#
# This file is licensed under the Affero General Public License (AGPL) version 3.
#
# Copyright 2020-2021 The Matrix.org Foundation C.I.C
# Copyright (C) 2023 New Vector, Ltd
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as
# published by the Free Software Foundation, either version 3 of the
# License, or (at your option) any later version.
#
# See the GNU Affero General Public License for more details:
# <https://www.gnu.org/licenses/agpl-3.0.html>.
#
# Originally licensed under the Apache License, Version 2.0:
# <http://www.apache.org/licenses/LICENSE-2.0>.
#
# [This file includes modifications made by New Vector Limited]
#
#
import re
from http import HTTPStatus
from typing import Any

from twisted.internet.defer import succeed
from twisted.internet.testing import MemoryReactor
from twisted.web.resource import Resource

import synapse.rest.admin
from synapse.api.constants import ApprovalNoticeMedium, LoginType
from synapse.api.errors import Codes, SynapseError
from synapse.handlers.ui_auth.checkers import UserInteractiveAuthChecker
from synapse.rest.client import account, auth, devices, login, logout, register
from synapse.rest.synapse.client import build_synapse_client_resource_tree
from synapse.server import HomeServer
from synapse.storage.database import LoggingTransaction
from synapse.types import JsonDict, UserID
from synapse.util.clock import Clock

from tests import unittest
from tests.handlers.test_oidc import HAS_OIDC
from tests.rest.client.utils import TEST_OIDC_CONFIG, TEST_OIDC_ISSUER
from tests.server import FakeChannel
from tests.unittest import override_config, skip_unless

TEST_MULTIPLE_OIDC_IDP_ID1 = "friendface"
TEST_MULTIPLE_OIDC_IDP_ID2 = "potatocloud"
TEST_MULTIPLE_OIDC_IDP_ID3 = "svnswitch"

TEST_MULTIPLE_OIDC_ISSUER1 = "https://friendface.invalid/"
TEST_MULTIPLE_OIDC_ISSUER2 = "https://potato.invalid/"
TEST_MULTIPLE_OIDC_ISSUER3 = "https://subversionswitch.invalid/"

TEST_MULTIPLE_OIDC_PROVIDERS = [
    {
        "idp_id": TEST_MULTIPLE_OIDC_IDP_ID1,
        "idp_name": "FriendFace",
        "idp_icon": "mxc://example.invalid/friendface",
        "idp_brand": "friendface",
        "issuer": TEST_MULTIPLE_OIDC_ISSUER1,
        "client_id": "id-for-friendface",
        "client_secret": "secret-for-friendface",
        "scopes": ["openid"],
        "discover": False,
        "authorization_endpoint": f"{TEST_MULTIPLE_OIDC_ISSUER1}oidc/auth",
        "token_endpoint": f"{TEST_MULTIPLE_OIDC_ISSUER1}oidc/token",
        "jwks_uri": f"{TEST_MULTIPLE_OIDC_ISSUER1}oidc/jwks",
    },
    {
        "idp_id": TEST_MULTIPLE_OIDC_IDP_ID2,
        "idp_name": "Potato Cloud",
        "idp_icon": "mxc://example.invalid/potatocloud",
        "idp_brand": "potato",
        "issuer": TEST_MULTIPLE_OIDC_ISSUER2,
        "client_id": "id-for-potato",
        "client_secret": "secret-for-potato",
        "scopes": ["openid"],
        "discover": False,
        "authorization_endpoint": f"{TEST_MULTIPLE_OIDC_ISSUER2}oidc/auth",
        "token_endpoint": f"{TEST_MULTIPLE_OIDC_ISSUER2}oidc/token",
        "jwks_uri": f"{TEST_MULTIPLE_OIDC_ISSUER2}oidc/jwks",
    },
    {
        "idp_id": TEST_MULTIPLE_OIDC_IDP_ID3,
        "idp_name": "SubversionSwitch",
        "idp_icon": "mxc://example.invalid/svnswitch",
        "idp_brand": "svnswitch",
        "issuer": TEST_MULTIPLE_OIDC_ISSUER3,
        "client_id": "id-for-svnswitch",
        "client_secret": "secret-for-svnswitch",
        "scopes": ["openid"],
        "discover": False,
        "authorization_endpoint": f"{TEST_MULTIPLE_OIDC_ISSUER3}oidc/auth",
        "token_endpoint": f"{TEST_MULTIPLE_OIDC_ISSUER3}oidc/token",
        "jwks_uri": f"{TEST_MULTIPLE_OIDC_ISSUER3}oidc/jwks",
    },
]
"""
`oidc_providers` config example for multiple OIDC providers.
"""


class DummyRecaptchaChecker(UserInteractiveAuthChecker):
    def __init__(self, hs: HomeServer) -> None:
        super().__init__(hs)
        self.recaptcha_attempts: list[tuple[dict, str]] = []

    def is_enabled(self) -> bool:
        return True

    def check_auth(self, authdict: dict, clientip: str) -> Any:
        self.recaptcha_attempts.append((authdict, clientip))
        return succeed(True)


class FallbackAuthTests(unittest.HomeserverTestCase):
    servlets = [
        auth.register_servlets,
        register.register_servlets,
    ]
    hijack_auth = False

    def make_homeserver(self, reactor: MemoryReactor, clock: Clock) -> HomeServer:
        config = self.default_config()

        config["enable_registration_captcha"] = True
        config["recaptcha_public_key"] = "brokencake"
        config["registrations_require_3pid"] = []

        hs = self.setup_test_homeserver(config=config)
        return hs

    def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
        self.recaptcha_checker = DummyRecaptchaChecker(hs)
        auth_handler = hs.get_auth_handler()
        auth_handler.checkers[LoginType.RECAPTCHA] = self.recaptcha_checker

    def register(self, expected_response: int, body: JsonDict) -> FakeChannel:
        """Make a register request."""
        channel = self.make_request("POST", "register", body)

        self.assertEqual(channel.code, expected_response)
        return channel

    def recaptcha(
        self,
        session: str,
        expected_post_response: int,
        post_session: str | None = None,
    ) -> None:
        """Get and respond to a fallback recaptcha. Returns the second request."""
        if post_session is None:
            post_session = session

        channel = self.make_request(
            "GET", "auth/m.login.recaptcha/fallback/web?session=" + session
        )
        self.assertEqual(channel.code, HTTPStatus.OK)

        channel = self.make_request(
            "POST",
            "auth/m.login.recaptcha/fallback/web?session="
            + post_session
            + "&g-recaptcha-response=a",
        )
        self.assertEqual(channel.code, expected_post_response)

