private void AdvanceIV()
{
Iv = Rand32.CrtRand(Iv);
}
public MaplePacket Read(DateTime pTransmitted, bool bMaple2)
{
if (mCursor < _expectedDataSize)
{
return(null);
}
if (bMaple2)
{
mRawSeq = BitConverter.ToUInt16(mBuffer, 0);
if (mOutbound && DecodeSeqBase(IV) != Build || !mOutbound && DecodeSeqBase(Rand32.CrtRand(IV)) != Build)
{
throw new Exception("Failed to confirm packet header");
}
}
else
{
if (!mAES.ConfirmHeader(mBuffer, 0))
{
throw new Exception("Failed to confirm packet header");
}
}
int headerLength = bMaple2 ? 6 : MapleAES.GetHeaderLength(mBuffer, mCursor, _usesOldHeader);
_expectedDataSize = headerLength;
if (mCursor < headerLength)
{
return(null);
}
int packetSize = MapleAES.GetPacketLength(mBuffer, mCursor, _usesOldHeader, bMaple2);
_expectedDataSize = packetSize + headerLength;
if (mCursor < (packetSize + headerLength))
{
return(null);
}
byte[] packetBuffer = new byte[packetSize];
Buffer.BlockCopy(mBuffer, headerLength, packetBuffer, 0, packetSize);
uint preDecodeIV;
if (bMaple2)
{
preDecodeIV = IV;
mCrypt.Decrypt(packetBuffer, packetSize, BlockIV, IV);
ShiftIV();
}
else
{
preDecodeIV = BitConverter.ToUInt32(mAES.mIV, 0);
Decrypt(packetBuffer, _transformMethod);
}
var postDecodeIV = bMaple2 ? IV : BitConverter.ToUInt32(mAES.mIV, 0);
mCursor -= _expectedDataSize;
if (mCursor > 0)
{
Buffer.BlockCopy(mBuffer, _expectedDataSize, mBuffer, 0, mCursor);
}
ushort opcode;
if (_usesByteHeader)
{
opcode = (ushort)(packetBuffer[0]);
Buffer.BlockCopy(packetBuffer, 1, packetBuffer, 0, packetSize - 1);
Array.Resize(ref packetBuffer, packetSize - 1);
}
else
{
opcode = (ushort)(packetBuffer[0] | (packetBuffer[1] << 8));
Buffer.BlockCopy(packetBuffer, 2, packetBuffer, 0, packetSize - 2);
Array.Resize(ref packetBuffer, packetSize - 2);
}
_expectedDataSize = bMaple2 ? 6 : 4;
Definition definition = Config.Instance.GetDefinition(Build, Locale, mOutbound, opcode);
return(new MaplePacket(pTransmitted, mOutbound, Build, Locale, opcode, definition == null ? "" : definition.Name, packetBuffer, preDecodeIV, postDecodeIV));
}
