deb-ceilometer/ceilometer/publisher/utils.py
gordon chung 7fc0d1e6c7 add event listener to collector
enable a listener in collector that listens to events queue. this
patch also renames 'metering_*' options which are now used by both
events and samples.

Change-Id: I6250c91e913864c3973e2d93022e38ad8bed8328
Implements: blueprint notification-pipelines
2015-02-02 11:00:47 -05:00

133 lines
4.4 KiB
Python

#
# Copyright 2012 New Dream Network, LLC (DreamHost)
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
"""Utils for publishers
"""
import hashlib
import hmac
from oslo_config import cfg
import six
from ceilometer import utils
OPTS = [
cfg.StrOpt('telemetry_secret',
secret=True,
default='change this or be hacked',
help='Secret value for signing metering messages.',
deprecated_opts=[cfg.DeprecatedOpt("metering_secret",
"DEFAULT"),
cfg.DeprecatedOpt("metering_secret",
"publisher_rpc"),
cfg.DeprecatedOpt("metering_secret",
"publisher")]
),
]
cfg.CONF.register_opts(OPTS, group="publisher")
def compute_signature(message, secret):
"""Return the signature for a message dictionary."""
digest_maker = hmac.new(secret, '', hashlib.sha256)
for name, value in utils.recursive_keypairs(message):
if name == 'message_signature':
# Skip any existing signature value, which would not have
# been part of the original message.
continue
digest_maker.update(six.text_type(name).encode('utf-8'))
digest_maker.update(six.text_type(value).encode('utf-8'))
return digest_maker.hexdigest()
def besteffort_compare_digest(first, second):
"""Returns True if both string inputs are equal, otherwise False.
This function should take a constant amount of time regardless of
how many characters in the strings match.
"""
# NOTE(sileht): compare_digest method protected for timing-attacks
# exists since python >= 2.7.7 and python >= 3.3
# this a bit less-secure python fallback version
# taken from https://github.com/openstack/python-keystoneclient/blob/
# master/keystoneclient/middleware/memcache_crypt.py#L88
if len(first) != len(second):
return False
result = 0
if six.PY3 and isinstance(first, bytes) and isinstance(second, bytes):
for x, y in zip(first, second):
result |= x ^ y
else:
for x, y in zip(first, second):
result |= ord(x) ^ ord(y)
return result == 0
if hasattr(hmac, 'compare_digest'):
compare_digest = hmac.compare_digest
else:
compare_digest = besteffort_compare_digest
def verify_signature(message, secret):
"""Check the signature in the message.
Message is verified against the value computed from the rest of the
contents.
"""
old_sig = message.get('message_signature', '')
new_sig = compute_signature(message, secret)
if isinstance(old_sig, six.text_type):
try:
old_sig = old_sig.encode('ascii')
except UnicodeDecodeError:
return False
return compare_digest(new_sig, old_sig)
def meter_message_from_counter(sample, secret):
"""Make a metering message ready to be published or stored.
Returns a dictionary containing a metering message
for a notification message and a Sample instance.
"""
msg = {'source': sample.source,
'counter_name': sample.name,
'counter_type': sample.type,
'counter_unit': sample.unit,
'counter_volume': sample.volume,
'user_id': sample.user_id,
'project_id': sample.project_id,
'resource_id': sample.resource_id,
'timestamp': sample.timestamp,
'resource_metadata': sample.resource_metadata,
'message_id': sample.id,
}
msg['message_signature'] = compute_signature(msg, secret)
return msg
def message_from_event(event, secret):
"""Make an event message ready to be published or stored.
Returns a serialized model of Event containing an event message
"""
msg = event.serialize()
msg['message_signature'] = compute_signature(msg, secret)
return msg