public void GetHeader(out NetHeader header)
{
header.code = buffer[0];
header.length = (ushort)(buffer[1] + (buffer[2] << 8));
header.randKey = buffer[3];
header.checkSum = buffer[4];
}
public bool Decryption(NetHeader header)
{
if (header.code != Protocol.PACKET_CODE)
{
MessageBox.Show("복호화 에러: 패킷 코드 에러");
return(false);
}
int offset = Protocol.SizeOfNetHeader;
int packetSize = UseSize;
byte randKey = header.randKey;
byte temp1;
byte temp2;
temp1 = (byte)(header.checkSum ^ (FIXED_KEY + 1));
temp2 = temp1;
byte decodeCheckSum = (byte)(temp1 ^ (byte)(randKey + 1));
byte checkSum = 0;
byte predata;
temp1 = (byte)(buffer[offset] ^ (byte)(FIXED_KEY + 2 + header.checkSum));
predata = buffer[offset];
buffer[offset] = (byte)(temp1 ^ (byte)(temp2 + randKey + 2));
temp2 = temp1;
checkSum += buffer[offset];
for (int i = 1; i < packetSize; i++)
{
temp1 = (byte)(buffer[offset + i] ^ (byte)(FIXED_KEY + (i + 2) + predata));
predata = buffer[offset + i];
buffer[offset + i] = (byte)(temp1 ^ (byte)(temp2 + randKey + (i + 2)));
temp2 = temp1;
checkSum += buffer[offset + i];
}
if (checkSum != decodeCheckSum)
{
MessageBox.Show("복호화 에러: 체크섬 에러 / checkSum :" + checkSum + "/ decode : " + decodeCheckSum);
return(false);
}
return(true);
}
