From b2bd54a2e31d9a248f73fadb184ae9b4cbdb49f9 Mon Sep 17 00:00:00 2001
From: Brendan Abolivier <babolivier@matrix.org>
Date: Mon, 2 Mar 2020 16:36:32 +0000
Subject: Add a confirmation step to the SSO login flow

---
 synapse/rest/client/v1/login.py | 40 ++++++++++++++++++++++++++++++++++------
 1 file changed, 34 insertions(+), 6 deletions(-)

(limited to 'synapse/rest/client/v1')

diff --git a/synapse/rest/client/v1/login.py b/synapse/rest/client/v1/login.py
index 1294e080dc..1acfd01d8e 100644
--- a/synapse/rest/client/v1/login.py
+++ b/synapse/rest/client/v1/login.py
@@ -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
+        )
+
+        # 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.redirect(redirect_url)
+
+        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)
 
-- 
cgit 1.5.1


From b68041df3dcbcf3ca04c500d1712aa22a3c2580c Mon Sep 17 00:00:00 2001
From: Richard van der Hoff <richard@matrix.org>
Date: Mon, 2 Mar 2020 17:05:09 +0000
Subject: Add a whitelist for the SSO confirmation step.

---
 docs/sample_config.yaml            | 22 +++++++++++++++++++---
 synapse/config/sso.py              | 18 ++++++++++++++++++
 synapse/rest/client/v1/login.py    | 26 ++++++++++++++++++--------
 tests/rest/client/v1/test_login.py | 32 +++++++++++++++++++++++++++++---
 4 files changed, 84 insertions(+), 14 deletions(-)

(limited to 'synapse/rest/client/v1')

diff --git a/docs/sample_config.yaml b/docs/sample_config.yaml
index bbb8a4d934..f719ec696f 100644
--- a/docs/sample_config.yaml
+++ b/docs/sample_config.yaml
@@ -1363,6 +1363,22 @@ saml2_config:
 # Additional settings to use with single-sign on systems such as SAML2 and CAS.
 #
 sso:
+    # A list of client URLs which are whitelisted so that the user does not
+    # have to confirm giving access to their account to the URL. Any client
+    # whose URL starts with an entry in the following list will not be subject
+    # to an additional confirmation step after the SSO login is completed.
+    #
+    # WARNING: An entry such as "https://my.client" is insecure, because it
+    # will also match "https://my.client.evil.site", exposing your users to
+    # phishing attacks from evil.site. To avoid this, include a slash after the
+    # hostname: "https://my.client/".
+    #
+    # By default, this list is empty.
+    #
+    #client_whitelist:
+    #  - https://riot.im/develop
+    #  - https://my.custom.client/
+
     # 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.
     #
@@ -1372,8 +1388,8 @@ sso:
     #
     # Synapse will look for the following templates in this directory:
     #
-    # * HTML page for confirmation of redirect during authentication:
-    #   'sso_redirect_confirm.html'.
+    # * 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
@@ -1381,7 +1397,7 @@ sso:
     #                     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 
+    #                    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).
diff --git a/synapse/config/sso.py b/synapse/config/sso.py
index f426b65b4f..56299bd4e4 100644
--- a/synapse/config/sso.py
+++ b/synapse/config/sso.py
@@ -37,11 +37,29 @@ class SSOConfig(Config):
 
         self.sso_redirect_confirm_template_dir = template_dir
 
+        self.sso_client_whitelist = sso_config.get("client_whitelist") or []
+
     def generate_config_section(self, **kwargs):
         return """\
         # Additional settings to use with single-sign on systems such as SAML2 and CAS.
         #
         sso:
+            # A list of client URLs which are whitelisted so that the user does not
+            # have to confirm giving access to their account to the URL. Any client
+            # whose URL starts with an entry in the following list will not be subject
+            # to an additional confirmation step after the SSO login is completed.
+            #
+            # WARNING: An entry such as "https://my.client" is insecure, because it
+            # will also match "https://my.client.evil.site", exposing your users to
+            # phishing attacks from evil.site. To avoid this, include a slash after the
+            # hostname: "https://my.client/".
+            #
+            # By default, this list is empty.
+            #
+            #client_whitelist:
+            #  - https://riot.im/develop
+            #  - https://my.custom.client/
+
             # 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.
             #
diff --git a/synapse/rest/client/v1/login.py b/synapse/rest/client/v1/login.py
index 1acfd01d8e..b2bc7537db 100644
--- a/synapse/rest/client/v1/login.py
+++ b/synapse/rest/client/v1/login.py
@@ -556,6 +556,9 @@ class SSOAuthHandler(object):
 
         self._server_name = hs.config.server_name
 
+        # cast to tuple for use with str.startswith
+        self._whitelisted_sso_clients = tuple(hs.config.sso_client_whitelist)
+
     async def on_successful_auth(
         self, username, request, client_redirect_url, user_display_name=None
     ):
@@ -605,11 +608,6 @@ class SSOAuthHandler(object):
             registered_user_id
         )
 
