Validate that the session is not modified during UI-Auth (#7068)

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Patrick Cloke 2020-03-26 07:39:34 -04:00 committed by GitHub
parent 6ca5e56fd1
commit 1c1242acba
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8 changed files with 117 additions and 14 deletions

1
changelog.d/7068.bugfix Normal file
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@ -0,0 +1 @@
Ensure that a user inteactive authentication session is tied to a single request.

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@ -125,7 +125,11 @@ class AuthHandler(BaseHandler):
@defer.inlineCallbacks @defer.inlineCallbacks
def validate_user_via_ui_auth( def validate_user_via_ui_auth(
self, requester: Requester, request_body: Dict[str, Any], clientip: str self,
requester: Requester,
request: SynapseRequest,
request_body: Dict[str, Any],
clientip: str,
): ):
""" """
Checks that the user is who they claim to be, via a UI auth. Checks that the user is who they claim to be, via a UI auth.
@ -137,6 +141,8 @@ class AuthHandler(BaseHandler):
Args: Args:
requester: The user, as given by the access token requester: The user, as given by the access token
request: The request sent by the client.
request_body: The body of the request sent by the client request_body: The body of the request sent by the client
clientip: The IP address of the client. clientip: The IP address of the client.
@ -172,7 +178,9 @@ class AuthHandler(BaseHandler):
flows = [[login_type] for login_type in self._supported_login_types] flows = [[login_type] for login_type in self._supported_login_types]
try: try:
result, params, _ = yield self.check_auth(flows, request_body, clientip) result, params, _ = yield self.check_auth(
flows, request, request_body, clientip
)
except LoginError: except LoginError:
# Update the ratelimite to say we failed (`can_do_action` doesn't raise). # Update the ratelimite to say we failed (`can_do_action` doesn't raise).
self._failed_uia_attempts_ratelimiter.can_do_action( self._failed_uia_attempts_ratelimiter.can_do_action(
@ -211,7 +219,11 @@ class AuthHandler(BaseHandler):
@defer.inlineCallbacks @defer.inlineCallbacks
def check_auth( def check_auth(
self, flows: List[List[str]], clientdict: Dict[str, Any], clientip: str self,
flows: List[List[str]],
request: SynapseRequest,
clientdict: Dict[str, Any],
clientip: str,
): ):
""" """
Takes a dictionary sent by the client in the login / registration Takes a dictionary sent by the client in the login / registration
@ -231,6 +243,8 @@ class AuthHandler(BaseHandler):
strings representing auth-types. At least one full strings representing auth-types. At least one full
flow must be completed in order for auth to be successful. flow must be completed in order for auth to be successful.
request: The request sent by the client.
clientdict: The dictionary from the client root level, not the clientdict: The dictionary from the client root level, not the
'auth' key: this method prompts for auth if none is sent. 'auth' key: this method prompts for auth if none is sent.
@ -270,13 +284,27 @@ class AuthHandler(BaseHandler):
# email auth link on there). It's probably too open to abuse # email auth link on there). It's probably too open to abuse
# because it lets unauthenticated clients store arbitrary objects # because it lets unauthenticated clients store arbitrary objects
# on a homeserver. # on a homeserver.
# Revisit: Assumimg the REST APIs do sensible validation, the data # Revisit: Assuming the REST APIs do sensible validation, the data
# isn't arbintrary. # isn't arbintrary.
session["clientdict"] = clientdict session["clientdict"] = clientdict
self._save_session(session) self._save_session(session)
elif "clientdict" in session: elif "clientdict" in session:
clientdict = session["clientdict"] 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 = (request.uri, request.method, clientdict)
if "ui_auth" not in session:
session["ui_auth"] = comparator
elif session["ui_auth"] != comparator:
raise SynapseError(
403,
"Requested operation has changed during the UI authentication session.",
)
if not authdict: if not authdict:
raise InteractiveAuthIncompleteError( raise InteractiveAuthIncompleteError(
self._auth_dict_for_flows(flows, session) self._auth_dict_for_flows(flows, session)
@ -322,6 +350,7 @@ class AuthHandler(BaseHandler):
creds, creds,
list(clientdict), list(clientdict),
) )
return creds, clientdict, session["id"] return creds, clientdict, session["id"]
ret = self._auth_dict_for_flows(flows, session) ret = self._auth_dict_for_flows(flows, session)

