synapse-product/synapse/config/saml2_config.py
2021-02-02 09:43:50 +00:00

428 lines
16 KiB
Python

# -*- coding: utf-8 -*-
# Copyright 2018 New Vector Ltd
# Copyright 2019 The Matrix.org Foundation C.I.C.
#
# 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.
import logging
from typing import Any, List
import attr
from synapse.python_dependencies import DependencyException, check_requirements
from synapse.util.module_loader import load_module, load_python_module
from ._base import Config, ConfigError
from ._util import validate_config
logger = logging.getLogger(__name__)
DEFAULT_USER_MAPPING_PROVIDER = (
"synapse.handlers.saml_handler.DefaultSamlMappingProvider"
)
def _dict_merge(merge_dict, into_dict):
"""Do a deep merge of two dicts
Recursively merges `merge_dict` into `into_dict`:
* For keys where both `merge_dict` and `into_dict` have a dict value, the values
are recursively merged
* For all other keys, the values in `into_dict` (if any) are overwritten with
the value from `merge_dict`.
Args:
merge_dict (dict): dict to merge
into_dict (dict): target dict
"""
for k, v in merge_dict.items():
if k not in into_dict:
into_dict[k] = v
continue
current_val = into_dict[k]
if isinstance(v, dict) and isinstance(current_val, dict):
_dict_merge(v, current_val)
continue
# otherwise we just overwrite
into_dict[k] = v
class SAML2Config(Config):
section = "saml2"
def read_config(self, config, **kwargs):
self.saml2_enabled = False
saml2_config = config.get("saml2_config")
if not saml2_config or not saml2_config.get("enabled", True):
return
if not saml2_config.get("sp_config") and not saml2_config.get("config_path"):
return
try:
check_requirements("saml2")
except DependencyException as e:
raise ConfigError(e.message)
self.saml2_enabled = True
attribute_requirements = saml2_config.get("attribute_requirements") or []
self.attribute_requirements = _parse_attribute_requirements_def(
attribute_requirements
)
self.saml2_grandfathered_mxid_source_attribute = saml2_config.get(
"grandfathered_mxid_source_attribute", "uid"
)
self.saml2_idp_entityid = saml2_config.get("idp_entityid", None)
# user_mapping_provider may be None if the key is present but has no value
ump_dict = saml2_config.get("user_mapping_provider") or {}
# Use the default user mapping provider if not set
ump_dict.setdefault("module", DEFAULT_USER_MAPPING_PROVIDER)
# Ensure a config is present
ump_dict["config"] = ump_dict.get("config") or {}
if ump_dict["module"] == DEFAULT_USER_MAPPING_PROVIDER:
# Load deprecated options for use by the default module
old_mxid_source_attribute = saml2_config.get("mxid_source_attribute")
if old_mxid_source_attribute:
logger.warning(
"The config option saml2_config.mxid_source_attribute is deprecated. "
"Please use saml2_config.user_mapping_provider.config"
".mxid_source_attribute instead."
)
ump_dict["config"]["mxid_source_attribute"] = old_mxid_source_attribute
old_mxid_mapping = saml2_config.get("mxid_mapping")
if old_mxid_mapping:
logger.warning(
"The config option saml2_config.mxid_mapping is deprecated. Please "
"use saml2_config.user_mapping_provider.config.mxid_mapping instead."
)
ump_dict["config"]["mxid_mapping"] = old_mxid_mapping
# Retrieve an instance of the module's class
# Pass the config dictionary to the module for processing
(
self.saml2_user_mapping_provider_class,
self.saml2_user_mapping_provider_config,
) = load_module(ump_dict, ("saml2_config", "user_mapping_provider"))
# Ensure loaded user mapping module has defined all necessary methods
# Note parse_config() is already checked during the call to load_module
required_methods = [
"get_saml_attributes",
"saml_response_to_user_attributes",
"get_remote_user_id",
]
missing_methods = [
method
for method in required_methods
if not hasattr(self.saml2_user_mapping_provider_class, method)
]
if missing_methods:
raise ConfigError(
"Class specified by saml2_config."
