1413 lines
		
	
	
		
			53 KiB
		
	
	
	
		
			Python
		
	
	
			
		
		
	
	
			1413 lines
		
	
	
		
			53 KiB
		
	
	
	
		
			Python
		
	
	
# Copyright 2020 Quentin Gliech
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# Copyright 2021 The Matrix.org Foundation C.I.C.
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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#     http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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import inspect
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import logging
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from typing import TYPE_CHECKING, Any, Dict, Generic, List, Optional, TypeVar, Union
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from urllib.parse import urlencode, urlparse
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import attr
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import pymacaroons
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from authlib.common.security import generate_token
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from authlib.jose import JsonWebToken, jwt
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from authlib.oauth2.auth import ClientAuth
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from authlib.oauth2.rfc6749.parameters import prepare_grant_uri
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from authlib.oidc.core import CodeIDToken, UserInfo
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from authlib.oidc.discovery import OpenIDProviderMetadata, get_well_known_url
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from jinja2 import Environment, Template
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from pymacaroons.exceptions import (
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    MacaroonDeserializationException,
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    MacaroonInitException,
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    MacaroonInvalidSignatureException,
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)
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from typing_extensions import TypedDict
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from twisted.web.client import readBody
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from twisted.web.http_headers import Headers
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from synapse.config import ConfigError
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from synapse.config.oidc import OidcProviderClientSecretJwtKey, OidcProviderConfig
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from synapse.handlers.sso import MappingException, UserAttributes
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from synapse.http.site import SynapseRequest
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from synapse.logging.context import make_deferred_yieldable
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from synapse.types import JsonDict, UserID, map_username_to_mxid_localpart
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from synapse.util import Clock, json_decoder
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from synapse.util.caches.cached_call import RetryOnExceptionCachedCall
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from synapse.util.macaroons import get_value_from_macaroon, satisfy_expiry
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if TYPE_CHECKING:
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    from synapse.server import HomeServer
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logger = logging.getLogger(__name__)
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# we want the cookie to be returned to us even when the request is the POSTed
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# result of a form on another domain, as is used with `response_mode=form_post`.
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#
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# Modern browsers will not do so unless we set SameSite=None; however *older*
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# browsers (including all versions of Safari on iOS 12?) don't support
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# SameSite=None, and interpret it as SameSite=Strict:
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# https://bugs.webkit.org/show_bug.cgi?id=198181
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#
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# As a rather painful workaround, we set *two* cookies, one with SameSite=None
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# and one with no SameSite, in the hope that at least one of them will get
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# back to us.
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#
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# Secure is necessary for SameSite=None (and, empirically, also breaks things
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# on iOS 12.)
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#
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# Here we have the names of the cookies, and the options we use to set them.
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_SESSION_COOKIES = [
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    (b"oidc_session", b"HttpOnly; Secure; SameSite=None"),
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    (b"oidc_session_no_samesite", b"HttpOnly"),
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]
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#: A token exchanged from the token endpoint, as per RFC6749 sec 5.1. and
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#: OpenID.Core sec 3.1.3.3.
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class Token(TypedDict):
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    access_token: str
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    token_type: str
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    id_token: Optional[str]
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    refresh_token: Optional[str]
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    expires_in: int
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    scope: Optional[str]
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#: A JWK, as per RFC7517 sec 4. The type could be more precise than that, but
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#: there is no real point of doing this in our case.
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JWK = Dict[str, str]
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#: A JWK Set, as per RFC7517 sec 5.
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class JWKS(TypedDict):
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    keys: List[JWK]
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class OidcHandler:
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    """Handles requests related to the OpenID Connect login flow."""
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    def __init__(self, hs: "HomeServer"):
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        self._sso_handler = hs.get_sso_handler()
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        provider_confs = hs.config.oidc.oidc_providers
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        # we should not have been instantiated if there is no configured provider.
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        assert provider_confs
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        self._token_generator = OidcSessionTokenGenerator(hs)
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        self._providers: Dict[str, "OidcProvider"] = {
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            p.idp_id: OidcProvider(hs, self._token_generator, p) for p in provider_confs
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        }
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    async def load_metadata(self) -> None:
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        """Validate the config and load the metadata from the remote endpoint.
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        Called at startup to ensure we have everything we need.
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        """
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        for idp_id, p in self._providers.items():
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            try:
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                await p.load_metadata()
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                if not p._uses_userinfo:
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                    await p.load_jwks()
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            except Exception as e:
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                raise Exception(
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                    "Error while initialising OIDC provider %r" % (idp_id,)
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                ) from e
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    async def handle_oidc_callback(self, request: SynapseRequest) -> None:
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        """Handle an incoming request to /_synapse/client/oidc/callback
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        Since we might want to display OIDC-related errors in a user-friendly
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        way, we don't raise SynapseError from here. Instead, we call
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        ``self._sso_handler.render_error`` which displays an HTML page for the error.
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        Most of the OpenID Connect logic happens here:
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          - first, we check if there was any error returned by the provider and
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            display it
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          - then we fetch the session cookie, decode and verify it
