ConsentResource to gather policy consent from users

Hopefully there are enough comments and docs in this that it makes sense on its
own.
This commit is contained in:
Richard van der Hoff 2018-05-11 00:17:11 +01:00
parent bd8d0cfab1
commit 47815edcfa
14 changed files with 446 additions and 5 deletions

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@ -0,0 +1,23 @@
If enabling the 'consent' resource in synapse, you will need some templates
for the HTML to be served to the user. This directory contains very simple
examples of the sort of thing that can be done.
You'll need to add this sort of thing to your homeserver.yaml:
```
form_secret: <unique but arbitrary secret>
user_consent:
template_dir: docs/privacy_policy_templates
default_version: 1.0
```
You should then be able to enable the `consent` resource under a `listener`
entry. For example:
```
listeners:
- port: 8008
resources:
- names: [client, consent]
```

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@ -0,0 +1,17 @@
<!doctype html>
<html lang="en">
<head>
<title>Matrix.org Privacy policy</title>
</head>
<body>
<p>
All your base are belong to us.
</p>
<form method="post" action="consent">
<input type="hidden" name="v" value="{{version}}"/>
<input type="hidden" name="u" value="{{user}}"/>
<input type="hidden" name="h" value="{{userhmac}}"/>
<input type="submit" value="Sure thing!"/>
</form>
</body>
</html>

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@ -0,0 +1,11 @@
<!doctype html>
<html lang="en">
<head>
<title>Matrix.org Privacy policy</title>
</head>
<body>
<p>
Sweet.
</p>
</body>
</html>

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@ -41,6 +41,7 @@ from synapse.python_dependencies import CONDITIONAL_REQUIREMENTS, \
from synapse.replication.http import ReplicationRestResource, REPLICATION_PREFIX
from synapse.replication.tcp.resource import ReplicationStreamProtocolFactory
from synapse.rest import ClientRestResource
from synapse.rest.consent.consent_resource import ConsentResource
from synapse.rest.key.v1.server_key_resource import LocalKey
from synapse.rest.key.v2 import KeyApiV2Resource
from synapse.rest.media.v0.content_repository import ContentRepoResource
@ -182,6 +183,14 @@ class SynapseHomeServer(HomeServer):
"/_matrix/client/versions": client_resource,
})
if name == "consent":
consent_resource = ConsentResource(self)
if compress:
consent_resource = gz_wrap(consent_resource)
resources.update({
"/_matrix/consent": consent_resource,
})
if name == "federation":
resources.update({
FEDERATION_PREFIX: TransportLayerServer(self),

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@ -12,3 +12,9 @@
# 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.
from ._base import ConfigError
# export ConfigError if somebody does import *
# this is largely a fudge to stop PEP8 moaning about the import
__all__ = ["ConfigError"]

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@ -0,0 +1,42 @@
# -*- coding: utf-8 -*-
# Copyright 2018 New Vector Ltd
#
# 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.
from ._base import Config
DEFAULT_CONFIG = """\
# User Consent configuration
#
# uncomment and configure if enabling the 'consent' resource under 'listeners'.
#
# 'template_dir' gives the location of the templates for the HTML forms.
# This directory should contain one subdirectory per language (eg, 'en', 'fr'),
# and each language directory should contain the policy document (named as
# '<version>.html') and a success page (success.html).
#
# 'default_version' gives the version of the policy document to serve up if
# there is no 'v' parameter.
#
# user_consent:
# template_dir: res/templates/privacy
# default_version: 1.0
"""
class ConsentConfig(Config):
def read_config(self, config):
self.consent_config = config.get("user_consent")
def default_config(self, **kwargs):
return DEFAULT_CONFIG