        # The recaptcha handler is called with the response given
        attempts = self.recaptcha_checker.recaptcha_attempts
        self.assertEqual(len(attempts), 1)
        self.assertEqual(attempts[0][0]["response"], "a")

    def test_fallback_captcha(self) -> None:
        """Ensure that fallback auth via a captcha works."""
        # Returns a 401 as per the spec
        channel = self.register(
            HTTPStatus.UNAUTHORIZED,
            {"username": "user", "type": "m.login.password", "password": "bar"},
        )

        # Grab the session
        session = channel.json_body["session"]
        # Assert our configured public key is being given
        self.assertEqual(
            channel.json_body["params"]["m.login.recaptcha"]["public_key"], "brokencake"
        )

        # Complete the recaptcha step.
        self.recaptcha(session, HTTPStatus.OK)

        # also complete the dummy auth
        self.register(
            HTTPStatus.OK, {"auth": {"session": session, "type": "m.login.dummy"}}
        )

        # Now we should have fulfilled a complete auth flow, including
        # the recaptcha fallback step, we can then send a
        # request to the register API with the session in the authdict.
        channel = self.register(HTTPStatus.OK, {"auth": {"session": session}})

        # We're given a registered user.
        self.assertEqual(channel.json_body["user_id"], "@user:test")

    def test_complete_operation_unknown_session(self) -> None:
        """
        Attempting to mark an invalid session as complete should error.
        """
        # Make the initial request to register. (Later on a different password
        # will be used.)
        # Returns a 401 as per the spec
        channel = self.register(
            HTTPStatus.UNAUTHORIZED,
            {"username": "user", "type": "m.login.password", "password": "bar"},
        )

        # Grab the session
        session = channel.json_body["session"]
        # Assert our configured public key is being given
        self.assertEqual(
            channel.json_body["params"]["m.login.recaptcha"]["public_key"], "brokencake"
        )

        # Attempt to complete the recaptcha step with an unknown session.
        # This results in an error.
        self.recaptcha(session, 400, session + "unknown")


class UIAuthTests(unittest.HomeserverTestCase):
    servlets = [
        auth.register_servlets,
        devices.register_servlets,
        login.register_servlets,
        synapse.rest.admin.register_servlets_for_client_rest_resource,
        register.register_servlets,
    ]

    def default_config(self) -> dict[str, Any]:
        config = super().default_config()

        # public_baseurl uses an http:// scheme because FakeChannel.isSecure() returns
        # False, so synapse will see the requested uri as http://..., so using http in
        # the public_baseurl stops Synapse trying to redirect to https.
        config["public_baseurl"] = "http://synapse.test"

        if HAS_OIDC:
            # we enable OIDC as a way of testing SSO flows
            oidc_config = {}
            oidc_config.update(TEST_OIDC_CONFIG)
            oidc_config["allow_existing_users"] = True
            config["oidc_config"] = oidc_config

        return config

    def create_resource_dict(self) -> dict[str, Resource]:
        resource_dict = super().create_resource_dict()
        resource_dict.update(build_synapse_client_resource_tree(self.hs))
        return resource_dict

    def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
        self.user_pass = "pass"
        self.user = self.register_user("test", self.user_pass)
        self.device_id = "dev1"

        # Force-enable password login for just long enough to log in.
        auth_handler = self.hs.get_auth_handler()
        allow_auth_for_login = auth_handler._password_enabled_for_login
        auth_handler._password_enabled_for_login = True

        self.user_tok = self.login("test", self.user_pass, self.device_id)

        # Restore password login to however it was.
        auth_handler._password_enabled_for_login = allow_auth_for_login

    def delete_device(
        self,
        access_token: str,
        device: str,
        expected_response: int,
        body: bytes | JsonDict = b"",
    ) -> FakeChannel:
        """Delete an individual device."""
        channel = self.make_request(
            "DELETE",
            "devices/" + device,
            body,
            access_token=access_token,
        )

        # Ensure the response is sane.
        self.assertEqual(channel.code, expected_response)

        return channel

    def delete_devices(self, expected_response: int, body: JsonDict) -> FakeChannel:
        """Delete 1 or more devices."""
        # Note that this uses the delete_devices endpoint so that we can modify
        # the payload half-way through some tests.
        channel = self.make_request(
            "POST",
            "delete_devices",
            body,
            access_token=self.user_tok,
        )

        # Ensure the response is sane.
        self.assertEqual(channel.code, expected_response)

        return channel

    def test_ui_auth(self) -> None:
        """
        Test user interactive authentication outside of registration.
        """
        # Attempt to delete this device.
        # Returns a 401 as per the spec
        channel = self.delete_device(
            self.user_tok, self.device_id, HTTPStatus.UNAUTHORIZED
        )

        # Grab the session
        session = channel.json_body["session"]
        # Ensure that flows are what is expected.
        self.assertIn({"stages": ["m.login.password"]}, channel.json_body["flows"])

        # Make another request providing the UI auth flow.
        self.delete_device(
            self.user_tok,
            self.device_id,
            HTTPStatus.OK,
            {
                "auth": {
                    "type": "m.login.password",
                    "identifier": {"type": "m.id.user", "user": self.user},
                    "password": self.user_pass,
                    "session": session,
                },
            },
        )

    @override_config({"password_config": {"enabled": "only_for_reauth"}})
    def test_ui_auth_with_passwords_for_reauth_only(self) -> None:
        """
        Test user interactive authentication outside of registration.
        """

        # Attempt to delete this device.
        # Returns a 401 as per the spec
        channel = self.delete_device(
            self.user_tok, self.device_id, HTTPStatus.UNAUTHORIZED
        )

        # Grab the session
        session = channel.json_body["session"]
        # Ensure that flows are what is expected.
        self.assertIn({"stages": ["m.login.password"]}, channel.json_body["flows"])

        # Make another request providing the UI auth flow.
        self.delete_device(
            self.user_tok,
            self.device_id,
            HTTPStatus.OK,
            {
                "auth": {
                    "type": "m.login.password",
                    "identifier": {"type": "m.id.user", "user": self.user},
                    "password": self.user_pass,
                    "session": session,
                },
            },
        )

    def test_grandfathered_identifier(self) -> None:
        """Check behaviour without "identifier" dict

        Synapse used to require clients to submit a "user" field for m.login.password
        UIA - check that still works.
        """

        channel = self.delete_device(
            self.user_tok, self.device_id, HTTPStatus.UNAUTHORIZED
        )
        session = channel.json_body["session"]

        # Make another request providing the UI auth flow.
        self.delete_device(
            self.user_tok,
            self.device_id,
            HTTPStatus.OK,
            {
                "auth": {
                    "type": "m.login.password",
                    "user": self.user,
                    "password": self.user_pass,
                    "session": session,
                },
            },
        )

    def test_can_change_body(self) -> None:
        """
        The client dict can be modified during the user interactive authentication session.

        Note that it is not spec compliant to modify the client dict during a
        user interactive authentication session, but many clients currently do.