-        # 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.
@@ -617,17 +615,29 @@ class SSOAuthHandler(object):
             client_redirect_url, "loginToken", login_token
         )
 
-        # Serve the redirect confirmation page
+        # if the client is whitelisted, we can redirect straight to it
+        if client_redirect_url.startswith(self._whitelisted_sso_clients):
+            request.redirect(redirect_url)
+            finish_request(request)
+            return
+
+        # Otherwise, serve the redirect confirmation page.
+
+        # 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]
+
         html = self._template.render(
             display_url=redirect_url_no_params,
             redirect_url=redirect_url,
             server_name=self._server_name,
-        )
+        ).encode("utf-8")
 
         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"))
+        request.write(html)
         finish_request(request)
 
     @staticmethod
diff --git a/tests/rest/client/v1/test_login.py b/tests/rest/client/v1/test_login.py
index 2b8ad5c753..da2c9bfa1e 100644
--- a/tests/rest/client/v1/test_login.py
+++ b/tests/rest/client/v1/test_login.py
@@ -268,13 +268,11 @@ class CASRedirectConfirmTestCase(unittest.HomeserverTestCase):
         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`
@@ -310,7 +308,7 @@ class CASRedirectConfirmTestCase(unittest.HomeserverTestCase):
         """Tests that the SSO login flow serves a confirmation page before redirecting a
         user to the redirect URL.
         """
-        base_url = "/login/cas/ticket?redirectUrl"
+        base_url = "/_matrix/client/r0/login/cas/ticket?redirectUrl"
         redirect_url = "https://dodgy-site.com/"
 
         url_parts = list(urllib.parse.urlparse(base_url))
@@ -325,6 +323,7 @@ class CASRedirectConfirmTestCase(unittest.HomeserverTestCase):
         self.render(request)
 
         # Test that the response is HTML.
+        self.assertEqual(channel.code, 200)
         content_type_header_value = ""
         for header in channel.result.get("headers", []):
             if header[0] == b"Content-Type":
@@ -337,3 +336,30 @@ class CASRedirectConfirmTestCase(unittest.HomeserverTestCase):
 
         # And that it contains our redirect link
         self.assertIn(redirect_url, channel.result["body"].decode("UTF-8"))
+
+    @override_config(
+        {
+            "sso": {
+                "client_whitelist": [
+                    "https://legit-site.com/",
+                    "https://other-site.com/",
+                ]
+            }
+        }
+    )
+    def test_cas_redirect_whitelisted(self):
+        """Tests that the SSO login flow serves a redirect to a whitelisted url
+        """
+        redirect_url = "https://legit-site.com/"
+        cas_ticket_url = (
+            "/_matrix/client/r0/login/cas/ticket?redirectUrl=%s&ticket=ticket"
+            % (urllib.parse.quote(redirect_url))
+        )
+
+        # Get Synapse to call the fake CAS and serve the template.
+        request, channel = self.make_request("GET", cas_ticket_url)
+        self.render(request)
+
+        self.assertEqual(channel.code, 302)
+        location_headers = channel.headers.getRawHeaders("Location")
+        self.assertEqual(location_headers[0][: len(redirect_url)], redirect_url)
-- 
cgit 1.5.1


From 65c73cdfec1876a9fec2fd2c3a74923cd146fe0b Mon Sep 17 00:00:00 2001
From: Brendan Abolivier <babolivier@matrix.org>
Date: Tue, 3 Mar 2020 10:54:44 +0000
Subject: Factor out complete_sso_login and expose it to the Module API

---
 synapse/config/sso.py           |  2 +-
 synapse/handlers/auth.py        | 74 +++++++++++++++++++++++++++++++++++++++++
 synapse/module_api/__init__.py  | 19 +++++++++++
 synapse/rest/client/v1/login.py | 58 ++------------------------------
 4 files changed, 96 insertions(+), 57 deletions(-)

