# -*- coding: utf-8 -*- # Copyright 2020 Quentin Gliech # Copyright 2020-2021 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 string from collections import Counter from typing import Iterable, Optional, Tuple, Type import attr from synapse.config._util import validate_config from synapse.python_dependencies import DependencyException, check_requirements from synapse.types import Collection, JsonDict from synapse.util.module_loader import load_module from synapse.util.stringutils import parse_and_validate_mxc_uri from ._base import Config, ConfigError DEFAULT_USER_MAPPING_PROVIDER = "synapse.handlers.oidc_handler.JinjaOidcMappingProvider" class OIDCConfig(Config): section = "oidc" def read_config(self, config, **kwargs): self.oidc_providers = tuple(_parse_oidc_provider_configs(config)) if not self.oidc_providers: return try: check_requirements("oidc") except DependencyException as e: raise ConfigError(e.message) from e # check we don't have any duplicate idp_ids now. (The SSO handler will also # check for duplicates when the REST listeners get registered, but that happens # after synapse has forked so doesn't give nice errors.) c = Counter([i.idp_id for i in self.oidc_providers]) for idp_id, count in c.items(): if count > 1: raise ConfigError( "Multiple OIDC providers have the idp_id %r." % idp_id ) self.oidc_callback_url = self.public_baseurl + "_synapse/oidc/callback" @property def oidc_enabled(self) -> bool: # OIDC is enabled if we have a provider return bool(self.oidc_providers) def generate_config_section(self, config_dir_path, server_name, **kwargs): return """\ # List of OpenID Connect (OIDC) / OAuth 2.0 identity providers, for registration # and login. # # Options for each entry include: # # idp_id: a unique identifier for this identity provider. Used internally # by Synapse; should be a single word such as 'github'. # # Note that, if this is changed, users authenticating via that provider # will no longer be recognised as the same user! # # idp_name: A user-facing name for this identity provider, which is used to # offer the user a choice of login mechanisms. # # idp_icon: An optional icon for this identity provider, which is presented # by identity picker pages. If given, must be an MXC URI of the format # mxc:///. (An easy way to obtain such an MXC URI # is to upload an image to an (unencrypted) room and then copy the "url" # from the source of the event.) # # discover: set to 'false' to disable the use of the OIDC discovery mechanism # to discover endpoints. Defaults to true. # # issuer: Required. The OIDC issuer. Used to validate tokens and (if discovery # is enabled) to discover the provider's endpoints. # # client_id: Required. oauth2 client id to use. # # client_secret: Required. oauth2 client secret to use. # # client_auth_method: auth method to use when exchanging the token. Valid # values are 'client_secret_basic' (default), 'client_secret_post' and # 'none'. # # scopes: list of scopes to request. This should normally include the "openid" # scope. Defaults to ["openid"]. # # authorization_endpoint: the oauth2 authorization endpoint. Required if # provider discovery is disabled. # # token_endpoint: the oauth2 token endpoint. Required if provider discovery is # disabled. # # userinfo_endpoint: the OIDC userinfo endpoint. Required if discovery is # disabled and the 'openid' scope is not requested. # # jwks_uri: URI where to fetch the JWKS. Required if discovery is disabled and # the 'openid' scope is used. # # skip_verification: set to 'true' to skip metadata verification. Use this if # you are connecting to a provider that is not OpenID Connect compliant. # Defaults to false. Avoid this in production. # # user_profile_method: Whether to fetch the user profile from the userinfo # endpoint. Valid values are: 'auto' or 'userinfo_endpoint'. # # Defaults to 'auto', which fetches the userinfo endpoint if 'openid' is # included in 'scopes'. Set to 'userinfo_endpoint' to always fetch the # userinfo endpoint. # # allow_existing_users: set to 'true' to allow a user logging in via OIDC to # match a pre-existing account instead of failing. This