如何在服务器端发送和接收WebSocket消息?

注意:这是关于如何实现一个非常琐碎的服务器的一些解释和伪代码,该服务器可以根据最终的帧格式处理传入和传出的WebSocket消息。它不包括握手过程。此外,这一回答是出于教育目的;它不是一个功能齐全的实现。

Specification (RFC 6455)

发送消息

(换句话说,服务器浏览器)

您发送的帧需要根据WebSocket帧格式进行格式化。对于发送消息,此格式如下:

• 一个字节,包含数据类型(以及一些超出普通服务器范围的附加信息)
• 一个包含长度的字节
• 如果长度不适合第二个字节,则为两个或八个字节(第二个是一个代码,说明长度使用了多少字节)
• 实际(原始)数据

第一个字节将是 1000 0001 (或 129 )用于文本框。

第二个字节的第一位设置为 0 因为我们没有对数据进行编码(从服务器到客户端的编码不是强制性的)。

有必要确定原始数据的长度,以便正确发送长度字节:

• 如果 0 <= length <= 125 ,不需要额外的字节
• 如果 126 <= length <= 65535 ,您需要两个额外的字节,第二个字节是 126
• 如果 length >= 65536 ,您需要另外八个字节,第二个字节是 127

长度必须被分割成单独的字节,这意味着你需要向右移位(数量为8位),然后只保留最后8位 AND 1111 1111 (即 255 )。

长度字节之后是原始数据。

这将导致以下伪代码:

bytesFormatted[0] = 129

indexStartRawData = -1 // it doesn't matter what value is
                       // set here - it will be set now:

if bytesRaw.length <= 125
    bytesFormatted[1] = bytesRaw.length

    indexStartRawData = 2

else if bytesRaw.length >= 126 and bytesRaw.length <= 65535
    bytesFormatted[1] = 126
    bytesFormatted[2] = ( bytesRaw.length >> 8 ) AND 255
    bytesFormatted[3] = ( bytesRaw.length      ) AND 255

    indexStartRawData = 4

else
    bytesFormatted[1] = 127
    bytesFormatted[2] = ( bytesRaw.length >> 56 ) AND 255
    bytesFormatted[3] = ( bytesRaw.length >> 48 ) AND 255
    bytesFormatted[4] = ( bytesRaw.length >> 40 ) AND 255
    bytesFormatted[5] = ( bytesRaw.length >> 32 ) AND 255
    bytesFormatted[6] = ( bytesRaw.length >> 24 ) AND 255
    bytesFormatted[7] = ( bytesRaw.length >> 16 ) AND 255
    bytesFormatted[8] = ( bytesRaw.length >>  8 ) AND 255
    bytesFormatted[9] = ( bytesRaw.length       ) AND 255

    indexStartRawData = 10

// put raw data at the correct index
bytesFormatted.put(bytesRaw, indexStartRawData)


// now send bytesFormatted (e.g. write it to the socket stream)

正在接收消息

(换句话说,浏览器服务器)

您获得的帧采用以下格式:

• 一个包含数据类型的字节
• 一个包含长度的字节
• 如果长度不适合第二个字节,则增加两个或八个字节
• 作为掩码的四个字节(=解码密钥)
• 实际数据

第一个字节通常并不重要——如果你只是发送文本,那么你只使用文本类型。会的 1000 0001 (或 129 )在这种情况下。

第二个字节和另外的两个或八个字节需要一些解析,因为您需要知道长度使用了多少字节(您需要知道实际数据从哪里开始)。长度本身通常是不必要的,因为您已经有了数据。

第二个字节的第一位总是 1 这意味着数据被屏蔽(=编码)。从客户端到服务器的消息总是被屏蔽的。你需要通过做 secondByte AND 0111 1111 有两种情况下,结果字节不表示长度,因为它不适合第二个字节:

• 的第二个字节 0111 1110 或 126 ,表示长度使用以下两个字节
• 的第二个字节 0111 1111 或 127 ,表示以下八个字节用于长度

四个掩码字节用于对已发送的实际数据进行解码。解码算法如下:

decodedByte = encodedByte XOR masks[encodedByteIndex MOD 4]

哪里 encodedByte 是数据中的原始字节, encodedByteIndex 是从第一个字节开始计数的字节的索引(偏移量) 真实数据的 ,具有索引 0 。 masks 是包含四个掩码字节的数组。

这导致以下用于解码的伪代码:

secondByte = bytes[1]

length = secondByte AND 127 // may not be the actual length in the two special cases

indexFirstMask = 2          // if not a special case

if length == 126            // if a special case, change indexFirstMask
    indexFirstMask = 4

else if length == 127       // ditto
    indexFirstMask = 10

masks = bytes.slice(indexFirstMask, 4) // four bytes starting from indexFirstMask

indexFirstDataByte = indexFirstMask + 4 // four bytes further

decoded = new array

decoded.length = bytes.length - indexFirstDataByte // length of real data

for i = indexFirstDataByte, j = 0; i < bytes.length; i++, j++
    decoded[j] = bytes[i] XOR masks[j MOD 4]


// now use "decoded" to interpret the received data

Java实现(如果有人需要)

正在读取:客户端到服务器

        int len = 0;            
        byte[] b = new byte[buffLenth];
        //rawIn is a Socket.getInputStream();
        while(true){
            len = rawIn.read(b);
            if(len!=-1){

                byte rLength = 0;
                int rMaskIndex = 2;
                int rDataStart = 0;
                //b[0] is always text in my case so no need to check;
                byte data = b[1];
                byte op = (byte) 127;
                rLength = (byte) (data & op);

                if(rLength==(byte)126) rMaskIndex=4;
                if(rLength==(byte)127) rMaskIndex=10;

                byte[] masks = new byte[4];

                int j=0;
                int i=0;
                for(i=rMaskIndex;i<(rMaskIndex+4);i++){
                    masks[j] = b[i];
                    j++;
                }

                rDataStart = rMaskIndex + 4;

                int messLen = len - rDataStart;

                byte[] message = new byte[messLen];

                for(i=rDataStart, j=0; i<len; i++, j++){
                    message[j] = (byte) (b[i] ^ masks[j % 4]);
                }

                parseMessage(new String(message)); 
                //parseMessage(new String(b));

                b = new byte[buffLenth];

            }
        }

写入:服务器到客户端

public void brodcast(String mess) throws IOException{
    byte[] rawData = mess.getBytes();

    int frameCount  = 0;
    byte[] frame = new byte[10];

    frame[0] = (byte) 129;

    if(rawData.length <= 125){
        frame[1] = (byte) rawData.length;
        frameCount = 2;
    }else if(rawData.length >= 126 && rawData.length <= 65535){
        frame[1] = (byte) 126;
        int len = rawData.length;
        frame[2] = (byte)((len >> 8 ) & (byte)255);
        frame[3] = (byte)(len & (byte)255); 
        frameCount = 4;
    }else{
        frame[1] = (byte) 127;
        int len = rawData.length;
        frame[2] = (byte)((len >> 56 ) & (byte)255);
        frame[3] = (byte)((len >> 48 ) & (byte)255);
        frame[4] = (byte)((len >> 40 ) & (byte)255);
        frame[5] = (byte)((len >> 32 ) & (byte)255);
        frame[6] = (byte)((len >> 24 ) & (byte)255);
        frame[7] = (byte)((len >> 16 ) & (byte)255);
        frame[8] = (byte)((len >> 8 ) & (byte)255);
        frame[9] = (byte)(len & (byte)255);
        frameCount = 10;
    }

    int bLength = frameCount + rawData.length;

    byte[] reply = new byte[bLength];

    int bLim = 0;
    for(int i=0; i<frameCount;i++){
        reply[bLim] = frame[i];
        bLim++;
    }
    for(int i=0; i<rawData.length;i++){
        reply[bLim] = rawData[i];
        bLim++;
    }

    out.write(reply);
    out.flush();

