diff options
| -rw-r--r-- | changelog.d/7455.bugfix | 1 | ||||
| -rw-r--r-- | synapse/handlers/auth.py | 54 | ||||
| -rw-r--r-- | synapse/rest/client/v2_alpha/register.py | 1 | ||||
| -rw-r--r-- | synapse/storage/data_stores/main/ui_auth.py | 21 | ||||
| -rw-r--r-- | tests/rest/client/v2_alpha/test_auth.py | 304 | ||||
| -rw-r--r-- | tox.ini | 1 |
6 files changed, 280 insertions, 102 deletions
diff --git a/changelog.d/7455.bugfix b/changelog.d/7455.bugfix new file mode 100644 index 0000000000..d1693a7f22 --- /dev/null +++ b/changelog.d/7455.bugfix @@ -0,0 +1 @@ +Ensure that a user inteactive authentication session is tied to a single request. diff --git a/synapse/handlers/auth.py b/synapse/handlers/auth.py index 7613e5b6ab..9c71702371 100644 --- a/synapse/handlers/auth.py +++ b/synapse/handlers/auth.py @@ -252,6 +252,7 @@ class AuthHandler(BaseHandler): clientdict: Dict[str, Any], clientip: str, description: str, + validate_clientdict: bool = True, ) -> Tuple[dict, dict, str]: """ Takes a dictionary sent by the client in the login / registration @@ -277,6 +278,10 @@ class AuthHandler(BaseHandler): description: A human readable string to be displayed to the user that describes the operation happening on their account. + validate_clientdict: Whether to validate that the operation happening + on the account has not changed. If this is false, + the client dict is persisted instead of validated. + Returns: A tuple of (creds, params, session_id). @@ -317,30 +322,51 @@ class AuthHandler(BaseHandler): except StoreError: raise SynapseError(400, "Unknown session ID: %s" % (sid,)) + # If the client provides parameters, update what is persisted, + # otherwise use whatever was last provided. + # + # This was designed to allow the client to omit the parameters + # and just supply the session in subsequent calls so it split + # auth between devices by just sharing the session, (eg. so you + # could continue registration from your phone having clicked the + # email auth link on there). It's probably too open to abuse + # because it lets unauthenticated clients store arbitrary objects + # on a homeserver. + # + # Revisit: Assuming the REST APIs do sensible validation, the data + # isn't arbitrary. + # + # Note that the registration endpoint explicitly removes the + # "initial_device_display_name" parameter if it is provided + # without a "password" parameter. See the changes to + # synapse.rest.client.v2_alpha.register.RegisterRestServlet.on_POST + # in commit 544722bad23fc31056b9240189c3cbbbf0ffd3f9. if not clientdict: - # This was designed to allow the client to omit the parameters - # and just supply the session in subsequent calls so it split - # auth between devices by just sharing the session, (eg. so you - # could continue registration from your phone having clicked the - # email auth link on there). It's probably too open to abuse - # because it lets unauthenticated clients store arbitrary objects - # on a homeserver. - # Revisit: Assuming the REST APIs do sensible validation, the data - # isn't arbitrary. clientdict = session.clientdict # Ensure that the queried operation does not vary between stages of # the UI authentication session. This is done by generating a stable - # comparator based on the URI, method, and body (minus the auth dict) - # and storing it during the initial query. Subsequent queries ensure - # that this comparator has not changed. - comparator = (uri, method, clientdict) - if (session.uri, session.method, session.clientdict) != comparator: + # comparator based on the URI, method, and client dict (minus the + # auth dict) and storing it during the initial query. Subsequent + # queries ensure that this comparator has not changed. + if validate_clientdict: + session_comparator = (session.uri, session.method, session.clientdict) + comparator = (uri, method, clientdict) + else: + session_comparator = (session.uri, session.method) # type: ignore + comparator = (uri, method) # type: ignore + + if session_comparator != comparator: raise SynapseError( 403, "Requested operation has changed during the UI authentication session.", ) + # For backwards compatibility the registration endpoint persists + # changes to the client dict instead of