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@ -234,13 +234,16 @@ class PasswordRestServlet(RestServlet):
if self.auth.has_access_token(request): if self.auth.has_access_token(request):
requester = await self.auth.get_user_by_req(request) requester = await self.auth.get_user_by_req(request)
params = await self.auth_handler.validate_user_via_ui_auth( params = await self.auth_handler.validate_user_via_ui_auth(
requester, body, self.hs.get_ip_from_request(request) requester, request, body, self.hs.get_ip_from_request(request),
) )
user_id = requester.user.to_string() user_id = requester.user.to_string()
else: else:
requester = None requester = None
result, params, _ = await self.auth_handler.check_auth( result, params, _ = await self.auth_handler.check_auth(
[[LoginType.EMAIL_IDENTITY]], body, self.hs.get_ip_from_request(request) [[LoginType.EMAIL_IDENTITY]],
request,
body,
self.hs.get_ip_from_request(request),
) )
if LoginType.EMAIL_IDENTITY in result: if LoginType.EMAIL_IDENTITY in result:
@ -308,7 +311,7 @@ class DeactivateAccountRestServlet(RestServlet):
return 200, {} return 200, {}
await self.auth_handler.validate_user_via_ui_auth( await self.auth_handler.validate_user_via_ui_auth(
requester, body, self.hs.get_ip_from_request(request) requester, request, body, self.hs.get_ip_from_request(request),
) )
result = await self._deactivate_account_handler.deactivate_account( result = await self._deactivate_account_handler.deactivate_account(
requester.user.to_string(), erase, id_server=body.get("id_server") requester.user.to_string(), erase, id_server=body.get("id_server")
@ -656,7 +659,7 @@ class ThreepidAddRestServlet(RestServlet):
assert_valid_client_secret(client_secret) assert_valid_client_secret(client_secret)
await self.auth_handler.validate_user_via_ui_auth( await self.auth_handler.validate_user_via_ui_auth(
requester, body, self.hs.get_ip_from_request(request) requester, request, body, self.hs.get_ip_from_request(request),
) )
validation_session = await self.identity_handler.validate_threepid_session( validation_session = await self.identity_handler.validate_threepid_session(

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@ -81,7 +81,7 @@ class DeleteDevicesRestServlet(RestServlet):
assert_params_in_dict(body, ["devices"]) assert_params_in_dict(body, ["devices"])
await self.auth_handler.validate_user_via_ui_auth( await self.auth_handler.validate_user_via_ui_auth(
requester, body, self.hs.get_ip_from_request(request) requester, request, body, self.hs.get_ip_from_request(request),
) )
await self.device_handler.delete_devices( await self.device_handler.delete_devices(
@ -127,7 +127,7 @@ class DeviceRestServlet(RestServlet):
raise raise
await self.auth_handler.validate_user_via_ui_auth( await self.auth_handler.validate_user_via_ui_auth(
requester, body, self.hs.get_ip_from_request(request) requester, request, body, self.hs.get_ip_from_request(request),
) )
await self.device_handler.delete_device(requester.user.to_string(), device_id) await self.device_handler.delete_device(requester.user.to_string(), device_id)

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@ -263,7 +263,7 @@ class SigningKeyUploadServlet(RestServlet):
body = parse_json_object_from_request(request) body = parse_json_object_from_request(request)
await self.auth_handler.validate_user_via_ui_auth( await self.auth_handler.validate_user_via_ui_auth(
requester, body, self.hs.get_ip_from_request(request) requester, request, body, self.hs.get_ip_from_request(request),
) )
result = await self.e2e_keys_handler.upload_signing_keys_for_user(user_id, body) result = await self.e2e_keys_handler.upload_signing_keys_for_user(user_id, body)

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@ -499,7 +499,10 @@ class RegisterRestServlet(RestServlet):
) )
auth_result, params, session_id = await self.auth_handler.check_auth( auth_result, params, session_id = await self.auth_handler.check_auth(
self._registration_flows, body, self.hs.get_ip_from_request(request) self._registration_flows,
request,
body,
self.hs.get_ip_from_request(request),
) )
# Check that we're not trying to register a denied 3pid. # Check that we're not trying to register a denied 3pid.

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@ -104,7 +104,7 @@ class FallbackAuthTests(unittest.HomeserverTestCase):
) )
self.render(request) self.render(request)
# Now we should have fufilled a complete auth flow, including # Now we should have fulfilled a complete auth flow, including
# the recaptcha fallback step, we can then send a # the recaptcha fallback step, we can then send a
# request to the register API with the session in the authdict. # request to the register API with the session in the authdict.
request, channel = self.make_request( request, channel = self.make_request(
@ -115,3 +115,69 @@ class FallbackAuthTests(unittest.HomeserverTestCase):
# We're given a registered user. # We're given a registered user.
self.assertEqual(channel.json_body["user_id"], "@user:test") self.assertEqual(channel.json_body["user_id"], "@user:test")
def test_cannot_change_operation(self):
"""
The initial requested operation cannot be modified during the user interactive authentication session.
"""
# 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"},
)
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"
)
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")
# also complete the dummy auth
request, channel = self.make_request(
"POST", "register", {"auth": {"session": session, "type": "m.login.dummy"}}
)
self.render(request)
# 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",
{
"username": "user",
"type": "m.login.password",
"password": "foo", # Note this doesn't match the original request.
"auth": {"session": session},
},
)
self.render(request)
self.assertEqual(channel.code, 403)

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@ -53,7 +53,8 @@ class TermsTestCase(unittest.HomeserverTestCase):
def test_ui_auth(self): def test_ui_auth(self):
# Do a UI auth request # Do a UI auth request
request, channel = self.make_request(b"POST", self.url, b"{}") request_data = json.dumps({"username": "kermit", "password": "monkey"})
request, channel = self.make_request(b"POST", self.url, request_data)
self.render(request) self.render(request)
self.assertEquals(channel.result["code"], b"401", channel.result) self.assertEquals(channel.result["code"], b"401", channel.result)