/// <summary>
/// Decrypts the packet data
/// </summary>
public void Decrypt(Span <byte> data)
{
if (!RecvCipher.Handshaken)
{
var pr = new BinaryReader(new MemoryStream(MapleCipher.Handshake(data).ToArray(), false),
Encoding.ASCII);
var version = pr.ReadInt16();
var subVersionLength = pr.ReadInt16();
var subVersion = new string(pr.ReadChars(subVersionLength));
var siv = pr.ReadUInt32();
var riv = pr.ReadUInt32();
var serverType = pr.ReadByte();
SendCipher.SetIv(siv);
RecvCipher.SetIv(riv);
HandshakeFinished?.Invoke(siv, riv, version, subVersion, serverType);
}
else
{
if (!RecvCipher.CheckHeader(data, !ToClient))
{
throw new InvalidOperationException($"Packet header mismatch Size:{data.Length}");
}
var decrypted = RecvCipher.Decrypt(data);
if (decrypted.Length == 0)
{
return;
}
PacketFinished?.Invoke(decrypted.ToArray());
}
}
/// <summary>
/// Add binary data to the buffer
/// </summary>
/// <param name="data">data buffer to add</param>
/// <param name="offset">data offset</param>
/// <param name="length">data length</param>
public void AddData(byte[] data, int offset, int length)
{
if (IsWaiting)
{
if (length < HeaderSize) // Packet error, not enough header byte
{
return;
}
PacketReader pr = new PacketReader(data);
int packetLength = pr.ReadInt(); // Get packet length
DataBuffer = new byte[packetLength + HeaderSize]; // Create new buffer with length = packetLength + HeaderSize
Buffer.BlockCopy(data, 0, DataBuffer, 0, length); // Copy data to general buffer
if (length < packetLength + HeaderSize) // If packet length including header size is smaller than actual size, wait for the remaining
{
WaitForData = packetLength + HeaderSize - length;
IsWaiting = false;
}
else // Finish processing packet
{
PacketFinished?.Invoke(DataBuffer); // Invoke Finish handler
}
}
else // Remaining received
{
Buffer.BlockCopy(data, 0, DataBuffer, DataBuffer.Length - WaitForData, length); // Add data in this buffer to general buffer
WaitForData -= length; // Decrease data amount to be waited
if (WaitForData <= 0) // Received all data
{
if (PacketFinished != null)
{
PacketFinished(DataBuffer);
}
IsWaiting = true; // Reset processor
}
}
}
