diff options
Diffstat (limited to 'synapse/config/oidc_config.py')
| -rw-r--r-- | synapse/config/oidc_config.py | 594 |
1 files changed, 422 insertions, 172 deletions
diff --git a/synapse/config/oidc_config.py b/synapse/config/oidc_config.py index 4e3055282d..bfeceeed18 100644 --- a/synapse/config/oidc_config.py +++ b/synapse/config/oidc_config.py @@ -1,5 +1,6 @@ # -*- 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. @@ -13,8 +14,17 @@ # 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 @@ -25,202 +35,442 @@ class OIDCConfig(Config): section = "oidc" def read_config(self, config, **kwargs): - self.oidc_enabled = False - - oidc_config = config.get("oidc_config") - - if not oidc_config or not oidc_config.get("enabled", False): + 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) + 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 + ) public_baseurl = self.public_baseurl - if public_baseurl is None: - raise ConfigError("oidc_config requires a public_baseurl to be set") self.oidc_callback_url = public_baseurl + "_synapse/oidc/callback" - self.oidc_enabled = True - self.oidc_discover = oidc_config.get("discover", True) - self.oidc_issuer = oidc_config["issuer"] - self.oidc_client_id = oidc_config["client_id"] - self.oidc_client_secret = oidc_config["client_secret"] - self.oidc_client_auth_method = oidc_config.get( - "client_auth_method", "client_secret_basic" - ) - self.oidc_scopes = oidc_config.get("scopes", ["openid"]) - self.oidc_authorization_endpoint = oidc_config.get("authorization_endpoint") - self.oidc_token_endpoint = oidc_config.get("token_endpoint") - self.oidc_userinfo_endpoint = oidc_config.get("userinfo_endpoint") - self.oidc_jwks_uri = oidc_config.get("jwks_uri") - self.oidc_skip_verification = oidc_config.get("skip_verification", False) - self.oidc_user_profile_method = oidc_config.get("user_profile_method", "auto") - self.oidc_allow_existing_users = oidc_config.get("allow_existing_users", False) - - ump_config = oidc_config.get("user_mapping_provider", {}) - ump_config.setdefault("module", DEFAULT_USER_MAPPING_PROVIDER) - ump_config.setdefault("config", {}) - - ( - self.oidc_user_mapping_provider_class, - self.oidc_user_mapping_provider_config, - ) = load_module(ump_config, ("oidc_config", "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(self.oidc_user_mapping_provider_class, method) - ] - if missing_methods: - raise ConfigError( - "Class specified by oidc_config." - "user_mapping_provider.module is missing required " - "methods: %s" % (", ".join(missing_methods),) - ) + @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 """\ - # Enable OpenID Connect (OIDC) / OAuth 2.0 for registration and login. + # 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://<server-name>/<media-id>. (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 some example configurations. + # for information on how to configure these options. # - oidc_config: - # Uncomment the following to enable authorization against an OpenID Connect - # server. Defaults to false. - # - #enabled: true - - # Uncomment the following to disable use of the OIDC discovery mechanism to - # discover endpoints. Defaults to true. - # - #discover: false - - # the OIDC issuer. Used to validate tokens and (if discovery is enabled) to - # discover the provider's endpoints. - # - # Required if 'enabled' is true. - # - #issuer: "https://accounts.example.com/" - - # oauth2 client id to use. - # - # Required if 'enabled' is true. - # - #client_id: "provided-by-your-issuer" - - # oauth2 client secret to use. + # 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 # - # Required if 'enabled' is true. + #- 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 # - #client_secret: "provided-by-your-issuer" - - # auth method to use when exchanging the token. - # Valid values are 'client_secret_basic' (default), 'client_secret_post' and - # 'none'. + #- 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 # - #client_auth_method: client_secret_post + #- 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 + ) - # list of scopes to request. This should normally include the "openid" scope. - # Defaults to ["openid"]. - # - #scopes: ["openid", "profile"] - # the oauth2 authorization endpoint. Required if provider discovery is disabled. - # - #authorization_endpoint: "https://accounts.example.com/oauth2/auth" +# 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", "<item %i>" % (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"), + ) - # the oauth2 token endpoint. Required if provider discovery is disabled. - # - #token_endpoint: "https://accounts.example.com/oauth2/token" + # 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") - # the OIDC userinfo endpoint. Required if discovery is disabled and the - # "openid" scope is not requested. - # - #userinfo_endpoint: "https://accounts.example.com/userinfo" + # TODO: update this validity check based on what MSC2858 decides. + valid_idp_chars = set(string.ascii_lowercase + string.digits + "-._") - # URI where to fetch the JWKS. Required if discovery is disabled and the - # "openid" scope is used. - # - #jwks_uri: "https://accounts.example.com/.well-known/jwks.json" + 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",), + ) - # Uncomment to skip metadata verification. Defaults to false. - # - # Use this if you are connecting to a provider that is not OpenID Connect - # compliant. - # Avoid this in production. - # - #skip_verification: true + if idp_id[0] not in string.ascii_lowercase: + raise ConfigError( + "idp_id must start with a-z", config_path + ("idp_id",), + ) - # 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`. Uncomment the following to always fetch the userinfo endpoint. - # - #user_profile_method: "userinfo_endpoint" + # 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). - # Uncomment 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. - # - #allow_existing_users: true + if idp_id != "oidc": + idp_id = "oidc-" + idp_id - # An external module can be provided here as a custom solution to mapping - # attributes returned from a OIDC provider onto a matrix user. - # - user_mapping_provider: - # The custom module's class. Uncomment to use a custom 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. - # - #module: mapping_provider.OidcMappingProvider - - # Custom configuration values for the module. This section will be passed as - # a Python dictionary to the user mapping provider module's `parse_config` - # method. - # - # The examples below are intended for the default provider: they should be - # changed if using a custom provider. - # - config: - # name of the claim containing a unique identifier for the user. - # Defaults to `sub`, which OpenID Connect compliant providers should provide. - # - #subject_claim: "sub" - - # Jinja2 template for the localpart of the MXID. - # - # When rendering, this template is given the following variables: - # * user: The claims returned by the UserInfo Endpoint and/or in the ID - # Token - # - # If this is not set, the user will be prompted to choose their - # own username. - # - #localpart_template: "{{{{ user.preferred_username }}}}" - - # Jinja2 template for the display name to set on first login. - # - # If unset, no displayname will be set. - # - #display_name_template: "{{{{ user.given_name }}}} {{{{ user.last_name }}}}" - - # 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. - # - #extra_attributes: - #birthdate: "{{{{ user.birthdate }}}}" - """.format( - mapping_provider=DEFAULT_USER_MAPPING_PROVIDER - ) + # 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() |