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          - the ``state`` query parameter should match with the one stored in the
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            session cookie
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        Once we know the session is legit, we then delegate to the OIDC Provider
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        implementation, which will exchange the code with the provider and complete the
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        login/authentication.
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        Args:
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            request: the incoming request from the browser.
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        """
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        # This will always be set by the time Twisted calls us.
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        assert request.args is not None
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        # The provider might redirect with an error.
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        # In that case, just display it as-is.
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        if b"error" in request.args:
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            # error response from the auth server. see:
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            #  https://tools.ietf.org/html/rfc6749#section-4.1.2.1
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            #  https://openid.net/specs/openid-connect-core-1_0.html#AuthError
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            error = request.args[b"error"][0].decode()
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            description = request.args.get(b"error_description", [b""])[0].decode()
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            # Most of the errors returned by the provider could be due by
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            # either the provider misbehaving or Synapse being misconfigured.
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            # The only exception of that is "access_denied", where the user
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            # probably cancelled the login flow. In other cases, log those errors.
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            logger.log(
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                logging.INFO if error == "access_denied" else logging.ERROR,
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                "Received OIDC callback with error: %s %s",
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                error,
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                description,
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            )
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            self._sso_handler.render_error(request, error, description)
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            return
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        # otherwise, it is presumably a successful response. see:
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        #   https://tools.ietf.org/html/rfc6749#section-4.1.2
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        # Fetch the session cookie. See the comments on SESSION_COOKIES for why there
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        # are two.
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        for cookie_name, _ in _SESSION_COOKIES:
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            session: Optional[bytes] = request.getCookie(cookie_name)
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            if session is not None:
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                break
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        else:
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            logger.info("Received OIDC callback, with no session cookie")
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            self._sso_handler.render_error(
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                request, "missing_session", "No session cookie found"
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            )
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            return
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        # Remove the cookies. There is a good chance that if the callback failed
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        # once, it will fail next time and the code will already be exchanged.
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        # Removing the cookies early avoids spamming the provider with token requests.
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        #
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        # we have to build the header by hand rather than calling request.addCookie
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        # because the latter does not support SameSite=None
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        # (https://twistedmatrix.com/trac/ticket/10088)
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        for cookie_name, options in _SESSION_COOKIES:
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            request.cookies.append(
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                b"%s=; Expires=Thu, Jan 01 1970 00:00:00 UTC; %s"
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                % (cookie_name, options)
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            )
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        # Check for the state query parameter
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        if b"state" not in request.args:
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            logger.info("Received OIDC callback, with no state parameter")
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            self._sso_handler.render_error(
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                request, "invalid_request", "State parameter is missing"
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            )
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            return
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        state = request.args[b"state"][0].decode()
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        # Deserialize the session token and verify it.
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        try:
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            session_data = self._token_generator.verify_oidc_session_token(
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                session, state
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            )
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        except (MacaroonInitException, MacaroonDeserializationException, KeyError) as e:
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            logger.exception("Invalid session for OIDC callback")
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            self._sso_handler.render_error(request, "invalid_session", str(e))
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            return
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        except MacaroonInvalidSignatureException as e:
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            logger.exception("Could not verify session for OIDC callback")
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            self._sso_handler.render_error(request, "mismatching_session", str(e))
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            return
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        logger.info("Received OIDC callback for IdP %s", session_data.idp_id)
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        oidc_provider = self._providers.get(session_data.idp_id)
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        if not oidc_provider:
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            logger.error("OIDC session uses unknown IdP %r", oidc_provider)
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            self._sso_handler.render_error(request, "unknown_idp", "Unknown IdP")
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            return
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        if b"code" not in request.args:
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            logger.info("Code parameter is missing")
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            self._sso_handler.render_error(
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                request, "invalid_request", "Code parameter is missing"
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            )
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            return
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        code = request.args[b"code"][0].decode()
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        await oidc_provider.handle_oidc_callback(request, session_data, code)
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class OidcError(Exception):
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    """Used to catch errors when calling the token_endpoint"""
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    def __init__(self, error: str, error_description: Optional[str] = None):
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        self.error = error
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        self.error_description = error_description
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    def __str__(self) -> str:
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        if self.error_description:
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            return f"{self.error}: {self.error_description}"
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        return self.error
