
_cInfo._supportedCipherAlgorithms = enc_cs;
_cInfo._algorithmForTransmittion = DecideCipherAlgorithm(enc_cs);
string enc_sc = enc.GetString(re.ReadString());
_cInfo._algorithmForReception = DecideCipherAlgorithm(enc_sc);
string mac_cs = enc.GetString(re.ReadString());
CheckAlgorithmSupport("mac", mac_cs, "hmac-sha1");
string mac_sc = enc.GetString(re.ReadString());
CheckAlgorithmSupport("mac", mac_sc, "hmac-sha1");
string comp_cs = enc.GetString(re.ReadString());
CheckAlgorithmSupport("compression", comp_cs, "none");
string comp_sc = enc.GetString(re.ReadString());
CheckAlgorithmSupport("compression", comp_sc, "none");
string lang_cs = enc.GetString(re.ReadString());
string lang_sc = enc.GetString(re.ReadString());
bool flag = re.ReadBool();
int reserved = re.ReadInt32();
Debug.Assert(re.Rest == 0);
if (_connection.IsEventTracerAvailable) {
StringBuilder bld = new StringBuilder();
bld.Append("kex_algorithm=");
bld.Append(kex);
bld.Append("; server_host_key_algorithms=");
bld.Append(host_key);
bld.Append("; encryption_algorithms_client_to_server=");
bld.Append(enc_cs);
bld.Append("; encryption_algorithms_server_to_client=");
bld.Append(enc_sc);
bld.Append("; mac_algorithms_client_to_server=");
bld.Append(mac_cs);
bld.Append("; mac_algorithms_server_to_client=");
bld.Append(mac_sc);
bld.Append("; comression_algorithms_client_to_server=");
bld.Append(comp_cs);
bld.Append("; comression_algorithms_server_to_client=");
bld.Append(comp_sc);
TraceReceptionNegotiation(PacketType.SSH_MSG_KEXINIT, bld.ToString());
}
if (flag)
throw new SSHException("Algorithm negotiation failed");
}
private void EstablishSession(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 remote_id = reader.ReadInt32();
int errcode = reader.ReadInt32();
string msg = Encoding.ASCII.GetString(reader.ReadString());
receiver.OnChannelError(new SSHException(msg));
}
Close();
}
else {
_remoteID = reader.ReadInt32();
_serverMaxPacketSize = reader.ReadInt32();
_negotiationStatus = NegotiationStatus.Ready;
receiver.OnChannelReady();
}
}
else
throw new SSHException("internal state error");
}
/// <summary>
/// Read PuTTY SSH2 private key parameters.
/// </summary>
/// <param name="passphrase">passphrase for decrypt the key file</param>
/// <param name="keyPair">key pair</param>
/// <param name="comment">comment or empty if it didn't exist</param>
public void Load(SecureString passphrase, out KeyPair keyPair, out string comment) {
if (keyFile == null)
throw new SSHException("A key file is not loaded yet");
int version;
string keyTypeName;
KeyType keyType;
string encryptionName;
CipherAlgorithm? encryption;
byte[] publicBlob;
byte[] privateBlob;
string privateMac;
string privateHash;
using (StreamReader sreader = GetStreamReader()) {
//*** Read header and key type
ReadHeaderLine(sreader, out version, out keyTypeName);
if (keyTypeName == "ssh-rsa")
keyType = KeyType.RSA;
else if (keyTypeName == "ssh-dss")
keyType = KeyType.DSA;
else
throw new SSHException(Strings.GetString("NotValidPrivateKeyFile") + " (unexpected key type)");
//*** Read encryption
ReadItemLine(sreader, "Encryption", out encryptionName);
if (encryptionName == "aes256-cbc")
encryption = CipherAlgorithm.AES256;
else if (encryptionName == "none")
encryption = null;
else
throw new SSHException(Strings.GetString("NotValidPrivateKeyFile") + " (unexpected encryption)");
//*** Read comment
ReadItemLine(sreader, "Comment", out comment);
