Rename handler and config modules which end in handler/config. (#9816)

synapse/config/saml2.py

@@ -0,0 +1,420 @@
+# 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
+
+from synapse.config.sso import SsoAttributeRequirement
+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.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, 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  # noqa: B306, DependencyException.message is a property
+            )
+
+        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)
+        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)
+            _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 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 + "_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
+        }
+
+
+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]