def compute_accept(key):
"""Computes value for the Sec-WebSocket-Accept header from value of the
Sec-WebSocket-Key header.
"""
accept_binary = util.sha1_hash(key + common.WEBSOCKET_ACCEPT_UUID).digest()
accept = base64.b64encode(accept_binary)
return (accept, accept_binary)
def compute_accept(key):
"""Computes value for the Sec-WebSocket-Accept header from value of the
Sec-WebSocket-Key header.
"""
accept_binary = util.sha1_hash(
key + common.WEBSOCKET_ACCEPT_UUID).digest()
accept = base64.b64encode(accept_binary)
return (accept, accept_binary)
class ClientHandshakeProcessor(ClientHandshakeBase):
"""WebSocket opening handshake processor for
draft-ietf-hybi-thewebsocketprotocol-06 and later.
"""
def __init__(self, socket, options):
super(ClientHandshakeProcessor, self).__init__()
self._socket = socket
self._options = options
self._logger = util.get_class_logger(self)
def handshake(self):
"""Performs opening handshake on the specified socket.
Raises:
ClientHandshakeError: handshake failed.
"""
request_line = _build_method_line(self._options.resource)
self._logger.debug('Client\'s opening handshake Request-Line: %r',
request_line)
self._socket.sendall(request_line)
fields = []
fields.append(_format_host_header(
self._options.server_host,
self._options.server_port,
self._options.use_tls))
fields.append(_UPGRADE_HEADER)
fields.append(_CONNECTION_HEADER)
if self._options.origin is not None:
if self._options.protocol_version == _PROTOCOL_VERSION_HYBI08:
fields.append(_origin_header(
common.SEC_WEBSOCKET_ORIGIN_HEADER,
self._options.origin))
else:
fields.append(_origin_header(common.ORIGIN_HEADER,
self._options.origin))
original_key = os.urandom(16)
self._key = base64.b64encode(original_key)
self._logger.debug(
'%s: %r (%s)',
common.SEC_WEBSOCKET_KEY_HEADER,
self._key,
util.hexify(original_key))
fields.append(
'%s: %s\r\n' % (common.SEC_WEBSOCKET_KEY_HEADER, self._key))
if self._options.version_header > 0:
fields.append('%s: %d\r\n' % (common.SEC_WEBSOCKET_VERSION_HEADER,
self._options.version_header))
elif self._options.protocol_version == _PROTOCOL_VERSION_HYBI08:
fields.append('%s: %d\r\n' % (common.SEC_WEBSOCKET_VERSION_HEADER,
common.VERSION_HYBI08))
else:
fields.append('%s: %d\r\n' % (common.SEC_WEBSOCKET_VERSION_HEADER,
common.VERSION_HYBI_LATEST))
extensions_to_request = []
if self._options.deflate_frame:
extensions_to_request.append(
common.ExtensionParameter(common.DEFLATE_FRAME_EXTENSION))
if self._options.use_permessage_deflate:
extension = common.ExtensionParameter(
common.PERMESSAGE_DEFLATE_EXTENSION)
# Accept the client_max_window_bits extension parameter by default.
extension.add_parameter(
PerMessageDeflateExtensionProcessor.
