From e8e2ddb60ae11db488f159901d918cb159695912 Mon Sep 17 00:00:00 2001 From: Dirk Klimpel <5740567+dklimpel@users.noreply.github.com> Date: Thu, 26 Mar 2020 17:51:13 +0100 Subject: [PATCH] Allow server admins to define and enforce a password policy (MSC2000). (#7118) --- changelog.d/7118.feature | 1 + docs/sample_config.yaml | 35 ++++ synapse/api/errors.py | 21 ++ synapse/config/password.py | 39 ++++ synapse/handlers/password_policy.py | 93 +++++++++ synapse/handlers/set_password.py | 2 + synapse/rest/__init__.py | 2 + .../rest/client/v2_alpha/password_policy.py | 58 ++++++ synapse/rest/client/v2_alpha/register.py | 2 + synapse/server.py | 5 + .../client/v2_alpha/test_password_policy.py | 179 ++++++++++++++++++ 11 files changed, 437 insertions(+) create mode 100644 changelog.d/7118.feature create mode 100644 synapse/handlers/password_policy.py create mode 100644 synapse/rest/client/v2_alpha/password_policy.py create mode 100644 tests/rest/client/v2_alpha/test_password_policy.py diff --git a/changelog.d/7118.feature b/changelog.d/7118.feature new file mode 100644 index 000000000..5cbfd9816 --- /dev/null +++ b/changelog.d/7118.feature @@ -0,0 +1 @@ +Allow server admins to define and enforce a password policy (MSC2000). \ No newline at end of file diff --git a/docs/sample_config.yaml b/docs/sample_config.yaml index 2ef83646b..1a1d06175 100644 --- a/docs/sample_config.yaml +++ b/docs/sample_config.yaml @@ -1482,6 +1482,41 @@ password_config: # #pepper: "EVEN_MORE_SECRET" + # Define and enforce a password policy. Each parameter is optional. + # This is an implementation of MSC2000. + # + policy: + # Whether to enforce the password policy. + # Defaults to 'false'. + # + #enabled: true + + # Minimum accepted length for a password. + # Defaults to 0. + # + #minimum_length: 15 + + # Whether a password must contain at least one digit. + # Defaults to 'false'. + # + #require_digit: true + + # Whether a password must contain at least one symbol. + # A symbol is any character that's not a number or a letter. + # Defaults to 'false'. + # + #require_symbol: true + + # Whether a password must contain at least one lowercase letter. + # Defaults to 'false'. + # + #require_lowercase: true + + # Whether a password must contain at least one lowercase letter. + # Defaults to 'false'. + # + #require_uppercase: true + # Configuration for sending emails from Synapse. # diff --git a/synapse/api/errors.py b/synapse/api/errors.py index 616942b05..11da016ac 100644 --- a/synapse/api/errors.py +++ b/synapse/api/errors.py @@ -64,6 +64,13 @@ class Codes(object): INCOMPATIBLE_ROOM_VERSION = "M_INCOMPATIBLE_ROOM_VERSION" WRONG_ROOM_KEYS_VERSION = "M_WRONG_ROOM_KEYS_VERSION" EXPIRED_ACCOUNT = "ORG_MATRIX_EXPIRED_ACCOUNT" + PASSWORD_TOO_SHORT = "M_PASSWORD_TOO_SHORT" + PASSWORD_NO_DIGIT = "M_PASSWORD_NO_DIGIT" + PASSWORD_NO_UPPERCASE = "M_PASSWORD_NO_UPPERCASE" + PASSWORD_NO_LOWERCASE = "M_PASSWORD_NO_LOWERCASE" + PASSWORD_NO_SYMBOL = "M_PASSWORD_NO_SYMBOL" + PASSWORD_IN_DICTIONARY = "M_PASSWORD_IN_DICTIONARY" + WEAK_PASSWORD = "M_WEAK_PASSWORD" INVALID_SIGNATURE = "M_INVALID_SIGNATURE" USER_DEACTIVATED = "M_USER_DEACTIVATED" BAD_ALIAS = "M_BAD_ALIAS" @@ -439,6 +446,20 @@ class IncompatibleRoomVersionError(SynapseError): return cs_error(self.msg, self.errcode, room_version=self._room_version) +class PasswordRefusedError(SynapseError): + """A password has been refused, either during password reset/change or registration. + """ + + def __init__( + self, + msg="This password doesn't comply with the server's policy", + errcode=Codes.WEAK_PASSWORD, + ): + super(PasswordRefusedError, self).__init__( + code=400, msg=msg, errcode=errcode, + ) + + class RequestSendFailed(RuntimeError): """Sending a HTTP request over federation failed due to not being able to talk to the remote server for some reason. diff --git a/synapse/config/password.py b/synapse/config/password.py index 2a634ac75..9c0ea8c30 100644 --- a/synapse/config/password.py +++ b/synapse/config/password.py @@ -31,6 +31,10 @@ class PasswordConfig(Config): self.password_localdb_enabled = password_config.get("localdb_enabled", True) self.password_pepper = password_config.get("pepper", "") + # Password policy + self.password_policy = password_config.get("policy") or {} + self.password_policy_enabled = self.password_policy.get("enabled", False) + def generate_config_section(self, config_dir_path, server_name, **kwargs): return """\ password_config: @@ -48,4 +52,39 @@ class PasswordConfig(Config): # DO NOT CHANGE THIS AFTER INITIAL