From 0640f8ebaa34e10a69ad7481b738ae36fda1c103 Mon Sep 17 00:00:00 2001 From: Brendan Abolivier Date: Tue, 8 Feb 2022 11:20:32 +0100 Subject: [PATCH] Add a callback to allow modules to deny 3PID (#11854) Part of the Tchap Synapse mainlining. This allows modules to implement extra logic to figure out whether a given 3PID can be added to the local homeserver. In the Tchap use case, this will allow a Synapse module to interface with the custom endpoint /internal_info. --- changelog.d/11854.feature | 1 + .../password_auth_provider_callbacks.md | 19 +++++ synapse/handlers/auth.py | 44 +++++++++++ synapse/module_api/__init__.py | 3 + synapse/rest/client/account.py | 4 +- synapse/rest/client/register.py | 8 +- synapse/util/threepids.py | 13 +++- tests/handlers/test_password_providers.py | 76 ++++++++++++++++++- 8 files changed, 161 insertions(+), 7 deletions(-) create mode 100644 changelog.d/11854.feature diff --git a/changelog.d/11854.feature b/changelog.d/11854.feature new file mode 100644 index 0000000000..975e95bc52 --- /dev/null +++ b/changelog.d/11854.feature @@ -0,0 +1 @@ +Add a callback to allow modules to allow or forbid a 3PID (email address, phone number) from being associated to a local account. diff --git a/docs/modules/password_auth_provider_callbacks.md b/docs/modules/password_auth_provider_callbacks.md index 3697e3782e..88b59bb09e 100644 --- a/docs/modules/password_auth_provider_callbacks.md +++ b/docs/modules/password_auth_provider_callbacks.md @@ -166,6 +166,25 @@ any of the subsequent implementations of this callback. If every callback return the username provided by the user is used, if any (otherwise one is automatically generated). +## `is_3pid_allowed` + +_First introduced in Synapse v1.53.0_ + +```python +async def is_3pid_allowed(self, medium: str, address: str, registration: bool) -> bool +``` + +Called when attempting to bind a third-party identifier (i.e. an email address or a phone +number). The module is given the medium of the third-party identifier (which is `email` if +the identifier is an email address, or `msisdn` if the identifier is a phone number) and +its address, as well as a boolean indicating whether the attempt to bind is happening as +part of registering a new user. The module must return a boolean indicating whether the +identifier can be allowed to be bound to an account on the local homeserver. + +If multiple modules implement this callback, they will be considered in order. If a +callback returns `True`, Synapse falls through to the next one. The value of the first +callback that does not return `True` will be used. If this happens, Synapse will not call +any of the subsequent implementations of this callback. ## Example diff --git a/synapse/handlers/auth.py b/synapse/handlers/auth.py index e32c93e234..6959d1aa7e 100644 --- a/synapse/handlers/auth.py +++ b/synapse/handlers/auth.py @@ -2064,6 +2064,7 @@ GET_USERNAME_FOR_REGISTRATION_CALLBACK = Callable[ [JsonDict, JsonDict], Awaitable[Optional[str]], ] +IS_3PID_ALLOWED_CALLBACK = Callable[[str, str, bool], Awaitable[bool]] class PasswordAuthProvider: @@ -2079,6 +2080,7 @@ class PasswordAuthProvider: self.get_username_for_registration_callbacks: List[ GET_USERNAME_FOR_REGISTRATION_CALLBACK ] = [] + self.is_3pid_allowed_callbacks: List[IS_3PID_ALLOWED_CALLBACK] = [] # Mapping from login type to login parameters self._supported_login_types: Dict[str, Iterable[str]] = {} @@ -2090,6 +2092,7 @@ class PasswordAuthProvider: self, check_3pid_auth: Optional[CHECK_3PID_AUTH_CALLBACK] = None, on_logged_out: Optional[ON_LOGGED_OUT_CALLBACK] = None, + is_3pid_allowed: Optional[IS_3PID_ALLOWED_CALLBACK] = None, auth_checkers: Optional[ Dict[Tuple[str, Tuple[str, ...]], CHECK_AUTH_CALLBACK] ] = None, @@ -2145,6 +2148,9 @@ class PasswordAuthProvider: get_username_for_registration, ) + if is_3pid_allowed is not None: + self.is_3pid_allowed_callbacks.append(is_3pid_allowed) + def get_supported_login_types(self) -> Mapping[str, Iterable[str]]: """Get the login types supported by this password provider @@ -2343,3 +2349,41 @@ class PasswordAuthProvider: raise SynapseError(code=500, msg="Internal Server Error") return None + + async def is_3pid_allowed( + self, + medium: str, + address: str, + registration: bool, + ) -> bool: + """Check if the user can be allowed to bind a 3PID on this homeserver. + + Args: + medium: The medium of the 3PID. + address: