import base64 import hashlib import json import logging logger = logging.getLogger(__name__) class WebSocketConnection(object): def __init__(self, handler, messageHandler): self.handler = handler self.messageHandler = messageHandler my_headers = self.handler.headers.items() my_header_keys = list(map(lambda x:x[0],my_headers)) h_key_exists = lambda x:my_header_keys.count(x) h_value = lambda x:my_headers[my_header_keys.index(x)][1] if (not h_key_exists("Upgrade")) or not (h_value("Upgrade")=="websocket") or (not h_key_exists("Sec-WebSocket-Key")): raise WebSocketException ws_key = h_value("Sec-WebSocket-Key") shakey = hashlib.sha1() shakey.update("{ws_key}258EAFA5-E914-47DA-95CA-C5AB0DC85B11".format(ws_key = ws_key).encode()) ws_key_toreturn = base64.b64encode(shakey.digest()) self.handler.wfile.write("HTTP/1.1 101 Switching Protocols\r\nUpgrade: websocket\r\nConnection: Upgrade\r\nSec-WebSocket-Accept: {0}\r\nCQ-CQ-de: HA5KFU\r\n\r\n".format(ws_key_toreturn.decode()).encode()) def get_header(self, size, opcode): ws_first_byte = 0b10000000 | (opcode & 0x0F) if (size > 125): return bytes([ws_first_byte, 126, (size>>8) & 0xff, size & 0xff]) else: # 256 bytes binary message in a single unmasked frame return bytes([ws_first_byte, size]) def send(self, data): # convenience if (type(data) == dict): # allow_nan = False disallows NaN and Infinty to be encoded. Browser JSON will not parse them anyway. data = json.dumps(data, allow_nan = False) # string-type messages are sent as text frames if (type(data) == str): header = self.get_header(len(data), 1) self.handler.wfile.write(header + data.encode('utf-8')) self.handler.wfile.flush() # anything else as binary else: header = self.get_header(len(data), 2) self.handler.wfile.write(header + data) self.handler.wfile.flush() def read_loop(self): open = True while (open): header = self.handler.rfile.read(2) opcode = header[0] & 0x0F length = header[1] & 0x7F mask = (header[1] & 0x80) >> 7 if (length == 126): header = self.handler.rfile.read(2) length = (header[0] << 8) + header[1] if (mask): masking_key = self.handler.rfile.read(4) data = self.handler.rfile.read(length) if (mask): data = bytes([b ^ masking_key[index % 4] for (index, b) in enumerate(data)]) if (opcode == 1): message = data.decode('utf-8') self.messageHandler.handleTextMessage(self, message) elif (opcode == 2): self.messageHandler.handleBinaryMessage(self, data) elif (opcode == 8): open = False self.messageHandler.handleClose(self) else: logger.warning("unsupported opcode: {0}".format(opcode)) def close(self): try: header = self.get_header(0, 8) self.handler.wfile.write(header) self.handler.wfile.flush() except ValueError: logger.exception("while writing close frame:") try: self.handler.finish() self.handler.connection.close() except Exception: logger.exception("while closing connection:") class WebSocketException(Exception): pass