Merge branch 'develop' into babolivier/mark_unread

13 files changed, 295 insertions, 103 deletions

diff --git a/synapse/__init__.py b/synapse/__init__.py
index 39c3a3ba4d..1d9d85a727 100644
--- a/synapse/__init__.py
+++ b/synapse/__init__.py
@@ -36,7 +36,7 @@ try:
 except ImportError:
     pass
 
-__version__ = "1.15.0rc1"
+__version__ = "1.15.0"
 
 if bool(os.environ.get("SYNAPSE_TEST_PATCH_LOG_CONTEXTS", False)):
     # We import here so that we don't have to install a bunch of deps when
diff --git a/synapse/api/constants.py b/synapse/api/constants.py
index 5ec4a77ccd..6a6d32c302 100644
--- a/synapse/api/constants.py
+++ b/synapse/api/constants.py
@@ -150,3 +150,8 @@ class EventContentFields(object):
     # Timestamp to delete the event after
     # cf https://github.com/matrix-org/matrix-doc/pull/2228
     SELF_DESTRUCT_AFTER = "org.matrix.self_destruct_after"
+
+
+class RoomEncryptionAlgorithms(object):
+    MEGOLM_V1_AES_SHA2 = "m.megolm.v1.aes-sha2"
+    DEFAULT = MEGOLM_V1_AES_SHA2
diff --git a/synapse/config/cache.py b/synapse/config/cache.py
index 0672538796..aff5b21ab2 100644
--- a/synapse/config/cache.py
+++ b/synapse/config/cache.py
@@ -15,6 +15,7 @@
 
 import os
 import re
+import threading
 from typing import Callable, Dict
 
 from ._base import Config, ConfigError
@@ -25,6 +26,9 @@ _CACHE_PREFIX = "SYNAPSE_CACHE_FACTOR"
 # Map from canonicalised cache name to cache.
 _CACHES = {}
 
+# a lock on the contents of _CACHES
+_CACHES_LOCK = threading.Lock()
+
 _DEFAULT_FACTOR_SIZE = 0.5
 _DEFAULT_EVENT_CACHE_SIZE = "10K"
 
@@ -66,7 +70,10 @@ def add_resizable_cache(cache_name: str, cache_resize_callback: Callable):
     # Some caches have '*' in them which we strip out.
     cache_name = _canonicalise_cache_name(cache_name)
 
-    _CACHES[cache_name] = cache_resize_callback
+    # sometimes caches are initialised from background threads, so we need to make
+    # sure we don't conflict with another thread running a resize operation
+    with _CACHES_LOCK:
+        _CACHES[cache_name] = cache_resize_callback
 
     # Ensure all loaded caches are sized appropriately
     #
@@ -87,7 +94,8 @@ class CacheConfig(Config):
             os.environ.get(_CACHE_PREFIX, _DEFAULT_FACTOR_SIZE)
         )
         properties.resize_all_caches_func = None
-        _CACHES.clear()
+        with _CACHES_LOCK:
+            _CACHES.clear()
 
