Add a confirmation step to the SSO login flow

This commit is contained in:
Brendan Abolivier 2020-03-02 16:36:32 +00:00
parent 380122866f
commit b2bd54a2e3
7 changed files with 245 additions and 6 deletions

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@ -1360,6 +1360,40 @@ saml2_config:
# # name: value
# Additional settings to use with single-sign on systems such as SAML2 and CAS.
#
sso:
# Directory in which Synapse will try to find the template files below.
# If not set, default templates from within the Synapse package will be used.
#
# DO NOT UNCOMMENT THIS SETTING unless you want to customise the templates.
# If you *do* uncomment it, you will need to make sure that all the templates
# below are in the directory.
#
# Synapse will look for the following templates in this directory:
#
# * HTML page for confirmation of redirect during authentication:
# 'sso_redirect_confirm.html'.
#
# When rendering, this template is given three variables:
# * redirect_url: the URL the user is about to be redirected to. Needs
# manual escaping (see
# https://jinja.palletsprojects.com/en/2.11.x/templates/#html-escaping).
#
# * display_url: the same as `redirect_url`, but with the query
# parameters stripped. The intention is to have a
# human-readable URL to show to users, not to use it as
# the final address to redirect to. Needs manual escaping
# (see https://jinja.palletsprojects.com/en/2.11.x/templates/#html-escaping).
#
# * server_name: the homeserver's name.
#
# You can see the default templates at:
# https://github.com/matrix-org/synapse/tree/master/synapse/res/templates
#
#template_dir: "res/templates"
# The JWT needs to contain a globally unique "sub" (subject) claim.
#
#jwt_config:

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@ -24,6 +24,7 @@ from synapse.config import (
server,
server_notices_config,
spam_checker,
sso,
stats,
third_party_event_rules,
tls,
@ -57,6 +58,7 @@ class RootConfig:
key: key.KeyConfig
saml2: saml2_config.SAML2Config
cas: cas.CasConfig
sso: sso.SSOConfig
jwt: jwt_config.JWTConfig
password: password.PasswordConfig
email: emailconfig.EmailConfig

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@ -38,6 +38,7 @@ from .saml2_config import SAML2Config
from .server import ServerConfig
from .server_notices_config import ServerNoticesConfig
from .spam_checker import SpamCheckerConfig
from .sso import SSOConfig
from .stats import StatsConfig
from .third_party_event_rules import ThirdPartyRulesConfig
from .tls import TlsConfig
@ -65,6 +66,7 @@ class HomeServerConfig(RootConfig):
KeyConfig,
SAML2Config,
CasConfig,
SSOConfig,
JWTConfig,
PasswordConfig,
EmailConfig,

74
synapse/config/sso.py Normal file
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@ -0,0 +1,74 @@
# -*- 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 typing import Any, Dict
import pkg_resources
from ._base import Config, ConfigError
class SSOConfig(Config):
"""SSO Configuration
"""
section = "sso"
def read_config(self, config, **kwargs):
sso_config = config.get("sso") or {} # type: Dict[str, Any]
# Pick a template directory in order of:
# * The sso-specific template_dir
# * /path/to/synapse/install/res/templates
template_dir = sso_config.get("template_dir")
if not template_dir:
template_dir = pkg_resources.resource_filename("synapse", "res/templates",)
self.sso_redirect_confirm_template_dir = template_dir
def generate_config_section(self, **kwargs):
return """\
# Additional settings to use with single-sign on systems such as SAML2 and CAS.
#
sso:
# Directory in which Synapse will try to find the template files below.
# If not set, default templates from within the Synapse package will be used.
#
# DO NOT UNCOMMENT THIS SETTING unless you want to customise the templates.
# If you *do* uncomment it, you will need to make sure that all the templates
# below are in the directory.
#
# Synapse will look for the following templates in this directory:
#
# * HTML page for a confirmation step before redirecting back to the client
# with the login token: 'sso_redirect_confirm.html'.
#
# When rendering, this template is given three variables:
# * redirect_url: the URL the user is about to be redirected to. Needs
# manual escaping (see
# https://jinja.palletsprojects.com/en/2.11.x/templates/#html-escaping).
#
# * display_url: the same as `redirect_url`, but with the query
# parameters stripped. The intention is to have a
# human-readable URL to show to users, not to use it as
# the final address to redirect to. Needs manual escaping
# (see https://jinja.palletsprojects.com/en/2.11.x/templates/#html-escaping).
#
# * server_name: the homeserver's name.
#
# You can see the default templates at:
# https://github.com/matrix-org/synapse/tree/master/synapse/res/templates
#
#template_dir: "res/templates"
"""

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@ -0,0 +1,14 @@
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>SSO redirect confirmation</title>
</head>
<body>
<p>The application at <span style="font-weight:bold">{{ display_url | e }}</span> is requesting full access to your <span style="font-weight:bold">{{ server_name }}</span> Matrix account.</p>
<p>If you don't recognise this address, you should ignore this and close this tab.</p>
<p>
<a href="{{ redirect_url | e }}">I trust this address</a>
</p>
</body>
</html>