could be used if # switching from password logins to OIDC. Defaults to false. # # user_mapping_provider: Configuration for how attributes returned from a OIDC # provider are mapped onto a matrix user. This setting has the following # sub-properties: # # module: The class name of a custom mapping module. Default is # {mapping_provider!r}. # See https://github.com/matrix-org/synapse/blob/master/docs/sso_mapping_providers.md#openid-mapping-providers # for information on implementing a custom mapping provider. # # config: Configuration for the mapping provider module. This section will # be passed as a Python dictionary to the user mapping provider # module's `parse_config` method. # # For the default provider, the following settings are available: # # sub: name of the claim containing a unique identifier for the # user. Defaults to 'sub', which OpenID Connect compliant # providers should provide. # # localpart_template: Jinja2 template for the localpart of the MXID. # If this is not set, the user will be prompted to choose their # own username. # # display_name_template: Jinja2 template for the display name to set # on first login. If unset, no displayname will be set. # # extra_attributes: a map of Jinja2 templates for extra attributes # to send back to the client during login. # Note that these are non-standard and clients will ignore them # without modifications. # # When rendering, the Jinja2 templates are given a 'user' variable, # which is set to the claims returned by the UserInfo Endpoint and/or # in the ID Token. # # See https://github.com/matrix-org/synapse/blob/master/docs/openid.md # for information on how to configure these options. # # For backwards compatibility, it is also possible to configure a single OIDC # provider via an 'oidc_config' setting. This is now deprecated and admins are # advised to migrate to the 'oidc_providers' format. (When doing that migration, # use 'oidc' for the idp_id to ensure that existing users continue to be # recognised.) # oidc_providers: # Generic example # #- idp_id: my_idp # idp_name: "My OpenID provider" # idp_icon: "mxc://example.com/mediaid" # discover: false # issuer: "https://accounts.example.com/" # client_id: "provided-by-your-issuer" # client_secret: "provided-by-your-issuer" # client_auth_method: client_secret_post # scopes: ["openid", "profile"] # authorization_endpoint: "https://accounts.example.com/oauth2/auth" # token_endpoint: "https://accounts.example.com/oauth2/token" # userinfo_endpoint: "https://accounts.example.com/userinfo" # jwks_uri: "https://accounts.example.com/.well-known/jwks.json" # skip_verification: true # For use with Keycloak # #- idp_id: keycloak # idp_name: Keycloak # issuer: "https://127.0.0.1:8443/auth/realms/my_realm_name" # client_id: "synapse" # client_secret: "copy secret generated in Keycloak UI" # scopes: ["openid", "profile"] # For use with Github # #- idp_id: github # idp_name: Github # discover: false # issuer: "https://github.com/" # client_id: "your-client-id" # TO BE FILLED # client_secret: "your-client-secret" # TO BE FILLED # authorization_endpoint: "https://github.com/login/oauth/authorize" # token_endpoint: "https://github.com/login/oauth/access_token" # userinfo_endpoint: "https://api.github.com/user" # scopes: ["read:user"] # user_mapping_provider: # config: # subject_claim: "id" # localpart_template: "{{ user.login }}" # display_name_template: "{{ user.name }}" """.format( mapping_provider=DEFAULT_USER_MAPPING_PROVIDER ) # jsonschema definition of the configuration settings for an oidc identity provider OIDC_PROVIDER_CONFIG_SCHEMA = { "type": "object", "required": ["issuer", "client_id", "client_secret"], "properties": { # TODO: fix the maxLength here depending on what MSC2528 decides # remember that we prefix the ID given here with `oidc-` "idp_id": {"type": "string", "minLength": 1, "maxLength": 128}, "idp_name": {"type": "string"}, "idp_icon": {"type": "string"}, "discover": {"type": "boolean"}, "issuer": {"type": "string"}, "client_id": {"type": "string"}, "client_secret": {"type": "string"}, "client_auth_method": { "type": "string", # the following