     def generate_config_section(self, **kwargs):
         return """\
@@ -193,6 +201,8 @@ class CacheConfig(Config):
         For each cache, run the mapped callback function with either
         a specific cache factor or the default, global one.
         """
-        for cache_name, callback in _CACHES.items():
-            new_factor = self.cache_factors.get(cache_name, self.global_factor)
-            callback(new_factor)
+        # block other threads from modifying _CACHES while we iterate it.
+        with _CACHES_LOCK:
+            for cache_name, callback in _CACHES.items():
+                new_factor = self.cache_factors.get(cache_name, self.global_factor)
+                callback(new_factor)
diff --git a/synapse/config/homeserver.py b/synapse/config/homeserver.py
index 2c7b3a699f..264c274c52 100644
--- a/synapse/config/homeserver.py
+++ b/synapse/config/homeserver.py
@@ -36,6 +36,7 @@ from .ratelimiting import RatelimitConfig
 from .redis import RedisConfig
 from .registration import RegistrationConfig
 from .repository import ContentRepositoryConfig
+from .room import RoomConfig
 from .room_directory import RoomDirectoryConfig
 from .saml2_config import SAML2Config
 from .server import ServerConfig
@@ -79,6 +80,7 @@ class HomeServerConfig(RootConfig):
         PasswordAuthProviderConfig,
         PushConfig,
         SpamCheckerConfig,
+        RoomConfig,
         GroupsConfig,
         UserDirectoryConfig,
         ConsentConfig,
diff --git a/synapse/config/room.py b/synapse/config/room.py
new file mode 100644
index 0000000000..6aa4de0672
--- /dev/null
+++ b/synapse/config/room.py
@@ -0,0 +1,80 @@
+# -*- 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.
+
+import logging
+
+from synapse.api.constants import RoomCreationPreset
+
+from ._base import Config, ConfigError
+
+logger = logging.Logger(__name__)
+
+
+class RoomDefaultEncryptionTypes(object):
+    """Possible values for the encryption_enabled_by_default_for_room_type config option"""
+
+    ALL = "all"
+    INVITE = "invite"
+    OFF = "off"
+
+
+class RoomConfig(Config):
+    section = "room"
+
+    def read_config(self, config, **kwargs):
+        # Whether new, locally-created rooms should have encryption enabled
+        encryption_for_room_type = config.get(
+            "encryption_enabled_by_default_for_room_type",
+            RoomDefaultEncryptionTypes.OFF,
+        )
+        if encryption_for_room_type == RoomDefaultEncryptionTypes.ALL:
+            self.encryption_enabled_by_default_for_room_presets = [
+                RoomCreationPreset.PRIVATE_CHAT,
+                RoomCreationPreset.TRUSTED_PRIVATE_CHAT,
+                RoomCreationPreset.PUBLIC_CHAT,
+            ]
+        elif encryption_for_room_type == RoomDefaultEncryptionTypes.INVITE:
+            self.encryption_enabled_by_default_for_room_presets = [
+                RoomCreationPreset.PRIVATE_CHAT,
+                RoomCreationPreset.TRUSTED_PRIVATE_CHAT,
+            ]
+        elif encryption_for_room_type == RoomDefaultEncryptionTypes.OFF:
+            self.encryption_enabled_by_default_for_room_presets = []
+        else:
+            raise ConfigError(
+                "Invalid value for encryption_enabled_by_default_for_room_type"
+            )
+
+    def generate_config_section(self, **kwargs):
+        return """\
+        ## Rooms ##
+
+        # Controls whether locally-created rooms should be end-to-end encrypted by
+        # default.
+        #
+        # Possible options are "all", "invite", and "off". They are defined as:
+        #
+        # * "all": any locally-created room
+        # * "invite": any room created with the "private_chat" or "trusted_private_chat"
+        #             room creation presets
+        # * "off": this option will take no effect
+        #
+        # The default value is "off".
+        #
+        # Note that this option will only affect rooms created after it is set. It
+        # will also not affect rooms created by other servers.
+        #
+        #encryption_enabled_by_default_for_room_type: invite
+        """
diff --git a/synapse/config/saml2_config.py b/synapse/config/saml2_config.py
index d0a19751e8..293643b2de 100644
--- a/synapse/config/saml2_config.py
+++ b/synapse/config/saml2_config.py
@@ -160,7 +160,7 @@ class SAML2Config(Config):
 
         # session lifetime: in milliseconds
         self.saml2_session_lifetime = self.parse_duration(
-            saml2_config.get("saml_session_lifetime", "5m")
+            saml2_config.get("saml_session_lifetime", "15m")
         )
 
         template_dir = saml2_config.get("template_dir")
@@ -286,7 +286,7 @@ class SAML2Config(Config):
 