The address of the 3PID. + registration: Whether the 3PID is being bound when registering a new user. + + Returns: + Whether the 3PID is allowed to be bound on this homeserver + """ + for callback in self.is_3pid_allowed_callbacks: + try: + res = await callback(medium, address, registration) + + if res is False: + return res + elif not isinstance(res, bool): + # mypy complains that this line is unreachable because it assumes the + # data returned by the module fits the expected type. We just want + # to make sure this is the case. + logger.warning( # type: ignore[unreachable] + "Ignoring non-string value returned by" + " is_3pid_allowed callback %s: %s", + callback, + res, + ) + except Exception as e: + logger.error("Module raised an exception in is_3pid_allowed: %s", e) + raise SynapseError(code=500, msg="Internal Server Error") + + return True diff --git a/synapse/module_api/__init__.py b/synapse/module_api/__init__.py index 29fbc73c97..a91a7fa3ce 100644 --- a/synapse/module_api/__init__.py +++ b/synapse/module_api/__init__.py @@ -72,6 +72,7 @@ from synapse.handlers.auth import ( CHECK_3PID_AUTH_CALLBACK, CHECK_AUTH_CALLBACK, GET_USERNAME_FOR_REGISTRATION_CALLBACK, + IS_3PID_ALLOWED_CALLBACK, ON_LOGGED_OUT_CALLBACK, AuthHandler, ) @@ -312,6 +313,7 @@ class ModuleApi: auth_checkers: Optional[ Dict[Tuple[str, Tuple[str, ...]], CHECK_AUTH_CALLBACK] ] = None, + is_3pid_allowed: Optional[IS_3PID_ALLOWED_CALLBACK] = None, get_username_for_registration: Optional[ GET_USERNAME_FOR_REGISTRATION_CALLBACK ] = None, @@ -323,6 +325,7 @@ class ModuleApi: return self._password_auth_provider.register_password_auth_provider_callbacks( check_3pid_auth=check_3pid_auth, on_logged_out=on_logged_out, + is_3pid_allowed=is_3pid_allowed, auth_checkers=auth_checkers, get_username_for_registration=get_username_for_registration, ) diff --git a/synapse/rest/client/account.py b/synapse/rest/client/account.py index 6b272658fc..cfa2aee76d 100644 --- a/synapse/rest/client/account.py +++ b/synapse/rest/client/account.py @@ -385,7 +385,7 @@ class EmailThreepidRequestTokenRestServlet(RestServlet): send_attempt = body["send_attempt"] next_link = body.get("next_link") # Optional param - if not check_3pid_allowed(self.hs, "email", email): + if not await check_3pid_allowed(self.hs, "email", email): raise SynapseError( 403, "Your email domain is not authorized on this server", @@ -468,7 +468,7 @@ class MsisdnThreepidRequestTokenRestServlet(RestServlet): msisdn = phone_number_to_msisdn(country, phone_number) - if not check_3pid_allowed(self.hs, "msisdn", msisdn): + if not await check_3pid_allowed(self.hs, "msisdn", msisdn): raise SynapseError( 403, "Account phone numbers are not authorized on this server", diff --git a/synapse/rest/client/register.py b/synapse/rest/client/register.py index c283313e8d..c965e2bda2 100644 --- a/synapse/rest/client/register.py +++ b/synapse/rest/client/register.py @@ -112,7 +112,7 @@ class EmailRegisterRequestTokenRestServlet(RestServlet): send_attempt = body["send_attempt"] next_link = body.get("next_link") # Optional param - if not check_3pid_allowed(self.hs, "email", email): + if not await check_3pid_allowed(self.hs, "email", email, registration=True): raise SynapseError( 403, "Your email domain is not authorized to register on this server", @@ -192,7 +192,7 @@ class MsisdnRegisterRequestTokenRestServlet(RestServlet): msisdn = phone_number_to_msisdn(country, phone_number) - if not check_3pid_allowed(self.hs, "msisdn", msisdn): + if not await check_3pid_allowed(self.hs, "msisdn", msisdn, registration=True): raise SynapseError( 403, "Phone numbers are not authorized to register on this server", @@ -616,7 +616,9 @@ class RegisterRestServlet(RestServlet): medium = auth_result[login_type]["medium"] address = auth_result[login_type]["address"] - if not check_3pid_allowed(self.hs, medium, address): + if not await check_3pid_allowed( + self.hs, medium, address, registration=True + ): raise SynapseError( 403, "Third party identifiers (email/phone numbers)" diff --git a/synapse/util/threepids.py b/synapse/util/threepids.py index 389adf00f6..1e9c2faa64 100644 --- a/synapse/util/threepids.py +++ b/synapse/util/threepids.py @@ -32,7 +32,12 @@ logger = logging.getLogger(__name__) MAX_EMAIL_ADDRESS_LENGTH = 500 -def check_3pid_allowed(hs: "HomeServer", medium: str, address: str) -> bool: +async def check_3pid_allowed( + hs: "HomeServer", + medium: str, + address: str, + registration: bool = False, +) -> bool: """Checks whether a given format of 3PID is allowed to be used on this HS Args: @@ -40,9 +45,15 @@ def check_3pid_allowed(hs: "HomeServer", medium: str, address: str) -> bool: medium: 3pid medium - e.g. email, msisdn address: address within that medium (e.g. "wotan@matrix.org") msisdns need to first have been canonicalised + registration: whether we want to bind the 3PID as part of registering a new user. + Returns: bool: whether the 3PID medium/address is allowed to be added to this HS """ + if not await hs.get_password_auth_provider().is_3pid_allowed( + medium, address, registration + ): + return False if hs.config.registration.allowed_local_3pids: for constraint in hs.config.registration.allowed_local_3pids: diff --git a/tests/handlers/test_password_providers.py b/tests/handlers/test_password_providers.py index 94809cb8be..4740dd0a65 100644 --- a/tests/handlers/test_password_providers.py +++ b/tests/handlers/test_password_providers.py @@ -21,13 +21,15 @@ from twisted.internet import defer import synapse from synapse.api.constants import LoginType +from synapse.api.errors import Codes from synapse.handlers.auth import load_legacy_password_auth_providers from synapse.module_api import ModuleApi -from synapse.rest.client import devices, login, logout, register +from synapse.rest.client import account, devices, login, logout, register from synapse.types import JsonDict, UserID from tests import unittest from tests.server import FakeChannel +from tests.test_utils import make_awaitable from tests.unittest import override_config # (possibly experimental) login flows we expect to appear in the list after the normal @@ -158,6 +160,7 @@ class PasswordAuthProviderTests(unittest.HomeserverTestCase): devices.register_servlets, logout.register_servlets, register.register_servlets, + account.register_servlets, ] def setUp(self): @@ -803,6 +806,77 @@ class PasswordAuthProviderTests(unittest.HomeserverTestCase): # Check that the callback has been called. m.assert_called_once() + # Set some email configuration so the test doesn't fail because of its absence. + @override_config({"email": {"notif_from": "noreply@test"}}) + def test_3pid_allowed(self): + """Tests that an is_3pid_allowed_callbacks forbidding a 3PID makes Synapse refuse + to bind the new 3PID, and that one allowing a 3PID makes Synapse accept to bind + the 3PID. Also checks that the module is passed a boolean indicating whether the + user to bind this 3PID to is currently registering. + """ + self._test_3pid_allowed("rin", False) + self._test_3pid_allowed("kitay", True) + + def _test_3pid_allowed(self, username: str, registration: bool): + """Tests that the "is_3pid_allowed" module callback is called correctly, using + either /register or /account URLs depending on the arguments. + + Args: + username: The username to use for the test. + registration: Whether to test with registration URLs. + """ + self.hs.get_identity_handler().send_threepid_validation = Mock( + return_value=make_awaitable(0), + ) + + m = Mock(return_value=make_awaitable(False)) + self.hs.get_password_auth_provider().is_3pid_allowed_callbacks = [m] + + self.register_user(username, "password") + tok = self.login(username, "password") + + if registration: + url = "/register/email/requestToken" + else: + url = "/account/3pid/email/requestToken" + + channel = self.make_request( + "POST", + url, + { + "client_secret": "foo", + "email": "foo@test.com", + "send_attempt": 0, + }, + access_token=tok, + ) + self.assertEqual(channel.code, 403, channel.result) + self.assertEqual( + channel.json_body["errcode"], + Codes.THREEPID_DENIED, + channel.json_body, + ) + + m.assert_called_once_with("email", "foo@test.com", registration) + + m = Mock(return_value=make_awaitable(True)) + self.hs.get_password_auth_provider().is_3pid_allowed_callbacks = [m] + + channel = self.make_request( + "POST", + url, + { + "client_secret": "foo", + "email": "bar@test.com", + "send_attempt": 0, + }, + access_token=tok, + ) + self.assertEqual(channel.code, 200, channel.result) + self.assertIn("sid", channel.json_body) + + m.assert_called_once_with("email", "bar@test.com", registration) + def _setup_get_username_for_registration(self) -> Mock: """Registers a get_username_for_registration callback that appends "-foo" to the username the client is trying to register.