class WebSocketResponse(HttpResponse):
"""Upgrade from a WSGI connection with the WebSocket handshake."""
status_code = 101
def __init__(self, environ, reader, writer, hdlr, hdlr_args, hdlr_kwargs):
super().__init__()
try:
key = self.check_request(environ)
except Exception:
self.status_code = 400
self.content = "Invalid WebSocket handshake."
else:
self.create_headers(key)
self.ws = WebSocket(reader, writer)
self.ws_handler = hdlr(self.ws, *hdlr_args, **hdlr_kwargs)
def check_request(self, environ):
# Host and Origin checking isn't handled at this level.
# RFC6455 - 4.2.1. Reading the Client's Opening Handshake
assert environ['SERVER_PROTOCOL'] == 'HTTP/1.1'
assert environ['HTTP_HOST'] # the server's authority isn't known
assert environ['HTTP_UPGRADE'].lower() == 'websocket'
assert any(token.strip() == 'upgrade'
for token in environ['HTTP_CONNECTION'].lower().split(','))
assert len(base64.b64decode(environ['HTTP_SEC_WEBSOCKET_KEY'])) == 16
assert environ['HTTP_SEC_WEBSOCKET_VERSION'] == '13'
return environ['HTTP_SEC_WEBSOCKET_KEY']
def create_headers(self, key):
# Reset headers (private API!)
self._headers = {}
# RFC6455 - 4.2.2. Sending the Server's Opening Handshake
guid = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"
sha1 = hashlib.sha1((key + guid).encode()).digest()
self['Upgrade'] = 'WebSocket'
self['Connection'] = 'Upgrade'
self['Sec-WebSocket-Accept'] = base64.b64encode(sha1)
@tulip.coroutine
def close(self):
# This is where the magic happens.
yield from self.ws_handler
self.ws.close()
super().close()
def __init__(self, environ, reader, writer, hdlr, hdlr_args, hdlr_kwargs):
super().__init__()
try:
key = self.check_request(environ)
except Exception:
self.status_code = 400
self.content = "Invalid WebSocket handshake."
else:
self.create_headers(key)
self.ws = WebSocket(reader, writer)
self.ws_handler = hdlr(self.ws, *hdlr_args, **hdlr_kwargs)