        When Synapse is updated to be spec compliant, the call to re-use the
        session ID should be rejected.
        """
        # Create a second login.
        self.login("test", self.user_pass, "dev2")

        # Attempt to delete the first device.
        # Returns a 401 as per the spec
        channel = self.delete_devices(
            HTTPStatus.UNAUTHORIZED, {"devices": [self.device_id]}
        )

        # Grab the session
        session = channel.json_body["session"]
        # Ensure that flows are what is expected.
        self.assertIn({"stages": ["m.login.password"]}, channel.json_body["flows"])

        # Make another request providing the UI auth flow, but try to delete the
        # second device.
        self.delete_devices(
            HTTPStatus.OK,
            {
                "devices": ["dev2"],
                "auth": {
                    "type": "m.login.password",
                    "identifier": {"type": "m.id.user", "user": self.user},
                    "password": self.user_pass,
                    "session": session,
                },
            },
        )

    def test_cannot_change_uri(self) -> None:
        """
        The initial requested URI cannot be modified during the user interactive authentication session.
        """
        # Create a second login.
        self.login("test", self.user_pass, "dev2")

        # Attempt to delete the first device.
        # Returns a 401 as per the spec
        channel = self.delete_device(
            self.user_tok, self.device_id, HTTPStatus.UNAUTHORIZED
        )

        # Grab the session
        session = channel.json_body["session"]
        # Ensure that flows are what is expected.
        self.assertIn({"stages": ["m.login.password"]}, channel.json_body["flows"])

        # Make another request providing the UI auth flow, but try to delete the
        # second device. This results in an error.
        #
        # This makes use of the fact that the device ID is embedded into the URL.
        self.delete_device(
            self.user_tok,
            "dev2",
            HTTPStatus.FORBIDDEN,
            {
                "auth": {
                    "type": "m.login.password",
                    "identifier": {"type": "m.id.user", "user": self.user},
                    "password": self.user_pass,
                    "session": session,
                },
            },
        )

    @unittest.override_config({"ui_auth": {"session_timeout": "5s"}})
    def test_can_reuse_session(self) -> None:
        """
        The session can be reused if configured.

        Compare to test_cannot_change_uri.
        """
        # Create a second and third login.
        self.login("test", self.user_pass, "dev2")
        self.login("test", self.user_pass, "dev3")

        # Attempt to delete a device. This works since the user just logged in.
        self.delete_device(self.user_tok, "dev2", HTTPStatus.OK)

        # Move the clock forward past the validation timeout.
        self.reactor.advance(6)

        # Deleting another devices throws the user into UI auth.
        channel = self.delete_device(self.user_tok, "dev3", HTTPStatus.UNAUTHORIZED)

        # Grab the session
        session = channel.json_body["session"]
        # Ensure that flows are what is expected.
        self.assertIn({"stages": ["m.login.password"]}, channel.json_body["flows"])

        # Make another request providing the UI auth flow.
        self.delete_device(
            self.user_tok,
            "dev3",
            HTTPStatus.OK,
            {
                "auth": {
                    "type": "m.login.password",
                    "identifier": {"type": "m.id.user", "user": self.user},
                    "password": self.user_pass,
                    "session": session,
                },
            },
        )

        # Make another request, but try to delete the first device. This works
        # due to re-using the previous session.
        #
        # Note that *no auth* information is provided, not even a session iD!
        self.delete_device(self.user_tok, self.device_id, HTTPStatus.OK)

    @skip_unless(HAS_OIDC, "requires OIDC")
    @override_config({"oidc_config": TEST_OIDC_CONFIG})
    def test_ui_auth_via_sso(self) -> None:
        """Test a successful UI Auth flow via SSO

        This includes:
          * hitting the UIA SSO redirect endpoint
          * checking it serves a confirmation page which links to the OIDC provider
          * calling back to the synapse oidc callback
          * checking that the original operation succeeds
        """

        fake_oidc_server = self.helper.fake_oidc_server()

        # log the user in
        remote_user_id = UserID.from_string(self.user).localpart
        login_resp, _ = self.helper.login_via_oidc(fake_oidc_server, remote_user_id)
        self.assertEqual(login_resp["user_id"], self.user)

        # initiate a UI Auth process by attempting to delete the device
        channel = self.delete_device(
            self.user_tok, self.device_id, HTTPStatus.UNAUTHORIZED
        )

        # check that SSO is offered
        flows = channel.json_body["flows"]
        self.assertIn({"stages": ["m.login.sso"]}, flows)

        # run the UIA-via-SSO flow
        session_id = channel.json_body["session"]
        channel, _ = self.helper.auth_via_oidc(
            fake_oidc_server, {"sub": remote_user_id}, ui_auth_session_id=session_id
        )

        # that should serve a confirmation page
        self.assertEqual(channel.code, HTTPStatus.OK, channel.result)

        # and now the delete request should succeed.
        self.delete_device(
            self.user_tok,
            self.device_id,
            HTTPStatus.OK,
            body={"auth": {"session": session_id}},
        )

    @skip_unless(HAS_OIDC, "requires OIDC")
    @override_config(
        {
            "oidc_providers": TEST_MULTIPLE_OIDC_PROVIDERS,
            "experimental_features": {"msc4450_enabled": True},
        }
    )
    def test_msc4450_select_idp_id(self) -> None:
        """
        Test for MSC4450: Identity Provider selection for
        User-Interactive Authentication with Legacy Single Sign-On.

        We configure 3 OIDC providers and then check that we can select
        which one to redirect to for User-Interactive Authentication.
        """

        # Attach the user to the OIDC providers manually
        for idp_id in (
            TEST_MULTIPLE_OIDC_IDP_ID1,
            TEST_MULTIPLE_OIDC_IDP_ID2,
        ):
            self.get_success(
                self.hs.get_datastores().main.record_user_external_id(
                    # `oidc-` is a magic prefix needed for OIDC providers
                    f"oidc-{idp_id}",
                    # arbitrary/opaque provider-specific external ID, doesn't really matter
                    "some.ext.user.id",
                    self.user,
                )
            )

        # Start a user-interactive authentication session by
        # calling the device deletion API
        channel = self.delete_device(
            self.user_tok, self.device_id, HTTPStatus.UNAUTHORIZED
        )
        auth_session = channel.json_body["session"]
        flows = channel.json_body["flows"]
        self.assertCountEqual(
            flows, [{"stages": ["m.login.sso"]}, {"stages": ["m.login.password"]}]
        )

