internal System.String GetRemoteIdentification(SSHTransport transport)
{
try
{
System.String remoteIdentification = "";
// Now wait for a reply and evaluate the ident string
System.Text.StringBuilder buffer;
Stream stream = transport.GetStream();
int MAX_BUFFER_LENGTH = 255;
// Look for a string starting with "SSH-"
while (!remoteIdentification.StartsWith("SSH-"))
{
// Get the next string
int ch;
buffer = new System.Text.StringBuilder(MAX_BUFFER_LENGTH);
while (((ch = stream.ReadByte()) != '\n') &&
(buffer.Length < MAX_BUFFER_LENGTH) &&
ch > -1)
{
buffer.Append((char)ch);
}
if (ch == -1)
{
throw new SSHException("Failed to read remote identification", SSHException.CONNECT_FAILED);
}
// Set trimming off any EOL characters
remoteIdentification = buffer.ToString().Trim();
}
return(remoteIdentification);
}
catch (System.Exception ex)
{
throw new SSHException(ex.Message, SSHException.CONNECT_FAILED);
}
}
internal SSHPacket ReadMessage()
{
lock (kexlock)
{
try
{
SSHPacket packet = GetSSHPacket(false);
packet.ReadFromStream(transport.GetStream(), incomingCipherLength);
// Mark the current position so we can read more data
packet.Mark();
packet.MoveToPosition(0);
// Decrypt the data if we have a valid cipher
if (decryption != null)
{
decryption.Transform(packet.Array, 0, packet.Array, 0, incomingCipherLength);
}
int msglen = (int)packet.ReadUINT32();
int padlen = packet.ReadByte();
int remaining = (msglen - (incomingCipherLength - 4));
// Verify that the packet length is good
if (remaining < 0)
{
InternalDisconnect();
throw new SSHException("EOF whilst reading message data block", SSHException.UNEXPECTED_TERMINATION);
}
else if (remaining > packet.Limit - packet.Length)
{
InternalDisconnect();
throw new SSHException("Incoming packet length violates SSH protocol",
SSHException.UNEXPECTED_TERMINATION);
}
// Read, decrypt and save the remaining data
packet.MoveToMark();
packet.ReadFromStream(transport.GetStream(), remaining);
if (decryption != null)
{
decryption.Transform(packet.Array, incomingCipherLength, packet.Array, incomingCipherLength, remaining);
}
// Tell the packet where the payload ends
//packet.PayloadLength = (int)msglen - padlen - 1;
if (incomingMac != null)
{
packet.ReadFromStream(transport.GetStream(), incomingMacLength);
// Verify the mac
if (!incomingMac.Verify(incomingSequence, packet.Array, 0, incomingCipherLength + remaining,
packet.Array, incomingCipherLength + remaining))
{
Disconnect("Corrupt Mac on input", DisconnectionReason.MAC_ERROR);
throw new SSHException("Corrupt Mac on input", SSHException.PROTOCOL_VIOLATION);
}
}
if (++incomingSequence > 4294967295)
{
incomingSequence = 0;
}
incomingBytes += incomingCipherLength + remaining + incomingMacLength;
// Uncompress the message payload if necersary
/*if (incomingCompression != null)
* {
* return incomingCompression.uncompress(payload, 0, payload.Length);
* }*/
numIncomingBytesSinceKEX += (uint)packet.Length;
numIncomingSSHPacketsSinceKEX++;
if (numIncomingBytesSinceKEX >= MAX_NUM_BYTES_BEFORE_REKEY ||
numIncomingSSHPacketsSinceKEX >= MAX_NUM_PACKETS_BEFORE_REKEY)
{
SendKeyExchangeInit();
}
// Get the packet ready for reading
packet.MoveToPosition(6);
return(packet);
}
catch (System.ObjectDisposedException ex)
{
InternalDisconnect();
throw new SSHException("Unexpected terminaton: " + ex.Message,
SSHException.UNEXPECTED_TERMINATION);
}
catch (System.IO.IOException ex)
{
InternalDisconnect();
throw new SSHException("Unexpected terminaton: "
+ (ex.Message != null? ex.Message:ex.GetType().FullName)
+ " sequenceNo = " + incomingSequence + " bytesIn = "
+ incomingBytes + " bytesOut = " + outgoingBytes,
SSHException.UNEXPECTED_TERMINATION);
}
}
}
/// <summary>
/// Create a new connection to an SSH server. This method takes a newly created <see cref="Maverick.SSH.SSHTransport"/>
/// instance and performs the initial protocol negotiation to determine which type of client to
/// create.
/// </summary>
/// <param name="transport">The transport layer to use</param>
/// <param name="username">The name of the user making the connection</param>
/// <param name="threaded">Should the client buffer input to ensure the smooth running of events. If you do not buffer input
/// and require the use of state or data events they may not operate correctly as the API will operate in single threaded
/// mode.</param>
/// <param name="context">The configuration context to use for the connection</param>
/// <param name="events">A delegate state listener for receiving state change events</param>
/// <returns></returns>
internal SSHClient Connect(SSHTransport transport,
System.String username, bool threaded, SSHContext context, SSHStateListener events)
{
System.String localIdentification;
System.String remoteIdentification = GetRemoteIdentification(transport);
// Lets try SSH2 first because its a better protocol
SSHClient client;
System.Exception lastError = null;
bool pointOfNoReturn = false;
Stream stream = transport.GetStream();
if ((ssh2Context != null || (context != null &&
context is SSH2Context)) &&
(supportedVersions & SSH2) != 0)
{
// Send our identification depending upon which versions we can support
if ((SelectVersion(remoteIdentification) & SSH2) != 0)
{
try
{
if (context == null)
{
context = ssh2Context;
}
client = (SSHClient) new SSH2Client();
localIdentification = "SSH-2.0-" + softwareComments + "\n";
pointOfNoReturn = true;
byte[] tempArray = SupportClass.ToByteArray(localIdentification);
stream.Write(tempArray, 0, tempArray.Length);
client.StateChange += events;
// Now get the client to connect using the selected protocol
client.Connect(transport,
context,
this,
username,
localIdentification.Trim(),
remoteIdentification,
threaded);
return(client);
}
catch (System.Exception t)
{
lastError = t;
}
finally
{
if (lastError != null && pointOfNoReturn)
{
if (lastError is SSHException)
{
throw (SSHException)lastError;
}
else
{
throw new SSHException(lastError.Message != null?lastError.Message:lastError.GetType().FullName, SSHException.CONNECT_FAILED);
}
}
}
}
}
try
{
transport.Close();
}
catch (System.IO.IOException)
{
}
if (lastError == null)
{
throw new SSHException("Failed to negotiate a version with the server! " + remoteIdentification, SSHException.CONNECT_FAILED);
}
else
{
if (lastError is SSHException)
{
throw (SSHException)lastError;
}
else
{
throw new SSHException(lastError.Message != null?lastError.Message:lastError.GetType().FullName, SSHException.CONNECT_FAILED);
}
}
}