_CLIENT_MAX_WINDOW_BITS_PARAM,
None)
extensions_to_request.append(extension)
if len(extensions_to_request) != 0:
fields.append(
'%s: %s\r\n' %
(common.SEC_WEBSOCKET_EXTENSIONS_HEADER,
common.format_extensions(extensions_to_request)))
for field in fields:
self._socket.sendall(field)
self._socket.sendall('\r\n')
self._logger.debug('Sent client\'s opening handshake headers: %r',
fields)
self._logger.debug('Start reading Status-Line')
status_line = ''
while True:
ch = _receive_bytes(self._socket, 1)
status_line += ch
if ch == '\n':
break
m = re.match('HTTP/\\d+\.\\d+ (\\d\\d\\d) .*\r\n', status_line)
if m is None:
raise ClientHandshakeError(
'Wrong status line format: %r' % status_line)
status_code = m.group(1)
if status_code != '101':
self._logger.debug('Unexpected status code %s with following '
'headers: %r', status_code, self._read_fields())
raise ClientHandshakeError(
'Expected HTTP status code 101 but found %r' % status_code)
self._logger.debug('Received valid Status-Line')
self._logger.debug('Start reading headers until we see an empty line')
fields = self._read_fields()
ch = _receive_bytes(self._socket, 1)
if ch != '\n': # 0x0A
raise ClientHandshakeError(
'Expected LF but found %r while reading value %r for header '
'name %r' % (ch, value, name))
self._logger.debug('Received an empty line')
self._logger.debug('Server\'s opening handshake headers: %r', fields)
_validate_mandatory_header(
fields,
common.UPGRADE_HEADER,
common.WEBSOCKET_UPGRADE_TYPE,
False)
_validate_mandatory_header(
fields,
common.CONNECTION_HEADER,
common.UPGRADE_CONNECTION_TYPE,
False)
accept = _get_mandatory_header(
fields, common.SEC_WEBSOCKET_ACCEPT_HEADER)
# Validate
try:
binary_accept = base64.b64decode(accept)
except TypeError, e:
raise HandshakeError(
'Illegal value for header %s: %r' %
(common.SEC_WEBSOCKET_ACCEPT_HEADER, accept))
if len(binary_accept) != 20:
raise ClientHandshakeError(
'Decoded value of %s is not 20-byte long' %
common.SEC_WEBSOCKET_ACCEPT_HEADER)
self._logger.debug(
'Response for challenge : %r (%s)',
accept, util.hexify(binary_accept))
binary_expected_accept = util.sha1_hash(
self._key + common.WEBSOCKET_ACCEPT_UUID).digest()
expected_accept = base64.b64encode(binary_expected_accept)
self._logger.debug(
'Expected response for challenge: %r (%s)',
expected_accept, util.hexify(binary_expected_accept))
if accept != expected_accept:
raise ClientHandshakeError(
'Invalid %s header: %r (expected: %s)' %
(common.SEC_WEBSOCKET_ACCEPT_HEADER, accept, expected_accept))
deflate_frame_accepted = False
permessage_deflate_accepted = False
extensions_header = fields.get(
common.SEC_WEBSOCKET_EXTENSIONS_HEADER.lower())
accepted_extensions = []
if extensions_header is not None and len(extensions_header) != 0:
accepted_extensions = common.parse_extensions(extensions_header[0])
# TODO(bashi): Support the new style perframe compression extension.
for extension in accepted_extensions:
extension_name = extension.name()
if (extension_name == common.DEFLATE_FRAME_EXTENSION and
self._options.deflate_frame):
deflate_frame_accepted = True
processor = DeflateFrameExtensionProcessor(extension)
unused_extension_response = processor.get_extension_response()
self._options.deflate_frame = processor
continue
elif (extension_name == common.PERMESSAGE_DEFLATE_EXTENSION and
self._options.use_permessage_deflate):
permessage_deflate_accepted = True
framer = _get_permessage_deflate_framer(extension)
framer.set_compress_outgoing_enabled(True)
self._options.use_permessage_deflate = framer
continue
raise ClientHandshakeError(
'Unexpected extension %r' % extension_name)