           # The lifetime of a SAML session. This defines how long a user has to
           # complete the authentication process, if allow_unsolicited is unset.
-          # The default is 5 minutes.
+          # The default is 15 minutes.
           #
           #saml_session_lifetime: 5m
 
diff --git a/synapse/config/server.py b/synapse/config/server.py
index f57eefc99c..73226e63d5 100644
--- a/synapse/config/server.py
+++ b/synapse/config/server.py
@@ -856,7 +856,7 @@ class ServerConfig(Config):
         # number of monthly active users.
         #
         # 'limit_usage_by_mau' disables/enables monthly active user blocking. When
-        # anabled and a limit is reached the server returns a 'ResourceLimitError'
+        # enabled and a limit is reached the server returns a 'ResourceLimitError'
         # with error type Codes.RESOURCE_LIMIT_EXCEEDED
         #
         # 'max_mau_value' is the hard limit of monthly active users above which
diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py
index 3e60774b33..b30f41dc4b 100644
--- a/synapse/handlers/federation.py
+++ b/synapse/handlers/federation.py
@@ -33,7 +33,12 @@ from unpaddedbase64 import decode_base64
 from twisted.internet import defer
 
 from synapse import event_auth
-from synapse.api.constants import EventTypes, Membership, RejectedReason
+from synapse.api.constants import (
+    EventTypes,
+    Membership,
+    RejectedReason,
+    RoomEncryptionAlgorithms,
+)
 from synapse.api.errors import (
     AuthError,
     CodeMessageException,
@@ -742,7 +747,10 @@ class FederationHandler(BaseHandler):
                 if device:
                     keys = device.get("keys", {}).get("keys", {})
 
-                    if event.content.get("algorithm") == "m.megolm.v1.aes-sha2":
+                    if (
+                        event.content.get("algorithm")
+                        == RoomEncryptionAlgorithms.MEGOLM_V1_AES_SHA2
+                    ):
                         # For this algorithm we expect a curve25519 key.
                         key_name = "curve25519:%s" % (device_id,)
                         current_keys = [keys.get(key_name)]
diff --git a/synapse/handlers/room.py b/synapse/handlers/room.py
index 61db3ccc43..46c2739143 100644
--- a/synapse/handlers/room.py
+++ b/synapse/handlers/room.py
@@ -26,7 +26,12 @@ from typing import Tuple
 
 from six import iteritems, string_types
 
-from synapse.api.constants import EventTypes, JoinRules, RoomCreationPreset
+from synapse.api.constants import (
+    EventTypes,
+    JoinRules,
+    RoomCreationPreset,
+    RoomEncryptionAlgorithms,
+)
 from synapse.api.errors import AuthError, Codes, NotFoundError, StoreError, SynapseError
 from synapse.api.room_versions import KNOWN_ROOM_VERSIONS, RoomVersion
 from synapse.events.utils import copy_power_levels_contents
@@ -56,31 +61,6 @@ FIVE_MINUTES_IN_MS = 5 * 60 * 1000
 
 
 class RoomCreationHandler(BaseHandler):
-
-    PRESETS_DICT = {
-        RoomCreationPreset.PRIVATE_CHAT: {
-            "join_rules": JoinRules.INVITE,
-            "history_visibility": "shared",
-            "original_invitees_have_ops": False,
-            "guest_can_join": True,
-            "power_level_content_override": {"invite": 0},
-        },
-        RoomCreationPreset.TRUSTED_PRIVATE_CHAT: {
-            "join_rules": JoinRules.INVITE,
-            "history_visibility": "shared",
-            "original_invitees_have_ops": True,
-            "guest_can_join": True,
-            "power_level_content_override": {"invite": 0},
-        },
-        RoomCreationPreset.PUBLIC_CHAT: {
-            "join_rules": JoinRules.PUBLIC,
-            "history_visibility": "shared",
-            "original_invitees_have_ops": False,
-            "guest_can_join": False,
-            "power_level_content_override": {},
-        },
-    }
-
     def __init__(self, hs):
         super(RoomCreationHandler, self).__init__(hs)
 
@@ -89,6 +69,39 @@ class RoomCreationHandler(BaseHandler):
         self.room_member_handler = hs.get_room_member_handler()
         self.config = hs.config
 