        # Try to start the User-Interactive Auth against both identity providers.
        # Make sure we get the identity provider that we ask for.
        #
        # We need to try against both to be sure that Synapse doesn't just conveniently happen to
        # arbitrarily select the identity provider we test.
        for idp_id, provider_config in (
            (
                TEST_MULTIPLE_OIDC_IDP_ID1,
                TEST_MULTIPLE_OIDC_PROVIDERS[0],
            ),
            (
                TEST_MULTIPLE_OIDC_IDP_ID2,
                TEST_MULTIPLE_OIDC_PROVIDERS[1],
            ),
        ):
            endpoint = f"/_matrix/client/v3/auth/m.login.sso/fallback/web?session={auth_session}&io.element.idp_id=oidc-{idp_id}"
            channel = self.make_request("GET", endpoint)
            self.assertEqual(
                channel.code,
                HTTPStatus.OK,
                f"Failed to use the {endpoint} endpoint as part of the UIA flow for idp_id={idp_id} : response_body={channel.text_body}",
            )

            # This 'Continue with ...' text is templated by `synapse/res/templates/sso_auth_confirm.html`
            self.assertIn(
                f"Continue with {provider_config['idp_name']}",
                channel.text_body,
            )

            self.assertIn(provider_config["authorization_endpoint"], channel.text_body)

        # Test that we can't use the 3rd OIDC provider as we're not
        # registered with it
        channel = self.make_request(
            "GET",
            f"/_matrix/client/v3/auth/m.login.sso/fallback/web?session={auth_session}&io.element.idp_id=oidc-{TEST_MULTIPLE_OIDC_IDP_ID3}",
        )
        self.assertEqual(channel.code, HTTPStatus.BAD_REQUEST, channel.json_body)
        self.assertEqual(
            channel.json_body["errcode"], Codes.INVALID_PARAM, channel.json_body
        )

    @skip_unless(HAS_OIDC, "requires OIDC")
    @override_config({"oidc_config": TEST_OIDC_CONFIG})
    def test_does_not_offer_password_for_sso_user(self) -> None:
        fake_oidc_server = self.helper.fake_oidc_server()
        login_resp, _ = self.helper.login_via_oidc(fake_oidc_server, "username")
        user_tok = login_resp["access_token"]
        device_id = login_resp["device_id"]

        # now call the device deletion API: we should get the option to auth with SSO
        # and not password.
        channel = self.delete_device(user_tok, device_id, HTTPStatus.UNAUTHORIZED)

        flows = channel.json_body["flows"]
        self.assertEqual(flows, [{"stages": ["m.login.sso"]}])

    def test_does_not_offer_sso_for_password_user(self) -> None:
        channel = self.delete_device(
            self.user_tok, self.device_id, HTTPStatus.UNAUTHORIZED
        )

        flows = channel.json_body["flows"]
        self.assertEqual(flows, [{"stages": ["m.login.password"]}])

    @skip_unless(HAS_OIDC, "requires OIDC")
    @override_config({"oidc_config": TEST_OIDC_CONFIG})
    def test_offers_both_flows_for_upgraded_user(self) -> None:
        """A user that had a password and then logged in with SSO should get both flows"""
        fake_oidc_server = self.helper.fake_oidc_server()
        login_resp, _ = self.helper.login_via_oidc(
            fake_oidc_server, UserID.from_string(self.user).localpart
        )
        self.assertEqual(login_resp["user_id"], self.user)

        channel = self.delete_device(
            self.user_tok, self.device_id, HTTPStatus.UNAUTHORIZED
        )

        flows = channel.json_body["flows"]
        # we have no particular expectations of ordering here
        self.assertIn({"stages": ["m.login.password"]}, flows)
        self.assertIn({"stages": ["m.login.sso"]}, flows)
        self.assertEqual(len(flows), 2)

    @skip_unless(HAS_OIDC, "requires OIDC")
    @override_config({"oidc_config": TEST_OIDC_CONFIG})
    def test_ui_auth_fails_for_incorrect_sso_user(self) -> None:
        """If the user tries to authenticate with the wrong SSO user, they get an error"""

        fake_oidc_server = self.helper.fake_oidc_server()

        # log the user in
        login_resp, _ = self.helper.login_via_oidc(
            fake_oidc_server, UserID.from_string(self.user).localpart
        )
        self.assertEqual(login_resp["user_id"], self.user)

        # start a UI Auth flow by attempting to delete a device
        channel = self.delete_device(
            self.user_tok, self.device_id, HTTPStatus.UNAUTHORIZED
        )

        flows = channel.json_body["flows"]
        self.assertIn({"stages": ["m.login.sso"]}, flows)
        session_id = channel.json_body["session"]

        # do the OIDC auth, but auth as the wrong user
        channel, _ = self.helper.auth_via_oidc(
            fake_oidc_server, {"sub": "wrong_user"}, ui_auth_session_id=session_id
        )

        # that should return a failure message
        self.assertSubstring("We were unable to validate", channel.text_body)

        # ... and the delete op should now fail with a 403
        self.delete_device(
            self.user_tok,
            self.device_id,
            HTTPStatus.FORBIDDEN,
            body={"auth": {"session": session_id}},
        )

    @skip_unless(HAS_OIDC, "requires OIDC")
    @override_config(
        {
            "oidc_config": TEST_OIDC_CONFIG,
            "experimental_features": {
                "msc3866": {
                    "enabled": True,
                    "require_approval_for_new_accounts": True,
                }
            },
        }
    )
    def test_sso_not_approved(self) -> None:
        """Tests that if we register a user via SSO while requiring approval for new
        accounts, we still raise the correct error before logging the user in.
        """
        fake_oidc_server = self.helper.fake_oidc_server()
        login_resp, _ = self.helper.login_via_oidc(
            fake_oidc_server, "username", expected_status=403
        )

        self.assertEqual(login_resp["errcode"], Codes.USER_AWAITING_APPROVAL)
        self.assertEqual(
            ApprovalNoticeMedium.NONE, login_resp["approval_notice_medium"]
        )

        # Check that we didn't register a device for the user during the login attempt.
        devices = self.get_success(
            self.hs.get_datastores().main.get_devices_by_user("@username:test")
        )

        self.assertEqual(len(devices), 0)


class RefreshAuthTests(unittest.HomeserverTestCase):
    servlets = [
        auth.register_servlets,
        account.register_servlets,
        login.register_servlets,
        logout.register_servlets,
        synapse.rest.admin.register_servlets_for_client_rest_resource,
        register.register_servlets,
    ]
    hijack_auth = False

    def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
        self.user_pass = "pass"
        self.user = self.register_user("test", self.user_pass)

    def use_refresh_token(self, refresh_token: str) -> FakeChannel:
        """
        Helper that makes a request to use a refresh token.
        """
        return self.make_request(
            "POST",
            "/_matrix/client/v3/refresh",
            {"refresh_token": refresh_token},
        )

    def test_login_issue_refresh_token(self) -> None:
        """
        A login response should include a refresh_token only if asked.
        """
        # Test login
        body = {
            "type": "m.login.password",
            "user": "test",
            "password": self.user_pass,
        }

