1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
|
"""
websocket - WebSocket client library for Python
Copyright (C) 2010 Hiroki Ohtani(liris)
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1335 USA
"""
import six
if six.PY3:
from base64 import encodebytes as base64encode
else:
from base64 import encodestring as base64encode
import uuid
import hashlib
from ._logging import *
from ._url import *
from ._socket import*
from ._http import *
from ._exceptions import *
__all__ = ["handshake_response", "handshake"]
# websocket supported version.
VERSION = 13
class handshake_response(object):
def __init__(self, status, headers, subprotocol):
self.status = status
self.headers = headers
self.subprotocol = subprotocol
def handshake(sock, hostname, port, resource, **options):
headers, key = _get_handshake_headers(resource, hostname, port, options)
header_str = "\r\n".join(headers)
send(sock, header_str)
dump("request header", header_str)
status, resp = _get_resp_headers(sock)
success, subproto = _validate(resp, key, options.get("subprotocols"))
if not success:
raise WebSocketException("Invalid WebSocket Header")
return handshake_response(status, resp, subproto)
def _get_handshake_headers(resource, host, port, options):
headers = []
headers.append("GET %s HTTP/1.1" % resource)
headers.append("Upgrade: websocket")
headers.append("Connection: Upgrade")
if port == 80:
hostport = host
else:
hostport = "%s:%d" % (host, port)
if "host" in options and options["host"]:
headers.append("Host: %s" % options["host"])
else:
headers.append("Host: %s" % hostport)
if "origin" in options and options["origin"]:
headers.append("Origin: %s" % options["origin"])
else:
headers.append("Origin: http://%s" % hostport)
key = _create_sec_websocket_key()
headers.append("Sec-WebSocket-Key: %s" % key)
headers.append("Sec-WebSocket-Version: %s" % VERSION)
subprotocols = options.get("subprotocols")
if subprotocols:
headers.append("Sec-WebSocket-Protocol: %s" % ",".join(subprotocols))
if "header" in options:
headers.extend(options["header"])
cookie = options.get("cookie", None)
if cookie:
headers.append("Cookie: %s" % cookie)
headers.append("")
headers.append("")
return headers, key
def _get_resp_headers(sock, success_status=101):
status, resp_headers = read_headers(sock)
if status != success_status:
raise WebSocketException("Handshake status %d" % status)
return status, resp_headers
_HEADERS_TO_CHECK = {
"upgrade": "websocket",
"connection": "upgrade",
}
def _validate(headers, key, subprotocols):
subproto = None
for k, v in _HEADERS_TO_CHECK.items():
r = headers.get(k, None)
if not r:
return False, None
r = r.lower()
if v != r:
return False, None
if subprotocols:
subproto = headers.get("sec-websocket-protocol", None).lower()
if not subproto or subproto not in [s.lower() for s in subprotocols]:
error("Invalid subprotocol: " + str(subprotocols))
return False, None
result = headers.get("sec-websocket-accept", None)
if not result:
return False, None
result = result.lower()
if isinstance(result, six.text_type):
result = result.encode('utf-8')
value = (key + "258EAFA5-E914-47DA-95CA-C5AB0DC85B11").encode('utf-8')
hashed = base64encode(hashlib.sha1(value).digest()).strip().lower()
success = (hashed == result)
if success:
return True, subproto
else:
return False, None
def _create_sec_websocket_key():
uid = uuid.uuid4()
return base64encode(uid.bytes).decode('utf-8').strip()
|