//*** Read public lines
string publicLinesStr;
ReadItemLine(sreader, "Public-Lines", out publicLinesStr);
int publicLines;
if (!Int32.TryParse(publicLinesStr, out publicLines) || publicLines < 0)
throw new SSHException(Strings.GetString("NotValidPrivateKeyFile") + " (invalid public lines)");
ReadBlob(sreader, publicLines, out publicBlob);
//*** Read private lines
string privateLinesStr;
ReadItemLine(sreader, "Private-Lines", out privateLinesStr);
int privateLines;
if (!Int32.TryParse(privateLinesStr, out privateLines) || privateLines < 0)
throw new SSHException(Strings.GetString("NotValidPrivateKeyFile") + " (invalid private lines)");
ReadBlob(sreader, privateLines, out privateBlob);
//*** Read private MAC
ReadPrivateMACLine(sreader, version, out privateMac, out privateHash);
}
if (encryption.HasValue) {
byte[] key = PuTTYPassphraseToKey(passphrase);
byte[] iv = new byte[16];
Cipher cipher = CipherFactory.CreateCipher(SSHProtocol.SSH2, encryption.Value, key, iv);
if (privateBlob.Length % cipher.BlockSize != 0)
throw new SSHException(Strings.GetString("NotValidPrivateKeyFile") + " (invalid key data size)");
cipher.Decrypt(privateBlob, 0, privateBlob.Length, privateBlob, 0);
}
bool verified = Verify(version, privateMac, privateHash,
passphrase, keyTypeName, encryptionName, comment, publicBlob, privateBlob);
if (!verified) {
if (encryption.HasValue)
throw new SSHException(Strings.GetString("WrongPassphrase"));
else
throw new SSHException(Strings.GetString("NotValidPrivateKeyFile") + " (HMAC verification failed)");
}
if (keyType == KeyType.RSA) {
SSH2DataReader reader = new SSH2DataReader(publicBlob);
byte[] magic = reader.ReadString();
if (!ByteArrayUtil.AreEqual(magic, Encoding.ASCII.GetBytes("ssh-rsa")))
throw new SSHException(Strings.GetString("NotValidPrivateKeyFile") + " (missing magic)");
BigInteger e = reader.ReadMPInt();
BigInteger n = reader.ReadMPInt();
reader = new SSH2DataReader(privateBlob);
BigInteger d = reader.ReadMPInt();
BigInteger p = reader.ReadMPInt();
BigInteger q = reader.ReadMPInt();
BigInteger iqmp = reader.ReadMPInt();
BigInteger u = p.modInverse(q);
keyPair = new RSAKeyPair(e, d, n, u, p, q);
}
else if (keyType == KeyType.DSA) {
SSH2DataReader reader = new SSH2DataReader(publicBlob);
byte[] magic = reader.ReadString();
if (!ByteArrayUtil.AreEqual(magic, Encoding.ASCII.GetBytes("ssh-dss")))
throw new SSHException(Strings.GetString("NotValidPrivateKeyFile") + " (missing magic)");
BigInteger p = reader.ReadMPInt();
BigInteger q = reader.ReadMPInt();
BigInteger g = reader.ReadMPInt();
BigInteger y = reader.ReadMPInt();
reader = new SSH2DataReader(privateBlob);
BigInteger x = reader.ReadMPInt();
keyPair = new DSAKeyPair(p, g, q, y, x);
}
else {
throw new SSHException("Unknown file type. This should not happen.");
}
}
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 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);
}
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 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());
}
// 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 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());
}
public void OnData(byte[] data, int offset, int length) {
_buffer.Write(data, offset, length);
int expectedLength = SSHUtil.ReadInt32(_buffer.UnderlyingBuffer, 0);
if (expectedLength + 4 <= _buffer.Length) {
SSH2DataReader r = new SSH2DataReader(new DataFragment(_buffer.UnderlyingBuffer, 4, _buffer.Length - 4));