list is the same as the keys of # authlib.oauth2.auth.ClientAuth.DEFAULT_AUTH_METHODS. We inline it # to avoid importing authlib here. "enum": ["client_secret_basic", "client_secret_post", "none"], }, "scopes": {"type": "array", "items": {"type": "string"}}, "authorization_endpoint": {"type": "string"}, "token_endpoint": {"type": "string"}, "userinfo_endpoint": {"type": "string"}, "jwks_uri": {"type": "string"}, "skip_verification": {"type": "boolean"}, "user_profile_method": { "type": "string", "enum": ["auto", "userinfo_endpoint"], }, "allow_existing_users": {"type": "boolean"}, "user_mapping_provider": {"type": ["object", "null"]}, }, } # the same as OIDC_PROVIDER_CONFIG_SCHEMA, but with compulsory idp_id and idp_name OIDC_PROVIDER_CONFIG_WITH_ID_SCHEMA = { "allOf": [OIDC_PROVIDER_CONFIG_SCHEMA, {"required": ["idp_id", "idp_name"]}] } # the `oidc_providers` list can either be None (as it is in the default config), or # a list of provider configs, each of which requires an explicit ID and name. OIDC_PROVIDER_LIST_SCHEMA = { "oneOf": [ {"type": "null"}, {"type": "array", "items": OIDC_PROVIDER_CONFIG_WITH_ID_SCHEMA}, ] } # the `oidc_config` setting can either be None (which it used to be in the default # config), or an object. If an object, it is ignored unless it has an "enabled: True" # property. # # It's *possible* to represent this with jsonschema, but the resultant errors aren't # particularly clear, so we just check for either an object or a null here, and do # additional checks in the code. OIDC_CONFIG_SCHEMA = {"oneOf": [{"type": "null"}, {"type": "object"}]} # the top-level schema can contain an "oidc_config" and/or an "oidc_providers". MAIN_CONFIG_SCHEMA = { "type": "object", "properties": { "oidc_config": OIDC_CONFIG_SCHEMA, "oidc_providers": OIDC_PROVIDER_LIST_SCHEMA, }, } def _parse_oidc_provider_configs(config: JsonDict) -> Iterable["OidcProviderConfig"]: """extract and parse the OIDC provider configs from the config dict The configuration may contain either a single `oidc_config` object with an `enabled: True` property, or a list of provider configurations under `oidc_providers`, *or both*. Returns a generator which yields the OidcProviderConfig objects """ validate_config(MAIN_CONFIG_SCHEMA, config, ()) for i, p in enumerate(config.get("oidc_providers") or []): yield _parse_oidc_config_dict(p, ("oidc_providers", "" % (i,))) # for backwards-compatibility, it is also possible to provide a single "oidc_config" # object with an "enabled: True" property. oidc_config = config.get("oidc_config") if oidc_config and oidc_config.get("enabled", False): # MAIN_CONFIG_SCHEMA checks that `oidc_config` is an object, but not that # it matches OIDC_PROVIDER_CONFIG_SCHEMA (see the comments on OIDC_CONFIG_SCHEMA # above), so now we need to validate it. validate_config(OIDC_PROVIDER_CONFIG_SCHEMA, oidc_config, ("oidc_config",)) yield _parse_oidc_config_dict(oidc_config, ("oidc_config",)) def _parse_oidc_config_dict( oidc_config: JsonDict, config_path: Tuple[str, ...] ) -> "OidcProviderConfig": """Take the configuration dict and parse it into an OidcProviderConfig Raises: ConfigError if the configuration is malformed. """ ump_config = oidc_config.get("user_mapping_provider", {}) ump_config.setdefault("module", DEFAULT_USER_MAPPING_PROVIDER) ump_config.setdefault("config", {}) (user_mapping_provider_class, user_mapping_provider_config,) = load_module( ump_config, config_path + ("user_mapping_provider",) ) # Ensure loaded user mapping module has defined all necessary methods required_methods = [ "get_remote_user_id", "map_user_attributes", ] missing_methods = [ method for method in required_methods if not hasattr(user_mapping_provider_class, method) ] if missing_methods: raise ConfigError( "Class %s is missing required " "methods: %s" % (user_mapping_provider_class, ", ".join(missing_methods),), config_path + ("user_mapping_provider", "module"), ) # MSC2858 will apply certain limits in what can be used as an IdP id, so let's # enforce those limits now. # TODO: factor out this stuff to a generic function idp_id = oidc_config.get("idp_id", "oidc") # TODO: update