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class OidcProvider:
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    """Wraps the config for a single OIDC IdentityProvider
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    Provides methods for handling redirect requests and callbacks via that particular
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    IdP.
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    """
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    def __init__(
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        self,
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        hs: "HomeServer",
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        token_generator: "OidcSessionTokenGenerator",
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        provider: OidcProviderConfig,
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    ):
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        self._store = hs.get_datastores().main
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        self._token_generator = token_generator
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        self._config = provider
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        self._callback_url: str = hs.config.oidc.oidc_callback_url
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        # Calculate the prefix for OIDC callback paths based on the public_baseurl.
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        # We'll insert this into the Path= parameter of any session cookies we set.
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        public_baseurl_path = urlparse(hs.config.server.public_baseurl).path
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        self._callback_path_prefix = (
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            public_baseurl_path.encode("utf-8") + b"_synapse/client/oidc"
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        )
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        self._oidc_attribute_requirements = provider.attribute_requirements
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        self._scopes = provider.scopes
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        self._user_profile_method = provider.user_profile_method
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        client_secret: Optional[Union[str, JwtClientSecret]] = None
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        if provider.client_secret:
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            client_secret = provider.client_secret
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        elif provider.client_secret_jwt_key:
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            client_secret = JwtClientSecret(
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                provider.client_secret_jwt_key,
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                provider.client_id,
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                provider.issuer,
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                hs.get_clock(),
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            )
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        self._client_auth = ClientAuth(
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            provider.client_id,
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            client_secret,
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            provider.client_auth_method,
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        )
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        self._client_auth_method = provider.client_auth_method
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        # cache of metadata for the identity provider (endpoint uris, mostly). This is
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        # loaded on-demand from the discovery endpoint (if discovery is enabled), with
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        # possible overrides from the config.  Access via `load_metadata`.
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        self._provider_metadata = RetryOnExceptionCachedCall(self._load_metadata)
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        # cache of JWKs used by the identity provider to sign tokens. Loaded on demand
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        # from the IdP's jwks_uri, if required.
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        self._jwks = RetryOnExceptionCachedCall(self._load_jwks)
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        self._user_mapping_provider = provider.user_mapping_provider_class(
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            provider.user_mapping_provider_config
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        )
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        self._skip_verification = provider.skip_verification
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        self._allow_existing_users = provider.allow_existing_users
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        self._http_client = hs.get_proxied_http_client()
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        self._server_name: str = hs.config.server.server_name
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        # identifier for the external_ids table
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        self.idp_id = provider.idp_id
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        # user-facing name of this auth provider
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        self.idp_name = provider.idp_name
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        # MXC URI for icon for this auth provider
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        self.idp_icon = provider.idp_icon
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        # optional brand identifier for this auth provider
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        self.idp_brand = provider.idp_brand
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        self._sso_handler = hs.get_sso_handler()
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        self._sso_handler.register_identity_provider(self)
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    def _validate_metadata(self, m: OpenIDProviderMetadata) -> None:
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        """Verifies the provider metadata.
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        This checks the validity of the currently loaded provider. Not
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        everything is checked, only:
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          - ``issuer``
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          - ``authorization_endpoint``
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          - ``token_endpoint``
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          - ``response_types_supported`` (checks if "code" is in it)
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          - ``jwks_uri``
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        Raises:
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            ValueError: if something in the provider is not valid
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        """
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        # Skip verification to allow non-compliant providers (e.g. issuers not running on a secure origin)
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        if self._skip_verification is True:
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            return
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        m.validate_issuer()
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        m.validate_authorization_endpoint()
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        m.validate_token_endpoint()
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						|
        if m.get("token_endpoint_auth_methods_supported") is not None:
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            m.validate_token_endpoint_auth_methods_supported()
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            if (
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                self._client_auth_method
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                not in m["token_endpoint_auth_methods_supported"]
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            ):
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                raise ValueError(
 | 
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                    '"{auth_method}" not in "token_endpoint_auth_methods_supported" ({supported!r})'.format(
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                        auth_method=self._client_auth_method,
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                        supported=m["token_endpoint_auth_methods_supported"],
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                    )
 | 
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                )
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 | 
						|
        if m.get("response_types_supported") is not None:
 | 
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            m.validate_response_types_supported()
 | 
						|
 | 
						|
            if "code" not in m["response_types_supported"]:
 | 
						|
                raise ValueError(
 | 
						|
                    '"code" not in "response_types_supported" (%r)'
 | 
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                    % (m["response_types_supported"],)
 | 
						|
                )
 | 
						|
 | 
						|
        # Ensure there's a userinfo endpoint to fetch from if it is required.
 | 
						|
        if self._uses_userinfo:
 | 
						|
            if m.get("userinfo_endpoint") is None:
 | 
						|
                raise ValueError(
 | 
						|
                    'provider has no "userinfo_endpoint", even though it is required'
 | 
						|
                )
 | 
