// Transfers raw incoming data into the security object. Call TransferIncoming to
// obtain a list of ready to process packets.
public void Recv(TransferBuffer raw_buffer)
{
List<TransferBuffer> incoming_buffers_tmp = new List<TransferBuffer>();
lock (m_class_lock)
{
int length = raw_buffer.Size - raw_buffer.Offset;
int index = 0;
while (length > 0)
{
int max_length = length;
int calc_length = m_recv_buffer.Buffer.Length - m_recv_buffer.Size;
if (max_length > calc_length)
{
max_length = calc_length;
}
length -= max_length;
Buffer.BlockCopy(raw_buffer.Buffer, raw_buffer.Offset + index, m_recv_buffer.Buffer, m_recv_buffer.Size, max_length);
m_recv_buffer.Size += max_length;
index += max_length;
// Loop while we have data to process
while (m_recv_buffer.Size > 0)
{
// If we do not have a current packet object, try to allocate one.
if (m_current_buffer == null)
{
// We need at least two bytes to allocate a packet.
if (m_recv_buffer.Size < 2)
{
break;
}
// Calculate the packet size.
int packet_size = m_recv_buffer.Buffer[1] << 8 | m_recv_buffer.Buffer[0];
// Check to see if this packet is encrypted.
if ((packet_size & 0x8000) > 0)
{
// If so, calculate the total payload size.
packet_size &= 0x7FFF; // Mask off the encryption.
if (m_security_flags.blowfish == 1)
{
packet_size = 2 + m_blowfish.GetOutputLength(packet_size + 4);
}
else
{
packet_size += 6;
}
}
else
{
// The packet is unencrypted. The final size is simply
// header size + payload size.
packet_size += 6;
}
// Allocate the final buffer the packet will be written to
m_current_buffer = new TransferBuffer(packet_size, 0, packet_size);
}
// Calculate how many bytes are left to receive in the packet.
int max_copy_count = m_current_buffer.Size - m_current_buffer.Offset;
// If we need more bytes than we currently have, update the size.
if (max_copy_count > m_recv_buffer.Size)
{
max_copy_count = m_recv_buffer.Size;
}
// Copy the buffer data to the packet buffer
Buffer.BlockCopy(m_recv_buffer.Buffer, 0, m_current_buffer.Buffer, m_current_buffer.Offset, max_copy_count);
// Update how many bytes we now have
m_current_buffer.Offset += max_copy_count;
m_recv_buffer.Size -= max_copy_count;
// If there is data remaining in the buffer, copy it over the data
// we just removed (sliding buffer).
if (m_recv_buffer.Size > 0)
{
Buffer.BlockCopy(m_recv_buffer.Buffer, max_copy_count, m_recv_buffer.Buffer, 0, m_recv_buffer.Size);
}
// Check to see if the current packet is now complete.
if (m_current_buffer.Size == m_current_buffer.Offset)
{
// If so, dispatch it to the manager class for processing by the system.
m_current_buffer.Offset = 0;
incoming_buffers_tmp.Add(m_current_buffer);
// Set the current packet to null so we can process the next packet
// in the stream.
m_current_buffer = null;
}
else
{
// Otherwise, we are done with this loop, since we need more
// data for the current packet.
break;
}
}
}
if (incoming_buffers_tmp.Count > 0)
{
foreach (TransferBuffer buffer in incoming_buffers_tmp)
{
PacketReader packet_data = null;
try
{
bool packet_encrypted = false;
int packet_size = buffer.Buffer[1] << 8 | buffer.Buffer[0];
if ((packet_size & 0x8000) > 0)
{
if (m_security_flags.blowfish == 1)
{
packet_size &= 0x7FFF;
packet_encrypted = true;
}
else
{
packet_size &= 0x7FFF;
}
}
if (packet_encrypted)
{
byte[] decrypted = m_blowfish.Decode(buffer.Buffer, 2, buffer.Size - 2);
byte[] new_buffer = new byte[6 + packet_size];
Buffer.BlockCopy(BitConverter.GetBytes((ushort)packet_size), 0, new_buffer, 0, 2);
Buffer.BlockCopy(decrypted, 0, new_buffer, 2, 4 + packet_size);
buffer.Buffer = null;
buffer.Buffer = new_buffer;
}
packet_data = new PacketReader(buffer.Buffer);
packet_size = packet_data.ReadUInt16();
ushort packet_opcode = packet_data.ReadUInt16();
byte packet_security_count = packet_data.ReadByte();
byte packet_security_crc = packet_data.ReadByte();
// Client object whose bytes the server might need to verify
if (m_client_security)
{
if (m_security_flags.security_bytes == 1)
{
byte expected_count = GenerateCountByte(true);
if (packet_security_count != expected_count)
{
throw (new Exception("[SecurityAPI::Recv] Count byte mismatch."));
}
if (packet_encrypted || (m_security_flags.security_bytes == 1 && m_security_flags.blowfish == 0))
{
if (packet_encrypted || m_enc_opcodes.Contains(packet_opcode))
{
packet_size |= 0x8000;
Buffer.BlockCopy(BitConverter.GetBytes((ushort)packet_size), 0, buffer.Buffer, 0, 2);
}
}
buffer.Buffer[5] = 0;
byte expected_crc = GenerateCheckByte(buffer.Buffer);
if (packet_security_crc != expected_crc)
{
throw (new Exception("[SecurityAPI::Recv] CRC byte mismatch."));
}
buffer.Buffer[4] = 0;
if (packet_encrypted || (m_security_flags.security_bytes == 1 && m_security_flags.blowfish == 0))
{
if (packet_encrypted || m_enc_opcodes.Contains(packet_opcode))
{
packet_size &= 0x7FFF;
Buffer.BlockCopy(BitConverter.GetBytes((ushort)packet_size), 0, buffer.Buffer, 0, 2);
}
}
}
}
if (packet_opcode == 0x5000 || packet_opcode == 0x9000) // New logic processing!
{
Handshake(packet_opcode, packet_data, packet_encrypted);
// Pass the handshake packets to the user so they can at least see them.
// They do not need to actually do anything with them. This was added to
// help debugging and make output logs complete.
//CA2000 dont care
Packet packet = new Packet(packet_opcode, packet_encrypted, false, buffer.Buffer, 6, packet_size);
packet.Lock();
m_incoming_packets.Add(packet);
}
else
{
if (m_client_security)
{
// Make sure the client accepted the security system first
if (!m_accepted_handshake)
{
throw (new Exception("[SecurityAPI::Recv] The client has not accepted the handshake."));
}
}
if (packet_opcode == 0x600D) // Auto process massive messages for the user
{
byte mode = packet_data.ReadByte();
if (mode == 1)
{
m_massive_count = packet_data.ReadUInt16();
ushort contained_packet_opcode = packet_data.ReadUInt16();
m_massive_packet = new Packet(contained_packet_opcode, packet_encrypted, true);
}
else
{
if (m_massive_packet == null)
{
throw (new Exception("[SecurityAPI::Recv] A malformed 0x600D packet was received."));
}
m_massive_packet.WriteUInt8Array(packet_data.ReadBytes(packet_size - 1));
m_massive_count--;
if (m_massive_count == 0)
{
m_massive_packet.Lock();
m_incoming_packets.Add(m_massive_packet);
m_massive_packet = null;
}
}
}
else
{
//CA2000 dont care
Packet packet = new Packet(packet_opcode, packet_encrypted, false, buffer.Buffer, 6, packet_size);
packet.Lock();
m_incoming_packets.Add(packet);
}
}
}
finally
{
if (packet_data != null)
{
packet_data.Close();
}
}
}
}
}
}
