forked-synapse/synapse/config/saml2.py
2023-11-21 15:29:58 -05:00

248 lines
9.0 KiB
Python

#
# This file is licensed under the Affero General Public License (AGPL) version 3.
#
# Copyright (C) 2023 New Vector, Ltd
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as
# published by the Free Software Foundation, either version 3 of the
# License, or (at your option) any later version.
#
# See the GNU Affero General Public License for more details:
# <https://www.gnu.org/licenses/agpl-3.0.html>.
#
# Originally licensed under the Apache License, Version 2.0:
# <http://www.apache.org/licenses/LICENSE-2.0>.
#
# [This file includes modifications made by New Vector Limited]
#
#
import logging
from typing import Any, List, Set
from synapse.config.sso import SsoAttributeRequirement
from synapse.types import JsonDict
from synapse.util.check_dependencies import 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.DefaultSamlMappingProvider"
# The module that DefaultSamlMappingProvider is in was renamed, we want to
# transparently handle both the same.
LEGACY_USER_MAPPING_PROVIDER = (
"synapse.handlers.saml_handler.DefaultSamlMappingProvider"
)
def _dict_merge(merge_dict: dict, into_dict: dict) -> None:
"""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 to merge
into_dict: target dict to be modified
"""
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: JsonDict, **kwargs: Any) -> None:
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
check_requirements("saml2")
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"
)
# refers to a SAML IdP entity ID
self.saml2_idp_entityid = saml2_config.get("idp_entityid", None)
# IdP properties for Matrix clients
self.idp_name = saml2_config.get("idp_name", "SAML")
self.idp_icon = saml2_config.get("idp_icon")
self.idp_brand = saml2_config.get("idp_brand")
# 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)
if ump_dict.get("module") == LEGACY_USER_MAPPING_PROVIDER:
ump_dict["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)
config_dict_from_file = getattr(mod, "CONFIG", None)
if config_dict_from_file is None:
raise ConfigError(
"Config path specified by saml2_config.config_path does not "
"have a CONFIG property."
)
_dict_merge(merge_dict=config_dict_from_file, 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[str], optional_attributes: Set[str]
) -> JsonDict:
"""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:
A SAML configuration dictionary
"""
import saml2
if self.saml2_grandfathered_mxid_source_attribute:
optional_attributes.add(self.saml2_grandfathered_mxid_source_attribute)
optional_attributes -= required_attributes
public_baseurl = self.root.server.public_baseurl
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,
}
},
}
ATTRIBUTE_REQUIREMENTS_SCHEMA = {
"type": "array",
"items": SsoAttributeRequirement.JSON_SCHEMA,
}
def _parse_attribute_requirements_def(
attribute_requirements: Any,
) -> List[SsoAttributeRequirement]:
validate_config(
ATTRIBUTE_REQUIREMENTS_SCHEMA,
attribute_requirements,
config_path=("saml2_config", "attribute_requirements"),
)
return [SsoAttributeRequirement(**x) for x in attribute_requirements]