如何保证Socket传输数据的安全

　　作者：Unity游戏开发大本营

　　服务器与客户端进行数据传输要考虑到效率和安全的问题，那么就需要对数据包体进行重新定义，包括加密，数据校验，包体内容以及数据长度组成。

　　首先对数据进行压缩，压缩是有条件的，当数据的长度大于某个长度的时候进行压缩，压缩工具是一个开源的压缩工具。

　　//1.如果数据包的长度大于了m_CompressLen则进行压缩

　　boolisCompress=data.Length>m_CompressLen?true:false;

　　if(isCompress)

　　{

　　data=ZlibHelper.CompressBytes(data);

　　}

　　接着我们对数据进行加密，加密使用异或的方式，异或因子是我们自己定的，这样可以实现数据只有我们自己的异或因子能解开。

　　data=SecurityUtil.Xor(data);

　　publicsealedclassSecurityUtil

　　{

　　///异或因子

　　privatestaticreadonlybyte[]xorScale=newbyte[]{45,66,38,55,23,254,9,165,90,19,41,45,201,58,55,37,254,185,165,169,19,171};//.data文件的xor加解密因子

　　#endregion

　　privateSecurityUtil()

　　{

　　}

　　///对数组进行异或

　　publicstaticbyte[]Xor(byte[]buffer)

　　{

　　//------------------

　　//第3步：xor解密

　　//------------------

　　intiScaleLen=xorScale.Length;

　　for(inti=0;i<buffer.Length;i++)

　　{

　　buffer[i]=(byte)(buffer[i]^xorScale[i%iScaleLen]);

　　}

　　returnbuffer;

　　}

　　}

　　之后对处理后的数据进行crc校验，循环冗余检查（CRC）是一种数据传输检错功能，对数据进行多项式计算，并将得到的结果附在帧的后面，接收设备也执行类似的算法，以保证数据传输的正确性和完整性。

　　ushortcrc=Crc16.CalculateCrc16(data);

　　publicclassCrc16

　　{

　　//TableofCRCvaluesforhigh-orderbyte

　　privatestaticreadonlybyte[]_auchCRCHi=newbyte[]{0x00,0xC1,0x81,0x40,0x01,0xC0,0x80,0x41,0x01,0xC0,0x80,0x41,0x00,0xC1,0x81,0x40,0x01,0xC0,0x80,0x41,0x00,0xC1,0x81,0x40,0x00,0xC1,0x81,0x40,0x01,0xC0,0x80,0x41,0x01,0xC0,0x80,0x41,0x00,0xC1,0x81,0x40,0x00,0xC1,0x81,0x40,0x01,0xC0,0x80,0x41,0x00,0xC1,0x81,0x40,0x01,0xC0,0x80,0x41,0x01,0xC0,0x80,0x41,0x00,0xC1,0x81,0x40,0x01,0xC0,0x80,0x41,0x00,0xC1,0x81,0x40,0x00,0xC1,0x81,0x40,0x01,0xC0,0x80,0x41,0x00,0xC1,0x81,0x40,0x01,0xC0,0x80,0x41,0x01,0xC0,0x80,0x41,0x00,0xC1,0x81,0x40,0x00,0xC1,0x81,0x40,0x01,0xC0,0x80,0x41,0x01,0xC0,0x80,0x41,0x00,0xC1,0x81,0x40,0x01,0xC0,0x80,0x41,0x00,0xC1,0x81,0x40,0x00,0xC1,0x81,0x40,0x01,0xC0,0x80,0x41,0x01,0xC0,0x80,0x41,0x00,0xC1,0x81,0x40,0x00,0xC1,0x81,0x40,0x01,0xC0,0x80,0x41,0x00,0xC1,0x81,0x40,0x01,0xC0,0x80,0x41,0x01,0xC0,0x80,0x41,0x00,0xC1,0x81,0x40,0x00,0xC1,0x81,0x40,0x01,0xC0,0x80,0x41,0x01,0xC0,0x80,0x41,0x00,0xC1,0x81,0x40,0x01,0xC0,0x80,0x41,0x00,0xC1,0x81,0x40,0x00,0xC1,0x81,0x40,0x01,0xC0,0x80,0x41,0x00,0xC1,0x81,0x40,0x01,0xC0,0x80,0x41,0x01,0xC0,0x80,0x41,0x00,0xC1,0x81,0x40,0x01,0xC0,0x80,0x41,0x00,0xC1,0x81,0x40,0x00,0xC1,0x81,0x40,0x01,0xC0,0x80,0x41,0x01,0xC0,0x80,0x41,0x00,0xC1,0x81,0x40,0x00,0xC1,0x81,0x40,0x01,0xC0,0x80,0x41,0x00,0xC1,0x81,0x40,0x01,0xC0,0x80,0x41,0x01,0xC0,0x80,0x41,0x00,0xC1,0x81,0x40};

