diff --git a/changelog.d/7068.bugfix b/changelog.d/7068.bugfix
new file mode 100644
index 0000000000..d1693a7f22
--- /dev/null
+++ b/changelog.d/7068.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 7860f9625e..2ce1425dfa 100644
--- a/synapse/handlers/auth.py
+++ b/synapse/handlers/auth.py
@@ -125,7 +125,11 @@ class AuthHandler(BaseHandler):
@defer.inlineCallbacks
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.
@@ -137,6 +141,8 @@ class AuthHandler(BaseHandler):
Args:
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
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]
try:
- result, params, _ = yield self.check_auth(flows, request_body, clientip)
+ result, params, _ = yield self.check_auth(
+ flows, request, request_body, clientip
+ )
except LoginError:
# Update the ratelimite to say we failed (`can_do_action` doesn't raise).
self._failed_uia_attempts_ratelimiter.can_do_action(
@@ -211,7 +219,11 @@ class AuthHandler(BaseHandler):
@defer.inlineCallbacks
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
@@ -231,6 +243,8 @@ class AuthHandler(BaseHandler):
strings representing auth-types. At least one full
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
'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
# because it lets unauthenticated clients store arbitrary objects
# 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.
session["clientdict"] = clientdict
self._save_session(session)
elif "clientdict" in session:
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:
raise InteractiveAuthIncompleteError(
self._auth_dict_for_flows(flows, session)
@@ -322,6 +350,7 @@ class AuthHandler(BaseHandler):
creds,
list(clientdict),
)
+
return creds, clientdict, session["id"]
ret = self._auth_dict_for_flows(flows, session)
diff --git a/synapse/rest/client/v2_alpha/account.py b/synapse/rest/client/v2_alpha/account.py
index 631cc74cb4..b1249b664c 100644
--- a/synapse/rest/client/v2_alpha/account.py
+++ b/synapse/rest/client/v2_alpha/account.py
@@ -234,13 +234,16 @@ class PasswordRestServlet(RestServlet):
if self.auth.has_access_token(request):
requester = await self.auth.get_user_by_req(request)
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()
else:
requester = None
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:
@@ -308,7 +311,7 @@ class DeactivateAccountRestServlet(RestServlet):
return 200, {}
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(
requester.user.to_string(), erase, id_server=body.get("id_server")
@@ -656,7 +659,7 @@ class ThreepidAddRestServlet(RestServlet):
assert_valid_client_secret(client_secret)
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(
diff --git a/synapse/rest/client/v2_alpha/devices.py b/synapse/rest/client/v2_alpha/devices.py
index 94ff73f384..119d979052 100644
--- a/synapse/rest/client/v2_alpha/devices.py
+++ b/synapse/rest/client/v2_alpha/devices.py
@@ -81,7 +81,7 @@ class DeleteDevicesRestServlet(RestServlet):
assert_params_in_dict(body, ["devices"])
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(
@@ -127,7 +127,7 @@ class DeviceRestServlet(RestServlet):
raise
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)
diff --git a/synapse/rest/client/v2_alpha/keys.py b/synapse/rest/client/v2_alpha/keys.py
index f7ed4daf90..5eb7ef35a4 100644
--- a/synapse/rest/client/v2_alpha/keys.py
+++ b/synapse/rest/client/v2_alpha/keys.py
@@ -263,7 +263,7 @@ class SigningKeyUploadServlet(RestServlet):
body = parse_json_object_from_request(request)
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)
diff --git a/synapse/rest/client/v2_alpha/register.py b/synapse/rest/client/v2_alpha/register.py
index a09189b1b4..6963d79310 100644
--- a/synapse/rest/client/v2_alpha/register.py
+++ b/synapse/rest/client/v2_alpha/register.py
@@ -499,7 +499,10 @@ class RegisterRestServlet(RestServlet):
)
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.
diff --git a/tests/rest/client/v2_alpha/test_auth.py b/tests/rest/client/v2_alpha/test_auth.py
index b6df1396ad..624bf5ada2 100644
--- a/tests/rest/client/v2_alpha/test_auth.py
+++ b/tests/rest/client/v2_alpha/test_auth.py
@@ -104,7 +104,7 @@ class FallbackAuthTests(unittest.HomeserverTestCase):
)
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
# request to the register API with the session in the authdict.
request, channel = self.make_request(
@@ -115,3 +115,69 @@ class FallbackAuthTests(unittest.HomeserverTestCase):
# We're given a registered user.
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)
diff --git a/tests/test_terms_auth.py b/tests/test_terms_auth.py
index 5ec5d2b358..a3f98a1412 100644
--- a/tests/test_terms_auth.py
+++ b/tests/test_terms_auth.py
@@ -53,7 +53,8 @@ class TermsTestCase(unittest.HomeserverTestCase):
def test_ui_auth(self):
# 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.assertEquals(channel.result["code"], b"401", channel.result)
|