+        # Room state based off defined presets
+        self._presets_dict = {
+            RoomCreationPreset.PRIVATE_CHAT: {
+                "join_rules": JoinRules.INVITE,
+                "history_visibility": "shared",
+                "original_invitees_have_ops": False,
+                "guest_can_join": True,
+                "power_level_content_override": {"invite": 0},
+            },
+            RoomCreationPreset.TRUSTED_PRIVATE_CHAT: {
+                "join_rules": JoinRules.INVITE,
+                "history_visibility": "shared",
+                "original_invitees_have_ops": True,
+                "guest_can_join": True,
+                "power_level_content_override": {"invite": 0},
+            },
+            RoomCreationPreset.PUBLIC_CHAT: {
+                "join_rules": JoinRules.PUBLIC,
+                "history_visibility": "shared",
+                "original_invitees_have_ops": False,
+                "guest_can_join": False,
+                "power_level_content_override": {},
+            },
+        }
+
+        # Modify presets to selectively enable encryption by default per homeserver config
+        for preset_name, preset_config in self._presets_dict.items():
+            encrypted = (
+                preset_name
+                in self.config.encryption_enabled_by_default_for_room_presets
+            )
+            preset_config["encrypted"] = encrypted
+
         self._replication = hs.get_replication_data_handler()
 
         # linearizer to stop two upgrades happening at once
@@ -798,7 +811,7 @@ class RoomCreationHandler(BaseHandler):
             )
             return last_stream_id
 
-        config = RoomCreationHandler.PRESETS_DICT[preset_config]
+        config = self._presets_dict[preset_config]
 
         creator_id = creator.user.to_string()
 
@@ -888,6 +901,13 @@ class RoomCreationHandler(BaseHandler):
                 etype=etype, state_key=state_key, content=content
             )
 
+        if config["encrypted"]:
+            last_sent_stream_id = await send(
+                etype=EventTypes.RoomEncryption,
+                state_key="",
+                content={"algorithm": RoomEncryptionAlgorithms.DEFAULT},
+            )
+
         return last_sent_stream_id
 
     async def _generate_room_id(
diff --git a/synapse/rest/client/v1/presence.py b/synapse/rest/client/v1/presence.py
index eec16f8ad8..7cf007d35e 100644
--- a/synapse/rest/client/v1/presence.py
+++ b/synapse/rest/client/v1/presence.py
@@ -51,7 +51,9 @@ class PresenceStatusRestServlet(RestServlet):
                 raise AuthError(403, "You are not allowed to see their presence.")
 
         state = await self.presence_handler.get_state(target_user=user)
-        state = format_user_presence_state(state, self.clock.time_msec())
+        state = format_user_presence_state(
+            state, self.clock.time_msec(), include_user_id=False
+        )
 
         return 200, state
 
diff --git a/synapse/static/client/login/index.html b/synapse/static/client/login/index.html
index 6fefdaaff7..9e6daf38ac 100644
--- a/synapse/static/client/login/index.html
+++ b/synapse/static/client/login/index.html
@@ -1,24 +1,24 @@
 <!doctype html>
 <html>
 <head>
-<title> Login </title>
-<meta name='viewport' content='width=device-width, initial-scale=1, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0'>
-<link rel="stylesheet" href="style.css">
-<script src="js/jquery-3.4.1.min.js"></script>
-<script src="js/login.js"></script>
+    <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
+    <title> Login </title>
+    <meta name='viewport' content='width=device-width, initial-scale=1, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0'>
+    <link rel="stylesheet" href="style.css">
+    <script src="js/jquery-3.4.1.min.js"></script>
+    <script src="js/login.js"></script>
 </head>
 <body onload="matrixLogin.onLoad()">
-    <center>
-        <br/>
+    <div id="container">
         <h1 id="title"></h1>
 
-        <span id="feedback" style="color: #f00"></span>
+        <span id="feedback"></span>
 