        login_without_refresh = self.make_request(
            "POST", "/_matrix/client/r0/login", body
        )
        self.assertEqual(
            login_without_refresh.code, HTTPStatus.OK, login_without_refresh.result
        )
        self.assertNotIn("refresh_token", login_without_refresh.json_body)

        login_with_refresh = self.make_request(
            "POST",
            "/_matrix/client/r0/login",
            {"refresh_token": True, **body},
        )
        self.assertEqual(
            login_with_refresh.code, HTTPStatus.OK, login_with_refresh.result
        )
        self.assertIn("refresh_token", login_with_refresh.json_body)
        self.assertIn("expires_in_ms", login_with_refresh.json_body)

    def test_register_issue_refresh_token(self) -> None:
        """
        A register response should include a refresh_token only if asked.
        """
        register_without_refresh = self.make_request(
            "POST",
            "/_matrix/client/r0/register",
            {
                "username": "test2",
                "password": self.user_pass,
                "auth": {"type": LoginType.DUMMY},
            },
        )
        self.assertEqual(
            register_without_refresh.code,
            HTTPStatus.OK,
            register_without_refresh.result,
        )
        self.assertNotIn("refresh_token", register_without_refresh.json_body)

        register_with_refresh = self.make_request(
            "POST",
            "/_matrix/client/r0/register",
            {
                "username": "test3",
                "password": self.user_pass,
                "auth": {"type": LoginType.DUMMY},
                "refresh_token": True,
            },
        )
        self.assertEqual(
            register_with_refresh.code, HTTPStatus.OK, register_with_refresh.result
        )
        self.assertIn("refresh_token", register_with_refresh.json_body)
        self.assertIn("expires_in_ms", register_with_refresh.json_body)

    def test_token_refresh(self) -> None:
        """
        A refresh token can be used to issue a new access token.
        """
        body = {
            "type": "m.login.password",
            "user": "test",
            "password": self.user_pass,
            "refresh_token": True,
        }
        login_response = self.make_request(
            "POST",
            "/_matrix/client/r0/login",
            body,
        )
        self.assertEqual(login_response.code, HTTPStatus.OK, login_response.result)

        refresh_response = self.make_request(
            "POST",
            "/_matrix/client/v3/refresh",
            {"refresh_token": login_response.json_body["refresh_token"]},
        )
        self.assertEqual(refresh_response.code, HTTPStatus.OK, refresh_response.result)
        self.assertIn("access_token", refresh_response.json_body)
        self.assertIn("refresh_token", refresh_response.json_body)
        self.assertIn("expires_in_ms", refresh_response.json_body)

        # The access and refresh tokens should be different from the original ones after refresh
        self.assertNotEqual(
            login_response.json_body["access_token"],
            refresh_response.json_body["access_token"],
        )
        self.assertNotEqual(
            login_response.json_body["refresh_token"],
            refresh_response.json_body["refresh_token"],
        )

    @override_config({"refreshable_access_token_lifetime": "1m"})
    def test_refreshable_access_token_expiration(self) -> None:
        """
        The access token should have some time as specified in the config.
        """
        body = {
            "type": "m.login.password",
            "user": "test",
            "password": self.user_pass,
            "refresh_token": True,
        }
        login_response = self.make_request(
            "POST",
            "/_matrix/client/r0/login",
            body,
        )
        self.assertEqual(login_response.code, HTTPStatus.OK, login_response.result)
        self.assertApproximates(
            login_response.json_body["expires_in_ms"], 60 * 1000, 100
        )

        refresh_response = self.make_request(
            "POST",
            "/_matrix/client/v3/refresh",
            {"refresh_token": login_response.json_body["refresh_token"]},
        )
        self.assertEqual(refresh_response.code, HTTPStatus.OK, refresh_response.result)
        self.assertApproximates(
            refresh_response.json_body["expires_in_ms"], 60 * 1000, 100
        )
        access_token = refresh_response.json_body["access_token"]

        # Advance 59 seconds in the future (just shy of 1 minute, the time of expiry)
        self.reactor.advance(59.0)
        # Check that our token is valid
        self.assertEqual(
            self.make_request(
                "GET", "/_matrix/client/v3/account/whoami", access_token=access_token
            ).code,
            HTTPStatus.OK,
        )

        # Advance 2 more seconds (just past the time of expiry)
        self.reactor.advance(2.0)
        # Check that our token is invalid
        self.assertEqual(
            self.make_request(
                "GET", "/_matrix/client/v3/account/whoami", access_token=access_token
            ).code,
            HTTPStatus.UNAUTHORIZED,
        )

    @override_config(
        {
            "refreshable_access_token_lifetime": "1m",
            "nonrefreshable_access_token_lifetime": "10m",
        }
    )
    def test_different_expiry_for_refreshable_and_nonrefreshable_access_tokens(
        self,
    ) -> None:
        """
        Tests that the expiry times for refreshable and non-refreshable access
        tokens can be different.
        """
        body = {
            "type": "m.login.password",
            "user": "test",
            "password": self.user_pass,
        }
        login_response1 = self.make_request(
            "POST",
            "/_matrix/client/r0/login",
            {"refresh_token": True, **body},
        )
        self.assertEqual(login_response1.code, HTTPStatus.OK, login_response1.result)
        self.assertApproximates(
            login_response1.json_body["expires_in_ms"], 60 * 1000, 100
        )
        refreshable_access_token = login_response1.json_body["access_token"]

        login_response2 = self.make_request(
            "POST",
            "/_matrix/client/r0/login",
            body,
        )
        self.assertEqual(login_response2.code, HTTPStatus.OK, login_response2.result)
        nonrefreshable_access_token = login_response2.json_body["access_token"]

        # Advance 59 seconds in the future (just shy of 1 minute, the time of expiry)
        self.reactor.advance(59.0)

        # Both tokens should still be valid.
        self.helper.whoami(refreshable_access_token, expect_code=HTTPStatus.OK)
        self.helper.whoami(nonrefreshable_access_token, expect_code=HTTPStatus.OK)

        # Advance to 61 s (just past 1 minute, the time of expiry)
        self.reactor.advance(2.0)

        # Only the non-refreshable token is still valid.
        self.helper.whoami(
            refreshable_access_token, expect_code=HTTPStatus.UNAUTHORIZED
        )
        self.helper.whoami(nonrefreshable_access_token, expect_code=HTTPStatus.OK)

        # Advance to 599 s (just shy of 10 minutes, the time of expiry)
        self.reactor.advance(599.0 - 61.0)

        # It's still the case that only the non-refreshable token is still valid.
        self.helper.whoami(
            refreshable_access_token, expect_code=HTTPStatus.UNAUTHORIZED
        )
        self.helper.whoami(nonrefreshable_access_token, expect_code=HTTPStatus.OK)

