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Diffstat (limited to 'testing/mochitest/pywebsocket/mod_pywebsocket/handshake/hybi00.py')
| -rw-r--r-- | testing/mochitest/pywebsocket/mod_pywebsocket/handshake/hybi00.py | 293 |
1 files changed, 293 insertions, 0 deletions
diff --git a/testing/mochitest/pywebsocket/mod_pywebsocket/handshake/hybi00.py b/testing/mochitest/pywebsocket/mod_pywebsocket/handshake/hybi00.py new file mode 100644 index 000000000..8757717a6 --- /dev/null +++ b/testing/mochitest/pywebsocket/mod_pywebsocket/handshake/hybi00.py @@ -0,0 +1,293 @@ +# Copyright 2011, Google Inc. +# All rights reserved. +# +# Redistribution and use in source and binary forms, with or without +# modification, are permitted provided that the following conditions are +# met: +# +# * Redistributions of source code must retain the above copyright +# notice, this list of conditions and the following disclaimer. +# * Redistributions in binary form must reproduce the above +# copyright notice, this list of conditions and the following disclaimer +# in the documentation and/or other materials provided with the +# distribution. +# * Neither the name of Google Inc. nor the names of its +# contributors may be used to endorse or promote products derived from +# this software without specific prior written permission. +# +# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + + +"""This file provides the opening handshake processor for the WebSocket +protocol version HyBi 00. + +Specification: +http://tools.ietf.org/html/draft-ietf-hybi-thewebsocketprotocol-00 +""" + + +# Note: request.connection.write/read are used in this module, even though +# mod_python document says that they should be used only in connection +# handlers. Unfortunately, we have no other options. For example, +# request.write/read are not suitable because they don't allow direct raw bytes +# writing/reading. + + +import logging +import re +import struct + +from mod_pywebsocket import common +from mod_pywebsocket.stream import StreamHixie75 +from mod_pywebsocket import util +from mod_pywebsocket.handshake._base import HandshakeException +from mod_pywebsocket.handshake._base import check_request_line +from mod_pywebsocket.handshake._base import format_header +from mod_pywebsocket.handshake._base import get_default_port +from mod_pywebsocket.handshake._base import get_mandatory_header +from mod_pywebsocket.handshake._base import parse_host_header +from mod_pywebsocket.handshake._base import validate_mandatory_header + + +_MANDATORY_HEADERS = [ + # key, expected value or None + [common.UPGRADE_HEADER, common.WEBSOCKET_UPGRADE_TYPE_HIXIE75], + [common.CONNECTION_HEADER, common.UPGRADE_CONNECTION_TYPE], +] + + +def _validate_subprotocol(subprotocol): + """Checks if characters in subprotocol are in range between U+0020 and + U+007E. A value in the Sec-WebSocket-Protocol field need to satisfy this + requirement. + + See the Section 4.1. Opening handshake of the spec. + """ + + if not subprotocol: + raise HandshakeException('Invalid subprotocol name: empty') + + # Parameter should be in the range U+0020 to U+007E. + for c in subprotocol: + if not 0x20 <= ord(c) <= 0x7e: + raise HandshakeException( + 'Illegal character in subprotocol name: %r' % c) + + +def _check_header_lines(request, mandatory_headers): + check_request_line(request) + + # The expected field names, and the meaning of their corresponding + # values, are as follows. + # |Upgrade| and |Connection| + for key, expected_value in mandatory_headers: + validate_mandatory_header(request, key, expected_value) + + +def _build_location(request): + """Build WebSocket location for request.""" + + location_parts = [] + if request.is_https(): + location_parts.append(common.WEB_SOCKET_SECURE_SCHEME) + else: + location_parts.append(common.WEB_SOCKET_SCHEME) + location_parts.append('://') + host, port = parse_host_header(request) + connection_port = request.connection.local_addr[1] + if port != connection_port: + raise HandshakeException('Header/connection port mismatch: %d/%d' % + (port, connection_port)) + location_parts.append(host) + if (port != get_default_port(request.is_https())): + location_parts.append(':') + location_parts.append(str(port)) + location_parts.append(request.unparsed_uri) + return ''.join(location_parts) + + +class Handshaker(object): + """Opening handshake processor for the WebSocket protocol version HyBi 00. + """ + + def __init__(self, request, dispatcher): + """Construct an instance. + + Args: + request: mod_python request. + dispatcher: Dispatcher (dispatch.Dispatcher). + + Handshaker will add attributes such as ws_resource in performing + handshake. + """ + + self._logger = util.get_class_logger(self) + + self._request = request + self._dispatcher = dispatcher + + def do_handshake(self): + """Perform WebSocket Handshake. + + On _request, we set + ws_resource, ws_protocol, ws_location, ws_origin, ws_challenge, + ws_challenge_md5: WebSocket handshake information. + ws_stream: Frame generation/parsing