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");
}
private bool ProcessPacket(SSH2Packet packet)
{
SSH2DataReader r = new SSH2DataReader(packet.Data);
PacketType pt = r.ReadPacketType();
//Debug.WriteLine("ProcessPacket pt="+pt);
if(pt==PacketType.SSH_MSG_DISCONNECT) {
int errorcode = r.ReadInt32();
//string description = Encoding.ASCII.GetString(r.ReadString());
_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) {
ProcessPortforwardingRequest(_eventReceiver, r);
return true;
}
else if(pt>=PacketType.SSH_MSG_CHANNEL_OPEN_CONFIRMATION && pt<=PacketType.SSH_MSG_CHANNEL_FAILURE) {
int local_channel = r.ReadInt32();
ChannelEntry e = FindChannelEntry(local_channel);
if(e!=null) //throw new SSHException("Unknown channel "+local_channel);
((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 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());
}
//synchronous reception
internal SSH2Packet ReceivePacket()
{
while(true) {
SSH2Packet p = null;
SynchronizedSSH2PacketHandler handler = (SynchronizedSSH2PacketHandler)_packetBuilder.Handler;
if(!handler.HasPacket) {
handler.Wait();
if(handler.State==ReceiverState.Error)
throw new SSHException(handler.ErrorMessage);
else if(handler.State==ReceiverState.Closed)
throw new SSHException("socket closed");
}
p = handler.PopPacket();
SSH2DataReader r = new SSH2DataReader(p.Data);
PacketType pt = r.ReadPacketType();
if(pt==PacketType.SSH_MSG_IGNORE) {
if(_eventReceiver!=null) _eventReceiver.OnIgnoreMessage(r.ReadString());
}
else if(pt==PacketType.SSH_MSG_DEBUG) {
bool f = r.ReadBool();
if(_eventReceiver!=null) _eventReceiver.OnDebugMessage(f, r.ReadString());
}
else
return p;
}
}
private AuthenticationResult ProcessAuthenticationResponse()
{
do {
SSH2DataReader response = new SSH2DataReader(ReceivePacket().Data);
PacketType h = response.ReadPacketType();
if(h==PacketType.SSH_MSG_USERAUTH_FAILURE) {
string msg = Encoding.ASCII.GetString(response.ReadString());
return AuthenticationResult.Failure;
}
else if(h==PacketType.SSH_MSG_USERAUTH_BANNER) {
Debug.WriteLine("USERAUTH_BANNER");
}
else if(h==PacketType.SSH_MSG_USERAUTH_SUCCESS) {
_packetBuilder.Handler = 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);
return AuthenticationResult.Prompt;
}
else
throw new SSHException("protocol error: unexpected packet type "+h);
} while(true);
}
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 void ReceivePortForwardingResponse(ISSHChannelEventReceiver receiver, PacketType pt, SSH2DataReader reader)
{
if(_negotiationStatus==1) {
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();
_negotiationStatus = 0;
receiver.OnChannelReady();
}
}
else
Debug.Assert(false);
}
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;
}
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 ProcessKEXINIT(SSH2Packet packet)
{
_serverKEXINITPayload = packet.Data;
SSH2DataReader re = new SSH2DataReader(_serverKEXINITPayload);
byte[] head = re.Read(17); //Type and cookie
if(head[0]!=(byte)PacketType.SSH_MSG_KEXINIT) throw new SSHException(String.Format("Server response is not SSH_MSG_KEXINIT but {0}", head[0]));
Encoding enc = Encoding.ASCII;
string kex = enc.GetString(re.ReadString());
_cInfo._supportedKEXAlgorithms = kex;
CheckAlgorithmSupport("keyexchange", kex, "diffie-hellman-group1-sha1");
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(flag) throw new SSHException("Algorithm negotiation failed");
}
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;
}
/*
* 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)
*/
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");
}
l = r.ReadLine();
StringBuilder buf = new StringBuilder();
while (l != "---- END SSH2 ENCRYPTED PRIVATE KEY ----")
{
if (l.IndexOf(':') == -1)
{
buf.Append(l);
}
else
{
while (l.EndsWith("\\"))
{
l = r.ReadLine();
}
}
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));
/*
* FileStream fs = new FileStream("C:\\IOPort\\keydata1.bin", FileMode.Create);
* fs.Write(keydata, 0, keydata.Length);
* fs.Close();
*/
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)));
}
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)));
}
else
{
throw new SSHException("unknown authentication method " + type);
}
}
/*
* 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)
*/
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");
l = r.ReadLine();
StringBuilder buf = new StringBuilder();
while(l!="---- END SSH2 ENCRYPTED PRIVATE KEY ----") {
if(l.IndexOf(':')==-1)
buf.Append(l);
else {
while(l.EndsWith("\\")) l = r.ReadLine();
}
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));
/*
FileStream fs = new FileStream("C:\\IOPort\\keydata1.bin", FileMode.Create);
fs.Write(keydata, 0, keydata.Length);
fs.Close();
*/
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));
}
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));
}
else
throw new SSHException("unknown authentication method "+type);
}
public static SSH2UserAuthKey FromByteArray(byte[] keydata, string passphrase)
{
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)));
}
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)));
}
else
{
throw new SSHException("unknown authentication method " + type);
}
}