222 lines
6.6 KiB
Python
Executable File
222 lines
6.6 KiB
Python
Executable File
#!/usr/bin/python
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'''
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Python WebSocket library with support for "wss://" encryption.
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You can make a cert/key with openssl using:
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openssl req -new -x509 -days 365 -nodes -out self.pem -keyout self.pem
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as taken from http://docs.python.org/dev/library/ssl.html#certificates
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'''
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import sys, socket, ssl, struct, traceback
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import os, resource, errno, signal # daemonizing
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from base64 import b64encode, b64decode
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from hashlib import md5
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settings = {
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'listen_host' : '',
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'listen_port' : None,
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'handler' : None,
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'cert' : None,
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'ssl_only' : False,
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'daemon' : True,
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'record' : None, }
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client_settings = {
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'b64encode' : False,
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'seq_num' : False, }
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send_seq = 0
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server_handshake = """HTTP/1.1 101 Web Socket Protocol Handshake\r
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Upgrade: WebSocket\r
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Connection: Upgrade\r
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%sWebSocket-Origin: %s\r
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%sWebSocket-Location: %s://%s%s\r
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%sWebSocket-Protocol: sample\r
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\r
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%s"""
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policy_response = """<cross-domain-policy><allow-access-from domain="*" to-ports="*" /></cross-domain-policy>\n"""
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def traffic(token="."):
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sys.stdout.write(token)
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sys.stdout.flush()
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def encode(buf):
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global send_seq
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if client_settings['b64encode']:
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buf = b64encode(buf)
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else:
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# Modified UTF-8 encode
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buf = buf.decode('latin-1').encode('utf-8').replace("\x00", "\xc4\x80")
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if client_settings['seq_num']:
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send_seq += 1
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return "\x00%d:%s\xff" % (send_seq-1, buf)
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else:
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return "\x00%s\xff" % buf
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def decode(buf):
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""" Parse out WebSocket packets. """
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if buf.count('\xff') > 1:
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if client_settings['b64encode']:
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return [b64decode(d[1:]) for d in buf.split('\xff')]
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else:
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# Modified UTF-8 decode
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return [d[1:].replace("\xc4\x80", "\x00").decode('utf-8').encode('latin-1') for d in buf.split('\xff')]
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else:
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if client_settings['b64encode']:
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return [b64decode(buf[1:-1])]
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else:
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return [buf[1:-1].replace("\xc4\x80", "\x00").decode('utf-8').encode('latin-1')]
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def parse_handshake(handshake):
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ret = {}
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req_lines = handshake.split("\r\n")
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if not req_lines[0].startswith("GET "):
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raise Exception("Invalid handshake: no GET request line")
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ret['path'] = req_lines[0].split(" ")[1]
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for line in req_lines[1:]:
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if line == "": break
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var, delim, val = line.partition(": ")
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ret[var] = val
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if req_lines[-2] == "":
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ret['key3'] = req_lines[-1]
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return ret
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def gen_md5(keys):
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key1 = keys['Sec-WebSocket-Key1']
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key2 = keys['Sec-WebSocket-Key2']
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key3 = keys['key3']
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spaces1 = key1.count(" ")
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spaces2 = key2.count(" ")
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num1 = int("".join([c for c in key1 if c.isdigit()])) / spaces1
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num2 = int("".join([c for c in key2 if c.isdigit()])) / spaces2
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return md5(struct.pack('>II8s', num1, num2, key3)).digest()
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def do_handshake(sock):
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global client_settings, send_seq
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client_settings['b64encode'] = False
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client_settings['seq_num'] = False
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send_seq = 0
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# Peek, but don't read the data
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handshake = sock.recv(1024, socket.MSG_PEEK)
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#print "Handshake [%s]" % repr(handshake)
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if handshake == "":
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print "Ignoring empty handshake"
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sock.close()
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return False
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elif handshake.startswith("<policy-file-request/>"):
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handshake = sock.recv(1024)
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print "Sending flash policy response"
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sock.send(policy_response)
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sock.close()
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return False
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elif handshake.startswith("\x16"):
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retsock = ssl.wrap_socket(
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sock,
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server_side=True,
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certfile=settings['cert'],
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ssl_version=ssl.PROTOCOL_TLSv1)
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scheme = "wss"
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print " using SSL/TLS"
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elif settings['ssl_only']:
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print "Non-SSL connection disallowed"
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sock.close()
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return False
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else:
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retsock = sock
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scheme = "ws"
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print " using plain (not SSL) socket"
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handshake = retsock.recv(4096)
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#print "handshake: " + repr(handshake)
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h = parse_handshake(handshake)
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# Parse client settings from the GET path
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cvars = h['path'].partition('?')[2].partition('#')[0].split('&')
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for cvar in [c for c in cvars if c]:
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name, _, val = cvar.partition('=')
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if name not in ['b64encode', 'seq_num']: continue
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value = val and val or True
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client_settings[name] = value
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print " %s=%s" % (name, value)
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if h.get('key3'):
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trailer = gen_md5(h)
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pre = "Sec-"
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print " using protocol version 76"
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else:
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trailer = ""
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pre = ""
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print " using protocol version 75"
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response = server_handshake % (pre, h['Origin'], pre, scheme,
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h['Host'], h['path'], pre, trailer)
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#print "sending response:", repr(response)
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retsock.send(response)
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return retsock
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def daemonize():
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os.umask(0)
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os.chdir('/')
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os.setgid(os.getgid()) # relinquish elevations
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os.setuid(os.getuid()) # relinquish elevations
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# Double fork to daemonize
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if os.fork() > 0: os._exit(0) # Parent exits
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os.setsid() # Obtain new process group
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if os.fork() > 0: os._exit(0) # Parent exits
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# Signal handling
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def terminate(a,b): os._exit(0)
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signal.signal(signal.SIGTERM, terminate)
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signal.signal(signal.SIGINT, signal.SIG_IGN)
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# Close open files
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maxfd = resource.getrlimit(resource.RLIMIT_NOFILE)[1]
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if maxfd == resource.RLIM_INFINITY: maxfd = 256
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for fd in reversed(range(maxfd)):
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try:
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os.close(fd)
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except OSError, exc:
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if exc.errno != errno.EBADF: raise
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# Redirect I/O to /dev/null
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os.dup2(os.open(os.devnull, os.O_RDWR), sys.stdin.fileno())
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os.dup2(os.open(os.devnull, os.O_RDWR), sys.stdout.fileno())
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os.dup2(os.open(os.devnull, os.O_RDWR), sys.stderr.fileno())
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def start_server():
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if settings['daemon']: daemonize()
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lsock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
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lsock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
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lsock.bind((settings['listen_host'], settings['listen_port']))
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lsock.listen(100)
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while True:
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try:
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csock = startsock = None
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print 'waiting for connection on port %s' % settings['listen_port']
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startsock, address = lsock.accept()
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print 'Got client connection from %s' % address[0]
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csock = do_handshake(startsock)
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if not csock: continue
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settings['handler'](csock)
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except Exception:
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print "Ignoring exception:"
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print traceback.format_exc()
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if csock: csock.close()
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if startsock and startsock != csock: startsock.close()
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