}

JavaScript实现:

function encodeWebSocket(bytesRaw){
    var bytesFormatted = new Array();
    bytesFormatted[0] = 129;
    if (bytesRaw.length <= 125) {
        bytesFormatted[1] = bytesRaw.length;
    } else if (bytesRaw.length >= 126 && bytesRaw.length <= 65535) {
        bytesFormatted[1] = 126;
        bytesFormatted[2] = ( bytesRaw.length >> 8 ) & 255;
        bytesFormatted[3] = ( bytesRaw.length      ) & 255;
    } else {
        bytesFormatted[1] = 127;
        bytesFormatted[2] = ( bytesRaw.length >> 56 ) & 255;
        bytesFormatted[3] = ( bytesRaw.length >> 48 ) & 255;
        bytesFormatted[4] = ( bytesRaw.length >> 40 ) & 255;
        bytesFormatted[5] = ( bytesRaw.length >> 32 ) & 255;
        bytesFormatted[6] = ( bytesRaw.length >> 24 ) & 255;
        bytesFormatted[7] = ( bytesRaw.length >> 16 ) & 255;
        bytesFormatted[8] = ( bytesRaw.length >>  8 ) & 255;
        bytesFormatted[9] = ( bytesRaw.length       ) & 255;
    }
    for (var i = 0; i < bytesRaw.length; i++){
        bytesFormatted.push(bytesRaw.charCodeAt(i));
    }
    return bytesFormatted;
}

function decodeWebSocket (data){
    var datalength = data[1] & 127;
    var indexFirstMask = 2;
    if (datalength == 126) {
        indexFirstMask = 4;
    } else if (datalength == 127) {
        indexFirstMask = 10;
    }
    var masks = data.slice(indexFirstMask,indexFirstMask + 4);
    var i = indexFirstMask + 4;
    var index = 0;
    var output = "";
    while (i < data.length) {
        output += String.fromCharCode(data[i++] ^ masks[index++ % 4]);
    }
    return output;
}

C#实现

浏览器->服务器

    private String DecodeMessage(Byte[] bytes)
    {
        String incomingData = String.Empty;
        Byte secondByte = bytes[1];
        Int32 dataLength = secondByte & 127;
        Int32 indexFirstMask = 2;
        if (dataLength == 126)
            indexFirstMask = 4;
        else if (dataLength == 127)
            indexFirstMask = 10;

        IEnumerable<Byte> keys = bytes.Skip(indexFirstMask).Take(4);
        Int32 indexFirstDataByte = indexFirstMask + 4;

        Byte[] decoded = new Byte[bytes.Length - indexFirstDataByte];
        for (Int32 i = indexFirstDataByte, j = 0; i < bytes.Length; i++, j++)
        {
            decoded[j] = (Byte)(bytes[i] ^ keys.ElementAt(j % 4));
        }

        return incomingData = Encoding.UTF8.GetString(decoded, 0, decoded.Length);
    }

服务器->浏览器

    private static Byte[] EncodeMessageToSend(String message)
    {
        Byte[] response;
        Byte[] bytesRaw = Encoding.UTF8.GetBytes(message);
        Byte[] frame = new Byte[10];