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@ -1,5 +1,6 @@
# -*- coding: utf-8 -*-
# Copyright 2014-2016 OpenMarket Ltd
# Copyright 2018 New Vector Ltd
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
@ -12,7 +13,6 @@
# 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.
from .tls import TlsConfig
from .server import ServerConfig
from .logger import LoggingConfig
@ -37,6 +37,7 @@ from .push import PushConfig
from .spam_checker import SpamCheckerConfig
from .groups import GroupsConfig
from .user_directory import UserDirectoryConfig
from .consent_config import ConsentConfig
class HomeServerConfig(TlsConfig, ServerConfig, DatabaseConfig, LoggingConfig,
@ -45,12 +46,13 @@ class HomeServerConfig(TlsConfig, ServerConfig, DatabaseConfig, LoggingConfig,
AppServiceConfig, KeyConfig, SAML2Config, CasConfig,
JWTConfig, PasswordConfig, EmailConfig,
WorkerConfig, PasswordAuthProviderConfig, PushConfig,
SpamCheckerConfig, GroupsConfig, UserDirectoryConfig,):
SpamCheckerConfig, GroupsConfig, UserDirectoryConfig,
ConsentConfig):
pass
if __name__ == '__main__':
import sys
sys.stdout.write(
HomeServerConfig().generate_config(sys.argv[1], sys.argv[2])[0]
HomeServerConfig().generate_config(sys.argv[1], sys.argv[2], True)[0]
)

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@ -59,14 +59,20 @@ class KeyConfig(Config):
self.expire_access_token = config.get("expire_access_token", False)
# a secret which is used to calculate HMACs for form values, to stop
# falsification of values
self.form_secret = config.get("form_secret", None)
def default_config(self, config_dir_path, server_name, is_generating_file=False,
**kwargs):
base_key_name = os.path.join(config_dir_path, server_name)
if is_generating_file:
macaroon_secret_key = random_string_with_symbols(50)
form_secret = '"%s"' % random_string_with_symbols(50)
else:
macaroon_secret_key = None
form_secret = 'null'
return """\
macaroon_secret_key: "%(macaroon_secret_key)s"
@ -74,6 +80,10 @@ class KeyConfig(Config):
# Used to enable access token expiration.
expire_access_token: False
# a secret which is used to calculate HMACs for form values, to stop
# falsification of values
form_secret: %(form_secret)s
## Signing Keys ##
# Path to the signing key to sign messages with

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@ -13,7 +13,8 @@
# 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.
import cgi
from six.moves import http_client
from synapse.api.errors import (
cs_exception, SynapseError, CodeMessageException, UnrecognizedRequestError, Codes
@ -44,6 +45,18 @@ import simplejson
logger = logging.getLogger(__name__)
HTML_ERROR_TEMPLATE = """<!DOCTYPE html>
<html lang=en>
<head>
<meta charset="utf-8">
<title>Error {code}</title>
</head>
<body>
<p>{msg}</p>
</body>
</html>
"""
def wrap_json_request_handler(h):
"""Wraps a request handler method with exception handling.
@ -104,6 +117,65 @@ def wrap_json_request_handler(h):
return wrap_request_handler_with_logging(wrapped_request_handler)
def wrap_html_request_handler(h):
"""Wraps a request handler method with exception handling.
Also adds logging as per wrap_request_handler_with_logging.
The handler method must have a signature of "handle_foo(self, request)",
where "self" must have a "clock" attribute (and "request" must be a
SynapseRequest).
"""
def wrapped_request_handler(self, request):
d = defer.maybeDeferred(h, self, request)
d.addErrback(_return_html_error, request)
return d
return wrap_request_handler_with_logging(wrapped_request_handler)
def _return_html_error(f, request):
"""Sends an HTML error page corresponding to the given failure
Args:
f (twisted.python.failure.Failure):
request (twisted.web.iweb.IRequest):
"""
if f.check(CodeMessageException):
cme = f.value
code = cme.code
msg = cme.msg
if isinstance(cme, SynapseError):
logger.info(
"%s SynapseError: %s - %s", request, code, msg
)
else:
logger.error(
"Failed handle request %r: %s",
request,
f.getTraceback().rstrip(),
)
else:
code = http_client.INTERNAL_SERVER_ERROR
msg = "Internal server error"
logger.error(
"Failed handle request %r: %s",
request,
f.getTraceback().rstrip(),
)
body = HTML_ERROR_TEMPLATE.format(
code=code, msg=cgi.escape(msg),
).encode("utf-8")
request.setResponseCode(code)
request.setHeader(b"Content-Type", b"text/html; charset=utf-8")
request.setHeader(b"Content-Length", b"%i" % (len(body),))
request.write(body)
finish_request(request)
def wrap_request_handler_with_logging(h):
"""Wraps a request handler to provide logging and metrics
@ -134,7 +206,7 @@ def wrap_request_handler_with_logging(h):
servlet_name = self.__class__.__name__
with request.processing(servlet_name):
with PreserveLoggingContext(request_context):
d = h(self, request)
d = defer.maybeDeferred(h, self, request)
# record the arrival of the request *after*
# dispatching to the handler, so that the handler

