diff options
Diffstat (limited to 'testing/mochitest/pywebsocket3/mod_pywebsocket/handshake/hybi.py')
| -rw-r--r-- | testing/mochitest/pywebsocket3/mod_pywebsocket/handshake/hybi.py | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/testing/mochitest/pywebsocket3/mod_pywebsocket/handshake/hybi.py b/testing/mochitest/pywebsocket3/mod_pywebsocket/handshake/hybi.py new file mode 100644 index 0000000000..5290ea24fb --- /dev/null +++ b/testing/mochitest/pywebsocket3/mod_pywebsocket/handshake/hybi.py @@ -0,0 +1,229 @@ +# Copyright 2012, 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 (RFC 6455). + +Specification: +http://tools.ietf.org/html/rfc6455 +""" + +from __future__ import absolute_import +import base64 +import re +from hashlib import sha1 + +from mod_pywebsocket import common +from mod_pywebsocket.handshake.base import get_mandatory_header +from mod_pywebsocket.handshake.base import HandshakeException +from mod_pywebsocket.handshake.base import parse_token_list +from mod_pywebsocket.handshake.base import validate_mandatory_header +from mod_pywebsocket.handshake.base import HandshakerBase +from mod_pywebsocket import util + +# Used to validate the value in the Sec-WebSocket-Key header strictly. RFC 4648 +# disallows non-zero padding, so the character right before == must be any of +# A, Q, g and w. +_SEC_WEBSOCKET_KEY_REGEX = re.compile('^[+/0-9A-Za-z]{21}[AQgw]==$') + + +def check_request_line(request): + # 5.1 1. The three character UTF-8 string "GET". + # 5.1 2. A UTF-8-encoded U+0020 SPACE character (0x20 byte). + if request.method != u'GET': + raise HandshakeException('Method is not GET: %r' % request.method) + + if request.protocol != u'HTTP/1.1': + raise HandshakeException('Version is not HTTP/1.1: %r' % + request.protocol) + + +def compute_accept(key): + """Computes value for the Sec-WebSocket-Accept header from value of the + Sec-WebSocket-Key header. + """ + + accept_binary = sha1(key + common.WEBSOCKET_ACCEPT_UUID).digest() + accept = base64.b64encode(accept_binary) + + return accept + + +def compute_accept_from_unicode(unicode_key): + """A wrapper function for compute_accept which takes a unicode string as an + argument, and encodes it to byte string. It then passes it on to + compute_accept. + """ + + key = unicode_key.encode('UTF-8') + return compute_accept(key) + + +def format_header(name, value): + return u'%s: %s\r\n' % (name, value) + + +class Handshaker(HandshakerBase): + """Opening handshake processor for the WebSocket protocol (RFC 6455).""" + 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 during handshake. + """ + super(Handshaker, self).__init__(request, dispatcher) + + def _transform_header(self, header): + return header + + def _protocol_rfc(self): + return 'RFC 6455' + + def _validate_connection_header(self): + connection = get_mandatory_header(self._request, + common.CONNECTION_HEADER) + + try: + connection_tokens = parse_token_list(connection) + except HandshakeException as e: + raise HandshakeException('Failed to parse %s: %s' % + (common.CONNECTION_HEADER, e)) + + connection_is_valid = False + for token in connection_tokens: + if token.lower() == common.UPGRADE_CONNECTION_TYPE.lower(): + connection_is_valid = True + break + if not connection_is_valid: + raise HandshakeException( + '%s header doesn\'t contain "%s"' % + (common.CONNECTION_HEADER, common.UPGRADE_CONNECTION_TYPE)) + + def _validate_request(self): + check_request_line(self._request) + validate_mandatory_header(self._request, common.UPGRADE_HEADER, + common.WEBSOCKET_UPGRADE_TYPE) + self._validate_connection_header() + unused_host = get_mandatory_header(self._request, common.HOST_HEADER) + + def _set_accept(self): + # Key validation, response generation. + key = self._get_key() + accept = compute_accept(key) + self._logger.debug('%s: %r (%s)', common.SEC_WEBSOCKET_ACCEPT_HEADER, + accept, util.hexify(base64.b64decode(accept))) + self._request._accept = accept + + def _validate_key(self, key): + if key.find(',') >= 0: + raise HandshakeException('Request has multiple %s header lines or ' + 'contains illegal character \',\': %r' % + (common.SEC_WEBSOCKET_KEY_HEADER, key)) + + # Validate + key_is_valid = False + try: + # Validate key by quick regex match before parsing by base64 + # module. Because base64 module skips invalid characters, we have + # to do this in advance to make this server strictly reject illegal + # keys. + if _SEC_WEBSOCKET_KEY_REGEX.match(key): + decoded_key = base64.b64decode(key) + if len(decoded_key) == 16: + key_is_valid = True + except TypeError as e: + pass + + if not key_is_valid: + raise HandshakeException('Illegal value for header %s: %r' % + (common.SEC_WEBSOCKET_KEY_HEADER, key)) + + return decoded_key + + def _get_key(self): + key = get_mandatory_header(self._request, + common.SEC_WEBSOCKET_KEY_HEADER) + + decoded_key = self._validate_key(key) + + self._logger.debug('%s: %r (%s)', common.SEC_WEBSOCKET_KEY_HEADER, key, + util.hexify(decoded_key)) + + return key.encode('UTF-8') + + def _create_handshake_response(self, accept): + response = [] + + response.append(u'HTTP/1.1 101 Switching Protocols\r\n') + + # WebSocket headers + response.append( + format_header(common.UPGRADE_HEADER, + common.WEBSOCKET_UPGRADE_TYPE)) + response.append( + format_header(common.CONNECTION_HEADER, + common.UPGRADE_CONNECTION_TYPE)) + response.append( + format_header(common.SEC_WEBSOCKET_ACCEPT_HEADER, + accept.decode('UTF-8'))) + if self._request.ws_protocol is not None: + response.append( + format_header(common.SEC_WEBSOCKET_PROTOCOL_HEADER, + self._request.ws_protocol)) + if (self._request.ws_extensions is not None + and len(self._request.ws_extensions) != 0): + response.append( + format_header( + common.SEC_WEBSOCKET_EXTENSIONS_HEADER, + common.format_extensions(self._request.ws_extensions))) + + # MOZILLA + if self._request.sts is not None: + response.append(format_header("Strict-Transport-Security", + self._request.sts)) + # /MOZILLA + + # Headers not specific for WebSocket + for name, value in self._request.extra_headers: + response.append(format_header(name, value)) + + response.append(u'\r\n') + + return u''.join(response) + + def _send_handshake(self): + raw_response = self._create_handshake_response(self._request._accept) + self._request.connection.write(raw_response.encode('UTF-8')) + self._logger.debug('Sent server\'s opening handshake: %r', + raw_response) + + +# vi:sts=4 sw=4 et |