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        else:
 | 
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            # If we're not using userinfo, we need a valid jwks to validate the ID token
 | 
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            m.validate_jwks_uri()
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 | 
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    @property
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    def _uses_userinfo(self) -> bool:
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        """Returns True if the ``userinfo_endpoint`` should be used.
 | 
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 | 
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        This is based on the requested scopes: if the scopes include
 | 
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        ``openid``, the provider should give use an ID token containing the
 | 
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        user information. If not, we should fetch them using the
 | 
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        ``access_token`` with the ``userinfo_endpoint``.
 | 
						|
        """
 | 
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 | 
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        return (
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            "openid" not in self._scopes
 | 
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            or self._user_profile_method == "userinfo_endpoint"
 | 
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        )
 | 
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 | 
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    async def load_metadata(self, force: bool = False) -> OpenIDProviderMetadata:
 | 
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        """Return the provider metadata.
 | 
						|
 | 
						|
        If this is the first call, the metadata is built from the config and from the
 | 
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        metadata discovery endpoint (if enabled), and then validated. If the metadata
 | 
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        is successfully validated, it is then cached for future use.
 | 
						|
 | 
						|
        Args:
 | 
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            force: If true, any cached metadata is discarded to force a reload.
 | 
						|
 | 
						|
        Raises:
 | 
						|
            ValueError: if something in the provider is not valid
 | 
						|
 | 
						|
        Returns:
 | 
						|
            The provider's metadata.
 | 
						|
        """
 | 
						|
        if force:
 | 
						|
            # reset the cached call to ensure we get a new result
 | 
						|
            self._provider_metadata = RetryOnExceptionCachedCall(self._load_metadata)
 | 
						|
 | 
						|
        return await self._provider_metadata.get()
 | 
						|
 | 
						|
    async def _load_metadata(self) -> OpenIDProviderMetadata:
 | 
						|
        # start out with just the issuer (unlike the other settings, discovered issuer
 | 
						|
        # takes precedence over configured issuer, because configured issuer is
 | 
						|
        # required for discovery to take place.)
 | 
						|
        #
 | 
						|
        metadata = OpenIDProviderMetadata(issuer=self._config.issuer)
 | 
						|
 | 
						|
        # load any data from the discovery endpoint, if enabled
 | 
						|
        if self._config.discover:
 | 
						|
            url = get_well_known_url(self._config.issuer, external=True)
 | 
						|
            metadata_response = await self._http_client.get_json(url)
 | 
						|
            metadata.update(metadata_response)
 | 
						|
 | 
						|
        # override any discovered data with any settings in our config
 | 
						|
        if self._config.authorization_endpoint:
 | 
						|
            metadata["authorization_endpoint"] = self._config.authorization_endpoint
 | 
						|
 | 
						|
        if self._config.token_endpoint:
 | 
						|
            metadata["token_endpoint"] = self._config.token_endpoint
 | 
						|
 | 
						|
        if self._config.userinfo_endpoint:
 | 
						|
            metadata["userinfo_endpoint"] = self._config.userinfo_endpoint
 | 
						|
 | 
						|
        if self._config.jwks_uri:
 | 
						|
            metadata["jwks_uri"] = self._config.jwks_uri
 | 
						|
 | 
						|
        self._validate_metadata(metadata)
 | 
						|
 | 
						|
        return metadata
 | 
						|
 | 
						|
    async def load_jwks(self, force: bool = False) -> JWKS:
 | 
						|
        """Load the JSON Web Key Set used to sign ID tokens.
 | 
						|
 | 
						|
        If we're not using the ``userinfo_endpoint``, user infos are extracted
 | 
						|
        from the ID token, which is a JWT signed by keys given by the provider.
 | 
						|
        The keys are then cached.
 | 
						|
 | 
						|
        Args:
 | 
						|
            force: Force reloading the keys.
 | 
						|
 | 
						|
        Returns:
 | 
						|
            The key set
 | 
						|
 | 
						|
            Looks like this::
 | 
						|
 | 
						|
                {
 | 
						|
                    'keys': [
 | 
						|
                        {
 | 
						|
                            'kid': 'abcdef',
 | 
						|
                            'kty': 'RSA',
 | 
						|
                            'alg': 'RS256',
 | 
						|
                            'use': 'sig',
 | 
						|
                            'e': 'XXXX',
 | 
						|
                            'n': 'XXXX',
 | 
						|
                        }
 | 
						|
                    ]
 | 
						|
                }
 | 
						|
        """
 | 
						|
        if force:
 | 
						|
            # reset the cached call to ensure we get a new result
 | 
						|
            self._jwks = RetryOnExceptionCachedCall(self._load_jwks)
 | 
						|
        return await self._jwks.get()
 | 
						|
 | 
						|
    async def _load_jwks(self) -> JWKS:
 | 
						|
        metadata = await self.load_metadata()
 | 
						|
 | 
						|
        # Load the JWKS using the `jwks_uri` metadata.
 | 
						|
        uri = metadata.get("jwks_uri")
 | 
						|
        if not uri:
 | 
						|
            # this should be unreachable: load_metadata validates that
 | 
						|
            # there is a jwks_uri in the metadata if _uses_userinfo is unset
 | 
						|
            raise RuntimeError('Missing "jwks_uri" in metadata')
 | 
						|
 | 
						|
        jwk_set = await self._http_client.get_json(uri)
 | 
						|
 | 
						|
        return jwk_set
 | 
						|
 | 
						|
    async def _exchange_code(self, code: str) -> Token:
 | 
						|
        """Exchange an authorization code for a token.
 | 
						|
 | 
						|
        This calls the ``token_endpoint`` with the authorization code we
 | 
						|
        received in the callback to exchange it for a token. The call uses the
 | 
						|
        ``ClientAuth`` to authenticate with the client with its ID and secret.
 | 
						|
 | 
						|
        See:
 | 
						|
           https://tools.ietf.org/html/rfc6749#section-3.2
 | 
						|
           https://openid.net/specs/openid-connect-core-1_0.html#TokenEndpoint
 | 
						|
 | 
						|
        Args:
 | 
						|
            code: The authorization code we got from the callback.
 | 
						|
 | 
						|
        Returns:
 | 
						|
            A dict containing various tokens.
 | 
						|
 | 
						|
            May look like this::
 | 
						|
 | 
						|
                {
 | 
						|
                    'token_type': 'bearer',
 | 
						|
                    'access_token': 'abcdef',
 | 
						|
                    'expires_in': 3599,
 | 
						|
                    'id_token': 'ghijkl',
 | 
						|
                    'refresh_token': 'mnopqr',
 | 
						|
                }
 | 
						|
 | 
						|
        Raises:
 | 
						|
            OidcError: when the ``token_endpoint`` returned an error.
 | 
						|
        """
 | 
						|
        metadata = await self.load_metadata()
 | 
						|
        token_endpoint = metadata.get("token_endpoint")
 | 
						|
        raw_headers: Dict[str, str] = {
 | 
						|
            "Content-Type": "application/x-www-form-urlencoded",
 | 
						|
            "User-Agent": self._http_client.user_agent.decode("ascii"),
 | 
						|
            "Accept": "application/json",
 | 
						|
        }
 | 
						|
 | 
						|
        args = {
 | 
						|
            "grant_type": "authorization_code",
 | 
						|
            "code": code,
 | 
						|
            "redirect_uri": self._callback_url,
 | 
						|
        }
 | 
						|
        body = urlencode(args, True)
 | 
						|
 | 
						|
        # Fill the body/headers with credentials
 | 
						|
        uri, raw_headers, body = self._client_auth.prepare(
 | 
						|
            method="POST", uri=token_endpoint, headers=raw_headers, body=body
 | 
						|
        )
 | 
						|
        headers = Headers({k: [v] for (k, v) in raw_headers.items()})
 | 
						|
 | 
						|
        # Do the actual request
 | 
						|
        # We're not using the SimpleHttpClient util methods as we don't want to
 | 
						|
        # check the HTTP status code and we do the body encoding ourself.
 | 
						|
        response = await self._http_client.request(
 | 
						|
            method="POST",
 | 
						|
            uri=uri,
 | 
						|
            data=body.encode("utf-8"),
 | 
						|
            headers=headers,
 | 
						|
        )
 | 
						|
 | 
						|
        # This is used in multiple error messages below
 | 
						|
        status = "{code} {phrase}".format(
 | 
						|
            code=response.code, phrase=response.phrase.decode("utf-8")
 | 
						|
        )
 | 
						|
 | 
						|
        resp_body = await make_deferred_yieldable(readBody(response))
 | 
						|
 | 
						|
        if response.code >= 500:
 | 
						|
            # In case of a server error, we should first try to decode the body
 | 
						|
            # and check for an error field. If not, we respond with a generic
 | 
						|
            # error message.
 | 
						|
            try:
 | 
						|
                resp = json_decoder.decode(resp_body.decode("utf-8"))
 | 
						|
                error = resp["error"]
 | 
						|