if (self._options.deflate_frame and not deflate_frame_accepted):
raise ClientHandshakeError(
'Requested %s, but the server rejected it' %
common.DEFLATE_FRAME_EXTENSION)
if (self._options.use_permessage_deflate and
not permessage_deflate_accepted):
raise ClientHandshakeError(
'Requested %s, but the server rejected it' %
common.PERMESSAGE_DEFLATE_EXTENSION)
raise Exception('Wrong Connection header')
if not 'sec-websocket-accept' in fields:
raise Exception('No Sec-WebSocket-Accept header')
accept = fields['sec-websocket-accept']
try:
decoded_accept = base64.b64decode(accept)
except TypeError, e:
raise Exception('Illegal value for header Sec-WebSocket-Accept: ' +
accept)
if len(decoded_accept) != 20:
raise Exception(
'Decoded value of Sec-WebSocket-Accept is not 20-byte long')
original_expected_accept = util.sha1_hash(
key + client_for_testing.WEBSOCKET_ACCEPT_UUID).digest()
expected_accept = base64.b64encode(original_expected_accept)
if accept != expected_accept:
raise Exception(
'Invalid Sec-WebSocket-Accept header: %r (expected) != %r '
'(actual)' % (accept, expected_accept))
self._logical_channels_condition.acquire()
self._logical_channels[channel_id] = _LogicalChannelData()
self._logical_channels[channel_id].send_quota = send_quota
self._logical_channels_condition.release()
self._logger.debug('Logical channel %d established' % channel_id)
def _check_logical_channel_is_opened(self, channel_id):
raise Exception('Wrong Connection header')
if not 'sec-websocket-accept' in fields:
raise Exception('No Sec-WebSocket-Accept header')
accept = fields['sec-websocket-accept']
try:
decoded_accept = base64.b64decode(accept)
except TypeError, e:
raise Exception(
'Illegal value for header Sec-WebSocket-Accept: ' + accept)
if len(decoded_accept) != 20:
raise Exception(
'Decoded value of Sec-WebSocket-Accept is not 20-byte long')
original_expected_accept = util.sha1_hash(
key + client_for_testing.WEBSOCKET_ACCEPT_UUID).digest()
expected_accept = base64.b64encode(original_expected_accept)
if accept != expected_accept:
raise Exception(
'Invalid Sec-WebSocket-Accept header: %r (expected) != %r '
'(actual)' % (accept, expected_accept))
self._logical_channels_condition.acquire()
self._logical_channels[channel_id] = _LogicalChannelData()
self._logical_channels[channel_id].send_quota = send_quota
self._logical_channels_condition.release()
self._logger.debug('Logical channel %d established' % channel_id)
def _check_logical_channel_is_opened(self, channel_id):
class WebSocketHandshake(object):
"""Opening handshake processor for the WebSocket protocol (RFC 6455)."""
def __init__(self, options):
self._logger = util.get_class_logger(self)
self._options = options
def handshake(self, socket):
"""Handshake WebSocket.
Raises:
Exception: handshake failed.
"""
self._socket = socket
request_line = _method_line(self._options.resource)
self._logger.debug('Opening handshake Request-Line: %r', request_line)
self._socket.sendall(request_line)
fields = []
fields.append(_UPGRADE_HEADER)
fields.append(_CONNECTION_HEADER)
fields.append(_format_host_header(
self._options.server_host,
self._options.server_port,
self._options.use_tls))
if self._options.version is 8:
fields.append(_sec_origin_header(self._options.origin))
else:
fields.append(_origin_header(self._options.origin))
original_key = os.urandom(16)
key = base64.b64encode(original_key)
self._logger.debug(
'Sec-WebSocket-Key: %s (%s)', key, util.hexify(original_key))
fields.append('Sec-WebSocket-Key: %s\r\n' % key)
fields.append('Sec-WebSocket-Version: %d\r\n' % self._options.version)