SETUP! # #pepper: "EVEN_MORE_SECRET" + + # Define and enforce a password policy. Each parameter is optional. + # This is an implementation of MSC2000. + # + policy: + # Whether to enforce the password policy. + # Defaults to 'false'. + # + #enabled: true + + # Minimum accepted length for a password. + # Defaults to 0. + # + #minimum_length: 15 + + # Whether a password must contain at least one digit. + # Defaults to 'false'. + # + #require_digit: true + + # Whether a password must contain at least one symbol. + # A symbol is any character that's not a number or a letter. + # Defaults to 'false'. + # + #require_symbol: true + + # Whether a password must contain at least one lowercase letter. + # Defaults to 'false'. + # + #require_lowercase: true + + # Whether a password must contain at least one lowercase letter. + # Defaults to 'false'. + # + #require_uppercase: true """ diff --git a/synapse/handlers/password_policy.py b/synapse/handlers/password_policy.py new file mode 100644 index 000000000..d06b11026 --- /dev/null +++ b/synapse/handlers/password_policy.py @@ -0,0 +1,93 @@ +# -*- coding: utf-8 -*- +# Copyright 2019 New Vector Ltd +# Copyright 2019 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. + +import logging +import re + +from synapse.api.errors import Codes, PasswordRefusedError + +logger = logging.getLogger(__name__) + + +class PasswordPolicyHandler(object): + def __init__(self, hs): + self.policy = hs.config.password_policy + self.enabled = hs.config.password_policy_enabled + + # Regexps for the spec'd policy parameters. + self.regexp_digit = re.compile("[0-9]") + self.regexp_symbol = re.compile("[^a-zA-Z0-9]") + self.regexp_uppercase = re.compile("[A-Z]") + self.regexp_lowercase = re.compile("[a-z]") + + def validate_password(self, password): + """Checks whether a given password complies with the server's policy. + + Args: + password (str): The password to check against the server's policy. + + Raises: + PasswordRefusedError: The password doesn't comply with the server's policy. + """ + + if not self.enabled: + return + + minimum_accepted_length = self.policy.get("minimum_length", 0) + if len(password) < minimum_accepted_length: + raise PasswordRefusedError( + msg=( + "The password must be at least %d characters long" + % minimum_accepted_length + ), + errcode=Codes.PASSWORD_TOO_SHORT, + ) + + if ( + self.policy.get("require_digit", False) + and self.regexp_digit.search(password) is None + ): + raise PasswordRefusedError( + msg="The password must include at least one digit", + errcode=Codes.PASSWORD_NO_DIGIT, + ) + + if ( + self.policy.get("require_symbol", False) + and self.regexp_symbol.search(password) is None + ): + raise PasswordRefusedError( + msg="The password must include at least one symbol", + errcode=Codes.PASSWORD_NO_SYMBOL, + ) + + if ( + self.policy.get("require_uppercase", False) + and self.regexp_uppercase.search(password) is None + ): + raise PasswordRefusedError( + msg="The password must include at least one uppercase letter", + errcode=Codes.PASSWORD_NO_UPPERCASE, + ) + + if ( + self.policy.get("require_lowercase", False) + and self.regexp_lowercase.search(password) is None + ): + raise PasswordRefusedError( + msg="The password must include at least one lowercase letter", + errcode=Codes.PASSWORD_NO_LOWERCASE, + ) diff --git a/synapse/handlers/set_password.py b/synapse/handlers/set_password.py index 12657ca69..7d1263caf 100644 --- a/synapse/handlers/set_password.py +++ b/synapse/handlers/set_password.py @@ -32,6 +32,7 @@ class SetPasswordHandler(BaseHandler): super(SetPasswordHandler, self).__init__(hs) self._auth_handler = hs.get_auth_handler() self._device_handler = hs.get_device_handler() + self._password_policy_handler = hs.get_password_policy_handler() @defer.inlineCallbacks def set_password( @@ -44,6 +45,7 @@ class SetPasswordHandler(BaseHandler): if not self.hs.config.password_localdb_enabled: raise SynapseError(403, "Password change disabled", errcode=Codes.FORBIDDEN) + self._password_policy_handler.validate_password(new_password) password_hash = yield self._auth_handler.hash(new_password) try: diff --git a/synapse/rest/__init__.py b/synapse/rest/__init__.py index 4a1fc2ec2..46e458e95 100644 --- a/synapse/rest/__init__.py +++ b/synapse/rest/__init__.py @@ -41,6 +41,7 @@ from synapse.rest.client.v2_alpha import ( keys, notifications, openid, + password_policy, read_marker, receipts, register, @@ -118,6 +119,7 @@ class