javascript – websocket握手问题

我正在使用 python来实现一个简单的websocket服务器.
我正在使用的握手来自 http://en.wikipedia.org/w/index.php?title=WebSockets&oldid=372387414.

握手本身似乎有效,但是当我点击发送时,我收到一个javascript错误：

Uncaught Error: INVALID_STATE_ERR: DOM Exception 11

这是html：

<!doctype html>
<html>
    <head>
        <title>ws_json</title>

    </head>
    <body onload="handleLoad();" onunload="handleUnload();">
        <input type="text" id='input' />
        <input type="button" value="submit" onclick="handleSubmit()" />
        <div id="display"></div>

        <script type="text/javascript">
            function showmsg(str){
                display = document.getElementById("display");
                display.innerHTML += "<p>" + str + "</p>";
            }

            function send(str){
                ws.send(str.length);
                ws.send(str);
            }

            function handleSubmit(){
                input = document.getElementById('input');
                send(input.value);
                input.focus();
                input.value = '';
            }

            function handleLoad(){
                ws = new WebSocket("ws://localhost:8888/");
                ws.onopen = function(){
                    showmsg("websocket opened.");
                }

                ws.onclose = function(){
                    showmsg("websocket closed.");
                }
            }

            function handleUnload(){
                ws.close();
            }
        </script>
    </body>
</html>

这是python代码：

import socket
import threading
import json

PORT = 8888
LOCATION = "localhost:8888"

def handler(s):

    print " in handler "

    ip,_ = s.getpeername()
    print "New connection from %s" % ip
    request = s.recv(1024)

    print "\n%s\n" % request
    print s.getpeername()

    # send response
    response = "HTTP/1.1 101 Web Socket Protocol Handshake\r\n"
    response += "Upgrade: WebSocket\r\n"
    response += "Connection: Upgrade\r\n"
    try:
        peername = s.getpeername()
        response += "Sec-WebSocket-Origin: http://%s\r\n" % peername[0] # % request[request.index("Origin: ")+8:-4]
    except ValueError:
        print "Bad Request"
        raise socket.error
    response += "Sec-WebSocket-Location: ws://%s\r\n" % LOCATION
    response += "Sec-WebSocket-Protocol: sample"
    response = response.strip() + "\r\n\r\n"

    print response
    s.send(response)

    while True:
        length = s.recv(1)
        print length
        if not length:
            break
        length = int(length)
        print "Length: %i" % length
        data = s.recv(length)
        print "Received: %s" % data
        print ""

s = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
s.setsockopt(socket.SOL_SOCKET,socket.SO_REUSEADDR,1)
s.bind(('localhost',PORT))
s.listen(5)

print "server is running..."
while True:
    sock,addr = s.accept()
    threading.Thread(target=handler,args=(sock,)).start()

有谁知道我在这里做错了什么？

解决方法

我在Firefox 4上测试了你的代码并在发送时遇到了同样的错误,但在此之前我得到了

Firefox can’t establish a connection
to the server at ws://localhost:8888/.

这可能是WebSocket对象被销毁的原因.我怀疑你的握手响应丢失了,所以Firefox正在关闭套接字.

来自Wikipedia上关于Websockets的文章：

The Sec-WebSocket-Key1 and
Sec-WebSocket-Key2 fields and the
eight bytes after the fields are
random tokens which the server uses to
construct a 16 byte token at the end
of its handshake to prove that it has
read the client’s handshake.

您的服务器响应底部没有此特殊编号,因此我认为我们需要弄清楚如何生成它并包含它.

编辑：如何生成该数字

让我们从key1,key2和握手结束时的8个字节开始

key1 = "18x 6]8vM;54 *(5:  {   U1]8  z [  8"
key2 = "1_ tx7X d  <  nw  334J702) 7]o}` 0"
end8 = "Tm[K T2u"

我们通过忽略每个不是数字0-9的字符为每个键创建一个数字.在Python中：

def numFromKey(key):
    return int(filter(lambda c: c in map(str,range(10)),key))

接下来我们将该数字除以原始键字符串中的空格数,因此这里是一个计算字符串中空格的函数.

def spacesIn(key):
    return len(filter(lambda c: c==' ',key))

键产生的两个数字是：

pkey1 = numFromKey(key1)/spacesIn(key1)
pkey2 = numFromKey(key2)/spacesIn(key2)

现在我们需要连接pkey1,pkey2和end8的字节.处理后的密钥需要表示为32位Big-Endian数字.

from struct import pack
catstring = pack('>L',pkey1) + pack('>L',pkey2) + end8

然后我们采用这些字节的md5哈希值来获得在握手结束时我们处理的幻数

import md5
magic = md5.new(catstring).digest()

多数民众赞成我认为它至少有用

javascript – websocket握手问题

解决方法

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