validating them. + if not validate_clientdict: + await self.store.set_ui_auth_clientdict(sid, clientdict) + if not authdict: raise InteractiveAuthIncompleteError( self._auth_dict_for_flows(flows, session.session_id) diff --git a/synapse/rest/client/v2_alpha/register.py b/synapse/rest/client/v2_alpha/register.py index af08cc6cce..e77dd6bf92 100644 --- a/synapse/rest/client/v2_alpha/register.py +++ b/synapse/rest/client/v2_alpha/register.py @@ -516,6 +516,7 @@ class RegisterRestServlet(RestServlet): body, self.hs.get_ip_from_request(request), "register a new account", + validate_clientdict=False, ) # Check that we're not trying to register a denied 3pid. diff --git a/synapse/storage/data_stores/main/ui_auth.py b/synapse/storage/data_stores/main/ui_auth.py index c8eebc9378..1d8ee22fb1 100644 --- a/synapse/storage/data_stores/main/ui_auth.py +++ b/synapse/storage/data_stores/main/ui_auth.py @@ -172,6 +172,27 @@ class UIAuthWorkerStore(SQLBaseStore): return results + async def set_ui_auth_clientdict( + self, session_id: str, clientdict: JsonDict + ) -> None: + """ + Store an updated clientdict for a given session ID. + + Args: + session_id: The ID of this session as returned from check_auth + clientdict: + The dictionary from the client root level, not the 'auth' key. + """ + # The clientdict gets stored as JSON. + clientdict_json = json.dumps(clientdict) + + self.db.simple_update_one( + table="ui_auth_sessions", + keyvalues={"session_id": session_id}, + updatevalues={"clientdict": clientdict_json}, + desc="set_ui_auth_client_dict", + ) + async def set_ui_auth_session_data(self, session_id: str, key: str, value: Any): """ Store a key-value pair into the sessions data associated with this diff --git a/tests/rest/client/v2_alpha/test_auth.py b/tests/rest/client/v2_alpha/test_auth.py index 587be7b2e7..a56c50a5b7 100644 --- a/tests/rest/client/v2_alpha/test_auth.py +++ b/tests/rest/client/v2_alpha/test_auth.py @@ -12,16 +12,20 @@ # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. - +from typing import List, Union from twisted.internet.defer import succeed import synapse.rest.admin from synapse.api.constants import LoginType from synapse.handlers.ui_auth.checkers import UserInteractiveAuthChecker -from synapse.rest.client.v2_alpha import auth, register +from synapse.http.site import SynapseRequest +from synapse.rest.client.v1 import login +from synapse.rest.client.v2_alpha import auth, devices, register +from synapse.types import JsonDict from tests import unittest +from tests.server import FakeChannel class DummyRecaptchaChecker(UserInteractiveAuthChecker): @@ -34,11 +38,15 @@ class DummyRecaptchaChecker(UserInteractiveAuthChecker): return succeed(True) +class DummyPasswordChecker(UserInteractiveAuthChecker): + def check_auth(self, authdict, clientip): + return succeed(authdict["identifier"]["user"]) + + class FallbackAuthTests(unittest.HomeserverTestCase): servlets = [ auth.register_servlets, - synapse.rest.admin.register_servlets_for_client_rest_resource, register.register_servlets, ] hijack_auth = False @@ -59,79 +67,84 @@ class FallbackAuthTests(unittest.HomeserverTestCase): auth_handler = hs.get_auth_handler() auth_handler.checkers[LoginType.RECAPTCHA] = self.recaptcha_checker - @unittest.INFO - def test_fallback_captcha(self): - + def register(self, expected_response: int, body: JsonDict) -> FakeChannel: + """Make a register request.""" request, channel = self.make_request( - "POST", - "register", - {"username": "user", "type": "m.login.password", "password": "bar"}, - ) + "POST", "register", body + ) # type: SynapseRequest, FakeChannel self.render(request) - # Returns a 401 as per the spec - self.assertEqual(request.code, 401) - # 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" - ) + self.assertEqual(request.code, expected_response) + return channel + + def recaptcha( + self, session: str, expected_post_response: int, post_session: str = None + ) -> None: + """Get and respond to a fallback recaptcha. Returns the second request.""" + if post_session is None: + post_session = session request, channel = self.make_request( "GET", "auth/m.login.recaptcha/fallback/web?session=" + session - ) + ) # type: SynapseRequest, FakeChannel self.render(request) self.assertEqual(request.code, 200) request, channel = self.make_request( "POST", "auth/m.login.recaptcha/fallback/web?session=" - + session + + post_session + "&g-recaptcha-response=a", ) self.render(request) - self.assertEqual(request.code, 200) + self.assertEqual(request.