        Int32 indexStartRawData = -1;
        Int32 length = bytesRaw.Length;

        frame[0] = (Byte)129;
        if (length <= 125)
        {
            frame[1] = (Byte)length;
            indexStartRawData = 2;
        }
        else if (length >= 126 && length <= 65535)
        {
            frame[1] = (Byte)126;
            frame[2] = (Byte)((length >> 8) & 255);
            frame[3] = (Byte)(length & 255);
            indexStartRawData = 4;
        }
        else
        {
            frame[1] = (Byte)127;
            frame[2] = (Byte)((length >> 56) & 255);
            frame[3] = (Byte)((length >> 48) & 255);
            frame[4] = (Byte)((length >> 40) & 255);
            frame[5] = (Byte)((length >> 32) & 255);
            frame[6] = (Byte)((length >> 24) & 255);
            frame[7] = (Byte)((length >> 16) & 255);
            frame[8] = (Byte)((length >> 8) & 255);
            frame[9] = (Byte)(length & 255);

            indexStartRawData = 10;
        }

        response = new Byte[indexStartRawData + length];

        Int32 i, reponseIdx = 0;

        //Add the frame bytes to the reponse
        for (i = 0; i < indexStartRawData; i++)
        {
            response[reponseIdx] = frame[i];
            reponseIdx++;
        }

        //Add the data bytes to the response
        for (i = 0; i < length; i++)
        {
            response[reponseIdx] = bytesRaw[i];
            reponseIdx++;
        }

        return response;
    }

pimvdb的答案在python中实现:

def DecodedCharArrayFromByteStreamIn(stringStreamIn):
    #turn string values into opererable numeric byte values
    byteArray = [ord(character) for character in stringStreamIn]
    datalength = byteArray[1] & 127
    indexFirstMask = 2 
    if datalength == 126:
        indexFirstMask = 4
    elif datalength == 127:
        indexFirstMask = 10
    masks = [m for m in byteArray[indexFirstMask : indexFirstMask+4]]
    indexFirstDataByte = indexFirstMask + 4
    decodedChars = []
    i = indexFirstDataByte
    j = 0
    while i < len(byteArray):
        decodedChars.append( chr(byteArray[i] ^ masks[j % 4]) )
        i += 1
        j += 1
    return decodedChars

用法示例:

fromclient = '\x81\x8c\xff\xb8\xbd\xbd\xb7\xdd\xd1\xd1\x90\x98\xea\xd2\x8d\xd4\xd9\x9c'
# this looks like "?ŒOÇ¿¢gÓ ç\Ð=«ož" in unicode, received by server
print DecodedCharArrayFromByteStreamIn(fromclient)
# ['H', 'e', 'l', 'l', 'o', ' ', 'W', 'o', 'r', 'l', 'd', '!']

除了PHP帧编码函数外,下面还有一个解码函数:

function Decode($M){
    $M = array_map("ord", str_split($M));
    $L = $M[1] AND 127;

    if ($L == 126)
        $iFM = 4;
    else if ($L == 127)
        $iFM = 10;
    else
        $iFM = 2;

    $Masks = array_slice($M, $iFM, 4);

    $Out = "";
    for ($i = $iFM + 4, $j = 0; $i < count($M); $i++, $j++ ) {
        $Out .= chr($M[$i] ^ $Masks[$j % 4]);
    }
    return $Out;
}

我已经在一个易于使用的WebSocket PHP类中实现了这个以及其他函数 here 。

PHP实现:

function encode($message)
{
    $length = strlen($message);

    $bytesHeader = [];
    $bytesHeader[0] = 129; // 0x1 text frame (FIN + opcode)

    if ($length <= 125) {
            $bytesHeader[1] = $length;
    } else if ($length >= 126 && $length <= 65535) {
            $bytesHeader[1] = 126;
            $bytesHeader[2] = ( $length >> 8 ) & 255;
            $bytesHeader[3] = ( $length      ) & 255;
    } else {
            $bytesHeader[1] = 127;
            $bytesHeader[2] = ( $length >> 56 ) & 255;
            $bytesHeader[3] = ( $length >> 48 ) & 255;
            $bytesHeader[4] = ( $length >> 40 ) & 255;
            $bytesHeader[5] = ( $length >> 32 ) & 255;
            $bytesHeader[6] = ( $length >> 24 ) & 255;
            $bytesHeader[7] = ( $length >> 16 ) & 255;
            $bytesHeader[8] = ( $length >>  8 ) & 255;
            $bytesHeader[9] = ( $length       ) & 255;
    }