         <div id="loading">
             <img src="spinner.gif" />
         </div>
 
-        <div id="sso_flow" class="login_flow" style="display:none">
+        <div id="sso_flow" class="login_flow" style="display: none;">
             Single-sign on:
             <form id="sso_form" action="/_matrix/client/r0/login/sso/redirect" method="get">
                 <input id="sso_redirect_url" type="hidden" name="redirectUrl" value=""/>
@@ -26,9 +26,9 @@
             </form>
         </div>
 
-        <div id="password_flow" class="login_flow" style="display:none">
+        <div id="password_flow" class="login_flow" style="display: none;">
             Password Authentication:
-            <form onsubmit="matrixLogin.password_login(); return false;">
+            <form onsubmit="matrixLogin.passwordLogin(); return false;">
                 <input id="user_id" size="32" type="text" placeholder="Matrix ID (e.g. bob)" autocapitalize="off" autocorrect="off" />
                 <br/>
                 <input id="password" size="32" type="password" placeholder="Password"/>
@@ -38,9 +38,9 @@
             </form>
         </div>
 
-        <div id="no_login_types" type="button" class="login_flow" style="display:none">
+        <div id="no_login_types" type="button" class="login_flow" style="display: none;">
             Log in currently unavailable.
         </div>
-    </center>
+    </div>
 </body>
 </html>
diff --git a/synapse/static/client/login/js/login.js b/synapse/static/client/login/js/login.js
index ba8048b23f..3678670ec7 100644
--- a/synapse/static/client/login/js/login.js
+++ b/synapse/static/client/login/js/login.js
@@ -5,11 +5,11 @@ window.matrixLogin = {
 };
 
 // Titles get updated through the process to give users feedback.
-var TITLE_PRE_AUTH = "Log in with one of the following methods";
-var TITLE_POST_AUTH = "Logging in...";
+const TITLE_PRE_AUTH = "Log in with one of the following methods";
+const TITLE_POST_AUTH = "Logging in...";
 
 // The cookie used to store the original query parameters when using SSO.
-var COOKIE_KEY = "synapse_login_fallback_qs";
+const COOKIE_KEY = "synapse_login_fallback_qs";
 
 /*
  * Submit a login request.
@@ -20,9 +20,9 @@ var COOKIE_KEY = "synapse_login_fallback_qs";
  *     login request, e.g. device_id.
  * callback: (Optional) Function to call on successful login.
  */
-var submitLogin = function(type, data, extra, callback) {
+function submitLogin(type, data, extra, callback) {
     console.log("Logging in with " + type);
-    set_title(TITLE_POST_AUTH);
+    setTitle(TITLE_POST_AUTH);
 
     // Add the login type.
     data.type = type;
@@ -41,12 +41,15 @@ var submitLogin = function(type, data, extra, callback) {
         }
         matrixLogin.onLogin(response);
     }).fail(errorFunc);
-};
+}
 
-var errorFunc = function(err) {
+/*
+ * Display an error to the user and show the login form again.
+ */
+function errorFunc(err) {
     // We want to show the error to the user rather than redirecting immediately to the
     // SSO portal (if SSO is the only login option), so we inhibit the redirect.
-    show_login(true);
+    showLogin(true);
 
     if (err.responseJSON && err.responseJSON.error) {
         setFeedbackString(err.responseJSON.error + " (" + err.responseJSON.errcode + ")");
@@ -54,27 +57,42 @@ var errorFunc = function(err) {
     else {
         setFeedbackString("Request failed: " + err.status);
     }
-};
+}
 
-var setFeedbackString = function(text) {
+/*
+ * Display an error to the user.
+ */
+function setFeedbackString(text) {
     $("#feedback").text(text);
-};
+}
 
-var show_login = function(inhibit_redirect) {
-    // Set the redirect to come back to this page, a login token will get added
-    // and handled after the redirect.
-    var this_page = window.location.origin + window.location.pathname;
-    $("#sso_redirect_url").val(this_page);
+/*
+ * (Maybe) Show the login forms.
+ *
+ * This actually does a few unrelated functions:
+ *
+ * * Configures the SSO redirect URL to come back to this page.
+ * * Configures and shows the SSO form, if the server supports SSO.
+ * * Otherwise, shows the password form.
+ */
+function showLogin(inhibitRedirect) {
+    setTitle(TITLE_PRE_AUTH);
 