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@ -0,0 +1,210 @@
# -*- coding: utf-8 -*-
# Copyright 2018 New Vector Ltd
#
# 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.
from hashlib import sha256
import hmac
import logging
from os import path
from six.moves import http_client
import jinja2
from jinja2 import TemplateNotFound
from twisted.internet import defer
from twisted.web.resource import Resource
from twisted.web.server import NOT_DONE_YET
from synapse.api.errors import NotFoundError, SynapseError, StoreError
from synapse.config import ConfigError
from synapse.http.server import (
finish_request,
wrap_html_request_handler,
)
from synapse.http.servlet import parse_string
from synapse.types import UserID
# language to use for the templates. TODO: figure this out from Accept-Language
TEMPLATE_LANGUAGE = "en"
logger = logging.getLogger(__name__)
# use hmac.compare_digest if we have it (python 2.7.7), else just use equality
if hasattr(hmac, "compare_digest"):
compare_digest = hmac.compare_digest
else:
def compare_digest(a, b):
return a == b
class ConsentResource(Resource):
"""A twisted Resource to display a privacy policy and gather consent to it
When accessed via GET, returns the privacy policy via a template.
When accessed via POST, records the user's consent in the database and
displays a success page.
The config should include a template_dir setting which contains templates
for the HTML. The directory should contain one subdirectory per language
(eg, 'en', 'fr'), and each language directory should contain the policy
document (named as '<version>.html') and a success page (success.html).
Both forms take a set of parameters from the browser. For the POST form,
these are normally sent as form parameters (but may be query-params); for
GET requests they must be query params. These are:
u: the complete mxid, or the localpart of the user giving their
consent. Required for both GET (where it is used as an input to the
template) and for POST (where it is used to find the row in the db
to update).
h: hmac_sha256(secret, u), where 'secret' is the privacy_secret in the
config file. If it doesn't match, the request is 403ed.
v: the version of the privacy policy being agreed to.
For GET: optional, and defaults to whatever was set in the config
file. Used to choose the version of the policy to pick from the
templates directory.
For POST: required; gives the value to be recorded in the database
against the user.
"""
def __init__(self, hs):
"""
Args:
hs (synapse.server.HomeServer): homeserver
"""
Resource.__init__(self)
self.hs = hs
self.store = hs.get_datastore()
# this is required by the request_handler wrapper
self.clock = hs.get_clock()
consent_config = hs.config.consent_config
if consent_config is None:
raise ConfigError(
"Consent resource is enabled but user_consent section is "
"missing in config file.",
)
# daemonize changes the cwd to /, so make the path absolute now.
consent_template_directory = path.abspath(
consent_config["template_dir"],
)
if not path.isdir(consent_template_directory):
raise ConfigError(
"Could not find template directory '%s'" % (
consent_template_directory,
),
)
loader = jinja2.FileSystemLoader(consent_template_directory)
self._jinja_env = jinja2.Environment(loader=loader)
self._default_consent_verison = consent_config["default_version"]
if hs.config.form_secret is None:
raise ConfigError(
"Consent resource is enabled but form_secret is not set in "
"config file. It should be set to an arbitrary secret string.",
)
self._hmac_secret = hs.config.form_secret.encode("utf-8")