    $str = implode(array_map("chr", $bytesHeader)) . $message;

    return $str;
}

谢谢你的回答,我想补充一下 hfern的 (上图)Python版本,如果有人感兴趣,可以包含Sending函数。

def DecodedWebsockRecieve(stringStreamIn):
    byteArray =  stringStreamIn 
    datalength = byteArray[1] & 127
    indexFirstMask = 2 
    if datalength == 126:
        indexFirstMask = 4
    elif datalength == 127:
        indexFirstMask = 10
    masks = [m for m in byteArray[indexFirstMask : indexFirstMask+4]]
    indexFirstDataByte = indexFirstMask + 4
    decodedChars = []
    i = indexFirstDataByte
    j = 0
    while i < len(byteArray):
        decodedChars.append( chr(byteArray[i] ^ masks[j % 4]) )
        i += 1
        j += 1
    return ''.join(decodedChars)

def EncodeWebSockSend(socket,data):
    bytesFormatted = []
    bytesFormatted.append(129)

    bytesRaw = data.encode()
    bytesLength = len(bytesRaw)
    if bytesLength <= 125 :
        bytesFormatted.append(bytesLength)
    elif bytesLength >= 126 and bytesLength <= 65535 :
        bytesFormatted.append(126)
        bytesFormatted.append( ( bytesLength >> 8 ) & 255 )
        bytesFormatted.append( bytesLength & 255 )
    else :
        bytesFormatted.append( 127 )
        bytesFormatted.append( ( bytesLength >> 56 ) & 255 )
        bytesFormatted.append( ( bytesLength >> 48 ) & 255 )
        bytesFormatted.append( ( bytesLength >> 40 ) & 255 )
        bytesFormatted.append( ( bytesLength >> 32 ) & 255 )
        bytesFormatted.append( ( bytesLength >> 24 ) & 255 )
        bytesFormatted.append( ( bytesLength >> 16 ) & 255 )
        bytesFormatted.append( ( bytesLength >>  8 ) & 255 )
        bytesFormatted.append( bytesLength & 255 )

    bytesFormatted = bytes(bytesFormatted)
    bytesFormatted = bytesFormatted + bytesRaw
    socket.send(bytesFormatted) 

阅读用途:

bufSize = 1024     
read = DecodedWebsockRecieve(socket.recv(bufSize))

书写用法:

EncodeWebSockSend(sock,"hellooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo")

围棋中的实施

编码部件(服务器->浏览器)

func encode (message string) (result []byte) {
  rawBytes := []byte(message)
  var idxData int

  length := byte(len(rawBytes))
  if len(rawBytes) <= 125 { //one byte to store data length
    result = make([]byte, len(rawBytes) + 2)
    result[1] = length
    idxData = 2
  } else if len(rawBytes) >= 126 && len(rawBytes) <= 65535 { //two bytes to store data length
    result = make([]byte, len(rawBytes) + 4)
    result[1] = 126 //extra storage needed
    result[2] = ( length >> 8 ) & 255
    result[3] = ( length      ) & 255
    idxData = 4
  } else {
    result = make([]byte, len(rawBytes) + 10)
    result[1] = 127
    result[2] = ( length >> 56 ) & 255
    result[3] = ( length >> 48 ) & 255
    result[4] = ( length >> 40 ) & 255
    result[5] = ( length >> 32 ) & 255
    result[6] = ( length >> 24 ) & 255
    result[7] = ( length >> 16 ) & 255
    result[8] = ( length >>  8 ) & 255
    result[9] = ( length       ) & 255
    idxData = 10
  }

  result[0] = 129 //only text is supported

  // put raw data at the correct index
  for i, b := range rawBytes {
    result[idxData + i] = b
  }
  return
}