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") - # also complete the dummy auth - request, channel = self.make_request( - "POST", "register", {"auth": {"session": session, "type": "m.login.dummy"}} + @unittest.INFO + def test_fallback_captcha(self): + """Ensure that fallback auth via a captcha works.""" + # Returns a 401 as per the spec + channel = self.register( + 401, {"username": "user", "type": "m.login.password", "password": "bar"}, ) - self.render(request) + + # 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, 200) + + # also complete the dummy auth + self.register(200, {"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. - request, channel = self.make_request( - "POST", "register", {"auth": {"session": session}} - ) - self.render(request) - self.assertEqual(channel.code, 200) + channel = self.register(200, {"auth": {"session": session}}) # We're given a registered user. self.assertEqual(channel.json_body["user_id"], "@user:test") - def test_cannot_change_operation(self): + def test_legacy_registration(self): """ - The initial requested operation cannot be modified during the user interactive authentication session. + Registration allows the parameters to vary through the process. """ # Make the initial request to register. (Later on a different password # will be used.) - request, channel = self.make_request( - "POST", - "register", - {"username": "user", "type": "m.login.password", "password": "bar"}, + # Returns a 401 as per the spec + channel = self.register( + 401, {"username": "user", "type": "m.login.password", "password": "bar"}, ) - self.render(request) - # Returns a 401 as per the spec - self.assertEqual(request.code, 401) # Grab the session session = channel.json_body["session"] # Assert our configured public key is being given @@ -139,65 +152,39 @@ class FallbackAuthTests(unittest.HomeserverTestCase): channel.json_body["params"]["m.login.recaptcha"]["public_key"], "brokencake" ) - request, channel = self.make_request( - "GET", "auth/m.login.recaptcha/fallback/web?session=" + session - ) - self.render(request) - self.assertEqual(request.code, 200) - - request, channel = self.make_request( - "POST", - "auth/m.login.recaptcha/fallback/web?session=" - + session - + "&g-recaptcha-response=a", - ) - self.render(request) - self.assertEqual(request.code, 200) - - # 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") + # Complete the recaptcha step. + self.recaptcha(session, 200) # also complete the dummy auth - request, channel = self.make_request( - "POST", "register", {"auth": {"session": session, "type": "m.login.dummy"}} - ) - self.render(request) + self.register(200, {"auth": {"session": session, "type": "m.login.dummy"}}) # Now we should have fulfilled a complete auth flow, including # the recaptcha fallback step. Make the initial request again, but - # with a different password. This causes the request to fail since the - # operaiton was modified during the ui auth session. - request, channel = self.make_request( - "POST", - "register", + # with a changed password. This still completes. + channel = self.register( + 200, { "username": "user", "type": "m.login.password", - "password": "foo", # Note this doesn't match the original request. + "password": "foo", # Note that this is different. "auth": {"session": session}, }, ) - self.render(request) - self.assertEqual(channel.code, 403) + + # We're given a registered user. + self.assertEqual(channel.json_body["user_id"], "@user:test") def test_complete_operation_unknown_session(self): """ Attempting to mark an invalid session as complete should error. """ - # Make the initial request to register. (Later on a different password # will be used.) - request, channel = self.make_request( - "POST", - "register", - {"username": "user", "type": "m.login.password", "password": "bar"}, + # Returns a 401 as per the spec + channel = self.register( + 