Show a confirmation page during user password reset (#8004)

This PR adds a confirmation step to resetting your user password between clicking the link in your email and your password actually being reset.

This is to better align our password reset flow with the industry standard of requiring a confirmation from the user after email validation.

UPGRADE.rst

@@ -88,6 +88,30 @@ for example:
      wget https://packages.matrix.org/debian/pool/main/m/matrix-synapse-py3/matrix-synapse-py3_1.3.0+stretch1_amd64.deb
      dpkg -i matrix-synapse-py3_1.3.0+stretch1_amd64.deb
 
+Upgrading to v1.21.0
+====================
+
+New HTML templates
+------------------
+
+A new HTML template,
+`password_reset_confirmation.html <https://github.com/matrix-org/synapse/blob/develop/synapse/res/templates/password_reset_confirmation.html>`_,
+has been added to the ``synapse/res/templates`` directory. If you are using a
+custom template directory, you may want to copy the template over and modify it.
+
+Note that as of v1.20.0, templates do not need to be included in custom template
+directories for Synapse to start. The default templates will be used if a custom
+template cannot be found.
+
+This page will appear to the user after clicking a password reset link that has
+been emailed to them.
+
+To complete password reset, the page must include a way to make a `POST`
+request to
+``/_synapse/client/password_reset/{medium}/submit_token``
+with the query parameters from the original link, presented as a URL-encoded form. See the file
+itself for more details.
+
 Upgrading to v1.18.0
 ====================
 

changelog.d/8004.feature

@@ -0,0 +1 @@
+Require the user to confirm that their password should be reset after clicking the email confirmation link.

docs/sample_config.yaml

@@ -2039,9 +2039,13 @@ email:
   # * The contents of password reset emails sent by the homeserver:
   #   'password_reset.html' and 'password_reset.txt'
   #
-  # * HTML pages for success and failure that a user will see when they follow
-  #   the link in the password reset email: 'password_reset_success.html' and
-  #   'password_reset_failure.html'
+  # * An HTML page that a user will see when they follow the link in the password
+  #   reset email. The user will be asked to confirm the action before their
+  #   password is reset: 'password_reset_confirmation.html'
+  #
+  # * HTML pages for success and failure that a user will see when they confirm
+  #   the password reset flow using the page above: 'password_reset_success.html'
+  #   and 'password_reset_failure.html'
   #
   # * The contents of address verification emails sent during registration:
   #   'registration.html' and 'registration.txt'

synapse/api/urls.py

@@ -21,6 +21,7 @@
 
 from synapse.config import ConfigError
 
+SYNAPSE_CLIENT_API_PREFIX = "/_synapse/client"
 CLIENT_API_PREFIX = "/_matrix/client"
 FEDERATION_PREFIX = "/_matrix/federation"
 FEDERATION_V1_PREFIX = FEDERATION_PREFIX + "/v1"

synapse/app/homeserver.py

@@ -48,6 +48,7 @@
 from synapse.app import _base
 from synapse.app._base import listen_ssl, listen_tcp, quit_with_error
 from synapse.config._base import ConfigError
+from synapse.config.emailconfig import ThreepidBehaviour
 from synapse.config.homeserver import HomeServerConfig
 from synapse.config.server import ListenerConfig
 from synapse.federation.transport.server import TransportLayerServer
@@ -209,6 +210,15 @@ def _configure_named_resource(self, name, compress=False):
 
                 resources["/_matrix/saml2"] = SAML2Resource(self)
 
+            if self.get_config().threepid_behaviour_email == ThreepidBehaviour.LOCAL:
+                from synapse.rest.synapse.client.password_reset import (
+                    PasswordResetSubmitTokenResource,
+                )
+
+                resources[
+                    "/_synapse/client/password_reset/email/submit_token"
+                ] = PasswordResetSubmitTokenResource(self)
+
         if name == "consent":
             from synapse.rest.consent.consent_resource import ConsentResource
 

synapse/config/emailconfig.py

@@ -228,6 +228,7 @@ def read_config(self, config, **kwargs):
                 self.email_registration_template_text,
                 self.email_add_threepid_template_html,
                 self.email_add_threepid_template_text,
+                self.email_password_reset_template_confirmation_html,
                 self.email_password_reset_template_failure_html,
                 self.email_registration_template_failure_html,
                 self.email_add_threepid_template_failure_html,
@@ -242,6 +243,7 @@ def read_config(self, config, **kwargs):
                     registration_template_text,
                     add_threepid_template_html,
                     add_threepid_template_text,
+                    "password_reset_confirmation.html",
                     password_reset_template_failure_html,
                     registration_template_failure_html,
                     add_threepid_template_failure_html,
@@ -404,9 +406,13 @@ def generate_config_section(self, config_dir_path, server_name, **kwargs):
           # * The contents of password reset emails sent by the homeserver:
           #   'password_reset.html' and 'password_reset.txt'
           #
-          # * HTML pages for success and failure that a user will see when they follow
-          #   the link in the password reset email: 'password_reset_success.html' and
-          #   'password_reset_failure.html'
+          # * An HTML page that a user will see when they follow the link in the password
+          #   reset email. The user will be asked to confirm the action before their
+          #   password is reset: 'password_reset_confirmation.html'
+          #
+          # * HTML pages for success and failure that a user will see when they confirm
+          #   the password reset flow using the page above: 'password_reset_success.html'
+          #   and 'password_reset_failure.html'
           #
           # * The contents of address verification emails sent during registration:
           #   'registration.html' and 'registration.txt'