AgentForwadPacketType pt = (AgentForwadPacketType)r.ReadByte();
//remaining len-1
_buffer.SetOffset(0);
switch (pt) {
case AgentForwadPacketType.SSH2_AGENTC_REQUEST_IDENTITIES:
SendKeyList();
break;
case AgentForwadPacketType.SSH2_AGENTC_SIGN_REQUEST:
SendSign(r);
break;
default:
//Debug.WriteLine("Unknown agent packet " + pt.ToString());
TransmitWriter(OpenWriter(AgentForwadPacketType.SSH_AGENT_FAILURE));
break;
}
}
}
/*
* Format style note
* ---- BEGIN SSH2 ENCRYPTED PRIVATE KEY ----
* Comment: *******
* <base64-encoded body>
* ---- END SSH2 ENCRYPTED PRIVATE KEY ----
*
* body = MAGIC_VAL || body-length || type(string) || encryption-algorithm-name(string) || encrypted-body(string)
* encrypted-body = array of BigInteger(algorithm-specific)
*/
#if !PODEROSA_KEYFORMAT
public static SSH2UserAuthKey FromSECSHStyleStream(Stream strm, string passphrase)
{
StreamReader r = new StreamReader(strm, Encoding.ASCII);
string l = r.ReadLine();
if (l == null || l != "---- BEGIN SSH2 ENCRYPTED PRIVATE KEY ----")
throw new SSHException("Wrong key format (expected SSH2 ENCRYPTED PRIVATE KEY)");
string comment = "";
l = r.ReadLine();
StringBuilder buf = new StringBuilder();
while (l != "---- END SSH2 ENCRYPTED PRIVATE KEY ----")
{
if (l.IndexOf(':') == -1)
buf.Append(l);
else if (l[l.Length - 1] == '\\')
buf.Append(l, 0, l.Length - 1);
else if (l.StartsWith("Comment: "))
comment = l.Substring("Comment: ".Length);
l = r.ReadLine();
if (l == null)
throw new SSHException("Key is broken");
}
r.Close();
byte[] keydata = Base64.Decode(Encoding.ASCII.GetBytes(buf.ToString()));
//Debug.WriteLine(DebugUtil.DumpByteArray(keydata));
SSH2DataReader re = new SSH2DataReader(keydata);
int magic = re.ReadInt32();
/*if (magic != MAGIC_VAL)
throw new SSHException("key file is broken");*/
int privateKeyLen = re.ReadInt32();
string type = Encoding.ASCII.GetString(re.ReadString());
string ciphername = Encoding.ASCII.GetString(re.ReadString());
int bufLen = re.ReadInt32();
if (ciphername != "none") {
CipherAlgorithm algo = CipherFactory.SSH2NameToAlgorithm(ciphername);
byte[] key = PassphraseToKey(passphrase, CipherFactory.GetKeySize(algo));
Cipher c = CipherFactory.CreateCipher(SSHProtocol.SSH2, algo, key);
byte[] tmp = new Byte[re.Image.Length - re.Offset];
c.Decrypt(re.Image, re.Offset, re.Image.Length - re.Offset, tmp, 0);
re = new SSH2DataReader(tmp);
}
int parmLen = re.ReadInt32();
if (parmLen < 0 || parmLen > re.Rest)
throw new SSHException(Strings.GetString("WrongPassphrase"));
if (type.IndexOf("if-modn") != -1) {
//mindterm mistaken this order of BigIntegers
BigInteger e = re.ReadBigIntWithBits();
BigInteger d = re.ReadBigIntWithBits();
BigInteger n = re.ReadBigIntWithBits();
BigInteger u = re.ReadBigIntWithBits();
BigInteger p = re.ReadBigIntWithBits();
BigInteger q = re.ReadBigIntWithBits();
return new SSH2UserAuthKey(new RSAKeyPair(e, d, n, u, p, q), comment);
}
else if (type.IndexOf("dl-modp") != -1) {
if (re.ReadInt32() != 0)
throw new SSHException("DSS Private Key File is broken");
BigInteger p = re.ReadBigIntWithBits();
BigInteger g = re.ReadBigIntWithBits();
BigInteger q = re.ReadBigIntWithBits();
BigInteger y = re.ReadBigIntWithBits();
BigInteger x = re.ReadBigIntWithBits();
return new SSH2UserAuthKey(new DSAKeyPair(p, g, q, y, x), comment);
}
else
throw new SSHException("unknown authentication method " + type);
}