        # Advance to 601 s (just past 10 minutes, the time of expiry)
        self.reactor.advance(2.0)

        # Now neither token is valid.
        self.helper.whoami(
            refreshable_access_token, expect_code=HTTPStatus.UNAUTHORIZED
        )
        self.helper.whoami(
            nonrefreshable_access_token, expect_code=HTTPStatus.UNAUTHORIZED
        )

    @override_config(
        {"refreshable_access_token_lifetime": "1m", "refresh_token_lifetime": "2m"}
    )
    def test_refresh_token_expiry(self) -> None:
        """
        The refresh token can be configured to have a limited lifetime.
        When that lifetime has ended, the refresh token can no longer be used to
        refresh the session.
        """

        body = {
            "type": "m.login.password",
            "user": "test",
            "password": self.user_pass,
            "refresh_token": True,
        }
        login_response = self.make_request(
            "POST",
            "/_matrix/client/r0/login",
            body,
        )
        self.assertEqual(login_response.code, HTTPStatus.OK, login_response.result)
        refresh_token1 = login_response.json_body["refresh_token"]

        # Advance 119 seconds in the future (just shy of 2 minutes)
        self.reactor.advance(119.0)

        # Refresh our session. The refresh token should still JUST be valid right now.
        # By doing so, we get a new access token and a new refresh token.
        refresh_response = self.use_refresh_token(refresh_token1)
        self.assertEqual(refresh_response.code, HTTPStatus.OK, refresh_response.result)
        self.assertIn(
            "refresh_token",
            refresh_response.json_body,
            "No new refresh token returned after refresh.",
        )
        refresh_token2 = refresh_response.json_body["refresh_token"]

        # Advance 121 seconds in the future (just a bit more than 2 minutes)
        self.reactor.advance(121.0)

        # Try to refresh our session, but instead notice that the refresh token is
        # not valid (it just expired).
        refresh_response = self.use_refresh_token(refresh_token2)
        self.assertEqual(
            refresh_response.code, HTTPStatus.FORBIDDEN, refresh_response.result
        )

    @override_config(
        {
            "refreshable_access_token_lifetime": "2m",
            "refresh_token_lifetime": "2m",
            "session_lifetime": "3m",
        }
    )
    def test_ultimate_session_expiry(self) -> None:
        """
        The session can be configured to have an ultimate, limited lifetime.
        """

        body = {
            "type": "m.login.password",
            "user": "test",
            "password": self.user_pass,
            "refresh_token": True,
        }
        login_response = self.make_request(
            "POST",
            "/_matrix/client/r0/login",
            body,
        )
        self.assertEqual(login_response.code, HTTPStatus.OK, login_response.result)
        refresh_token = login_response.json_body["refresh_token"]

        # Advance shy of 2 minutes into the future
        self.reactor.advance(119.0)

        # Refresh our session. The refresh token should still be valid right now.
        refresh_response = self.use_refresh_token(refresh_token)
        self.assertEqual(refresh_response.code, HTTPStatus.OK, refresh_response.result)
        self.assertIn(
            "refresh_token",
            refresh_response.json_body,
            "No new refresh token returned after refresh.",
        )
        # Notice that our access token lifetime has been diminished to match the
        # session lifetime.
        # 3 minutes - 119 seconds = 61 seconds.
        self.assertEqual(refresh_response.json_body["expires_in_ms"], 61_000)
        refresh_token = refresh_response.json_body["refresh_token"]

        # Advance 61 seconds into the future. Our session should have expired
        # now, because we've had our 3 minutes.
        self.reactor.advance(61.0)

        # Try to issue a new, refreshed, access token.
        # This should fail because the refresh token's lifetime has also been
        # diminished as our session expired.
        refresh_response = self.use_refresh_token(refresh_token)
        self.assertEqual(
            refresh_response.code, HTTPStatus.FORBIDDEN, refresh_response.result
        )

    def test_refresh_token_invalidation(self) -> None:
        """Refresh tokens are invalidated after first use of the next token.

        A refresh token is considered invalid if:
            - it was already used at least once
            - and either
                - the next access token was used
                - the next refresh token was used

        The chain of tokens goes like this:

            login -|-> first_refresh -> third_refresh (fails)
                   |-> second_refresh -> fifth_refresh
                   |-> fourth_refresh (fails)
        """

        body = {
            "type": "m.login.password",
            "user": "test",
            "password": self.user_pass,
            "refresh_token": True,
        }
        login_response = self.make_request(
            "POST",
            "/_matrix/client/r0/login",
            body,
        )
        self.assertEqual(login_response.code, HTTPStatus.OK, login_response.result)

        # This first refresh should work properly
        first_refresh_response = self.make_request(
            "POST",
            "/_matrix/client/v3/refresh",
            {"refresh_token": login_response.json_body["refresh_token"]},
        )
        self.assertEqual(
            first_refresh_response.code, HTTPStatus.OK, first_refresh_response.result
        )

        # This one as well, since the token in the first one was never used
        second_refresh_response = self.make_request(
            "POST",
            "/_matrix/client/v3/refresh",
            {"refresh_token": login_response.json_body["refresh_token"]},
        )
        self.assertEqual(
            second_refresh_response.code, HTTPStatus.OK, second_refresh_response.result
        )

        # This one should not, since the token from the first refresh is not valid anymore
        third_refresh_response = self.make_request(
            "POST",
            "/_matrix/client/v3/refresh",
            {"refresh_token": first_refresh_response.json_body["refresh_token"]},
        )
        self.assertEqual(
            third_refresh_response.code,
            HTTPStatus.UNAUTHORIZED,
            third_refresh_response.result,
        )

        # The associated access token should also be invalid
        whoami_response = self.make_request(
            "GET",
            "/_matrix/client/r0/account/whoami",
            access_token=first_refresh_response.json_body["access_token"],
        )
        self.assertEqual(
            whoami_response.code, HTTPStatus.UNAUTHORIZED, whoami_response.result
        )

        # But all other tokens should work (they will expire after some time)
        for access_token in [
            second_refresh_response.json_body["access_token"],
            login_response.json_body["access_token"],
        ]:
            whoami_response = self.make_request(
                "GET", "/_matrix/client/r0/account/whoami", access_token=access_token
            )
            self.assertEqual(
                whoami_response.code, HTTPStatus.OK, whoami_response.result
            )

        # Now that the access token from the last valid refresh was used once, refreshing with the N-1 token should fail
        fourth_refresh_response = self.make_request(
            "POST",
            "/_matrix/client/v3/refresh",
            {"refresh_token": login_response.json_body["refresh_token"]},
        )
        self.assertEqual(
            fourth_refresh_response.code,
            HTTPStatus.FORBIDDEN,
            fourth_refresh_response.result,
        )

        # But refreshing from the last valid refresh token still works
        fifth_refresh_response = self.make_request(
            "POST",
            "/_matrix/client/v3/refresh",
            {"refresh_token": second_refresh_response.json_body["refresh_token"]},
        )
        self.assertEqual(
            fifth_refresh_response.code, HTTPStatus.OK, fifth_refresh_response.result
        )

    def test_many_token_refresh(self) -> None:
        """
        If a refresh is performed many times during a session, there shouldn't be
        extra 'cruft' built up over time.