                description = resp.get("error_description", error)
 | 
						|
            except (ValueError, KeyError):
 | 
						|
                # Catch ValueError for the JSON decoding and KeyError for the "error" field
 | 
						|
                error = "server_error"
 | 
						|
                description = (
 | 
						|
                    (
 | 
						|
                        'Authorization server responded with a "{status}" error '
 | 
						|
                        "while exchanging the authorization code."
 | 
						|
                    ).format(status=status),
 | 
						|
                )
 | 
						|
 | 
						|
            raise OidcError(error, description)
 | 
						|
 | 
						|
        # Since it is a not a 5xx code, body should be a valid JSON. It will
 | 
						|
        # raise if not.
 | 
						|
        resp = json_decoder.decode(resp_body.decode("utf-8"))
 | 
						|
 | 
						|
        if "error" in resp:
 | 
						|
            error = resp["error"]
 | 
						|
            # In case the authorization server responded with an error field,
 | 
						|
            # it should be a 4xx code. If not, warn about it but don't do
 | 
						|
            # anything special and report the original error message.
 | 
						|
            if response.code < 400:
 | 
						|
                logger.debug(
 | 
						|
                    "Invalid response from the authorization server: "
 | 
						|
                    'responded with a "{status}" '
 | 
						|
                    "but body has an error field: {error!r}".format(
 | 
						|
                        status=status, error=resp["error"]
 | 
						|
                    )
 | 
						|
                )
 | 
						|
 | 
						|
            description = resp.get("error_description", error)
 | 
						|
            raise OidcError(error, description)
 | 
						|
 | 
						|
        # Now, this should not be an error. According to RFC6749 sec 5.1, it
 | 
						|
        # should be a 200 code. We're a bit more flexible than that, and will
 | 
						|
        # only throw on a 4xx code.
 | 
						|
        if response.code >= 400:
 | 
						|
            description = (
 | 
						|
                'Authorization server responded with a "{status}" error '
 | 
						|
                'but did not include an "error" field in its response.'.format(
 | 
						|
                    status=status
 | 
						|
                )
 | 
						|
            )
 | 
						|
            logger.warning(description)
 | 
						|
            # Body was still valid JSON. Might be useful to log it for debugging.
 | 
						|
            logger.warning("Code exchange response: %r", resp)
 | 
						|
            raise OidcError("server_error", description)
 | 
						|
 | 
						|
        return resp
 | 
						|
 | 
						|
    async def _fetch_userinfo(self, token: Token) -> UserInfo:
 | 
						|
        """Fetch user information from the ``userinfo_endpoint``.
 | 
						|
 | 
						|
        Args:
 | 
						|
            token: the token given by the ``token_endpoint``.
 | 
						|
                Must include an ``access_token`` field.
 | 
						|
 | 
						|
        Returns:
 | 
						|
            UserInfo: an object representing the user.
 | 
						|
        """
 | 
						|
        logger.debug("Using the OAuth2 access_token to request userinfo")
 | 
						|
        metadata = await self.load_metadata()
 | 
						|
 | 
						|
        resp = await self._http_client.get_json(
 | 
						|
            metadata["userinfo_endpoint"],
 | 
						|
            headers={"Authorization": ["Bearer {}".format(token["access_token"])]},
 | 
						|
        )
 | 
						|
 | 
						|
        logger.debug("Retrieved user info from userinfo endpoint: %r", resp)
 | 
						|
 | 
						|
        return UserInfo(resp)
 | 
						|
 | 
						|
    async def _parse_id_token(self, token: Token, nonce: str) -> CodeIDToken:
 | 
						|
        """Return an instance of UserInfo from token's ``id_token``.
 | 
						|
 | 
						|
        Args:
 | 
						|
            token: the token given by the ``token_endpoint``.
 | 
						|
                Must include an ``id_token`` field.
 | 
						|
            nonce: the nonce value originally sent in the initial authorization
 | 
						|
                request. This value should match the one inside the token.
 | 
						|
 | 
						|
        Returns:
 | 
						|
            The decoded claims in the ID token.
 | 
						|
        """
 | 
						|
        metadata = await self.load_metadata()
 | 
						|
        claims_params = {
 | 
						|
            "nonce": nonce,
 | 
						|
            "client_id": self._client_auth.client_id,
 | 
						|
        }
 | 
						|
        if "access_token" in token:
 | 
						|
            # If we got an `access_token`, there should be an `at_hash` claim
 | 
						|
            # in the `id_token` that we can check against.
 | 
						|
            claims_params["access_token"] = token["access_token"]
 | 
						|
 | 
						|
        alg_values = metadata.get("id_token_signing_alg_values_supported", ["RS256"])
 | 
						|
        jwt = JsonWebToken(alg_values)
 | 
						|
 | 
						|
        claim_options = {"iss": {"values": [metadata["issuer"]]}}
 | 
						|
 | 
						|
        id_token = token["id_token"]
 | 
						|
        logger.debug("Attempting to decode JWT id_token %r", id_token)
 | 
						|
 | 
						|
        # Try to decode the keys in cache first, then retry by forcing the keys
 | 
						|
        # to be reloaded
 | 
						|
        jwk_set = await self.load_jwks()
 | 
						|
        try:
 | 
						|
            claims = jwt.decode(
 | 
						|
                id_token,
 | 
						|
                key=jwk_set,
 | 
						|
                claims_cls=CodeIDToken,
 | 
						|
                claims_options=claim_options,
 | 
						|
                claims_params=claims_params,
 | 
						|
            )
 | 
						|
        except ValueError:
 | 
						|
            logger.info("Reloading JWKS after decode error")
 | 
						|
            jwk_set = await self.load_jwks(force=True)  # try reloading the jwks
 | 
						|
            claims = jwt.decode(
 | 
						|
                id_token,
 | 
						|
                key=jwk_set,
 | 
						|
                claims_cls=CodeIDToken,
 | 
						|
                claims_options=claim_options,
 | 
						|
                claims_params=claims_params,
 | 
						|
            )
 | 
						|
 | 
						|
        logger.debug("Decoded id_token JWT %r; validating", claims)
 | 
						|
 | 
						|
        claims.validate(leeway=120)  # allows 2 min of clock skew
 | 
						|
 | 
						|
        return claims
 | 
						|
 | 
						|
    async def handle_redirect_request(
 | 
						|
        self,
 | 
						|
        request: SynapseRequest,
 | 
						|
        client_redirect_url: Optional[bytes],
 | 
						|
        ui_auth_session_id: Optional[str] = None,
 | 
						|
    ) -> str:
 | 
						|
        """Handle an incoming request to /login/sso/redirect
 | 
						|
 | 
						|
        It returns a redirect to the authorization endpoint with a few
 | 
						|
        parameters:
 | 
						|
 | 
						|
          - ``client_id``: the client ID set in ``oidc_config.client_id``
 | 
						|
          - ``response_type``: ``code``
 | 
						|
          - ``redirect_uri``: the callback URL ; ``{base url}/_synapse/client/oidc/callback``
 | 
						|
          - ``scope``: the list of scopes set in ``oidc_config.scopes``
 | 
						|
          - ``state``: a random string
 | 
						|
          - ``nonce``: a random string
 | 
						|
 | 
						|
        In addition generating a redirect URL, we are setting a cookie with
 | 
						|
        a signed macaroon token containing the state, the nonce and the
 | 
						|
        client_redirect_url params. Those are then checked when the client
 | 
						|
        comes back from the provider.
 | 
						|
 | 
						|
        Args:
 | 
						|
            request: the incoming request from the browser.
 | 
						|
                We'll respond to it with a redirect and a cookie.
 | 
						|
            client_redirect_url: the URL that we should redirect the client to
 | 
						|
                when everything is done (or None for UI Auth)
 | 
						|
            ui_auth_session_id: The session ID of the ongoing UI Auth (or
 | 
						|
                None if this is a login).
 | 
						|
 | 
						|
        Returns:
 | 
						|
            The redirect URL to the authorization endpoint.
 | 
						|
 | 
						|
        """
 | 
						|
 | 
						|
        state = generate_token()
 | 
						|
        nonce = generate_token()
 | 
						|
 | 
						|
        if not client_redirect_url:
 | 
						|
            client_redirect_url = b""
 | 
						|
 | 
						|
        cookie = self._token_generator.generate_oidc_session_token(
 | 
						|
            state=state,
 | 
						|
            session_data=OidcSessionData(
 | 
						|
                idp_id=self.idp_id,
 | 
						|
                nonce=nonce,
 | 
						|
                client_redirect_url=client_redirect_url.decode(),
 | 
						|
                ui_auth_session_id=ui_auth_session_id or "",
 | 
						|
            ),
 | 
						|
        )
 | 
						|
 | 
						|
        # Set the cookies. See the comments on _SESSION_COOKIES for why there are two.
 | 
						|
        #
 | 
						|
        # we have to build the header by hand rather than calling request.addCookie
 | 
						|
        # because the latter does not support SameSite=None
 | 
						|
        # (https://twistedmatrix.com/trac/ticket/10088)
 | 
						|
 | 
						|
        for cookie_name, options in _SESSION_COOKIES:
 | 
						|
            request.cookies.append(
 | 
						|
                b"%s=%s; Max-Age=3600; Path=%s; %s"
 | 
						|
                % (
 | 
						|
                    cookie_name,
 | 
						|
                    cookie.encode("utf-8"),
 | 
						|
                    self._callback_path_prefix,
 | 
						|
                    options,
 | 
						|
                )
 | 
						|
            )
 | 
						|
 | 
						|
        metadata = await self.load_metadata()
 | 
						|
        authorization_endpoint = metadata.get("authorization_endpoint")
 | 
						|
        return prepare_grant_uri(
 | 
						|
            authorization_endpoint,
 | 
						|
            client_id=self._client_auth.client_id,
 | 
						|
            response_type="code",
