/// <summary>
/// Assembles the current outgoing packet from the given payload data, crypto session, auth session and partial header.
/// </summary>
/// <param name="payloadData">The raw payload data.</param>
/// <param name="crypto">The crypto session being used.</param>
/// <param name="auth">The auth session being used.</param>
/// <param name="partialHeader">The outer packet header, except for the 2 first bytes (packet size).</param>
/// <returns>The assembled packet, ready to be sent.</returns>
private static byte[] AssemblePacket(byte[] payloadData, CryptoSession crypto, AuthSession auth, byte[] partialHeader)
{
PayloadReader reader = new PayloadReader(payloadData, 6);
if (reader.ReadBool())
{
payloadData = PayloadCompression.Compress(payloadData);
}
FixSize(payloadData);
byte[] iv = Generate.IV();
byte[] encryptedData = crypto.EncryptPacket(payloadData, iv);
HeaderWriter headerWriter = new HeaderWriter();
headerWriter.WriteData((short)(16 + encryptedData.Length + 10));
headerWriter.WriteData(partialHeader);
headerWriter.WriteData(iv);
byte[] partialBuffer = Sequence.Concat(headerWriter.GetHeader(), encryptedData);
byte[] hmac = auth.GetHmac(partialBuffer);
return(Sequence.Concat(partialBuffer, hmac));
}
/// <summary>
/// Initializes a new instance of InPacket from the given packet buffer and crypto session.
/// </summary>
/// <param name="packetBuffer">The packet buffer the way it was received.</param>
/// <param name="crypto">The current crypto session.</param>
public InPacket(byte[] packetBuffer, CryptoSession crypto)
{
ParseHeader(packetBuffer);
PayloadData = ProcessData(packetBuffer, crypto);
PayloadReader reader = new PayloadReader(PayloadData);
Id = reader.ReadInt16();
}
/// <summary>
/// Processes the current packet data and returns the raw packet payload.
/// </summary>
/// <param name="packetBuffer">The packet buffer the way it was received.</param>
/// <param name="crypto">The current crypto session.</param>
/// <returns>The packet payload (decrypted and uncompressed).</returns>
private static byte[] ProcessData(byte[] packetBuffer, CryptoSession crypto)
{
byte[] data = crypto.DecryptPacket(packetBuffer);
PayloadReader reader = new PayloadReader(data, 6);
if (reader.ReadBool())
{
data = PayloadCompression.Decompress(data);
}
return(data);
}
