diff --git a/changelog.d/6767.bugfix b/changelog.d/6767.bugfix new file mode 100644 index 000000000000..63c7c63315e9 --- /dev/null +++ b/changelog.d/6767.bugfix @@ -0,0 +1 @@ +Validate `client_secret` parameter using the regex provided by the Client-Server API, temporarily allowing `:` characters for older clients. The `:` character will be removed in a future release. diff --git a/synapse/handlers/identity.py b/synapse/handlers/identity.py index 000fbf090f83..23f07832e747 100644 --- a/synapse/handlers/identity.py +++ b/synapse/handlers/identity.py @@ -38,7 +38,7 @@ from synapse.config.emailconfig import ThreepidBehaviour from synapse.http.client import SimpleHttpClient from synapse.util.hash import sha256_and_url_safe_base64 -from synapse.util.stringutils import random_string +from synapse.util.stringutils import assert_valid_client_secret, random_string from ._base import BaseHandler @@ -84,6 +84,8 @@ def threepid_from_creds(self, id_server, creds): raise SynapseError( 400, "Missing param client_secret in creds", errcode=Codes.MISSING_PARAM ) + assert_valid_client_secret(client_secret) + session_id = creds.get("sid") if not session_id: raise SynapseError( diff --git a/synapse/rest/client/v2_alpha/account.py b/synapse/rest/client/v2_alpha/account.py index fc240f5cf818..dc837d6c7582 100644 --- a/synapse/rest/client/v2_alpha/account.py +++ b/synapse/rest/client/v2_alpha/account.py @@ -30,6 +30,7 @@ ) from synapse.push.mailer import Mailer, load_jinja2_templates from synapse.util.msisdn import phone_number_to_msisdn +from synapse.util.stringutils import assert_valid_client_secret from synapse.util.threepids import check_3pid_allowed from ._base import client_patterns, interactive_auth_handler @@ -81,6 +82,8 @@ async def on_POST(self, request): # Extract params from body client_secret = body["client_secret"] + assert_valid_client_secret(client_secret) + email = body["email"] send_attempt = body["send_attempt"] next_link = body.get("next_link") # Optional param @@ -166,8 +169,9 @@ async def on_GET(self, request, medium): ) sid = parse_string(request, "sid", required=True) - client_secret = parse_string(request, "client_secret", required=True) token = parse_string(request, "token", required=True) + client_secret = parse_string(request, "client_secret", required=True) + assert_valid_client_secret(client_secret) # Attempt to validate a 3PID session try: @@ -353,6 +357,8 @@ async def on_POST(self, request): body = parse_json_object_from_request(request) assert_params_in_dict(body, ["client_secret", "email", "send_attempt"]) client_secret = body["client_secret"] + assert_valid_client_secret(client_secret) + email = body["email"] send_attempt = body["send_attempt"] next_link = body.get("next_link") # Optional param @@ -413,6 +419,8 @@ async def on_POST(self, request): body, ["client_secret", "country", "phone_number", "send_attempt"] ) client_secret = body["client_secret"] + assert_valid_client_secret(client_secret) + country = body["country"] phone_number = body["phone_number"] send_attempt = body["send_attempt"] @@ -493,8 +501,9 @@ async def on_GET(self, request): ) sid = parse_string(request, "sid", required=True) - client_secret = parse_string(request, "client_secret", required=True) token = parse_string(request, "token", required=True) + client_secret = parse_string(request, "client_secret", required=True) + assert_valid_client_secret(client_secret) # Attempt to validate a 3PID session try: @@ -559,6 +568,7 @@ async def on_POST(self, request): body = parse_json_object_from_request(request) assert_params_in_dict(body, ["client_secret", "sid", "token"]) + assert_valid_client_secret(body["client_secret"]) # Proxy submit_token request to msisdn threepid delegate response = await self.identity_handler.proxy_msisdn_submit_token( @@ -600,8 +610,9 @@ async def on_POST(self, request): ) assert_params_in_dict(threepid_creds, ["client_secret", "sid"]) - client_secret = threepid_creds["client_secret"] sid = threepid_creds["sid"] + client_secret = threepid_creds["client_secret"] + assert_valid_client_secret(client_secret) validation_session = await self.identity_handler.validate_threepid_session( client_secret, sid @@ -637,8 +648,9 @@ async def on_POST(self, request): body = parse_json_object_from_request(request) assert_params_in_dict(body, ["client_secret", "sid"]) - client_secret = body["client_secret"] sid = body["sid"] + client_secret = body["client_secret"] + assert_valid_client_secret(client_secret) await self.auth_handler.validate_user_via_ui_auth( requester, body, self.hs.get_ip_from_request(request) @@ -676,8 +688,9 @@ async def on_POST(self, request): assert_params_in_dict(body, ["id_server", "sid", "client_secret"]) id_server = body["id_server"] sid = body["sid"] - client_secret = body["client_secret"] id_access_token = body.get("id_access_token") # optional + client_secret = body["client_secret"] + assert_valid_client_secret(client_secret) requester = await self.auth.get_user_by_req(request) user_id = requester.user.to_string() diff --git a/synapse/rest/client/v2_alpha/register.py b/synapse/rest/client/v2_alpha/register.py index 1bda9aec7ef6..a09189b1b469 100644 --- a/synapse/rest/client/v2_alpha/register.py +++ b/synapse/rest/client/v2_alpha/register.py @@ -49,6 +49,7 @@ from synapse.push.mailer import load_jinja2_templates from synapse.util.msisdn import phone_number_to_msisdn from synapse.util.ratelimitutils import FederationRateLimiter +from synapse.util.stringutils import assert_valid_client_secret from synapse.util.threepids import check_3pid_allowed from ._base import client_patterns, interactive_auth_handler @@ -116,6 +117,8 @@ async def on_POST(self, request): # Extract params from body client_secret = body["client_secret"] + assert_valid_client_secret(client_secret) + email = body["email"] send_attempt = body["send_attempt"] next_link = body.get("next_link") # Optional param diff --git a/synapse/util/stringutils.py b/synapse/util/stringutils.py index 982c6d81ca82..2c0dcb5208bd 100644 --- a/synapse/util/stringutils.py +++ b/synapse/util/stringutils.py @@ -1,5 +1,6 @@ # -*- coding: utf-8 -*- # Copyright 2014-2016 OpenMarket Ltd +# 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. @@ -14,14 +15,22 @@ # limitations under the License. import random +import re import string import six from six import PY2, PY3 from six.moves import range +from synapse.api.errors import Codes, SynapseError + _string_with_symbols = string.digits + string.ascii_letters + ".,;:^&*-_+=#~@" +# https://matrix.org/docs/spec/client_server/r0.6.0#post-matrix-client-r0-register-email-requesttoken +# Note: The : character is allowed here for older clients, but will be removed in a +# future release. Context: https://github.com/matrix-org/synapse/issues/6766 +client_secret_regex = re.compile(r"^[0-9a-zA-Z\.\=\_\-\:]+$") + # random_string and random_string_with_symbols are used for a range of things, # some cryptographically important, some less so. We use SystemRandom to make sure # we get cryptographically-secure randoms. @@ -109,3 +118,11 @@ def exception_to_unicode(e): return msg.decode("utf-8", errors="replace") else: return msg + + +def assert_valid_client_secret(client_secret): + """Validate that a given string matches the client_secret regex defined by the spec""" + if client_secret_regex.match(client_secret) is None: + raise SynapseError( + 400, "Invalid client_secret parameter", errcode=Codes.INVALID_PARAM + ) diff --git a/tests/util/test_stringutils.py b/tests/util/test_stringutils.py new file mode 100644 index 000000000000..4f4da29a98ba --- /dev/null +++ b/tests/util/test_stringutils.py @@ -0,0 +1,51 @@ +# -*- coding: utf-8 -*- +# 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. + +from synapse.api.errors import SynapseError +from synapse.util.stringutils import assert_valid_client_secret + +from .. import unittest + + +class StringUtilsTestCase(unittest.TestCase): + def test_client_secret_regex(self): + """Ensure that client_secret does not contain illegal characters""" + good = [ + "abcde12345", + "ABCabc123", + "_--something==_", + "...--==-18913", + "8Dj2odd-e9asd.cd==_--ddas-secret-", + # We temporarily allow : characters: https://github.com/matrix-org/synapse/issues/6766 + # To be removed in a future release + "SECRET:1234567890", + ] + + bad = [ + "--+-/secret", + "\\dx--dsa288", + "", + "AAS//", + "asdj**", + ">X>