-    // If inhibit_redirect is false, and SSO is the only supported login method,
+    // If inhibitRedirect is false, and SSO is the only supported login method,
     // we can redirect straight to the SSO page.
     if (matrixLogin.serverAcceptsSso) {
+        // Set the redirect to come back to this page, a login token will get
+        // added as a query parameter and handled after the redirect.
+        $("#sso_redirect_url").val(window.location.origin + window.location.pathname);
+
         // Before submitting SSO, set the current query parameters into a cookie
         // for retrieval later.
         var qs = parseQsFromUrl();
         setCookie(COOKIE_KEY, JSON.stringify(qs));
 
-        if (!inhibit_redirect && !matrixLogin.serverAcceptsPassword) {
+        // If password is not supported and redirects are allowed, then submit
+        // the form (redirecting to the SSO provider).
+        if (!inhibitRedirect && !matrixLogin.serverAcceptsPassword) {
             $("#sso_form").submit();
             return;
         }
@@ -87,30 +105,39 @@ var show_login = function(inhibit_redirect) {
         $("#password_flow").show();
     }
 
+    // If neither password or SSO are supported, show an error to the user.
     if (!matrixLogin.serverAcceptsPassword && !matrixLogin.serverAcceptsSso) {
         $("#no_login_types").show();
     }
 
-    set_title(TITLE_PRE_AUTH);
-
     $("#loading").hide();
-};
+}
 
-var show_spinner = function() {
+/*
+ * Hides the forms and shows a loading throbber.
+ */
+function showSpinner() {
     $("#password_flow").hide();
     $("#sso_flow").hide();
     $("#no_login_types").hide();
     $("#loading").show();
-};
+}
 
-var set_title = function(title) {
+/*
+ * Helper to show the page's main title.
+ */
+function setTitle(title) {
     $("#title").text(title);
-};
+}
 
-var fetch_info = function(cb) {
+/*
+ * Query the login endpoint for the homeserver's supported flows.
+ *
+ * This populates matrixLogin.serverAccepts* variables.
+ */
+function fetchLoginFlows(cb) {
     $.get(matrixLogin.endpoint, function(response) {
-        var serverAcceptsPassword = false;
-        for (var i=0; i<response.flows.length; i++) {
+        for (var i = 0; i < response.flows.length; i++) {
             var flow = response.flows[i];
             if ("m.login.sso" === flow.type) {
                 matrixLogin.serverAcceptsSso = true;
@@ -126,27 +153,41 @@ var fetch_info = function(cb) {
     }).fail(errorFunc);
 }
 
+/*
+ * Called on load to fetch login flows and attempt SSO login (if a token is available).
+ */
 matrixLogin.onLoad = function() {
-    fetch_info(function() {
-        if (!try_token()) {
-            show_login(false);
+    fetchLoginFlows(function() {
+        // (Maybe) attempt logging in via SSO if a token is available.
+        if (!tryTokenLogin()) {
+            showLogin(false);
         }
     });
 };
 
-matrixLogin.password_login = function() {
+/*
+ * Submit simple user & password login.
+ */
+matrixLogin.passwordLogin = function() {
     var user = $("#user_id").val();
     var pwd = $("#password").val();
 
     setFeedbackString("");
 
-    show_spinner();
+    showSpinner();
     submitLogin(
         "m.login.password",
         {user: user, password: pwd},
         parseQsFromUrl());
 };
 
