From 0bac276890567ef3a3fafd7f5b7b5cac91a1031b Mon Sep 17 00:00:00 2001 From: Richard van der Hoff Date: Tue, 1 Dec 2020 00:15:36 +0000 Subject: UIA: offer only available auth flows During user-interactive auth, do not offer password auth to users with no password, nor SSO auth to users with no SSO. Fixes #7559. --- synapse/handlers/auth.py | 58 ++++++++++++++++------ synapse/storage/databases/main/registration.py | 25 ++++++++++ .../delta/58/25user_external_ids_user_id_idx.sql | 17 +++++++ 3 files changed, 85 insertions(+), 15 deletions(-) create mode 100644 synapse/storage/databases/main/schema/delta/58/25user_external_ids_user_id_idx.sql (limited to 'synapse') diff --git a/synapse/handlers/auth.py b/synapse/handlers/auth.py index c7dc07008a..2e72298e05 100644 --- a/synapse/handlers/auth.py +++ b/synapse/handlers/auth.py @@ -193,9 +193,7 @@ class AuthHandler(BaseHandler): self.hs = hs # FIXME better possibility to access registrationHandler later? self.macaroon_gen = hs.get_macaroon_generator() self._password_enabled = hs.config.password_enabled - self._sso_enabled = ( - hs.config.cas_enabled or hs.config.saml2_enabled or hs.config.oidc_enabled - ) + self._password_localdb_enabled = hs.config.password_localdb_enabled # we keep this as a list despite the O(N^2) implication so that we can # keep PASSWORD first and avoid confusing clients which pick the first @@ -205,7 +203,7 @@ class AuthHandler(BaseHandler): # start out by assuming PASSWORD is enabled; we will remove it later if not. login_types = [] - if hs.config.password_localdb_enabled: + if self._password_localdb_enabled: login_types.append(LoginType.PASSWORD) for provider in self.password_providers: @@ -219,14 +217,6 @@ class AuthHandler(BaseHandler): self._supported_login_types = login_types - # Login types and UI Auth types have a heavy overlap, but are not - # necessarily identical. Login types have SSO (and other login types) - # added in the rest layer, see synapse.rest.client.v1.login.LoginRestServerlet.on_GET. - ui_auth_types = login_types.copy() - if self._sso_enabled: - ui_auth_types.append(LoginType.SSO) - self._supported_ui_auth_types = ui_auth_types - # Ratelimiter for failed auth during UIA. Uses same ratelimit config # as per `rc_login.failed_attempts`. self._failed_uia_attempts_ratelimiter = Ratelimiter( @@ -339,7 +329,10 @@ class AuthHandler(BaseHandler): self._failed_uia_attempts_ratelimiter.ratelimit(user_id, update=False) # build a list of supported flows - flows = [[login_type] for login_type in self._supported_ui_auth_types] + supported_ui_auth_types = await self._get_available_ui_auth_types( + requester.user + ) + flows = [[login_type] for login_type in supported_ui_auth_types] try: result, params, session_id = await self.check_ui_auth( @@ -351,7 +344,7 @@ class AuthHandler(BaseHandler): raise # find the completed login type - for login_type in self._supported_ui_auth_types: + for login_type in supported_ui_auth_types: if login_type not in result: continue @@ -367,6 +360,41 @@ class AuthHandler(BaseHandler): return params, session_id + async def _get_available_ui_auth_types(self, user: UserID) -> Iterable[str]: + """Get a list of the authentication types this user can use + """ + + ui_auth_types = set() + + # if the HS supports password auth, and the user has a non-null password, we + # support password auth + if self._password_localdb_enabled and self._password_enabled: + lookupres = await self._find_user_id_and_pwd_hash(user.to_string()) + if lookupres: + _, password_hash = lookupres + if password_hash: + ui_auth_types.add(LoginType.PASSWORD) + + # also allow auth from password providers + for provider in self.password_providers: + for t in provider.get_supported_login_types().keys(): + if t == LoginType.PASSWORD and not self._password_enabled: + continue + ui_auth_types.add(t) + + # if sso is enabled, allow the user to log in via SSO iff they have a mapping + # from sso to mxid. + if self.hs.config.saml2.saml2_enabled or self.hs.config.oidc.oidc_enabled: + if await self.store.get_external_ids_by_user(user.to_string()): + ui_auth_types.add(LoginType.SSO) + + # Our CAS impl does not (yet) correctly register users in user_external_ids, + # so always offer that if it's available. + if self.hs.config.cas.cas_enabled: + ui_auth_types.add(LoginType.SSO) + + return ui_auth_types + def get_enabled_auth_types(self): """Return the enabled user-interactive authentication types @@ -1029,7 +1057,7 @@ class AuthHandler(BaseHandler): if result: return result - if login_type == LoginType.PASSWORD and self.hs.config.password_localdb_enabled: + if login_type == LoginType.PASSWORD and self._password_localdb_enabled: known_login_type = True # we've already checked that there is a (valid) password field diff --git a/synapse/storage/databases/main/registration.py b/synapse/storage/databases/main/registration.py index fedb8a6c26..ff96c34c2e 100644 --- a/synapse/storage/databases/main/registration.py +++ b/synapse/storage/databases/main/registration.py @@ -463,6 +463,23 @@ class RegistrationWorkerStore(CacheInvalidationWorkerStore): desc="get_user_by_external_id", ) + async def get_external_ids_by_user(self, mxid: str) -> List[Tuple[str, str]]: + """Look up external ids for the given user + + Args: + mxid: the MXID to be looked up + + Returns: + Tuples of (auth_provider, external_id) + """ + res = await self.db_pool.simple_select_list( + table="user_external_ids", + keyvalues={"user_id": mxid}, + retcols=("auth_provider", "external_id"), + desc="get_external_ids_by_user", + ) + return [(r["auth_provider"], r["external_id"]) for r in res] + async def count_all_users(self): """Counts all users registered on the homeserver.""" @@ -963,6 +980,14 @@ class RegistrationBackgroundUpdateStore(RegistrationWorkerStore): "users_set_deactivated_flag", self._background_update_set_deactivated_flag ) + self.db_pool.updates.register_background_index_update( + "user_external_ids_user_id_idx", + index_name="user_external_ids_user_id_idx", + table="user_external_ids", + columns=["user_id"], + unique=False, + ) + async def _background_update_set_deactivated_flag(self, progress, batch_size): """Retrieves a list of all deactivated users and sets the 'deactivated' flag to 1 for each of them. diff --git a/synapse/storage/databases/main/schema/delta/58/25user_external_ids_user_id_idx.sql b/synapse/storage/databases/main/schema/delta/58/25user_external_ids_user_id_idx.sql new file mode 100644 index 0000000000..8f5e65aa71 --- /dev/null +++ b/synapse/storage/databases/main/schema/delta/58/25user_external_ids_user_id_idx.sql @@ -0,0 +1,17 @@ +/* Copyright 2020 The Matrix.org Foundation C.I.C + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * 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. + */ + +INSERT INTO background_updates (ordering, update_name, progress_json) VALUES + (5825, 'user_external_ids_user_id_idx', '{}'); -- cgit 1.4.1