/// <summary>
/// Send a message to the remote side of the connection.
/// </summary>
/// <param name="packet"></param>
/// <param name="returnPayload">Return the unecrypted payload of this packet.</param>
public byte[] SendMessage(SSHPacket packet, bool returnPayload)
{
byte[] payload = null;
lock (this)
{
if (currentState == TransportProtocolState.PERFORMING_KEYEXCHANGE &&
!IsTransportMessage(packet.MessageID))
{
lock (kexqueue)
{
kexqueue.Add(packet);
return(payload);
}
}
try
{
int padding = 4;
// Compress the payload if necersary
/*if (outgoingCompression != null)
* {
* msgdata = outgoingCompression.compress(msgdata, 0, msgdata.Length);
* }*/
// Determine the padding length
padding += ((outgoingCipherLength - ((packet.Length + padding) % outgoingCipherLength)) % outgoingCipherLength);
packet.MoveToPosition(0);
// Write the packet length field
packet.WriteUINT32(packet.Length - 4 + padding);
// Write the padding length
packet.WriteByte((byte)padding);
// Now skip back up to the end of the packet
packet.MoveToEnd();
if (returnPayload)
{
payload = packet.Payload;
}
// Create some random data for the padding
byte[] pad = new byte[padding];
rnd.GetBytes(pad);
packet.WriteBytes(pad);
// Generate the MAC
if (outgoingMac != null)
{
outgoingMac.Generate(outgoingSequence, packet.Array, 0, packet.Length, packet.Array, packet.Length);
}
// Perfrom encrpytion
if (encryption != null)
{
encryption.Transform(packet.Array, 0, packet.Array, 0, packet.Length);
}
packet.Skip(outgoingMacLength);
outgoingBytes += packet.Length;
// Send!
packet.WriteToStream(transport.GetStream());
outgoingSequence++;
numOutgoingBytesSinceKEX += (uint)packet.Length;
numOutgoingSSHPacketsSinceKEX++;
ReleaseSSHPacket(packet);
if (outgoingSequence > 4294967295)
{
outgoingSequence = 0;
}
if (numOutgoingBytesSinceKEX >= MAX_NUM_BYTES_BEFORE_REKEY ||
numOutgoingSSHPacketsSinceKEX >= MAX_NUM_PACKETS_BEFORE_REKEY)
{
SendKeyExchangeInit();
}
}
catch (System.IO.IOException ex)
{
InternalDisconnect();
throw new SSHException("Unexpected termination: " + ex.Message, SSHException.UNEXPECTED_TERMINATION);
}
catch (System.ObjectDisposedException ex)
{
InternalDisconnect();
throw new SSHException("Unexpected terminaton: " + ex.Message,
SSHException.UNEXPECTED_TERMINATION);
}
}
return(payload);
}
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);
}
}
}