ClientRestResource(JsonResource): capabilities.register_servlets(hs, client_resource) account_validity.register_servlets(hs, client_resource) relations.register_servlets(hs, client_resource) + password_policy.register_servlets(hs, client_resource) # moving to /_synapse/admin synapse.rest.admin.register_servlets_for_client_rest_resource( diff --git a/synapse/rest/client/v2_alpha/password_policy.py b/synapse/rest/client/v2_alpha/password_policy.py new file mode 100644 index 000000000..968403cca --- /dev/null +++ b/synapse/rest/client/v2_alpha/password_policy.py @@ -0,0 +1,58 @@ +# -*- coding: utf-8 -*- +# Copyright 2019 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. + +import logging + +from synapse.http.servlet import RestServlet + +from ._base import client_patterns + +logger = logging.getLogger(__name__) + + +class PasswordPolicyServlet(RestServlet): + PATTERNS = client_patterns("/password_policy$") + + def __init__(self, hs): + """ + Args: + hs (synapse.server.HomeServer): server + """ + super(PasswordPolicyServlet, self).__init__() + + self.policy = hs.config.password_policy + self.enabled = hs.config.password_policy_enabled + + def on_GET(self, request): + if not self.enabled or not self.policy: + return (200, {}) + + policy = {} + + for param in [ + "minimum_length", + "require_digit", + "require_symbol", + "require_lowercase", + "require_uppercase", + ]: + if param in self.policy: + policy["m.%s" % param] = self.policy[param] + + return (200, policy) + + +def register_servlets(hs, http_server): + PasswordPolicyServlet(hs).register(http_server) diff --git a/synapse/rest/client/v2_alpha/register.py b/synapse/rest/client/v2_alpha/register.py index 6963d7931..66fc8ec17 100644 --- a/synapse/rest/client/v2_alpha/register.py +++ b/synapse/rest/client/v2_alpha/register.py @@ -373,6 +373,7 @@ class RegisterRestServlet(RestServlet): self.room_member_handler = hs.get_room_member_handler() self.macaroon_gen = hs.get_macaroon_generator() self.ratelimiter = hs.get_registration_ratelimiter() + self.password_policy_handler = hs.get_password_policy_handler() self.clock = hs.get_clock() self._registration_flows = _calculate_registration_flows( @@ -420,6 +421,7 @@ class RegisterRestServlet(RestServlet): or len(body["password"]) > 512 ): raise SynapseError(400, "Invalid password") + self.password_policy_handler.validate_password(body["password"]) desired_username = None if "username" in body: diff --git a/synapse/server.py b/synapse/server.py index 9426eb167..d0d80e8ac 100644 --- a/synapse/server.py +++ b/synapse/server.py @@ -66,6 +66,7 @@ from synapse.handlers.groups_local import GroupsLocalHandler, GroupsLocalWorkerH from synapse.handlers.initial_sync import InitialSyncHandler from synapse.handlers.message import EventCreationHandler, MessageHandler from synapse.handlers.pagination import PaginationHandler +from synapse.handlers.password_policy import PasswordPolicyHandler from synapse.handlers.presence import PresenceHandler from synapse.handlers.profile import BaseProfileHandler, MasterProfileHandler from synapse.handlers.read_marker import ReadMarkerHandler @@ -199,6 +200,7 @@ class HomeServer(object): "account_validity_handler", "saml_handler", "event_client_serializer", + "password_policy_handler", "storage", "replication_streamer", ] @@ -535,6 +537,9 @@ class HomeServer(object): def build_event_client_serializer(self): return EventClientSerializer(self) + def build_password_policy_handler(self): + return PasswordPolicyHandler(self) + def build_storage(self) -> Storage: return Storage(self, self.datastores) diff --git a/tests/rest/client/v2_alpha/test_password_policy.py b/tests/rest/client/v2_alpha/test_password_policy.py new file mode 100644 index 000000000..c57072f50 --- /dev/null +++ b/tests/rest/client/v2_alpha/test_password_policy.py @@ -0,0 +1,179 @@ +# -*- coding: utf-8 -*- +# Copyright 2019 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. + +import json + +from synapse.api.constants import LoginType +from synapse.api.errors import Codes +from synapse.rest import admin +from synapse.rest.client.v1 import login +from synapse.rest.client.v2_alpha import account, password_policy, register + +from tests import unittest + + +class PasswordPolicyTestCase(unittest.HomeserverTestCase): + """Tests the password policy feature and its compliance with MSC2000. + + When validating a password, Synapse does the necessary checks in this order: + + 1. Password is long enough + 2. Password contains digit(s) + 3. Password contains symbol(s) + 4. Password contains uppercase letter(s) + 5. Password contains lowercase