def render_GET(self, request):
self._async_render_GET(request)
return NOT_DONE_YET
@wrap_html_request_handler
def _async_render_GET(self, request):
"""
Args:
request (twisted.web.http.Request):
"""
version = parse_string(request, "v",
default=self._default_consent_verison)
username = parse_string(request, "u", required=True)
userhmac = parse_string(request, "h", required=True)
self._check_hash(username, userhmac)
try:
self._render_template(
request, "%s.html" % (version,),
user=username, userhmac=userhmac, version=version,
)
except TemplateNotFound:
raise NotFoundError("Unknown policy version")
def render_POST(self, request):
self._async_render_POST(request)
return NOT_DONE_YET
@wrap_html_request_handler
@defer.inlineCallbacks
def _async_render_POST(self, request):
"""
Args:
request (twisted.web.http.Request):
"""
version = parse_string(request, "v", required=True)
username = parse_string(request, "u", required=True)
userhmac = parse_string(request, "h", required=True)
self._check_hash(username, userhmac)
if username.startswith('@'):
qualified_user_id = username
else:
qualified_user_id = UserID(username, self.hs.hostname).to_string()
try:
yield self.store.user_set_consent_version(qualified_user_id, version)
except StoreError as e:
if e.code != 404:
raise
raise NotFoundError("Unknown user")
try:
self._render_template(request, "success.html")
except TemplateNotFound:
raise NotFoundError("success.html not found")
def _render_template(self, request, template_name, **template_args):
# get_template checks for ".." so we don't need to worry too much
# about path traversal here.
template_html = self._jinja_env.get_template(
path.join(TEMPLATE_LANGUAGE, template_name)
)
html_bytes = template_html.render(**template_args).encode("utf8")
request.setHeader(b"Content-Type", b"text/html; charset=utf-8")
request.setHeader(b"Content-Length", b"%i" % len(html_bytes))
request.write(html_bytes)
finish_request(request)
def _check_hash(self, userid, userhmac):
want_mac = hmac.new(
key=self._hmac_secret,
msg=userid,
digestmod=sha256,
).hexdigest()
if not compare_digest(want_mac, userhmac):
raise SynapseError(http_client.FORBIDDEN, "HMAC incorrect")

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@ -97,6 +97,9 @@ class HomeServer(object):
which must be implemented by the subclass. This code may call any of the
required "get" methods on the instance to obtain the sub-dependencies that
one requires.
Attributes:
config (synapse.config.homeserver.HomeserverConfig):
"""
DEPENDENCIES = [

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@ -286,6 +286,24 @@ class RegistrationStore(RegistrationWorkerStore,
"user_set_password_hash", user_set_password_hash_txn
)
def user_set_consent_version(self, user_id, consent_version):
"""Updates the user table to record privacy policy consent
Args:
user_id (str): full mxid of the user to update
consent_version (str): version of the policy the user has consented
to
Raises:
StoreError(404) if user not found
"""
return self._simple_update_one(
table='users',
keyvalues={'name': user_id, },
updatevalues={'consent_version': consent_version, },
desc="user_set_consent_version"
)
def user_delete_access_tokens(self, user_id, except_token_id=None,
device_id=None):
"""

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@ -0,0 +1,18 @@
/* Copyright 2018 New Vector Ltd
*
* 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.
*/
/* record the version of the privacy policy the user has consented to
*/
ALTER TABLE users ADD COLUMN consent_version TEXT;