# Setting up extensions.
if len(self._options.extensions) > 0:
fields.append('Sec-WebSocket-Extensions: %s\r\n' %
', '.join(self._options.extensions))
self._logger.debug('Opening handshake request headers: %r', fields)
for field in fields:
self._socket.sendall(field)
self._socket.sendall('\r\n')
self._logger.info('Sent opening handshake request')
field = ''
while True:
ch = receive_bytes(self._socket, 1)
field += ch
if ch == '\n':
break
self._logger.debug('Opening handshake Response-Line: %r', field)
if len(field) < 7 or not field.endswith('\r\n'):
raise Exception('Wrong status line: %r' % field)
m = re.match('[^ ]* ([^ ]*) .*', field)
if m is None:
raise Exception(
'No HTTP status code found in status line: %r' % field)
code = m.group(1)
if not re.match('[0-9][0-9][0-9]', code):
raise Exception(
'HTTP status code %r is not three digit in status line: %r' %
(code, field))
if code != '101':
raise HttpStatusException(
'Expected HTTP status code 101 but found %r in status line: '
'%r' % (code, field), int(code))
fields = _read_fields(self._socket)
ch = receive_bytes(self._socket, 1)
if ch != '\n': # 0x0A
raise Exception('Expected LF but found: %r' % ch)
self._logger.debug('Opening handshake response headers: %r', fields)
# Check /fields/
if len(fields['upgrade']) != 1:
raise Exception(
'Multiple Upgrade headers found: %s' % fields['upgrade'])
if len(fields['connection']) != 1:
raise Exception(
'Multiple Connection headers found: %s' % fields['connection'])
if fields['upgrade'][0] != 'websocket':
raise Exception(
'Unexpected Upgrade header value: %s' % fields['upgrade'][0])
if fields['connection'][0].lower() != 'upgrade':
raise Exception(
'Unexpected Connection header value: %s' %
fields['connection'][0])
if len(fields['sec-websocket-accept']) != 1:
raise Exception(
'Multiple Sec-WebSocket-Accept headers found: %s' %
fields['sec-websocket-accept'])
accept = fields['sec-websocket-accept'][0]
# Validate
try:
decoded_accept = base64.b64decode(accept)
except TypeError, e:
raise HandshakeException(
'Illegal value for header Sec-WebSocket-Accept: ' + accept)
if len(decoded_accept) != 20:
raise HandshakeException(
'Decoded value of Sec-WebSocket-Accept is not 20-byte long')
self._logger.debug('Actual Sec-WebSocket-Accept: %r (%s)',
accept, util.hexify(decoded_accept))
original_expected_accept = util.sha1_hash(
key + WEBSOCKET_ACCEPT_UUID).digest()
expected_accept = base64.b64encode(original_expected_accept)
self._logger.debug('Expected Sec-WebSocket-Accept: %r (%s)',
expected_accept,
util.hexify(original_expected_accept))
if accept != expected_accept:
raise Exception(
'Invalid Sec-WebSocket-Accept header: %r (expected) != %r '
'(actual)' % (accept, expected_accept))
server_extensions_header = fields.get('sec-websocket-extensions')
accepted_extensions = []
if server_extensions_header is not None:
accepted_extensions = common.parse_extensions(
', '.join(server_extensions_header))
# Scan accepted extension list to check if there is any unrecognized
# extensions or extensions we didn't request in it. Then, for
# extensions we request, parse them and store parameters. They will be
# used later by each extension.
deflate_frame_accepted = False
mux_accepted = False
for extension in accepted_extensions:
if extension.name() == _DEFLATE_FRAME_EXTENSION:
if self._options.use_deflate_frame:
deflate_frame_accepted = True
continue
if extension.name() == _MUX_EXTENSION:
if self._options.use_mux:
mux_accepted = True
continue
if extension.name() == _PERMESSAGE_DEFLATE_EXTENSION:
checker = self._options.check_permessage_deflate
if checker:
checker(extension)
continue
raise Exception(
'Received unrecognized extension: %s' % extension.name())
# Let all extensions check the response for extension request.
if (self._options.use_deflate_frame and
not deflate_frame_accepted):
raise Exception('%s extension not accepted' %
_DEFLATE_FRAME_EXTENSION)
if self._options.use_mux and not mux_accepted:
raise Exception('%s extension not accepted' % _MUX_EXTENSION)