 | 
						|
            redirect_uri=self._callback_url,
 | 
						|
            scope=self._scopes,
 | 
						|
            state=state,
 | 
						|
            nonce=nonce,
 | 
						|
        )
 | 
						|
 | 
						|
    async def handle_oidc_callback(
 | 
						|
        self, request: SynapseRequest, session_data: "OidcSessionData", code: str
 | 
						|
    ) -> None:
 | 
						|
        """Handle an incoming request to /_synapse/client/oidc/callback
 | 
						|
 | 
						|
        By this time we have already validated the session on the synapse side, and
 | 
						|
        now need to do the provider-specific operations. This includes:
 | 
						|
 | 
						|
          - exchange the code with the provider using the ``token_endpoint`` (see
 | 
						|
            ``_exchange_code``)
 | 
						|
          - once we have the token, use it to either extract the UserInfo from
 | 
						|
            the ``id_token`` (``_parse_id_token``), or use the ``access_token``
 | 
						|
            to fetch UserInfo from the ``userinfo_endpoint``
 | 
						|
            (``_fetch_userinfo``)
 | 
						|
          - map those UserInfo to a Matrix user (``_map_userinfo_to_user``) and
 | 
						|
            finish the login
 | 
						|
 | 
						|
        Args:
 | 
						|
            request: the incoming request from the browser.
 | 
						|
            session_data: the session data, extracted from our cookie
 | 
						|
            code: The authorization code we got from the callback.
 | 
						|
        """
 | 
						|
        # Exchange the code with the provider
 | 
						|
        try:
 | 
						|
            logger.debug("Exchanging OAuth2 code for a token")
 | 
						|
            token = await self._exchange_code(code)
 | 
						|
        except OidcError as e:
 | 
						|
            logger.exception("Could not exchange OAuth2 code")
 | 
						|
            self._sso_handler.render_error(request, e.error, e.error_description)
 | 
						|
            return
 | 
						|
 | 
						|
        logger.debug("Successfully obtained OAuth2 token data: %r", token)
 | 
						|
 | 
						|
        # If there is an id_token, it should be validated, regardless of the
 | 
						|
        # userinfo endpoint is used or not.
 | 
						|
        if token.get("id_token") is not None:
 | 
						|
            try:
 | 
						|
                id_token = await self._parse_id_token(token, nonce=session_data.nonce)
 | 
						|
                sid = id_token.get("sid")
 | 
						|
            except Exception as e:
 | 
						|
                logger.exception("Invalid id_token")
 | 
						|
                self._sso_handler.render_error(request, "invalid_token", str(e))
 | 
						|
                return
 | 
						|
        else:
 | 
						|
            id_token = None
 | 
						|
            sid = None
 | 
						|
 | 
						|
        # Now that we have a token, get the userinfo either from the `id_token`
 | 
						|
        # claims or by fetching the `userinfo_endpoint`.
 | 
						|
        if self._uses_userinfo:
 | 
						|
            try:
 | 
						|
                userinfo = await self._fetch_userinfo(token)
 | 
						|
            except Exception as e:
 | 
						|
                logger.exception("Could not fetch userinfo")
 | 
						|
                self._sso_handler.render_error(request, "fetch_error", str(e))
 | 
						|
                return
 | 
						|
        elif id_token is not None:
 | 
						|
            userinfo = UserInfo(id_token)
 | 
						|
        else:
 | 
						|
            logger.error("Missing id_token in token response")
 | 
						|
            self._sso_handler.render_error(
 | 
						|
                request, "invalid_token", "Missing id_token in token response"
 | 
						|
            )
 | 
						|
            return
 | 
						|
 | 
						|
        # first check if we're doing a UIA
 | 
						|
        if session_data.ui_auth_session_id:
 | 
						|
            try:
 | 
						|
                remote_user_id = self._remote_id_from_userinfo(userinfo)
 | 
						|
            except Exception as e:
 | 
						|
                logger.exception("Could not extract remote user id")
 | 
						|
                self._sso_handler.render_error(request, "mapping_error", str(e))
 | 
						|
                return
 | 
						|
 | 
						|
            return await self._sso_handler.complete_sso_ui_auth_request(
 | 
						|
                self.idp_id, remote_user_id, session_data.ui_auth_session_id, request
 | 
						|
            )
 | 
						|
 | 
						|
        # otherwise, it's a login
 | 
						|
        logger.debug("Userinfo for OIDC login: %s", userinfo)
 | 
						|
 | 
						|
        # Ensure that the attributes of the logged in user meet the required
 | 
						|
        # attributes by checking the userinfo against attribute_requirements
 | 
						|
        # In order to deal with the fact that OIDC userinfo can contain many
 | 
						|
        # types of data, we wrap non-list values in lists.
 | 
						|
        if not self._sso_handler.check_required_attributes(
 | 
						|
            request,
 | 
						|
            {k: v if isinstance(v, list) else [v] for k, v in userinfo.items()},
 | 
						|
            self._oidc_attribute_requirements,
 | 
						|
        ):
 | 
						|
            return
 | 
						|
 | 
						|
        # Call the mapper to register/login the user
 | 
						|
        try:
 | 
						|
            await self._complete_oidc_login(
 | 
						|
                userinfo, token, request, session_data.client_redirect_url, sid
 | 
						|
            )
 | 
						|
        except MappingException as e:
 | 
						|
            logger.exception("Could not map user")
 | 
						|
            self._sso_handler.render_error(request, "mapping_error", str(e))
 | 
						|
 | 
						|
    async def _complete_oidc_login(
 | 
						|
        self,
 | 
						|
        userinfo: UserInfo,
 | 
						|
        token: Token,
 | 
						|
        request: SynapseRequest,
 | 
						|
        client_redirect_url: str,
 | 
						|
        sid: Optional[str],
 | 
						|
    ) -> None:
 | 
						|
        """Given a UserInfo response, complete the login flow
 | 
						|
 | 
						|
        UserInfo should have a claim that uniquely identifies users. This claim
 | 
						|
        is usually `sub`, but can be configured with `oidc_config.subject_claim`.
 | 
						|
        It is then used as an `external_id`.
 | 
						|
 | 
						|
        If we don't find the user that way, we should register the user,
 | 
						|
        mapping the localpart and the display name from the UserInfo.
 | 
						|
 | 
						|
        If a user already exists with the mxid we've mapped and allow_existing_users
 | 
						|
        is disabled, raise an exception.
 | 
						|
 | 
						|
        Otherwise, render a redirect back to the client_redirect_url with a loginToken.
 | 
						|
 | 
						|
        Args:
 | 
						|
            userinfo: an object representing the user
 | 
						|
            token: a dict with the tokens obtained from the provider
 | 
						|
            request: The request to respond to
 | 
						|
            client_redirect_url: The redirect URL passed in by the client.
 | 
						|
 | 
						|
        Raises:
 | 
						|
            MappingException: if there was an error while mapping some properties
 | 
						|
        """
 | 
						|
        try:
 | 
						|
            remote_user_id = self._remote_id_from_userinfo(userinfo)
 | 
						|
        except Exception as e:
 | 
						|
            raise MappingException(
 | 
						|
                "Failed to extract subject from OIDC response: %s" % (e,)
 | 
						|
            )
 | 
						|
 | 
						|
        # Older mapping providers don't accept the `failures` argument, so we
 | 
						|
        # try and detect support.
 | 
						|
        mapper_signature = inspect.signature(
 | 
						|
            self._user_mapping_provider.map_user_attributes
 | 
						|
        )
 | 
						|
        supports_failures = "failures" in mapper_signature.parameters
 | 
						|
 | 
						|
        async def oidc_response_to_user_attributes(failures: int) -> UserAttributes:
 | 
						|
            """
 | 
						|
            Call the mapping provider to map the OIDC userinfo and token to user attributes.
 | 
						|
 | 
						|
            This is backwards compatibility for abstraction for the SSO handler.
 | 
						|
            """
 | 
						|
            if supports_failures:
 | 
						|
                attributes = await self._user_mapping_provider.map_user_attributes(
 | 
						|
                    userinfo, token, failures
 | 
						|
                )
 | 
						|
            else:
 | 
						|
                # If the mapping provider does not support processing failures,
 | 
						|
                # do not continually generate the same Matrix ID since it will
 | 
						|
                # continue to already be in use. Note that the error raised is
 | 
						|
                # arbitrary and will get turned into a MappingException.
 | 
						|
                if failures:
 | 
						|
                    raise MappingException(
 | 
						|
                        "Mapping provider does not support de-duplicating Matrix IDs"
 | 
						|
                    )
 | 
						|
 | 
						|
                attributes = await self._user_mapping_provider.map_user_attributes(  # type: ignore
 | 
						|
                    userinfo, token
 | 
						|
                )
 | 
						|
 | 
						|
            return UserAttributes(**attributes)
 | 
						|
 | 
						|
        async def grandfather_existing_users() -> Optional[str]:
 | 
						|
            if self._allow_existing_users:
 | 
						|
                # If allowing existing users we want to generate a single localpart
 | 
						|
                # and attempt to match it.
 | 
						|
                attributes = await oidc_response_to_user_attributes(failures=0)
 | 
						|
 | 
						|
                if attributes.localpart is None:
 | 
						|
                    # If no localpart is returned then we will generate one, so
 | 
						|
                    # there is no need to search for existing users.
 | 
						|
                    return None
 | 
						|
 | 
						|
                user_id = UserID(attributes.localpart, self._server_name).to_string()
 | 
						|
