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 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!
}
}
}
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 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;
}
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;
}
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);
}
}