        This test was written specifically to troubleshoot a case where logout
        was very slow if a lot of refreshes had been performed for the session.
        """

        def _refresh(refresh_token: str) -> tuple[str, str]:
            """
            Performs one refresh, returning the next refresh token and access token.
            """
            refresh_response = self.use_refresh_token(refresh_token)
            self.assertEqual(
                refresh_response.code, HTTPStatus.OK, refresh_response.result
            )
            return (
                refresh_response.json_body["refresh_token"],
                refresh_response.json_body["access_token"],
            )

        def _table_length(table_name: str) -> int:
            """
            Helper to get the size of a table, in rows.
            For testing only; trivially vulnerable to SQL injection.
            """

            def _txn(txn: LoggingTransaction) -> int:
                txn.execute(f"SELECT COUNT(1) FROM {table_name}")
                row = txn.fetchone()
                # Query is infallible
                assert row is not None
                return row[0]

            return self.get_success(
                self.hs.get_datastores().main.db_pool.runInteraction(
                    "_table_length", _txn
                )
            )

        # Before we log in, there are no access tokens.
        self.assertEqual(_table_length("access_tokens"), 0)
        self.assertEqual(_table_length("refresh_tokens"), 0)

        body = {
            "type": "m.login.password",
            "user": "test",
            "password": self.user_pass,
            "refresh_token": True,
        }
        login_response = self.make_request(
            "POST",
            "/_matrix/client/v3/login",
            body,
        )
        self.assertEqual(login_response.code, HTTPStatus.OK, login_response.result)

        access_token = login_response.json_body["access_token"]
        refresh_token = login_response.json_body["refresh_token"]

        # Now that we have logged in, there should be one access token and one
        # refresh token
        self.assertEqual(_table_length("access_tokens"), 1)
        self.assertEqual(_table_length("refresh_tokens"), 1)

        for _ in range(5):
            refresh_token, access_token = _refresh(refresh_token)

        # After 5 sequential refreshes, there should only be the latest two
        # refresh/access token pairs.
        # (The last one is preserved because it's in use!
        # The one before that is preserved because it can still be used to
        # replace the last token pair, in case of e.g. a network interruption.)
        self.assertEqual(_table_length("access_tokens"), 2)
        self.assertEqual(_table_length("refresh_tokens"), 2)

        logout_response = self.make_request(
            "POST", "/_matrix/client/v3/logout", {}, access_token=access_token
        )
        self.assertEqual(logout_response.code, HTTPStatus.OK, logout_response.result)

        # Now that we have logged in, there should be no access token
        # and no refresh token
        self.assertEqual(_table_length("access_tokens"), 0)
        self.assertEqual(_table_length("refresh_tokens"), 0)


def oidc_config(
    id: str, with_localpart_template: bool, **kwargs: Any
) -> dict[str, Any]:
    """Sample OIDC provider config used in backchannel logout tests.

    Args:
        id: IDP ID for this provider
        with_localpart_template: Set to `true` to have a default localpart_template in
            the `user_mapping_provider` config and skip the user mapping session
        **kwargs: rest of the config

    Returns:
        A dict suitable for the `oidc_config` or the `oidc_providers[]` parts of
        the HS config
    """
    config: dict[str, Any] = {
        "idp_id": id,
        "idp_name": id,
        "issuer": TEST_OIDC_ISSUER,
        "client_id": "test-client-id",
        "client_secret": "test-client-secret",
        "scopes": ["openid"],
    }

    if with_localpart_template:
        config["user_mapping_provider"] = {
            "config": {"localpart_template": "{{ user.sub }}"}
        }
    else:
        config["user_mapping_provider"] = {"config": {}}

    config.update(kwargs)

    return config


@skip_unless(HAS_OIDC, "Requires OIDC")
class OidcBackchannelLogoutTests(unittest.HomeserverTestCase):
    servlets = [
        account.register_servlets,
        login.register_servlets,
    ]

    def default_config(self) -> dict[str, Any]:
        config = super().default_config()

        # public_baseurl uses an http:// scheme because FakeChannel.isSecure() returns
        # False, so synapse will see the requested uri as http://..., so using http in
        # the public_baseurl stops Synapse trying to redirect to https.
        config["public_baseurl"] = "http://synapse.test"

        return config

    def create_resource_dict(self) -> dict[str, Resource]:
        resource_dict = super().create_resource_dict()
        resource_dict.update(build_synapse_client_resource_tree(self.hs))
        return resource_dict

    def submit_logout_token(self, logout_token: str) -> FakeChannel:
        return self.make_request(
            "POST",
            "/_synapse/client/oidc/backchannel_logout",
            content=f"logout_token={logout_token}",
            content_is_form=True,
        )

    @override_config(
        {
            "oidc_providers": [
                oidc_config(
                    id="oidc",
                    with_localpart_template=True,
                    backchannel_logout_enabled=True,
                )
            ]
        }
    )
    def test_simple_logout(self) -> None:
        """
        Receiving a logout token should logout the user
        """
        fake_oidc_server = self.helper.fake_oidc_server()
        user = "john"

        login_resp, first_grant = self.helper.login_via_oidc(
            fake_oidc_server, user, with_sid=True
        )
        first_access_token: str = login_resp["access_token"]
        self.helper.whoami(first_access_token, expect_code=HTTPStatus.OK)

        login_resp, second_grant = self.helper.login_via_oidc(
            fake_oidc_server, user, with_sid=True
        )
        second_access_token: str = login_resp["access_token"]
        self.helper.whoami(second_access_token, expect_code=HTTPStatus.OK)

        self.assertNotEqual(first_grant.sid, second_grant.sid)
        self.assertEqual(first_grant.userinfo["sub"], second_grant.userinfo["sub"])

        # Logging out of the first session
        logout_token = fake_oidc_server.generate_logout_token(first_grant)
        channel = self.submit_logout_token(logout_token)
        self.assertEqual(channel.code, 200)

        self.helper.whoami(first_access_token, expect_code=HTTPStatus.UNAUTHORIZED)
        self.helper.whoami(second_access_token, expect_code=HTTPStatus.OK)

        # Logging out of the second session
        logout_token = fake_oidc_server.generate_logout_token(second_grant)
        channel = self.submit_logout_token(logout_token)
        self.assertEqual(channel.code, 200)