解码部分(浏览器->服务器)

func decode (rawBytes []byte) string {
  var idxMask int
  if rawBytes[1] == 126 {
    idxMask = 4
  } else if rawBytes[1] == 127 {
    idxMask = 10
  } else {
    idxMask = 2
  }

  masks := rawBytes[idxMask:idxMask + 4]
  data := rawBytes[idxMask + 4:len(rawBytes)]
  decoded := make([]byte, len(rawBytes) - idxMask + 4)

  for i, b := range data {
    decoded[i] = b ^ masks[i % 4]
  }
  return string(decoded)
}

Clojure,decode函数假设帧作为的映射发送 {:data byte-array-buffer :size int-size-of-buffer} ,因为实际大小可能与字节数组的大小不同,这取决于输入流的块大小。

此处发布的代码: https://gist.github.com/viperscape/8918565

(defn ws-decode [frame]
  "decodes websocket frame"
  (let [data (:data frame)
        dlen (bit-and (second data) 127)
        mstart (if (== dlen 127) 10 (if (== dlen 126) 4 2))
        mask (drop 2 (take (+ mstart 4) data))
        msg (make-array Byte/TYPE (- (:size frame) (+ mstart 4)))]
   (loop [i (+ mstart 4), j 0]
      (aset-byte msg j (byte (bit-xor (nth data i) (nth mask (mod j 4)))))
      (if (< i (dec(:size frame))) (recur (inc i) (inc j))))
    msg))

(defn ws-encode [data]
  "takes in bytes, return websocket frame"
  (let [len (count data)
        blen (if (> len 65535) 10 (if (> len 125) 4 2))
        buf (make-array Byte/TYPE (+ len blen))
        _ (aset-byte buf 0 -127) ;;(bit-or (unchecked-byte 0x80) 
                                           (unchecked-byte 0x1)
        _ (if (= 2 blen) 
            (aset-byte buf 1 len) ;;mask 0, len
            (do
              (dorun(map #(aset-byte buf %1 
                      (unchecked-byte (bit-and (bit-shift-right len (*(- %2 2) 8))
                                               255)))
                      (range 2 blen) (into ()(range 2 blen))))
              (aset-byte buf 1 (if (> blen 4) 127 126))))
        _ (System/arraycopy data 0 buf blen len)]
    buf))

C++实现(不是我做的) here 。请注意,当您的字节数超过65535时,您需要使用长值进行移位,如图所示 here 。

已更新 Haribabu Pasupathy 处理TCP分段的代码。在我的案例中,浏览器发送的大于1024字节的websocket数据包被拆分为TCP段,因此需要重新组装。

private static void processResponse(InputStream inputStream, OutputStream outputStream) throws IOException {
    int readPacketLength = 0;
    byte[] packet = new byte[1024];
    ByteArrayOutputStream packetStream = new ByteArrayOutputStream();

    while(true) {
        readPacketLength = inputStream.read(packet);

        if(readPacketLength != -1) {
            if ((packet[0] & (byte) 15) == (byte) 8) { // Disconnect packet
                outputStream.write(packet, 0, readPacketLength);
                // returning the same packet for client to terminate connection
                outputStream.flush();
                return;
            }
            byte messageLengthByte = 0;
            int messageLength = 0;
            int maskIndex = 2;
            int messageStart = 0;
            //b[0] is always text in my case so no need to check;
            byte data = packet[1];
            byte op = (byte) 127; // 0111 111
            messageLengthByte = (byte) (data & op);

