使用Python服务器的Websocket握手问题
这是一个关于在Websocket协议76中握手的问题。
我写了一个客户端和服务器，但在让客户端接受握手时遇到了麻烦。我能看到握手的响应被返回了，但客户端立刻就关闭了连接。我猜我的md5sum响应可能是错的。
根据我的理解，我应该是在按照正确的步骤进行操作，有人能告诉我我哪里做错了吗？
def create_handshake_resp(handshake):
# parse request
final_line = ""
lines = handshake.splitlines()
for line in lines:
parts = line.partition(":")
if parts[0] == "Sec-WebSocket-Key1":
key1 = parts[2]
elif parts[0] == "Sec-WebSocket-Key2":
key2 = parts[2]
final_line = line
#concat the keys and encrypt
e = hashlib.md5()
e.update(parse_key(key1))
e.update(parse_key(key2))
e.update(final_line)
return "HTTP/1.1 101 WebSocket Protocol Handshake\r\nUpgrade: WebSocket\r\nConnection: Upgrade\r\nWebSocket-Origin: http://%s\r\nWebSocket-Location: ws://%s/\r\nWebSocket-Protocol: sample\r\n\r\n%s" % (httphost, sockethost, e.digest())
def parse_key(key):
spaces = -1
digits = ""
for c in key:
if c == " ":
spaces += 1
if is_number(c):
digits = digits + c
new_key = int(digits) / spaces
return str(new_key)
如你所见，我在对密钥进行我认为正确的操作（根据空格数量划分数字，连接结果和请求的最后一行，然后进行MD5计算），并且确实返回了一个16字节的响应。
任何帮助都将非常感激，一旦我有了一个可用的版本，我会在这里分享。
谢谢。
编辑：
我更改了头部信息以符合kanaka的响应。握手仍然没有被客户端接受。我找到了在Chromium中显示请求的方法，这就是给出的请求和响应：
(P) t=1291739663323 [st=3101] WEB_SOCKET_SEND_REQUEST_HEADERS
--> GET / HTTP/1.1
Upgrade: WebSocket
Connection: Upgrade
Host: ---
Origin: http://---
Sec-WebSocket-Key1: 3E 203C 220 642;
Sec-WebSocket-Key2: Lg 590 ~5 703O G7 =%t 9
\x74\x66\xef\xab\x50\x60\x35\xc6\x0a
(P) t=1291739663324 [st=3102] SOCKET_STREAM_SENT
(P) t=1291739663348 [st=3126] SOCKET_STREAM_RECEIVED
(P) t=1291739663348 [st=3126] WEB_SOCKET_READ_RESPONSE_HEADERS
--> HTTP/1.1 101 WebSocket Protocol Handshake
Upgrade: WebSocket
Connection: Upgrade
Sec-WebSocket-Origin: http://---
Sec-WebSocket-Location: ws://---/
Sec-WebSocket-Protocol: sample
\xe7\x6f\xb9\xcf\xae\x70\x57\x43\xc6\x20\x85\xe7\x39\x2e\x83\xec\x0
逐字复制，除了出于明显的原因我去掉了IP地址。
2 个回答
2
这里有一个可以运行的WebSocket客户端/服务器示例（客户端用JavaScript，服务器用Python 2.6）
这个示例参考了很多地方的内容（包括kanaka的回答/noVNC，还有这个页面和这个页面）
它在Chrome 10.0.648.127、Safari 5.0.3和iPad上的MobileSafari（iOS 4.3及以上）中都能正常工作
代码写得并不好（示例的HTML页面尤其糟糕）——使用时请自行承担风险等等……
#!/usr/bin/env python
import socket
import threading
import struct
import hashlib
PORT = 9876
def create_handshake_resp(handshake):
final_line = ""
lines = handshake.splitlines()
for line in lines:
parts = line.partition(": ")
if parts[0] == "Sec-WebSocket-Key1":
key1 = parts[2]
elif parts[0] == "Sec-WebSocket-Key2":
key2 = parts[2]
elif parts[0] == "Host":
host = parts[2]
elif parts[0] == "Origin":
origin = parts[2]
final_line = line
spaces1 = key1.count(" ")
spaces2 = key2.count(" ")
num1 = int("".join([c for c in key1 if c.isdigit()])) / spaces1
num2 = int("".join([c for c in key2 if c.isdigit()])) / spaces2
token = hashlib.md5(struct.pack('>II8s', num1, num2, final_line)).digest()
return (
"HTTP/1.1 101 WebSocket Protocol Handshake\r\n"
"Upgrade: WebSocket\r\n"
"Connection: Upgrade\r\n"
"Sec-WebSocket-Origin: %s\r\n"
"Sec-WebSocket-Location: ws://%s/\r\n"
"\r\n"
"%s") % (
origin, host, token)
def handle(s, addr):
data = s.recv(1024)
s.send(create_handshake_resp(data))
lock = threading.Lock()
while 1:
print "Waiting for data from", s, addr
data = s.recv(1024)
print "Done"
if not data:
print "No data"
break
print 'Data from', addr, ':', data
# Broadcast received data to all clients
lock.acquire()
[conn.send(data) for conn in clients]
lock.release()
print 'Client closed:', addr
lock.acquire()
clients.remove(s)
lock.release()
s.close()
def start_server():
s = socket.socket()
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
s.bind(('', PORT))
s.listen(1)
while 1:
conn, addr = s.accept()
print 'Connected by', addr
clients.append(conn)
threading.Thread(target = handle, args = (conn, addr)).start()
clients = []
start_server()
另外，还有一个很糟糕的HTML页面，用来展示它是如何工作的：
<!DOCTYPE html>
<html lang="en">
<head>
<title>Test</title>
<script type="application/javascript">
var ws;
function init() {
var servermsg = document.getElementById("servermsg");
ws = new WebSocket("ws://localhost:9876/");
ws.onopen = function(){
servermsg.innerHTML = servermsg.innerHTML + "<br>Server connected";
servermsg.innerHTML = servermsg.innerHTML + "<br>Sending message to server";
ws.send("Hello Mr. Server!");
};
ws.onmessage = function(e){
servermsg.innerHTML = servermsg.innerHTML + "<br>Recieved data: " + e.data;
};
ws.onclose = function(){
console.log("Server disconnected");
servermsg.innerHTML = servermsg.innerHTML + "<br>Connected";
};
}
function postmsg(){
var text = document.getElementById("message").value;
ws.send(text);
servermsg.innerHTML = servermsg.innerHTML + "<br>Sent: " + text;
return false;
}
</script>
</head>
<body onload="init();">
<form action="" onSubmit="postmsg()">
<input type="text" name="message" value="" id="message">
<input type="submit" name="submit" value="" id="submit">
</form>
<div id="servermsg"><h1>Message log:</h1></div>
</body>
</html>
5
我看到你有几个问题需要注意：
- 你没有正确计算空格。你的计数器应该从0开始，而不是-1。
- 你的响应头还是v75的格式。任何以“WebSocket-”开头的头部（比如WebSocket-Origin、WebSocket-Location、WebSocket-Protocol）在v76中应该改为以“Sec-WebSocket-”开头。
下面是我在wsproxy中计算响应校验和的方法（wsproxy是noVNC这个HTML5 VNC客户端的一部分）：
import struct, md5
...
spaces1 = key1.count(" ")
spaces2 = key2.count(" ")
num1 = int("".join([c for c in key1 if c.isdigit()])) / spaces1
num2 = int("".join([c for c in key2 if c.isdigit()])) / spaces2
return md5(struct.pack('>II8s', num1, num2, key3)).digest()