+/*
+ * The onLogin function gets called after a succesful login.
+ *
+ * It is expected that implementations override this to be notified when the
+ * login is complete. The response to the login call is provided as the single
+ * parameter.
+ */
 matrixLogin.onLogin = function(response) {
     // clobber this function
     console.warn("onLogin - This function should be replaced to proceed.");
@@ -155,7 +196,7 @@ matrixLogin.onLogin = function(response) {
 /*
  * Process the query parameters from the current URL into an object.
  */
-var parseQsFromUrl = function() {
+function parseQsFromUrl() {
     var pos = window.location.href.indexOf("?");
     if (pos == -1) {
         return {};
@@ -174,12 +215,12 @@ var parseQsFromUrl = function() {
         result[key] = val;
     });
     return result;
-};
+}
 
 /*
  * Process the cookies and return an object.
  */
-var parseCookies = function() {
+function parseCookies() {
     var allCookies = document.cookie;
     var result = {};
     allCookies.split(";").forEach(function(part) {
@@ -196,32 +237,32 @@ var parseCookies = function() {
         result[key] = val;
     });
     return result;
-};
+}
 
 /*
  * Set a cookie that is valid for 1 hour.
  */
-var setCookie = function(key, value) {
+function setCookie(key, value) {
     // The maximum age is set in seconds.
     var maxAge = 60 * 60;
     // Set the cookie, this defaults to the current domain and path.
     document.cookie = key + "=" + encodeURIComponent(value) + ";max-age=" + maxAge + ";sameSite=lax";
-};
+}
 
 /*
  * Removes a cookie by key.
  */
-var deleteCookie = function(key) {
+function deleteCookie(key) {
     // Delete a cookie by setting the expiration to 0. (Note that the value
     // doesn't matter.)
     document.cookie = key + "=deleted;expires=0";
-};
+}
 
 /*
  * Submits the login token if one is found in the query parameters. Returns a
  * boolean of whether the login token was found or not.
  */
-var try_token = function() {
+function tryTokenLogin() {
     // Check if the login token is in the query parameters.
     var qs = parseQsFromUrl();
 
@@ -233,18 +274,18 @@ var try_token = function() {
     // Retrieve the original query parameters (from before the SSO redirect).
     // They are stored as JSON in a cookie.
     var cookies = parseCookies();
-    var original_query_params = JSON.parse(cookies[COOKIE_KEY] || "{}")
+    var originalQueryParams = JSON.parse(cookies[COOKIE_KEY] || "{}")
 
     // If the login is successful, delete the cookie.
-    var callback = function() {
+    function callback() {
         deleteCookie(COOKIE_KEY);
     }
 
     submitLogin(
         "m.login.token",
         {token: loginToken},
-        original_query_params,
+        originalQueryParams,
         callback);
 
     return true;
-};
+}
diff --git a/synapse/static/client/login/style.css b/synapse/static/client/login/style.css
index 1cce5ed950..83e4f6abc8 100644
--- a/synapse/static/client/login/style.css
+++ b/synapse/static/client/login/style.css
@@ -31,20 +31,44 @@ form {
     margin: 10px 0 0 0;
 }
 
+/*
+ * Add some padding to the viewport.
+ */
+#container {
+    padding: 10px;
+}
+/*
+ * Center all direct children of the main form.
+ */
+#container > * {
+    display: block;
+    margin-left: auto;
+    margin-right: auto;
+    text-align: center;
+}
+
+/*
+ * A wrapper around each login flow.
+ */
 .login_flow {
     width: 300px;
     text-align: left;
     padding: 10px;
     margin-bottom: 40px;
 
-    -webkit-border-radius: 10px;
-    -moz-border-radius: 10px;
     border-radius: 10px;
-
-    -webkit-box-shadow: 0px 0px 20px 0px rgba(0,0,0,0.15);
-    -moz-box-shadow: 0px 0px 20px 0px rgba(0,0,0,0.15);
     box-shadow: 0px 0px 20px 0px rgba(0,0,0,0.15);
 
     background-color: #f8f8f8;
     border: 1px #ccc solid;
 }
+
+/*
+ * Used to show error content.
+ */
+#feedback {
+    /* Red text. */
+    color: #ff0000;
+    /* A little space to not overlap the box-shadow. */
+    margin-bottom: 20px;
+}