class. + ws_version: Protocol version. + + Raises: + HandshakeException: when any error happened in parsing the opening + handshake request. + """ + + # 5.1 Reading the client's opening handshake. + # dispatcher sets it in self._request. + _check_header_lines(self._request, _MANDATORY_HEADERS) + self._set_resource() + self._set_subprotocol() + self._set_location() + self._set_origin() + self._set_challenge_response() + self._set_protocol_version() + + self._dispatcher.do_extra_handshake(self._request) + + self._send_handshake() + + def _set_resource(self): + self._request.ws_resource = self._request.uri + + def _set_subprotocol(self): + # |Sec-WebSocket-Protocol| + subprotocol = self._request.headers_in.get( + common.SEC_WEBSOCKET_PROTOCOL_HEADER) + if subprotocol is not None: + _validate_subprotocol(subprotocol) + self._request.ws_protocol = subprotocol + + def _set_location(self): + # |Host| + host = self._request.headers_in.get(common.HOST_HEADER) + if host is not None: + self._request.ws_location = _build_location(self._request) + # TODO(ukai): check host is this host. + + def _set_origin(self): + # |Origin| + origin = self._request.headers_in.get(common.ORIGIN_HEADER) + if origin is not None: + self._request.ws_origin = origin + + def _set_protocol_version(self): + # |Sec-WebSocket-Draft| + draft = self._request.headers_in.get(common.SEC_WEBSOCKET_DRAFT_HEADER) + if draft is not None and draft != '0': + raise HandshakeException('Illegal value for %s: %s' % + (common.SEC_WEBSOCKET_DRAFT_HEADER, + draft)) + + self._logger.debug('Protocol version is HyBi 00') + self._request.ws_version = common.VERSION_HYBI00 + self._request.ws_stream = StreamHixie75(self._request, True) + + def _set_challenge_response(self): + # 5.2 4-8. + self._request.ws_challenge = self._get_challenge() + # 5.2 9. let /response/ be the MD5 finterprint of /challenge/ + self._request.ws_challenge_md5 = util.md5_hash( + self._request.ws_challenge).digest() + self._logger.debug( + 'Challenge: %r (%s)', + self._request.ws_challenge, + util.hexify(self._request.ws_challenge)) + self._logger.debug( + 'Challenge response: %r (%s)', + self._request.ws_challenge_md5, + util.hexify(self._request.ws_challenge_md5)) + + def _get_key_value(self, key_field): + key_value = get_mandatory_header(self._request, key_field) + + self._logger.debug('%s: %r', key_field, key_value) + + # 5.2 4. let /key-number_n/ be the digits (characters in the range + # U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9)) in /key_n/, + # interpreted as a base ten integer, ignoring all other characters + # in /key_n/. + try: + key_number = int(re.sub("\\D", "", key_value)) + except: + raise HandshakeException('%s field contains no digit' % key_field) + # 5.2 5. let /spaces_n/ be the number of U+0020 SPACE characters + # in /key_n/. + spaces = re.subn(" ", "", key_value)[1] + if spaces == 0: + raise HandshakeException('%s field contains no space' % key_field) + + self._logger.debug( + '%s: Key-number is %d and number of spaces is %d', + key_field, key_number, spaces) + + # 5.2 6. if /key-number_n/ is not an integral multiple of /spaces_n/ + # then abort the WebSocket connection. + if key_number % spaces != 0: + raise HandshakeException( + '%s: Key-number (%d) is not an integral multiple of spaces ' + '(%d)' % (key_field, key_number, spaces)) + # 5.2 7. let /part_n/ be /key-number_n/ divided by /spaces_n/. + part = key_number / spaces + self._logger.debug('%s: Part is %d', key_field, part) + return part + + def _get_challenge(self): + # 5.2 4-7. + key1 = self._get_key_value(common.SEC_WEBSOCKET_KEY1_HEADER) + key2 = self._get_key_value(common.SEC_WEBSOCKET_KEY2_HEADER) + # 5.2 8. let /challenge/ be the concatenation of /part_1/, + challenge = '' + challenge += struct.pack('!I', key1) # network byteorder int + challenge += struct.pack('!I', key2) # network byteorder int + challenge += self._request.connection.read(8) + return challenge + + def _send_handshake(self): + response = [] + + # 5.2 10. send the following line. + response.append('HTTP/1.1 101 WebSocket Protocol Handshake\r\n') + + # 5.2 11. send the following fields to the client. + response.append(format_header( + common.UPGRADE_HEADER, common.WEBSOCKET_UPGRADE_TYPE_HIXIE75)) + response.append(format_header( + common.CONNECTION_HEADER, common.UPGRADE_CONNECTION_TYPE)) + response.append(format_header( + common.SEC_WEBSOCKET_LOCATION_HEADER, self._request.ws_location)) + response.append(format_header( + common.SEC_WEBSOCKET_ORIGIN_HEADER, self._request.ws_origin)) + if self._request.ws_protocol: + response.append(format_header( + common.SEC_WEBSOCKET_PROTOCOL_HEADER, + self._request.ws_protocol)) + # 5.2 12. send two bytes 0x0D 0x0A. + response.append('\r\n') + # 5.2 13. send /response/ + response.append(self._request.ws_challenge_md5) + + raw_response = ''.join(response) + self._request.connection.write(raw_response) + self._logger.debug('Sent server\'s opening handshake: %r', + raw_response) + + +# vi:sts=4 sw=4 et |