　　//TableofCRCvaluesforlow-orderbyte

　　privatestaticreadonlybyte[]_auchCRCLo=newbyte[]{0x00,0xC0,0xC1,0x01,0xC3,0x03,0x02,0xC2,0xC6,0x06,0x07,0xC7,0x05,0xC5,0xC4,0x04,0xCC,0x0C,0x0D,0xCD,0x0F,0xCF,0xCE,0x0E,0x0A,0xCA,0xCB,0x0B,0xC9,0x09,0x08,0xC8,0xD8,0x18,0x19,0xD9,0x1B,0xDB,0xDA,0x1A,0x1E,0xDE,0xDF,0x1F,0xDD,0x1D,0x1C,0xDC,0x14,0xD4,0xD5,0x15,0xD7,0x17,0x16,0xD6,0xD2,0x12,0x13,0xD3,0x11,0xD1,0xD0,0x10,0xF0,0x30,0x31,0xF1,0x33,0xF3,0xF2,0x32,0x36,0xF6,0xF7,0x37,0xF5,0x35,0x34,0xF4,0x3C,0xFC,0xFD,0x3D,0xFF,0x3F,0x3E,0xFE,0xFA,0x3A,0x3B,0xFB,0x39,0xF9,0xF8,0x38,0x28,0xE8,0xE9,0x29,0xEB,0x2B,0x2A,0xEA,0xEE,0x2E,0x2F,0xEF,0x2D,0xED,0xEC,0x2C,0xE4,0x24,0x25,0xE5,0x27,0xE7,0xE6,0x26,0x22,0xE2,0xE3,0x23,0xE1,0x21,0x20,0xE0,0xA0,0x60,0x61,0xA1,0x63,0xA3,0xA2,0x62,0x66,0xA6,0xA7,0x67,0xA5,0x65,0x64,0xA4,0x6C,0xAC,0xAD,0x6D,0xAF,0x6F,0x6E,0xAE,0xAA,0x6A,0x6B,0xAB,0x69,0xA9,0xA8,0x68,0x78,0xB8,0xB9,0x79,0xBB,0x7B,0x7A,0xBA,0xBE,0x7E,0x7F,0xBF,0x7D,0xBD,0xBC,0x7C,0xB4,0x74,0x75,0xB5,0x77,0xB7,0xB6,0x76,0x72,0xB2,0xB3,0x73,0xB1,0x71,0x70,0xB0,0x50,0x90,0x91,0x51,0x93,0x53,0x52,0x92,0x96,0x56,0x57,0x97,0x55,0x95,0x94,0x54,0x9C,0x5C,0x5D,0x9D,0x5F,0x9F,0x9E,0x5E,0x5A,0x9A,0x9B,0x5B,0x99,0x59,0x58,0x98,0x88,0x48,0x49,0x89,0x4B,0x8B,0x8A,0x4A,0x4E,0x8E,0x8F,0x4F,0x8D,0x4D,0x4C,0x8C,0x44,0x84,0x85,0x45,0x87,0x47,0x46,0x86,0x82,0x42,0x43,0x83,0x41,0x81,0x80,0x40};

　　///<summary>

　　///获得CRC16效验码

　　///</summary>

　　///<paramname="buffer"></param>

　　///<returns></returns>

　　publicstaticushortCalculateCrc16(byte[]buffer)

　　{

　　bytecrcHi=0xff;//highcrcbyteinitialized

　　bytecrcLo=0xff;//lowcrcbyteinitialized

　　for(inti=0;i<buffer.Length;i++)

　　{

　　intcrcIndex=crcHi^buffer[i];

　　//calculatethecrclookupindex

　　crcHi=(byte)(crcLo^_auchCRCHi[crcIndex]);

　　crcLo=_auchCRCLo[crcIndex];

　　}

　　return(ushort)(crcHi<<8|crcLo);

　　}

　　}

　　1

　　最后来写入数据，写入包体长度（包体还包括了长度，是否压缩标识，和crc标识，所以+3长度），用来在接收数据的时候判断数据是否接收完成，写入是否压缩的标识，写入crc校验码，最后写入处理完的数据。

　　using(MMO_MemoryStreamms=newMMO_MemoryStream())

　　{

　　ms.WriteUShort((ushort)(data.Length+3));

　　ms.WriteBool(isCompress);

　　ms.WriteUShort(crc);

　　ms.Write(data,0,data.Length);

　　retBuffer=ms.ToArray();

　　}

　　returnretBuffer;

　　拆分数据的数据执行相反的顺序即可，当然crc校验码不匹配的话，就不执行相应的数据处理。

　　byte[]bufferNew=newbyte[buffer.Length-3];

　　boolisCompress=false;

　　ushortcrc=0;

　　using(MMO_MemoryStreamms=newMMO_MemoryStream(buffer))

　　{

　　isCompress=ms.ReadBool();

　　crc=ms.ReadUShort();

　　ms.Read(bufferNew,0,bufferNew.Length);

　　}

　　//先crc

　　intnewCrc=Crc16.CalculateCrc16(bufferNew);

　　if(newCrc==crc)

　　{

　　//异或得到原始数据

　　bufferNew=SecurityUtil.Xor(bufferNew);

　　if(isCompress)

　　{

　　bufferNew=ZlibHelper.DeCompressBytes(bufferNew);

　　}

　　ushortprotoCode=0;

　　byte[]protoContent=newbyte[bufferNew.Length-2];

　　using(MMO_MemoryStreamms=newMMO_MemoryStream(bufferNew))

　　{

　　//协议编号

　　protoCode=ms.ReadUShort();

　　ms.Read(protoContent,0,protoContent.Length);

　　SocketDispatcher.Instance.Dispatch(protoCode,protoContent);

　　}

　　}

　　else

　　{

　　break;

　　}

　　Socket数据安全我们介绍完了，之后我们还会对Web的安全进行介绍。

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