            int totalPacketLength = 0;
            if (messageLengthByte == (byte) 126 || messageLengthByte == (byte) 127) {
                if (messageLengthByte == (byte) 126) {
                    maskIndex = 4;
                    // if (messageLengthInt==(byte)126), then 16-bit length is stored in packet[2] and [3]
                    ByteBuffer messageLength16Bit = ByteBuffer.allocateDirect(4);
                    messageLength16Bit.order(ByteOrder.BIG_ENDIAN);
                    messageLength16Bit.put((byte) 0x00);
                    messageLength16Bit.put((byte) 0x00);
                    messageLength16Bit.put(packet, 2, 2);
                    messageLength16Bit.flip();
                    messageLength = messageLength16Bit.getInt();
                    totalPacketLength = messageLength + 8;
                } else {
                    maskIndex = 10;
                    // if (messageLengthInt==(byte)127), then 64-bit length is stored in bytes [2] to [9]. Using only 32-bit
                    ByteBuffer messageLength64Bit = ByteBuffer.allocateDirect(4);
                    messageLength64Bit.order(ByteOrder.BIG_ENDIAN);
                    messageLength64Bit.put(packet, 6, 4);
                    messageLength64Bit.flip();
                    messageLength = messageLength64Bit.getInt();
                    totalPacketLength = messageLength + 14;
                }

                if (readPacketLength != totalPacketLength) {
                    packetStream.write(packet, 0, readPacketLength);

                    int lastPacketLength = 0;
                    while (readPacketLength < totalPacketLength) {
                        packet = new byte[1024];
                        readPacketLength += lastPacketLength = inputStream.read(packet);
                        packetStream.write(packet, 0, lastPacketLength);
                    }
                    packet = packetStream.toByteArray();
                    packetStream.reset();
                }
            }
            else { // using message length from packet[1]
                messageLength = messageLengthByte;
            }

            byte[] masks = new byte[4];
            int i=0; int j=0;
            for(i = maskIndex; i < (maskIndex+4); i++) {
                masks[j] = packet[i];
                j++;
            }

            messageStart = maskIndex + 4;

            byte[] message = new byte[messageLength];
            for(i = messageStart, j = 0; i < readPacketLength; i++, j++){
                message[j] = (byte) (packet[i] ^ masks[j % 4]);
            }
            System.out.println("Received message: " + new String(message));
            packet = new byte[1024];
        }
    }
}

我修复了>Nitij的C#实现中的65535消息长度问题。

private static Byte[] EncodeMessageToSend(String message)
{
    Byte[] response;
    Byte[] bytesRaw = Encoding.UTF8.GetBytes(message);
    Byte[] frame = new Byte[10];

    Int32 indexStartRawData = -1;
    Int32 length = bytesRaw.Length;

    frame[0] = (Byte)129;
    if (length <= 125)
    {
        frame[1] = (Byte)length;
        indexStartRawData = 2;
    }
    else if (length >= 126 && length <= 65535)
    {
        frame[1] = (Byte)126;
        frame[2] = (Byte)((length >> 8) & 255);
        frame[3] = (Byte)(length & 255);
        indexStartRawData = 4;
    }
    else
    {
        var lengthAsULong = Convert.ToUInt64(length);
        frame[1] = 127;
        frame[2] = (byte)((lengthAsULong >> 56) & 255);
        frame[3] = (byte)((lengthAsULong >> 48) & 255);
        frame[4] = (byte)((lengthAsULong >> 40) & 255);
        frame[5] = (byte)((lengthAsULong >> 32) & 255);
        frame[6] = (byte)((lengthAsULong >> 24) & 255);
        frame[7] = (byte)((lengthAsULong >> 16) & 255);
        frame[8] = (byte)((lengthAsULong >> 8) & 255);
        frame[9] = (byte)(lengthAsULong & 255);

        indexStartRawData = 10;
    }

    response = new Byte[indexStartRawData + length];

    Int32 i, reponseIdx = 0;

    //Add the frame bytes to the reponse
    for (i = 0; i < indexStartRawData; i++)
    {
        response[reponseIdx] = frame[i];
        reponseIdx++;
    }

    //Add the data bytes to the response
    for (i = 0; i < length; i++)
    {
        response[reponseIdx] = bytesRaw[i];
        reponseIdx++;
    }

    return response;
}