letter(s) + + For each test below that checks whether a password triggers the right error code, + that test provides a password good enough to pass the previous tests, but not the + one it is currently testing (nor any test that comes afterward). + """ + + servlets = [ + admin.register_servlets_for_client_rest_resource, + login.register_servlets, + register.register_servlets, + password_policy.register_servlets, + account.register_servlets, + ] + + def make_homeserver(self, reactor, clock): + self.register_url = "/_matrix/client/r0/register" + self.policy = { + "enabled": True, + "minimum_length": 10, + "require_digit": True, + "require_symbol": True, + "require_lowercase": True, + "require_uppercase": True, + } + + config = self.default_config() + config["password_config"] = { + "policy": self.policy, + } + + hs = self.setup_test_homeserver(config=config) + return hs + + def test_get_policy(self): + """Tests if the /password_policy endpoint returns the configured policy.""" + + request, channel = self.make_request( + "GET", "/_matrix/client/r0/password_policy" + ) + self.render(request) + + self.assertEqual(channel.code, 200, channel.result) + self.assertEqual( + channel.json_body, + { + "m.minimum_length": 10, + "m.require_digit": True, + "m.require_symbol": True, + "m.require_lowercase": True, + "m.require_uppercase": True, + }, + channel.result, + ) + + def test_password_too_short(self): + request_data = json.dumps({"username": "kermit", "password": "shorty"}) + request, channel = self.make_request("POST", self.register_url, request_data) + self.render(request) + + self.assertEqual(channel.code, 400, channel.result) + self.assertEqual( + channel.json_body["errcode"], Codes.PASSWORD_TOO_SHORT, channel.result, + ) + + def test_password_no_digit(self): + request_data = json.dumps({"username": "kermit", "password": "longerpassword"}) + request, channel = self.make_request("POST", self.register_url, request_data) + self.render(request) + + self.assertEqual(channel.code, 400, channel.result) + self.assertEqual( + channel.json_body["errcode"], Codes.PASSWORD_NO_DIGIT, channel.result, + ) + + def test_password_no_symbol(self): + request_data = json.dumps({"username": "kermit", "password": "l0ngerpassword"}) + request, channel = self.make_request("POST", self.register_url, request_data) + self.render(request) + + self.assertEqual(channel.code, 400, channel.result) + self.assertEqual( + channel.json_body["errcode"], Codes.PASSWORD_NO_SYMBOL, channel.result, + ) + + def test_password_no_uppercase(self): + request_data = json.dumps({"username": "kermit", "password": "l0ngerpassword!"}) + request, channel = self.make_request("POST", self.register_url, request_data) + self.render(request) + + self.assertEqual(channel.code, 400, channel.result) + self.assertEqual( + channel.json_body["errcode"], Codes.PASSWORD_NO_UPPERCASE, channel.result, + ) + + def test_password_no_lowercase(self): + request_data = json.dumps({"username": "kermit", "password": "L0NGERPASSWORD!"}) + request, channel = self.make_request("POST", self.register_url, request_data) + self.render(request) + + self.assertEqual(channel.code, 400, channel.result) + self.assertEqual( + channel.json_body["errcode"], Codes.PASSWORD_NO_LOWERCASE, channel.result, + ) + + def test_password_compliant(self): + request_data = json.dumps({"username": "kermit", "password": "L0ngerpassword!"}) + request, channel = self.make_request("POST", self.register_url, request_data) + self.render(request) + + # Getting a 401 here means the password has passed validation and the server has + # responded with a list of registration flows. + self.assertEqual(channel.code, 401, channel.result) + + def test_password_change(self): + """This doesn't test every possible use case, only that hitting /account/password + triggers the password validation code. + """ + compliant_password = "C0mpl!antpassword" + not_compliant_password = "notcompliantpassword" + + user_id = self.register_user("kermit", compliant_password) + tok = self.login("kermit", compliant_password) + + request_data = json.dumps( + { + "new_password": not_compliant_password, + "auth": { + "password": compliant_password, + "type": LoginType.PASSWORD, + "user": user_id, + }, + } + ) + request, channel = self.make_request( + "POST", + "/_matrix/client/r0/account/password", + request_data, + access_token=tok, + ) + self.render(request) + + self.assertEqual(channel.code, 400, channel.result) + self.assertEqual(channel.json_body["errcode"], Codes.PASSWORD_NO_DIGIT)