    @override_config(
        {
            "oidc_providers": [
                oidc_config(
                    id="oidc",
                    with_localpart_template=True,
                    backchannel_logout_enabled=True,
                )
            ]
        }
    )
    def test_logout_during_login(self) -> None:
        """
        It should revoke login tokens when receiving a logout token
        """
        fake_oidc_server = self.helper.fake_oidc_server()
        user = "john"

        # Get an authentication, and logout before submitting the logout token
        client_redirect_url = "https://x"
        userinfo = {"sub": user}
        channel, grant = self.helper.auth_via_oidc(
            fake_oidc_server,
            userinfo,
            client_redirect_url,
            with_sid=True,
        )

        # expect a confirmation page
        self.assertEqual(channel.code, HTTPStatus.OK, channel.result)

        # fish the matrix login token out of the body of the confirmation page
        m = re.search(
            'a href="%s.*loginToken=([^"]*)"' % (client_redirect_url,),
            channel.text_body,
        )
        assert m, channel.text_body
        login_token = m.group(1)

        # Submit a logout
        logout_token = fake_oidc_server.generate_logout_token(grant)
        channel = self.submit_logout_token(logout_token)
        self.assertEqual(channel.code, 200)

        # Now try to exchange the login token, it should fail.
        self.helper.login_via_token(login_token, 403)

    @override_config(
        {
            "oidc_providers": [
                oidc_config(
                    id="oidc",
                    with_localpart_template=False,
                    backchannel_logout_enabled=True,
                )
            ]
        }
    )
    def test_logout_during_mapping(self) -> None:
        """
        It should stop ongoing user mapping session when receiving a logout token
        """
        fake_oidc_server = self.helper.fake_oidc_server()
        user = "john"

        # Get an authentication, and logout before submitting the logout token
        client_redirect_url = "https://x"
        userinfo = {"sub": user}
        channel, grant = self.helper.auth_via_oidc(
            fake_oidc_server,
            userinfo,
            client_redirect_url,
            with_sid=True,
        )

        # Expect a user mapping page
        self.assertEqual(channel.code, HTTPStatus.FOUND, channel.result)

        # We should have a user_mapping_session cookie
        cookie_headers = channel.headers.getRawHeaders("Set-Cookie")
        assert cookie_headers
        cookies: dict[str, str] = {}
        for h in cookie_headers:
            key, value = h.split(";")[0].split("=", maxsplit=1)
            cookies[key] = value

        user_mapping_session_id = cookies["username_mapping_session"]

        # Getting that session should not raise
        session = self.hs.get_sso_handler().get_mapping_session(user_mapping_session_id)
        self.assertIsNotNone(session)

        # Submit a logout
        logout_token = fake_oidc_server.generate_logout_token(grant)
        channel = self.submit_logout_token(logout_token)
        self.assertEqual(channel.code, 200)

        # Now it should raise
        with self.assertRaises(SynapseError):
            self.hs.get_sso_handler().get_mapping_session(user_mapping_session_id)

    @override_config(
        {
            "oidc_providers": [
                oidc_config(
                    id="oidc",
                    with_localpart_template=True,
                    backchannel_logout_enabled=False,
                )
            ]
        }
    )
    def test_disabled(self) -> None:
        """
        Receiving a logout token should do nothing if it is disabled in the config
        """
        fake_oidc_server = self.helper.fake_oidc_server()
        user = "john"

        login_resp, grant = self.helper.login_via_oidc(
            fake_oidc_server, user, with_sid=True
        )
        access_token: str = login_resp["access_token"]
        self.helper.whoami(access_token, expect_code=HTTPStatus.OK)

        # Logging out shouldn't work
        logout_token = fake_oidc_server.generate_logout_token(grant)
        channel = self.submit_logout_token(logout_token)
        self.assertEqual(channel.code, 400)

        # And the token should still be valid
        self.helper.whoami(access_token, expect_code=HTTPStatus.OK)

    @override_config(
        {
            "oidc_providers": [
                oidc_config(
                    id="oidc",
                    with_localpart_template=True,
                    backchannel_logout_enabled=True,
                )
            ]
        }
    )
    def test_no_sid(self) -> None:
        """
        Receiving a logout token without `sid` during the login should do nothing
        """
        fake_oidc_server = self.helper.fake_oidc_server()
        user = "john"

        login_resp, grant = self.helper.login_via_oidc(
            fake_oidc_server, user, with_sid=False
        )
        access_token: str = login_resp["access_token"]
        self.helper.whoami(access_token, expect_code=HTTPStatus.OK)

        # Logging out shouldn't work
        logout_token = fake_oidc_server.generate_logout_token(grant)
        channel = self.submit_logout_token(logout_token)
        self.assertEqual(channel.code, 400)

        # And the token should still be valid
        self.helper.whoami(access_token, expect_code=HTTPStatus.OK)

    @override_config(
        {
            "oidc_providers": [
                oidc_config(
                    "first",
                    issuer="https://first-issuer.com/",
                    with_localpart_template=True,
                    backchannel_logout_enabled=True,
                ),
                oidc_config(
                    "second",
                    issuer="https://second-issuer.com/",
                    with_localpart_template=True,
                    backchannel_logout_enabled=True,
                ),
            ]
        }
    )
    def test_multiple_providers(self) -> None:
        """
        It should be able to distinguish login tokens from two different IdPs
        """
        first_server = self.helper.fake_oidc_server(issuer="https://first-issuer.com/")
        second_server = self.helper.fake_oidc_server(
            issuer="https://second-issuer.com/"
        )
        user = "john"

        login_resp, first_grant = self.helper.login_via_oidc(
            first_server, user, with_sid=True, idp_id="oidc-first"
        )
        first_access_token: str = login_resp["access_token"]
        self.helper.whoami(first_access_token, expect_code=HTTPStatus.OK)

        login_resp, second_grant = self.helper.login_via_oidc(
            second_server, user, with_sid=True, idp_id="oidc-second"
        )
        second_access_token: str = login_resp["access_token"]
        self.helper.whoami(second_access_token, expect_code=HTTPStatus.OK)

        # `sid` in the fake providers are generated by a counter, so the first grant of
        # each provider should give the same SID
        self.assertEqual(first_grant.sid, second_grant.sid)
        self.assertEqual(first_grant.userinfo["sub"], second_grant.userinfo["sub"])

        # Logging out of the first session
        logout_token = first_server.generate_logout_token(first_grant)
        channel = self.submit_logout_token(logout_token)
        self.assertEqual(channel.code, 200)

        self.helper.whoami(first_access_token, expect_code=HTTPStatus.UNAUTHORIZED)
        self.helper.whoami(second_access_token, expect_code=HTTPStatus.OK)

        # Logging out of the second session
        logout_token = second_server.generate_logout_token(second_grant)
        channel = self.submit_logout_token(logout_token)
        self.assertEqual(channel.code, 200)

        self.helper.whoami(second_access_token, expect_code=HTTPStatus.UNAUTHORIZED)