this validity check based on what MSC2858 decides. valid_idp_chars = set(string.ascii_lowercase + string.digits + "-._") if any(c not in valid_idp_chars for c in idp_id): raise ConfigError( 'idp_id may only contain a-z, 0-9, "-", ".", "_"', config_path + ("idp_id",), ) if idp_id[0] not in string.ascii_lowercase: raise ConfigError( "idp_id must start with a-z", config_path + ("idp_id",), ) # prefix the given IDP with a prefix specific to the SSO mechanism, to avoid # clashes with other mechs (such as SAML, CAS). # # We allow "oidc" as an exception so that people migrating from old-style # "oidc_config" format (which has long used "oidc" as its idp_id) can migrate to # a new-style "oidc_providers" entry without changing the idp_id for their provider # (and thereby invalidating their user_external_ids data). if idp_id != "oidc": idp_id = "oidc-" + idp_id # MSC2858 also specifies that the idp_icon must be a valid MXC uri idp_icon = oidc_config.get("idp_icon") if idp_icon is not None: try: parse_and_validate_mxc_uri(idp_icon) except ValueError as e: raise ConfigError( "idp_icon must be a valid MXC URI", config_path + ("idp_icon",) ) from e return OidcProviderConfig( idp_id=idp_id, idp_name=oidc_config.get("idp_name", "OIDC"), idp_icon=idp_icon, discover=oidc_config.get("discover", True), issuer=oidc_config["issuer"], client_id=oidc_config["client_id"], client_secret=oidc_config["client_secret"], client_auth_method=oidc_config.get("client_auth_method", "client_secret_basic"), scopes=oidc_config.get("scopes", ["openid"]), authorization_endpoint=oidc_config.get("authorization_endpoint"), token_endpoint=oidc_config.get("token_endpoint"), userinfo_endpoint=oidc_config.get("userinfo_endpoint"), jwks_uri=oidc_config.get("jwks_uri"), skip_verification=oidc_config.get("skip_verification", False), user_profile_method=oidc_config.get("user_profile_method", "auto"), allow_existing_users=oidc_config.get("allow_existing_users", False), user_mapping_provider_class=user_mapping_provider_class, user_mapping_provider_config=user_mapping_provider_config, ) @attr.s(slots=True, frozen=True) class OidcProviderConfig: # a unique identifier for this identity provider. Used in the 'user_external_ids' # table, as well as the query/path parameter used in the login protocol. idp_id = attr.ib(type=str) # user-facing name for this identity provider. idp_name = attr.ib(type=str) # Optional MXC URI for icon for this IdP. idp_icon = attr.ib(type=Optional[str]) # whether the OIDC discovery mechanism is used to discover endpoints discover = attr.ib(type=bool) # the OIDC issuer. Used to validate tokens and (if discovery is enabled) to # discover the provider's endpoints. issuer = attr.ib(type=str) # oauth2 client id to use client_id = attr.ib(type=str) # oauth2 client secret to use client_secret = attr.ib(type=str) # auth method to use when exchanging the token. # Valid values are 'client_secret_basic', 'client_secret_post' and # 'none'. client_auth_method = attr.ib(type=str) # list of scopes to request scopes = attr.ib(type=Collection[str]) # the oauth2 authorization endpoint. Required if discovery is disabled. authorization_endpoint = attr.ib(type=Optional[str]) # the oauth2 token endpoint. Required if discovery is disabled. token_endpoint = attr.ib(type=Optional[str]) # the OIDC userinfo endpoint. Required if discovery is disabled and the # "openid" scope is not requested. userinfo_endpoint = attr.ib(type=Optional[str]) # URI where to fetch the JWKS. Required if discovery is disabled and the # "openid" scope is used. jwks_uri = attr.ib(type=Optional[str]) # Whether to skip metadata verification skip_verification = attr.ib(type=bool) # Whether to fetch the user profile from the userinfo endpoint. Valid # values are: "auto" or "userinfo_endpoint". user_profile_method = attr.ib(type=str) # whether to allow a user logging in via OIDC to match a pre-existing account # instead of failing allow_existing_users = attr.ib(type=bool) # the class of the user mapping provider user_mapping_provider_class = attr.ib(type=Type) # the config of the user mapping provider user_mapping_provider_config = attr.ib()