                users = await self._store.get_users_by_id_case_insensitive(user_id)
 | 
						|
                if users:
 | 
						|
                    # If an existing matrix ID is returned, then use it.
 | 
						|
                    if len(users) == 1:
 | 
						|
                        previously_registered_user_id = next(iter(users))
 | 
						|
                    elif user_id in users:
 | 
						|
                        previously_registered_user_id = user_id
 | 
						|
                    else:
 | 
						|
                        # Do not attempt to continue generating Matrix IDs.
 | 
						|
                        raise MappingException(
 | 
						|
                            "Attempted to login as '{}' but it matches more than one user inexactly: {}".format(
 | 
						|
                                user_id, users
 | 
						|
                            )
 | 
						|
                        )
 | 
						|
 | 
						|
                    return previously_registered_user_id
 | 
						|
 | 
						|
            return None
 | 
						|
 | 
						|
        # Mapping providers might not have get_extra_attributes: only call this
 | 
						|
        # method if it exists.
 | 
						|
        extra_attributes = None
 | 
						|
        get_extra_attributes = getattr(
 | 
						|
            self._user_mapping_provider, "get_extra_attributes", None
 | 
						|
        )
 | 
						|
        if get_extra_attributes:
 | 
						|
            extra_attributes = await get_extra_attributes(userinfo, token)
 | 
						|
 | 
						|
        await self._sso_handler.complete_sso_login_request(
 | 
						|
            self.idp_id,
 | 
						|
            remote_user_id,
 | 
						|
            request,
 | 
						|
            client_redirect_url,
 | 
						|
            oidc_response_to_user_attributes,
 | 
						|
            grandfather_existing_users,
 | 
						|
            extra_attributes,
 | 
						|
            auth_provider_session_id=sid,
 | 
						|
        )
 | 
						|
 | 
						|
    def _remote_id_from_userinfo(self, userinfo: UserInfo) -> str:
 | 
						|
        """Extract the unique remote id from an OIDC UserInfo block
 | 
						|
 | 
						|
        Args:
 | 
						|
            userinfo: An object representing the user given by the OIDC provider
 | 
						|
        Returns:
 | 
						|
            remote user id
 | 
						|
        """
 | 
						|
        remote_user_id = self._user_mapping_provider.get_remote_user_id(userinfo)
 | 
						|
        # Some OIDC providers use integer IDs, but Synapse expects external IDs
 | 
						|
        # to be strings.
 | 
						|
        return str(remote_user_id)
 | 
						|
 | 
						|
 | 
						|
# number of seconds a newly-generated client secret should be valid for
 | 
						|
CLIENT_SECRET_VALIDITY_SECONDS = 3600
 | 
						|
 | 
						|
# minimum remaining validity on a client secret before we should generate a new one
 | 
						|
CLIENT_SECRET_MIN_VALIDITY_SECONDS = 600
 | 
						|
 | 
						|
 | 
						|
class JwtClientSecret:
 | 
						|
    """A class which generates a new client secret on demand, based on a JWK
 | 
						|
 | 
						|
    This implementation is designed to comply with the requirements for Apple Sign in:
 | 
						|
    https://developer.apple.com/documentation/sign_in_with_apple/generate_and_validate_tokens#3262048
 | 
						|
 | 
						|
    It looks like those requirements are based on https://tools.ietf.org/html/rfc7523,
 | 
						|
    but it's worth noting that we still put the generated secret in the "client_secret"
 | 
						|
    field (or rather, whereever client_auth_method puts it) rather than in a
 | 
						|
    client_assertion field in the body as that RFC seems to require.
 | 
						|
    """
 | 
						|
 | 
						|
    def __init__(
 | 
						|
        self,
 | 
						|
        key: OidcProviderClientSecretJwtKey,
 | 
						|
        oauth_client_id: str,
 | 
						|
        oauth_issuer: str,
 | 
						|
        clock: Clock,
 | 
						|
    ):
 | 
						|
        self._key = key
 | 
						|
        self._oauth_client_id = oauth_client_id
 | 
						|
        self._oauth_issuer = oauth_issuer
 | 
						|
        self._clock = clock
 | 
						|
        self._cached_secret = b""
 | 
						|
        self._cached_secret_replacement_time = 0
 | 
						|
 | 
						|
    def __str__(self) -> str:
 | 
						|
        # if client_auth_method is client_secret_basic, then ClientAuth.prepare calls
 | 
						|
        # encode_client_secret_basic, which calls "{}".format(secret), which ends up
 | 
						|
        # here.
 | 
						|
        return self._get_secret().decode("ascii")
 | 
						|
 | 
						|
    def __bytes__(self) -> bytes:
 | 
						|
        # if client_auth_method is client_secret_post, then ClientAuth.prepare calls
 | 
						|
        # encode_client_secret_post, which ends up here.
 | 
						|
        return self._get_secret()
 | 
						|
 | 
						|
    def _get_secret(self) -> bytes:
 | 
						|
        now = self._clock.time()
 | 
						|
 | 
						|
        # if we have enough validity on our existing secret, use it
 | 
						|
        if now < self._cached_secret_replacement_time:
 | 
						|
            return self._cached_secret
 | 
						|
 | 
						|
        issued_at = int(now)
 | 
						|
        expires_at = issued_at + CLIENT_SECRET_VALIDITY_SECONDS
 | 
						|
 | 
						|
        # we copy the configured header because jwt.encode modifies it.
 | 
						|
        header = dict(self._key.jwt_header)
 | 
						|
 | 
						|
        # see https://tools.ietf.org/html/rfc7523#section-3
 | 
						|
        payload = {
 | 
						|
            "sub": self._oauth_client_id,
 | 
						|
            "aud": self._oauth_issuer,
 | 
						|
            "iat": issued_at,
 | 
						|
            "exp": expires_at,
 | 
						|
            **self._key.jwt_payload,
 | 
						|
        }
 | 
						|
        logger.info(
 | 
						|
            "Generating new JWT for %s: %s %s", self._oauth_issuer, header, payload
 | 
						|
        )
 | 
						|
        self._cached_secret = jwt.encode(header, payload, self._key.key)
 | 
						|
        self._cached_secret_replacement_time = (
 | 
						|
            expires_at - CLIENT_SECRET_MIN_VALIDITY_SECONDS
 | 
						|
        )
 | 
						|
        return self._cached_secret
 | 
						|
 | 
						|
 | 
						|
class OidcSessionTokenGenerator:
 | 
						|
    """Methods for generating and checking OIDC Session cookies."""
 | 
						|
 | 
						|
    def __init__(self, hs: "HomeServer"):
 | 
						|
        self._clock = hs.get_clock()
 | 
						|
        self._server_name = hs.hostname
 | 
						|
        self._macaroon_secret_key = hs.config.key.macaroon_secret_key
 | 
						|
 | 
						|
    def generate_oidc_session_token(
 | 
						|
        self,
 | 
						|
        state: str,
 | 
						|
        session_data: "OidcSessionData",
 | 
						|
        duration_in_ms: int = (60 * 60 * 1000),
 | 
						|
    ) -> str:
 | 
						|
        """Generates a signed token storing data about an OIDC session.
 | 
						|
 | 
						|
        When Synapse initiates an authorization flow, it creates a random state
 | 
						|
        and a random nonce. Those parameters are given to the provider and
 | 
						|
        should be verified when the client comes back from the provider.
 | 
						|
        It is also used to store the client_redirect_url, which is used to
 | 
						|
        complete the SSO login flow.
 | 
						|
 | 
						|
        Args:
 | 
						|
            state: The ``state`` parameter passed to the OIDC provider.
 | 
						|
            session_data: data to include in the session token.
 | 
						|
            duration_in_ms: An optional duration for the token in milliseconds.
 | 
						|
                Defaults to an hour.
 | 
						|
 | 
						|
        Returns:
 | 
						|
            A signed macaroon token with the session information.
 | 
						|
        """
 | 
						|
        macaroon = pymacaroons.Macaroon(
 | 
						|
            location=self._server_name,
 | 
						|
            identifier="key",
 | 
						|
            key=self._macaroon_secret_key,
 | 
						|
        )
 | 
						|
        macaroon.add_first_party_caveat("gen = 1")
 | 
						|
        macaroon.add_first_party_caveat("type = session")
 | 
						|
        macaroon.add_first_party_caveat("state = %s" % (state,))
 | 
						|
        macaroon.add_first_party_caveat("idp_id = %s" % (session_data.idp_id,))
 | 
						|
        macaroon.add_first_party_caveat("nonce = %s" % (session_data.nonce,))
 | 
						|
        macaroon.add_first_party_caveat(
 | 
						|
            "client_redirect_url = %s" % (session_data.client_redirect_url,)
 | 
						|
        )
 | 
						|
        macaroon.add_first_party_caveat(
 | 
						|
            "ui_auth_session_id = %s" % (session_data.ui_auth_session_id,)
 | 
						|
        )
 | 
						|
        now = self._clock.time_msec()
 | 
						|
        expiry = now + duration_in_ms
 | 
						|
        macaroon.add_first_party_caveat("time < %d" % (expiry,))
 | 
						|
 | 
						|
        return macaroon.serialize()
 | 
						|
 | 
						|
    def verify_oidc_session_token(
 | 
						|
        self, session: bytes, state: str
 | 
						|
    ) -> "OidcSessionData":
 | 
						|
        """Verifies and extract an OIDC session token.
 | 
						|
 | 
						|
        This verifies that a given session token was issued by this homeserver
 | 
						|
        and extract the nonce and client_redirect_url caveats.
 | 
						|
 | 
						|
        Args:
 | 
						|
            session: The session token to verify
 | 
						|
            state: The state the OIDC provider gave back
 | 
						|
 | 
						|
        Returns:
 | 
						|
            The data extracted from the session cookie
 | 
						|
 | 
						|
        Raises:
 | 
						|
            KeyError if an expected caveat is missing from the macaroon.
 | 
						|
        """
 | 
						|
        macaroon = pymacaroons.Macaroon.deserialize(session)
 | 
						|
 | 
						|
        v = pymacaroons.Verifier()
 | 
						|
        v.satisfy_exact("gen = 1")
 | 
						|
        v.satisfy_exact("type = session")
 | 
						|
        v.satisfy_exact("state = %s" % (state,))
 | 
						|
        v.satisfy_general(lambda c: c.startswith("nonce = "))
 | 
						|
        v.satisfy_general(lambda c: c.startswith("idp_id = "))
 | 