401, {"username": "user", "type": "m.login.password", "password": "bar"} ) - self.render(request) - # Returns a 401 as per the spec - self.assertEqual(request.code, 401) # Grab the session session = channel.json_body["session"] # Assert our configured public key is being given @@ -205,19 +192,160 @@ class FallbackAuthTests(unittest.HomeserverTestCase): 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 prepare(self, reactor, clock, hs): + auth_handler = hs.get_auth_handler() + auth_handler.checkers[LoginType.PASSWORD] = DummyPasswordChecker(hs) + + self.user_pass = "pass" + self.user = self.register_user("test", self.user_pass) + self.user_tok = self.login("test", self.user_pass) + + def get_device_ids(self) -> List[str]: + # Get the list of devices so one can be deleted. request, channel = self.make_request( - "GET", "auth/m.login.recaptcha/fallback/web?session=" + session - ) + "GET", "devices", access_token=self.user_tok, + ) # type: SynapseRequest, FakeChannel self.render(request) + + # Get the ID of the device. self.assertEqual(request.code, 200) + return [d["device_id"] for d in channel.json_body["devices"]] - # Attempt to complete an unknown session, which should return an error. - unknown_session = session + "unknown" + def delete_device( + self, device: str, expected_response: int, body: Union[bytes, JsonDict] = b"" + ) -> FakeChannel: + """Delete an individual device.""" request, channel = self.make_request( - "POST", - "auth/m.login.recaptcha/fallback/web?session=" - + unknown_session - + "&g-recaptcha-response=a", - ) + "DELETE", "devices/" + device, body, access_token=self.user_tok + ) # type: SynapseRequest, FakeChannel self.render(request) - self.assertEqual(request.code, 400) + + # Ensure the response is sane. + self.assertEqual(request.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. + request, channel = self.make_request( + "POST", "delete_devices", body, access_token=self.user_tok, + ) # type: SynapseRequest, FakeChannel + self.render(request) + + # Ensure the response is sane. + self.assertEqual(request.code, expected_response) + + return channel + + def test_ui_auth(self): + """ + Test user interactive authentication outside of registration. + """ + device_id = self.get_device_ids()[0] + + # Attempt to delete this device. + # Returns a 401 as per the spec + channel = self.delete_device(device_id, 401) + + # 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( + device_id, + 200, + { + "auth": { + "type": "m.login.password", + "identifier": {"type": "m.id.user", "user": self.user}, + "password": self.user_pass, + "session": session, + }, + }, + ) + + def test_cannot_change_body(self): + """ + The initial requested client dict cannot be modified during the user interactive authentication session. + """ + # Create a second login. + self.login("test", self.user_pass) + + device_ids = self.get_device_ids() + self.assertEqual(len(device_ids), 2) + + # Attempt to delete the first device. + # Returns a 401 as per the spec + channel = self.delete_devices(401, {"devices": [device_ids[0]]}) + + # 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. + self.delete_devices( + 403, + { + "devices": [device_ids[1]], + "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): + """ + The initial requested URI cannot be modified during the user interactive authentication session. + """ + # Create a second login. + self.login("test", self.user_pass) + + device_ids = self.get_device_ids() + self.assertEqual(len(device_ids), 2) + + # Attempt to delete the first device. + # Returns a 401 as per the spec + channel = self.delete_device(device_ids[0], 401) + + # 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. + self.delete_device( + device_ids[1], + 403, + { + "auth": { + "type": "m.login.password", + "identifier": {"type": "m.id.user", "user": self.user}, + "password": self.user_pass, + "session": session, + }, + }, + ) diff --git a/tox.ini b/tox.ini index eccc44e436..8aef52021d 100644 --- a/tox.ini +++ b/tox.ini @@ -207,6 +207,7 @@ commands = mypy \ synapse/util/caches/stream_change_cache.py \ tests/replication/tcp/streams \ tests/test_utils \ + tests/rest/client/v2_alpha/test_auth.py \ tests/util/test_stream_change_cache.py # To find all folders that pass mypy you run: |