"user_mapping_provider.module is missing required "
"methods: %s" % (", ".join(missing_methods),)
)
# Get the desired saml auth response attributes from the module
saml2_config_dict = self._default_saml_config_dict(
*self.saml2_user_mapping_provider_class.get_saml_attributes(
self.saml2_user_mapping_provider_config
)
)
_dict_merge(
merge_dict=saml2_config.get("sp_config", {}), into_dict=saml2_config_dict
)
config_path = saml2_config.get("config_path", None)
if config_path is not None:
mod = load_python_module(config_path)
_dict_merge(merge_dict=mod.CONFIG, into_dict=saml2_config_dict)
import saml2.config
self.saml2_sp_config = saml2.config.SPConfig()
self.saml2_sp_config.load(saml2_config_dict)
# session lifetime: in milliseconds
self.saml2_session_lifetime = self.parse_duration(
saml2_config.get("saml_session_lifetime", "15m")
)
def _default_saml_config_dict(
self, required_attributes: set, optional_attributes: set
):
"""Generate a configuration dictionary with required and optional attributes that
will be needed to process new user registration
Args:
required_attributes: SAML auth response attributes that are
necessary to function
optional_attributes: SAML auth response attributes that can be used to add
additional information to Synapse user accounts, but are not required
Returns:
dict: A SAML configuration dictionary
"""
import saml2
public_baseurl = self.public_baseurl
if self.saml2_grandfathered_mxid_source_attribute:
optional_attributes.add(self.saml2_grandfathered_mxid_source_attribute)
optional_attributes -= required_attributes
metadata_url = public_baseurl + "_synapse/client/saml2/metadata.xml"
response_url = public_baseurl + "_synapse/client/saml2/authn_response"
return {
"entityid": metadata_url,
"service": {
"sp": {
"endpoints": {
"assertion_consumer_service": [
(response_url, saml2.BINDING_HTTP_POST)
]
},
"required_attributes": list(required_attributes),
"optional_attributes": list(optional_attributes),
# "name_id_format": saml2.saml.NAMEID_FORMAT_PERSISTENT,
}
},
}
def generate_config_section(self, config_dir_path, server_name, **kwargs):
return """\
## Single sign-on integration ##
# The following settings can be used to make Synapse use a single sign-on
# provider for authentication, instead of its internal password database.
#
# You will probably also want to set the following options to `false` to
# disable the regular login/registration flows:
# * enable_registration
# * password_config.enabled
#
# You will also want to investigate the settings under the "sso" configuration
# section below.
# Enable SAML2 for registration and login. Uses pysaml2.
#
# At least one of `sp_config` or `config_path` must be set in this section to
# enable SAML login.
#
# Once SAML support is enabled, a metadata file will be exposed at
# https://<server>:<port>/_synapse/client/saml2/metadata.xml, which you may be able to
# use to configure your SAML IdP with. Alternatively, you can manually configure
# the IdP to use an ACS location of
# https://<server>:<port>/_synapse/client/saml2/authn_response.
#
saml2_config:
# `sp_config` is the configuration for the pysaml2 Service Provider.
# See pysaml2 docs for format of config.
#
# Default values will be used for the 'entityid' and 'service' settings,
# so it is not normally necessary to specify them unless you need to
# override them.
#
sp_config:
# Point this to the IdP's metadata. You must provide either a local
# file via the `local` attribute or (preferably) a URL via the
# `remote` attribute.
#
#metadata:
# local: ["saml2/idp.xml"]
# remote:
# - url: https://our_idp/metadata.xml
# Allowed clock difference in seconds between the homeserver and IdP.
#
# Uncomment the below to increase the accepted time difference from 0 to 3 seconds.
#
#accepted_time_diff: 3
# By default, the user has to go to our login page first. If you'd like
# to allow IdP-initiated login, set 'allow_unsolicited: true' in a
# 'service.sp' section:
#
#service:
# sp:
# allow_unsolicited: true
# The examples below are just used to generate our metadata xml, and you
# may well not need them, depending on your setup. Alternatively you
# may need a whole lot more detail - see the pysaml2 docs!
#description: ["My awesome SP", "en"]
#name: ["Test SP", "en"]
#ui_info:
# display_name:
# - lang: en
# text: "Display Name is the descriptive name of your service."
# description:
# - lang: en
# text: "Description should be a short paragraph explaining the purpose of the service."
# information_url:
# - lang: en
# text: "https://example.com/terms-of-service"
# privacy_statement_url:
# - lang: en
# text: "https://example.com/privacy-policy"
# keywords:
# - lang: en
# text: ["Matrix", "Element"]
# logo:
# - lang: en
# text: "https://example.com/logo.svg"
# width: "200"
# height: "80"
#organization:
# name: Example com
# display_name:
# - ["Example co", "en"]
# url: "http://example.com"
#contact_person:
# - given_name: Bob
# sur_name: "the Sysadmin"
# email_address": ["admin@example.com"]
# contact_type": technical
# Instead of putting the config inline as above, you can specify a
# separate pysaml2 configuration file:
#
#config_path: "%(config_dir_path)s/sp_conf.py"
# The lifetime of a SAML session. This defines how long a user has to
# complete the authentication process, if allow_unsolicited is unset.
# The default is 15 minutes.
#
#saml_session_lifetime: 5m
# An external module can be provided here as a custom solution to
# mapping attributes returned from a saml provider onto a matrix user.
#
user_mapping_provider:
# The custom module's class. Uncomment to use a custom module.
#
#module: mapping_provider.SamlMappingProvider
# Custom configuration values for the module. Below options are
# intended for the built-in provider, they should be changed if
# using a custom module. This section will be passed as a Python
# dictionary to the module's `parse_config` method.
#
config:
# The SAML attribute (after mapping via the attribute maps) to use
# to derive the Matrix ID from. 'uid' by default.
#
# Note: This used to be configured by the
# saml2_config.mxid_source_attribute option. If that is still
# defined, its value will be used instead.
#
#mxid_source_attribute: displayName
# The mapping system to use for mapping the saml attribute onto a
# matrix ID.
#
# Options include:
# * 'hexencode' (which maps unpermitted characters to '=xx')
# * 'dotreplace' (which replaces unpermitted characters with
# '.').
# The default is 'hexencode'.
#
# Note: This used to be configured by the
# saml2_config.mxid_mapping option. If that is still defined, its
# value will be used instead.
#
#mxid_mapping: dotreplace
# In previous versions of synapse, the mapping from SAML attribute to
# MXID was always calculated dynamically rather than stored in a
# table. For backwards- compatibility, we will look for user_ids
# matching such a pattern before creating a new account.
#
# This setting controls the SAML attribute which will be used for this
# backwards-compatibility lookup. Typically it should be 'uid', but if
# the attribute maps are changed, it may be necessary to change it.
#
# The default is 'uid'.
#
#grandfathered_mxid_source_attribute: upn
# It is possible to configure Synapse to only allow logins if SAML attributes
# match particular values. The requirements can be listed under
# `attribute_requirements` as shown below. All of the listed attributes must
# match for the login to be permitted.
#
#attribute_requirements:
# - attribute: userGroup
# value: "staff"
# - attribute: department
# value: "sales"
# If the metadata XML contains multiple IdP entities then the `idp_entityid`
# option must be set to the entity to redirect users to.
#
# Most deployments only have a single IdP entity and so should omit this
# option.
#
#idp_entityid: 'https://our_idp/entityid'
""" % {
"config_dir_path": config_dir_path
}
@attr.s(frozen=True)
class SamlAttributeRequirement:
"""Object describing a single requirement for SAML attributes."""
attribute = attr.ib(type=str)
value = attr.ib(type=str)
JSON_SCHEMA = {
"type": "object",
"properties": {"attribute": {"type": "string"}, "value": {"type": "string"}},
"required": ["attribute", "value"],
}
ATTRIBUTE_REQUIREMENTS_SCHEMA = {
"type": "array",
"items": SamlAttributeRequirement.JSON_SCHEMA,
}
def _parse_attribute_requirements_def(
attribute_requirements: Any,
) -> List[SamlAttributeRequirement]:
validate_config(
ATTRIBUTE_REQUIREMENTS_SCHEMA,
attribute_requirements,
config_path=["saml2_config", "attribute_requirements"],
)
return [SamlAttributeRequirement(**x) for x in attribute_requirements]