GetCRC32Checksum() публичный Метод

public GetCRC32Checksum ( byte packet ) : uint
packet byte
Результат uint
Пример #1
0
        public void HandlePacket(SOEClient sender, byte[] rawPacket)
        {
            // Read the packet
            SOEReader reader     = new SOEReader(rawPacket);
            ushort    opCode     = reader.ReadUInt16();
            bool      goodPacket = true;

            // Get the packet data
            byte[] data = new byte[rawPacket.Length - (int)sender.GetCRCLength()];
            for (int i = 0; i < data.Length; i++)
            {
                data[i] = rawPacket[i];
            }

            // Get the CRC32 checksum for the packet
            uint crc32 = sender.GetCRC32Checksum(data);

            // Get our expected CRC32 checksum
            uint expectedCRC32 = 0;

            uint place = sender.GetCRCLength() - 1;

            for (int i = rawPacket.Length - (int)sender.GetCRCLength(); i < rawPacket.Length; i++)
            {
                expectedCRC32 += (uint)(rawPacket[i] << (8 * (int)place));
                place--;
            }

            // We have our CRCs! Check if the packet is formed correctly!
            byte[] crc         = BitConverter.GetBytes(crc32).Reverse().ToArray();
            byte[] expectedCRC = BitConverter.GetBytes(expectedCRC32).Reverse().ToArray();

            int start = 4 - (int)sender.GetCRCLength();

            for (int i = start; i < sender.GetCRCLength(); i++)
            {
                // If they're not the same, we're a bad packet
                if (crc[i] != expectedCRC[i])
                {
                    // Set that we're bad, and get outta the loop
                    goodPacket = false;
                    break;
                }
            }

            // Are we malformed?
            if (!goodPacket)
            {
                Log("[WARNING] Received malformed packet! Incorrect CRC Appended!");
                return;
            }

            // Remove the CRC
            rawPacket = data;

            // Do we need to worry about decryption/decompression?
            if (sender.HasSession())
            {
                // Is the client encrypted?
                if (sender.IsEncrypted())
                {
                    rawPacket = DecryptPacket(sender, rawPacket);
                }

                // Is the client compressable?
                if (sender.IsCompressable())
                {
                    // It seems that all packets after 0x02 are compressable..
                    rawPacket = DecompressPacket(sender, rawPacket);
                }
            }

            // Handle the decompressed/decrypted packet!
            HandlePacket(sender, new SOEPacket(opCode, rawPacket));
        }
Пример #2
0
        public void HandlePacket(SOEClient sender, byte[] rawPacket)
        {
            // Read the packet
            SOEReader reader = new SOEReader(rawPacket);
            ushort opCode = reader.ReadUInt16();
            bool goodPacket = true;

             // Get the packet data
            byte[] data = new byte[rawPacket.Length - (int)sender.GetCRCLength()];
            for (int i = 0; i < data.Length; i++)
            {
                data[i] = rawPacket[i];
            }

            // Get the CRC32 checksum for the packet
            uint crc32 = sender.GetCRC32Checksum(data);

            // Get our expected CRC32 checksum
            uint expectedCRC32 = 0;

            uint place = sender.GetCRCLength() - 1;
            for (int i = rawPacket.Length - (int)sender.GetCRCLength(); i < rawPacket.Length; i++)
            {
                expectedCRC32 += (uint)(rawPacket[i] << (8 * (int)place));
                place--;
            }

            // We have our CRCs! Check if the packet is formed correctly!
            byte[] crc = BitConverter.GetBytes(crc32).Reverse().ToArray();
            byte[] expectedCRC = BitConverter.GetBytes(expectedCRC32).Reverse().ToArray();

            int start = 4 - (int)sender.GetCRCLength();
            for (int i = start; i < sender.GetCRCLength(); i++)
            {
                // If they're not the same, we're a bad packet
                if (crc[i] != expectedCRC[i])
                {
                    // Set that we're bad, and get outta the loop
                    goodPacket = false;
                    break;
                }
            }

            // Are we malformed?
            if (!goodPacket)
            {
                Log("[WARNING] Received malformed packet! Incorrect CRC Appended!");
                return;
            }

            // Remove the CRC
            rawPacket = data;

            // Do we need to worry about decryption/decompression?
            if (sender.HasSession())
            {
                // Is the client encrypted?
                if (sender.IsEncrypted())
                {
                    rawPacket = DecryptPacket(sender, rawPacket);
                }

                // Is the client compressable?
                if (sender.IsCompressable())
                {
                    // It seems that all packets after 0x02 are compressable..
                    rawPacket = DecompressPacket(sender, rawPacket);
                }
            }

            // Handle the decompressed/decrypted packet!
            HandlePacket(sender, new SOEPacket(opCode, rawPacket));
        }