# -*- 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"
)
# 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)
# 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")
)
self.saml2_error_html_template = self.read_templates(
["saml_error.html"], saml2_config.get("template_dir")
)[0]
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 public_baseurl is None:
raise ConfigError("saml2_config requires a public_baseurl to be set")
if self.saml2_grandfathered_mxid_source_attribute:
optional_attributes.add(self.saml2_grandfathered_mxid_source_attribute)
optional_attributes -= required_attributes
metadata_url = public_baseurl + "_matrix/saml2/metadata.xml"
response_url = public_baseurl + "_matrix/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 ##
# 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.
#
# (You will probably also want to set the following options to `false` to
# disable the regular login/registration flows:
# * enable_registration
# * password_config.enabled
#
# Once SAML support is enabled, a metadata file will be exposed at
# https://<server>:<port>/_matrix/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>/_matrix/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 can use either a local file or
# # (preferably) a URL.
# metadata:
# #local: ["saml2/idp.xml"]
# remote:
# - url: https://our_idp/metadata.xml
#
# # 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"]
#
# 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"
# Directory in which Synapse will try to find the template files below.
# If not set, default templates from within the Synapse package will be used.
#
# DO NOT UNCOMMENT THIS SETTING unless you want to customise the templates.
# If you *do* uncomment it, you will need to make sure that all the templates
# below are in the directory.
#
# Synapse will look for the following templates in this directory:
#
# * HTML page to display to users if something goes wrong during the
# authentication process: 'saml_error.html'.
#
# When rendering, this template is given the following variables:
# * code: an HTML error code corresponding to the error that is being
# returned (typically 400 or 500)
#
# * msg: a textual message describing the error.
#
# The variables will automatically be HTML-escaped.
#
# You can see the default templates at:
# https://github.com/matrix-org/synapse/tree/master/synapse/res/templates
#
#template_dir: "res/templates"
""" % {
"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]