public Packet RecvPacket(ICryptoTransform decryptor)
{
if (decryptor == null)
{
Packet packet = new Packet();
uint packet_length = reader.ReadUInt32();
byte padding_length = reader.ReadByte();
byte[] payload = reader.ReadBytes(packet_length - padding_length - 1);
byte[] padding = reader.ReadBytes(padding_length);
packet.SetPayload(payload);
return packet;
}
else
{
int blocksize = Math.Max(decryptor.InputBlockSize, 8);
MemoryStream ms_packet = new MemoryStream();
NetworkByteWriter writer_packet = new NetworkByteWriter(ms_packet);
byte[] buffer = new byte[blocksize];
bool first = true;
int more = 0;
while (true)
{
// read a block
int ret = reader.ReadBytes(buffer, 0, blocksize);
// must be a real block size;
if (ret != blocksize) return null;
decryptor.TransformBlock(buffer, 0, buffer.Length, buffer, 0);
writer_packet.WriteBytes(buffer);
if (first) // it's first time, need parse packet_length and padding_length
{
NetworkByteReader reader_buffer = new NetworkByteReader(new MemoryStream(buffer));
uint packet_length_t = reader_buffer.ReadUInt32();
first = false;
more = (int)packet_length_t + 4 - blocksize;
if (more % blocksize != 0) return null;
}
else
{
more -= blocksize;
}
if (more <= 0) break;
}
byte[] mac = reader.ReadBytes(20);
ms_packet.Seek(0, SeekOrigin.Begin);
NetworkByteReader reader_packet = new NetworkByteReader(ms_packet);
Packet packet = new Packet();
uint packet_length = reader_packet.ReadUInt32();
byte padding_length = reader_packet.ReadByte();
byte[] payload = reader_packet.ReadBytes(packet_length - padding_length - 1);
byte[] padding = reader_packet.ReadBytes(padding_length);
packet.SetPayload(payload);
return packet;
}
}
public void SendPacket(ICryptoTransform encryptor, Packet packet)
{
byte[] payload = packet.GetPayload();
int blocksize = 16;
if (encryptor == null)
{
uint size = (uint)payload.Length;
size += 5;
size = (uint)((size + blocksize) / blocksize * blocksize);
uint packet_length = size - 4;
byte padding_length = (byte)(size - 5 - payload.Length);
MemoryStream ms = new MemoryStream();
NetworkByteWriter nbw = new NetworkByteWriter(ms);
nbw.WriteUInt32(packet_length);
nbw.WriteByte(padding_length);
nbw.WriteBytes(payload);
for (int i = 0; i < padding_length; i++ ) nbw.WriteByte(0x0C);
nbw.Flush();
writer.WriteBytes(ms.ToArray());
writer.Flush();
}
else
{
blocksize = Math.Max(encryptor.InputBlockSize, blocksize);
uint size = (uint)payload.Length;
size += (5 + (uint)encryptor.InputBlockSize);
size = (uint)((size + blocksize) / blocksize * blocksize);
uint packet_length = size - 4;
byte padding_length = (byte)(size - 5 - payload.Length);
MemoryStream ms = new MemoryStream();
NetworkByteWriter nbw = new NetworkByteWriter(ms);
nbw.WriteUInt32(packet_length);
nbw.WriteByte(padding_length);
nbw.WriteBytes(payload);
for (int i = 0; i < padding_length; i++) nbw.WriteByte(0x0C);
nbw.Flush();
// compute mac
byte[] cache = ms.ToArray();
MemoryStream ms_mac = new MemoryStream();
NetworkByteWriter nbw_mac = new NetworkByteWriter(ms_mac);
nbw_mac.WriteUInt32((uint)sequence);
nbw_mac.WriteBytes(cache);
nbw_mac.Flush();
byte[] mac = crypto_mac_encryptor.ComputeHash(ms_mac.ToArray());
crypto_encryptor.TransformBlock(cache, 0, cache.Length, cache, 0);
writer.WriteBytes(cache);
writer.Flush();
if (crypto_mac_encryptor != null)
{
writer.WriteBytes(mac);
}
}
sequence++;
}
public void DumpError(Packet packet)
{
MemoryStream ms = new MemoryStream(packet.GetPayload());
NetworkByteReader nbr = new NetworkByteReader(ms);
nbr.ReadByte();
nbr.ReadUInt32();
string xxx = nbr.ReadString();
}
public PacketChannelData(Packet p)
: base(p)
{
}
public Packet(Packet p)
{
SetPayload(p.GetPayload());
}
public PacketKeyExchangeDHReply(Packet p)
: base(p)
{
}
public PacketKeyExchange(Packet p)
: base(p)
{
}