						|
        v.satisfy_general(lambda c: c.startswith("client_redirect_url = "))
 | 
						|
        v.satisfy_general(lambda c: c.startswith("ui_auth_session_id = "))
 | 
						|
        satisfy_expiry(v, self._clock.time_msec)
 | 
						|
 | 
						|
        v.verify(macaroon, self._macaroon_secret_key)
 | 
						|
 | 
						|
        # Extract the session data from the token.
 | 
						|
        nonce = get_value_from_macaroon(macaroon, "nonce")
 | 
						|
        idp_id = get_value_from_macaroon(macaroon, "idp_id")
 | 
						|
        client_redirect_url = get_value_from_macaroon(macaroon, "client_redirect_url")
 | 
						|
        ui_auth_session_id = get_value_from_macaroon(macaroon, "ui_auth_session_id")
 | 
						|
        return OidcSessionData(
 | 
						|
            nonce=nonce,
 | 
						|
            idp_id=idp_id,
 | 
						|
            client_redirect_url=client_redirect_url,
 | 
						|
            ui_auth_session_id=ui_auth_session_id,
 | 
						|
        )
 | 
						|
 | 
						|
 | 
						|
@attr.s(frozen=True, slots=True, auto_attribs=True)
 | 
						|
class OidcSessionData:
 | 
						|
    """The attributes which are stored in a OIDC session cookie"""
 | 
						|
 | 
						|
    # the Identity Provider being used
 | 
						|
    idp_id: str
 | 
						|
 | 
						|
    # The `nonce` parameter passed to the OIDC provider.
 | 
						|
    nonce: str
 | 
						|
 | 
						|
    # The URL the client gave when it initiated the flow. ("" if this is a UI Auth)
 | 
						|
    client_redirect_url: str
 | 
						|
 | 
						|
    # The session ID of the ongoing UI Auth ("" if this is a login)
 | 
						|
    ui_auth_session_id: str
 | 
						|
 | 
						|
 | 
						|
class UserAttributeDict(TypedDict):
 | 
						|
    localpart: Optional[str]
 | 
						|
    display_name: Optional[str]
 | 
						|
    emails: List[str]
 | 
						|
 | 
						|
 | 
						|
C = TypeVar("C")
 | 
						|
 | 
						|
 | 
						|
class OidcMappingProvider(Generic[C]):
 | 
						|
    """A mapping provider maps a UserInfo object to user attributes.
 | 
						|
 | 
						|
    It should provide the API described by this class.
 | 
						|
    """
 | 
						|
 | 
						|
    def __init__(self, config: C):
 | 
						|
        """
 | 
						|
        Args:
 | 
						|
            config: A custom config object from this module, parsed by ``parse_config()``
 | 
						|
        """
 | 
						|
 | 
						|
    @staticmethod
 | 
						|
    def parse_config(config: dict) -> C:
 | 
						|
        """Parse the dict provided by the homeserver's config
 | 
						|
 | 
						|
        Args:
 | 
						|
            config: A dictionary containing configuration options for this provider
 | 
						|
 | 
						|
        Returns:
 | 
						|
            A custom config object for this module
 | 
						|
        """
 | 
						|
        raise NotImplementedError()
 | 
						|
 | 
						|
    def get_remote_user_id(self, userinfo: UserInfo) -> str:
 | 
						|
        """Get a unique user ID for this user.
 | 
						|
 | 
						|
        Usually, in an OIDC-compliant scenario, it should be the ``sub`` claim from the UserInfo object.
 | 
						|
 | 
						|
        Args:
 | 
						|
            userinfo: An object representing the user given by the OIDC provider
 | 
						|
 | 
						|
        Returns:
 | 
						|
            A unique user ID
 | 
						|
        """
 | 
						|
        raise NotImplementedError()
 | 
						|
 | 
						|
    async def map_user_attributes(
 | 
						|
        self, userinfo: UserInfo, token: Token, failures: int
 | 
						|
    ) -> UserAttributeDict:
 | 
						|
        """Map a `UserInfo` object into user attributes.
 | 
						|
 | 
						|
        Args:
 | 
						|
            userinfo: An object representing the user given by the OIDC provider
 | 
						|
            token: A dict with the tokens returned by the provider
 | 
						|
            failures: How many times a call to this function with this
 | 
						|
                UserInfo has resulted in a failure.
 | 
						|
 | 
						|
        Returns:
 | 
						|
            A dict containing the ``localpart`` and (optionally) the ``display_name``
 | 
						|
        """
 | 
						|
        raise NotImplementedError()
 | 
						|
 | 
						|
    async def get_extra_attributes(self, userinfo: UserInfo, token: Token) -> JsonDict:
 | 
						|
        """Map a `UserInfo` object into additional attributes passed to the client during login.
 | 
						|
 | 
						|
        Args:
 | 
						|
            userinfo: An object representing the user given by the OIDC provider
 | 
						|
            token: A dict with the tokens returned by the provider
 | 
						|
 | 
						|
        Returns:
 | 
						|
            A dict containing additional attributes. Must be JSON serializable.
 | 
						|
        """
 | 
						|
        return {}
 | 
						|
 | 
						|
 | 
						|
# Used to clear out "None" values in templates
 | 
						|
def jinja_finalize(thing: Any) -> Any:
 | 
						|
    return thing if thing is not None else ""
 | 
						|
 | 
						|
 | 
						|
env = Environment(finalize=jinja_finalize)
 | 
						|
 | 
						|
 | 
						|
@attr.s(slots=True, frozen=True, auto_attribs=True)
 | 
						|
class JinjaOidcMappingConfig:
 | 
						|
    subject_claim: str
 | 
						|
    localpart_template: Optional[Template]
 | 
						|
    display_name_template: Optional[Template]
 | 
						|
    email_template: Optional[Template]
 | 
						|
    extra_attributes: Dict[str, Template]
 | 
						|
 | 
						|
 | 
						|
class JinjaOidcMappingProvider(OidcMappingProvider[JinjaOidcMappingConfig]):
 | 
						|
    """An implementation of a mapping provider based on Jinja templates.
 | 
						|
 | 
						|
    This is the default mapping provider.
 | 
						|
    """
 | 
						|
 | 
						|
    def __init__(self, config: JinjaOidcMappingConfig):
 | 
						|
        self._config = config
 | 
						|
 | 
						|
    @staticmethod
 | 
						|
    def parse_config(config: dict) -> JinjaOidcMappingConfig:
 | 
						|
        subject_claim = config.get("subject_claim", "sub")
 | 
						|
 | 
						|
        def parse_template_config(option_name: str) -> Optional[Template]:
 | 
						|
            if option_name not in config:
 | 
						|
                return None
 | 
						|
            try:
 | 
						|
                return env.from_string(config[option_name])
 | 
						|
            except Exception as e:
 | 
						|
                raise ConfigError("invalid jinja template", path=[option_name]) from e
 | 
						|
 | 
						|
        localpart_template = parse_template_config("localpart_template")
 | 
						|
        display_name_template = parse_template_config("display_name_template")
 | 
						|
        email_template = parse_template_config("email_template")
 | 
						|
 | 
						|
        extra_attributes = {}  # type Dict[str, Template]
 | 
						|
        if "extra_attributes" in config:
 | 
						|
            extra_attributes_config = config.get("extra_attributes") or {}
 | 
						|
            if not isinstance(extra_attributes_config, dict):
 | 
						|
                raise ConfigError("must be a dict", path=["extra_attributes"])
 | 
						|
 | 
						|
            for key, value in extra_attributes_config.items():
 | 
						|
                try:
 | 
						|
                    extra_attributes[key] = env.from_string(value)
 | 
						|
                except Exception as e:
 | 
						|
                    raise ConfigError(
 | 
						|
                        "invalid jinja template", path=["extra_attributes", key]
 | 
						|
                    ) from e
 | 
						|
 | 
						|
        return JinjaOidcMappingConfig(
 | 
						|
            subject_claim=subject_claim,
 | 
						|
            localpart_template=localpart_template,
 | 
						|
            display_name_template=display_name_template,
 | 
						|
            email_template=email_template,
 | 
						|
            extra_attributes=extra_attributes,
 | 
						|
        )
 | 
						|
 | 
						|
    def get_remote_user_id(self, userinfo: UserInfo) -> str:
 | 
						|
        return userinfo[self._config.subject_claim]
 | 
						|
 | 
						|
    async def map_user_attributes(
 | 
						|
        self, userinfo: UserInfo, token: Token, failures: int
 | 
						|
    ) -> UserAttributeDict:
 | 
						|
        localpart = None
 | 
						|
 | 
						|
        if self._config.localpart_template:
 | 
						|
            localpart = self._config.localpart_template.render(user=userinfo).strip()
 | 
						|
 | 
						|
            # Ensure only valid characters are included in the MXID.
 | 
						|
            localpart = map_username_to_mxid_localpart(localpart)
 | 
						|
 | 
						|
            # Append suffix integer if last call to this function failed to produce
 | 
						|
            # a usable mxid.
 | 
						|
            localpart += str(failures) if failures else ""
 | 
						|
 | 
						|
        def render_template_field(template: Optional[Template]) -> Optional[str]:
 | 
						|
            if template is None:
 | 
						|
                return None
 | 
						|
            return template.render(user=userinfo).strip()
 | 
						|
 | 
						|
        display_name = render_template_field(self._config.display_name_template)
 | 
						|
        if display_name == "":
 | 
						|
            display_name = None
 | 
						|
 | 
						|
        emails: List[str] = []
 | 
						|
        email = render_template_field(self._config.email_template)
 | 
						|
        if email:
 | 
						|
            emails.append(email)
 | 
						|
 | 
						|
        return UserAttributeDict(
 | 
						|
            localpart=localpart, display_name=display_name, emails=emails
 | 
						|
        )
 | 
						|
 | 
						|
    async def get_extra_attributes(self, userinfo: UserInfo, token: Token) -> JsonDict:
 | 
						|
        extras: Dict[str, str] = {}
 | 
						|
        for key, template in self._config.extra_attributes.items():
 | 
						|
            try:
 | 
						|
                extras[key] = template.render(user=userinfo).strip()
 | 
						|
            except Exception as e:
 | 
						|
                # Log an error and skip this value (don't break login for this).
 | 
						|
                logger.error("Failed to render OIDC extra attribute %s: %s" % (key, e))
 | 
						|
        return extras
 |