synapse/push/mailer.py

@@ -123,7 +123,7 @@ async def send_password_reset_mail(self, email_address, token, client_secret, si
         params = {"token": token, "client_secret": client_secret, "sid": sid}
         link = (
             self.hs.config.public_baseurl
-            + "_matrix/client/unstable/password_reset/email/submit_token?%s"
+            + "_synapse/client/password_reset/email/submit_token?%s"
             % urllib.parse.urlencode(params)
         )
 

synapse/res/templates/password_reset_confirmation.html

@@ -0,0 +1,16 @@
+<html>
+<head></head>
+<body>
+<!--Use a hidden form to resubmit the information necessary to reset the password-->
+<form method="post">
+    <input type="hidden" name="sid" value="{{ sid }}">
+    <input type="hidden" name="token" value="{{ token }}">
+    <input type="hidden" name="client_secret" value="{{ client_secret }}">
+
+    <p>You have requested to <strong>reset your Matrix account password</strong>. Click the link below to confirm this action. <br /><br />
+        If you did not mean to do this, please close this page and your password will not be changed.</p>
+    <p><button type="submit">Confirm changing my password</button></p>
+</form>
+</body>
+</html>
+

synapse/rest/__init__.py

@@ -13,8 +13,8 @@
 # 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 synapse.rest.admin
 from synapse.http.server import JsonResource
+from synapse.rest import admin
 from synapse.rest.client import versions
 from synapse.rest.client.v1 import (
     directory,
@@ -123,9 +123,7 @@ def register_servlets(client_resource, hs):
         password_policy.register_servlets(hs, client_resource)
 
         # moving to /_synapse/admin
-        synapse.rest.admin.register_servlets_for_client_rest_resource(
-            hs, client_resource
-        )
+        admin.register_servlets_for_client_rest_resource(hs, client_resource)
 
         # unstable
         shared_rooms.register_servlets(hs, client_resource)

synapse/rest/client/v2_alpha/account.py

@@ -152,81 +152,6 @@ async def on_POST(self, request):
         return 200, ret
 
 
-class PasswordResetSubmitTokenServlet(RestServlet):
-    """Handles 3PID validation token submission"""
-
-    PATTERNS = client_patterns(
-        "/password_reset/(?P<medium>[^/]*)/submit_token$", releases=(), unstable=True
-    )
-
-    def __init__(self, hs):
-        """
-        Args:
-            hs (synapse.server.HomeServer): server
-        """
-        super(PasswordResetSubmitTokenServlet, self).__init__()
-        self.hs = hs
-        self.auth = hs.get_auth()
-        self.config = hs.config
-        self.clock = hs.get_clock()
-        self.store = hs.get_datastore()
-        if self.config.threepid_behaviour_email == ThreepidBehaviour.LOCAL:
-            self._failure_email_template = (
-                self.config.email_password_reset_template_failure_html
-            )
-
-    async def on_GET(self, request, medium):
-        # We currently only handle threepid token submissions for email
-        if medium != "email":
-            raise SynapseError(
-                400, "This medium is currently not supported for password resets"
-            )
-        if self.config.threepid_behaviour_email == ThreepidBehaviour.OFF:
-            if self.config.local_threepid_handling_disabled_due_to_email_config:
-                logger.warning(
-                    "Password reset emails have been disabled due to lack of an email config"
-                )
-            raise SynapseError(
-                400, "Email-based password resets are disabled on this server"
-            )
-
-        sid = parse_string(request, "sid", 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:
-            # Mark the session as valid
-            next_link = await self.store.validate_threepid_session(
-                sid, client_secret, token, self.clock.time_msec()
-            )
-
-            # Perform a 302 redirect if next_link is set
-            if next_link:
-                if next_link.startswith("file:///"):
-                    logger.warning(
-                        "Not redirecting to next_link as it is a local file: address"
-                    )
-                else:
-                    request.setResponseCode(302)
-                    request.setHeader("Location", next_link)
-                    finish_request(request)
-                    return None
-
-            # Otherwise show the success template
-            html = self.config.email_password_reset_template_success_html_content
-            status_code = 200
-        except ThreepidValidationError as e:
-            status_code = e.code
-
-            # Show a failure page with a reason
-            template_vars = {"failure_reason": e.msg}
-            html = self._failure_email_template.render(**template_vars)
-
-        respond_with_html(request, status_code, html)
-
-
 class PasswordRestServlet(RestServlet):
     PATTERNS = client_patterns("/account/password$")
 
@@ -938,7 +863,6 @@ async def on_GET(self, request):
 
 def register_servlets(hs, http_server):
     EmailPasswordRequestTokenRestServlet(hs).register(http_server)
-    PasswordResetSubmitTokenServlet(hs).register(http_server)
     PasswordRestServlet(hs).register(http_server)
     DeactivateAccountRestServlet(hs).register(http_server)
     EmailThreepidRequestTokenRestServlet(hs).register(http_server)

synapse/rest/synapse/__init__.py

@@ -0,0 +1,14 @@
+# -*- 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.

synapse/rest/synapse/client/__init__.py

@@ -0,0 +1,14 @@
+# -*- 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.