48421f902e
Usually, the number of characters in FORBIDDEN_CHARS are fewer than the number of characters in the req.path - so it's better to use smaller count for the outer loop. Change-Id: I78b7e0ff4cae1cc90e8d29d7bddcec7fe0ba4bd4
143 lines
5.0 KiB
Python
143 lines
5.0 KiB
Python
# Copyright (c) 2012 OpenStack Foundation
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
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# implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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'''
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Created on February 27, 2012
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A filter that disallows any paths that contain defined forbidden characters or
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that exceed a defined length.
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Place early in the proxy-server pipeline after the left-most occurrence of the
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``proxy-logging`` middleware (if present) and before the final
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``proxy-logging`` middleware (if present) or the ``proxy-serer`` app itself,
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e.g.::
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[pipeline:main]
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pipeline = catch_errors healthcheck proxy-logging name_check cache \
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ratelimit tempauth sos proxy-logging proxy-server
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[filter:name_check]
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use = egg:swift#name_check
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forbidden_chars = '"`<>
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maximum_length = 255
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There are default settings for forbidden_chars (FORBIDDEN_CHARS) and
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maximum_length (MAX_LENGTH)
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The filter returns HTTPBadRequest if path is invalid.
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@author: eamonn-otoole
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'''
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from six.moves.urllib.parse import unquote
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import re
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from swift.common.utils import get_logger
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from swift.common.swob import Request, HTTPBadRequest
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FORBIDDEN_CHARS = "\'\"`<>"
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MAX_LENGTH = 255
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FORBIDDEN_REGEXP = "/\./|/\.\./|/\.$|/\.\.$"
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class NameCheckMiddleware(object):
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def __init__(self, app, conf):
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self.app = app
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self.conf = conf
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self.forbidden_chars = self.conf.get('forbidden_chars',
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FORBIDDEN_CHARS)
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self.maximum_length = int(self.conf.get('maximum_length', MAX_LENGTH))
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self.forbidden_regexp = self.conf.get('forbidden_regexp',
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FORBIDDEN_REGEXP)
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if self.forbidden_regexp:
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self.forbidden_regexp_compiled = re.compile(self.forbidden_regexp)
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else:
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self.forbidden_regexp_compiled = None
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self.logger = get_logger(self.conf, log_route='name_check')
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def check_character(self, req):
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'''
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Checks req.path for any forbidden characters
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Returns True if there are any forbidden characters
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Returns False if there aren't any forbidden characters
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'''
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self.logger.debug("name_check: path %s" % req.path)
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self.logger.debug("name_check: self.forbidden_chars %s" %
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self.forbidden_chars)
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return any((c in unquote(req.path)) for c in self.forbidden_chars)
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def check_length(self, req):
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'''
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Checks that req.path doesn't exceed the defined maximum length
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Returns True if the length exceeds the maximum
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Returns False if the length is <= the maximum
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'''
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length = len(unquote(req.path))
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return length > self.maximum_length
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def check_regexp(self, req):
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'''
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Checks that req.path doesn't contain a substring matching regexps.
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Returns True if there are any forbidden substring
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Returns False if there aren't any forbidden substring
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'''
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if self.forbidden_regexp_compiled is None:
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return False
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self.logger.debug("name_check: path %s" % req.path)
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self.logger.debug("name_check: self.forbidden_regexp %s" %
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self.forbidden_regexp)
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unquoted_path = unquote(req.path)
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match = self.forbidden_regexp_compiled.search(unquoted_path)
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return (match is not None)
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def __call__(self, env, start_response):
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req = Request(env)
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if self.check_character(req):
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return HTTPBadRequest(
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request=req,
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body=("Object/Container/Account name contains forbidden "
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"chars from %s"
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% self.forbidden_chars))(env, start_response)
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elif self.check_length(req):
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return HTTPBadRequest(
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request=req,
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body=("Object/Container/Account name longer than the "
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"allowed maximum "
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"%s" % self.maximum_length))(env, start_response)
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elif self.check_regexp(req):
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return HTTPBadRequest(
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request=req,
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body=("Object/Container/Account name contains a forbidden "
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"substring from regular expression %s"
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% self.forbidden_regexp))(env, start_response)
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else:
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# Pass on to downstream WSGI component
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return self.app(env, start_response)
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def filter_factory(global_conf, **local_conf):
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conf = global_conf.copy()
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conf.update(local_conf)
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def name_check_filter(app):
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return NameCheckMiddleware(app, conf)
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return name_check_filter
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