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@ -29,6 +29,7 @@ from synapse.http.servlet import (
parse_string,
)
from synapse.http.site import SynapseRequest
from synapse.push.mailer import load_jinja2_templates
from synapse.rest.client.v2_alpha._base import client_patterns
from synapse.rest.well_known import WellKnownBuilder
from synapse.types import UserID, map_username_to_mxid_localpart
@ -548,6 +549,13 @@ class SSOAuthHandler(object):
self._registration_handler = hs.get_registration_handler()
self._macaroon_gen = hs.get_macaroon_generator()
# Load the redirect page HTML template
self._template = load_jinja2_templates(
hs.config.sso_redirect_confirm_template_dir, ["sso_redirect_confirm.html"],
)[0]
self._server_name = hs.config.server_name
async def on_successful_auth(
self, username, request, client_redirect_url, user_display_name=None
):
@ -592,21 +600,41 @@ class SSOAuthHandler(object):
request:
client_redirect_url:
"""
# Create a login token
login_token = self._macaroon_gen.generate_short_term_login_token(
registered_user_id
)
redirect_url = self._add_login_token_to_redirect_url(
client_redirect_url, login_token
# Remove the query parameters from the redirect URL to get a shorter version of
# it. This is only to display a human-readable URL in the template, but not the
# URL we redirect users to.
redirect_url_no_params = client_redirect_url.split("?")[0]
# Append the login token to the original redirect URL (i.e. with its query
# parameters kept intact) to build the URL to which the template needs to
# redirect the users once they have clicked on the confirmation link.
redirect_url = self._add_query_param_to_url(
client_redirect_url, "loginToken", login_token
)
request.redirect(redirect_url)
# Serve the redirect confirmation page
html = self._template.render(
display_url=redirect_url_no_params,
redirect_url=redirect_url,
server_name=self._server_name,
)
request.setResponseCode(200)
request.setHeader(b"Content-Type", b"text/html; charset=utf-8")
request.setHeader(b"Content-Length", b"%d" % (len(html),))
request.write(html.encode("utf8"))
finish_request(request)
@staticmethod
def _add_login_token_to_redirect_url(url, token):
def _add_query_param_to_url(url, param_name, param):
url_parts = list(urllib.parse.urlparse(url))
query = dict(urllib.parse.parse_qsl(url_parts[4]))
query.update({"loginToken": token})
query.update({param_name: param})
url_parts[4] = urllib.parse.urlencode(query)
return urllib.parse.urlunparse(url_parts)

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@ -1,4 +1,7 @@
import json
import urllib.parse
from mock import Mock
import synapse.rest.admin
from synapse.rest.client.v1 import login
@ -252,3 +255,85 @@ class LoginRestServletTestCase(unittest.HomeserverTestCase):
)
self.render(request)
self.assertEquals(channel.code, 200, channel.result)
class CASRedirectConfirmTestCase(unittest.HomeserverTestCase):
servlets = [
login.register_servlets,
]
def make_homeserver(self, reactor, clock):
self.base_url = "https://matrix.goodserver.com/"
self.redirect_path = "_synapse/client/login/sso/redirect/confirm"
config = self.default_config()
config["enable_registration"] = True
config["cas_config"] = {
"enabled": True,
"server_url": "https://fake.test",
"service_url": "https://matrix.goodserver.com:8448",
}
config["public_baseurl"] = self.base_url
async def get_raw(uri, args):
"""Return an example response payload from a call to the `/proxyValidate`
endpoint of a CAS server, copied from
https://apereo.github.io/cas/5.0.x/protocol/CAS-Protocol-V2-Specification.html#26-proxyvalidate-cas-20
This needs to be returned by an async function (as opposed to set as the
mock's return value) because the corresponding Synapse code awaits on it.
"""
return """
<cas:serviceResponse xmlns:cas='http://www.yale.edu/tp/cas'>
<cas:authenticationSuccess>
<cas:user>username</cas:user>
<cas:proxyGrantingTicket>PGTIOU-84678-8a9d...</cas:proxyGrantingTicket>
<cas:proxies>
<cas:proxy>https://proxy2/pgtUrl</cas:proxy>
<cas:proxy>https://proxy1/pgtUrl</cas:proxy>
</cas:proxies>
</cas:authenticationSuccess>
</cas:serviceResponse>
"""
mocked_http_client = Mock(spec=["get_raw"])
mocked_http_client.get_raw.side_effect = get_raw
self.hs = self.setup_test_homeserver(
config=config, proxied_http_client=mocked_http_client,
)
return self.hs
def test_cas_redirect_confirm(self):
"""Tests that the SSO login flow serves a confirmation page before redirecting a
user to the redirect URL.
"""
base_url = "/login/cas/ticket?redirectUrl"
redirect_url = "https://dodgy-site.com/"
url_parts = list(urllib.parse.urlparse(base_url))
query = dict(urllib.parse.parse_qsl(url_parts[4]))
query.update({"redirectUrl": redirect_url})
query.update({"ticket": "ticket"})
url_parts[4] = urllib.parse.urlencode(query)
cas_ticket_url = urllib.parse.urlunparse(url_parts)
# Get Synapse to call the fake CAS and serve the template.
request, channel = self.make_request("GET", cas_ticket_url)
self.render(request)
# Test that the response is HTML.
content_type_header_value = ""
for header in channel.result.get("headers", []):
if header[0] == b"Content-Type":
content_type_header_value = header[1].decode("utf8")
self.assertTrue(content_type_header_value.startswith("text/html"))
# Test that the body isn't empty.
self.assertTrue(len(channel.result["body"]) > 0)
# And that it contains our redirect link
self.assertIn(redirect_url, channel.result["body"].decode("UTF-8"))