(limited to 'synapse/rest/client/v1')

diff --git a/synapse/config/sso.py b/synapse/config/sso.py
index 56299bd4e4..95762689bc 100644
--- a/synapse/config/sso.py
+++ b/synapse/config/sso.py
@@ -16,7 +16,7 @@ from typing import Any, Dict
 
 import pkg_resources
 
-from ._base import Config, ConfigError
+from ._base import Config
 
 
 class SSOConfig(Config):
diff --git a/synapse/handlers/auth.py b/synapse/handlers/auth.py
index 48a88d3c2a..7ca90f91c4 100644
--- a/synapse/handlers/auth.py
+++ b/synapse/handlers/auth.py
@@ -17,6 +17,8 @@
 import logging
 import time
 import unicodedata
+import urllib.parse
+from typing import Any
 
 import attr
 import bcrypt
@@ -38,8 +40,11 @@ from synapse.api.errors import (
 from synapse.api.ratelimiting import Ratelimiter
 from synapse.handlers.ui_auth import INTERACTIVE_AUTH_CHECKERS
 from synapse.handlers.ui_auth.checkers import UserInteractiveAuthChecker
+from synapse.http.server import finish_request
+from synapse.http.site import SynapseRequest
 from synapse.logging.context import defer_to_thread
 from synapse.module_api import ModuleApi
+from synapse.push.mailer import load_jinja2_templates
 from synapse.types import UserID
 from synapse.util.caches.expiringcache import ExpiringCache
 
@@ -108,6 +113,16 @@ class AuthHandler(BaseHandler):
 
         self._clock = self.hs.get_clock()
 
+        # Load the SSO redirect confirmation page HTML template
+        self._sso_redirect_confirm_template = load_jinja2_templates(
+            hs.config.sso_redirect_confirm_template_dir, ["sso_redirect_confirm.html"],
+        )[0]
+
+        self._server_name = hs.config.server_name
+
+        # cast to tuple for use with str.startswith
+        self._whitelisted_sso_clients = tuple(hs.config.sso_client_whitelist)
+
     @defer.inlineCallbacks
     def validate_user_via_ui_auth(self, requester, request_body, clientip):
         """
@@ -927,6 +942,65 @@ class AuthHandler(BaseHandler):
         else:
             return defer.succeed(False)
 
+    def complete_sso_login(
+        self,
+        registered_user_id: str,
+        request: SynapseRequest,
+        client_redirect_url: str,
+    ):
+        """Having figured out a mxid for this user, complete the HTTP request
+
+        Args:
+            registered_user_id: The registered user ID to complete SSO login for.
+            request: The request to complete.
+            client_redirect_url: The URL to which to redirect the user at the end of the
+                process.
+        """
+        # Create a login token
+        login_token = self.macaroon_gen.generate_short_term_login_token(
+            registered_user_id
+        )
+
+        # 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
+        )
+
+        # if the client is whitelisted, we can redirect straight to it
+        if client_redirect_url.startswith(self._whitelisted_sso_clients):
+            request.redirect(redirect_url)
+            finish_request(request)
+            return
+
+        # Otherwise, serve the redirect confirmation page.
+
+        # 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]
+
+        html = self._sso_redirect_confirm_template.render(
+            display_url=redirect_url_no_params,
+            redirect_url=redirect_url,
+            server_name=self._server_name,
+        ).encode("utf-8")
+
+        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)
+        finish_request(request)
+
+    @staticmethod
+    def add_query_param_to_url(url: str, param_name: str, param: Any):
+        url_parts = list(urllib.parse.urlparse(url))
+        query = dict(urllib.parse.parse_qsl(url_parts[4]))
+        query.update({param_name: param})
+        url_parts[4] = urllib.parse.urlencode(query)
+        return urllib.parse.urlunparse(url_parts)
+
 
 @attr.s
 class MacaroonGenerator(object):
diff --git a/synapse/module_api/__init__.py b/synapse/module_api/__init__.py
index d680ee95e1..c7fffd72f2 100644
--- a/synapse/module_api/__init__.py
+++ b/synapse/module_api/__init__.py
@@ -17,6 +17,7 @@ import logging
 
 from twisted.internet import defer
 
+from synapse.http.site import SynapseRequest
 from synapse.logging.context import make_deferred_yieldable, run_in_background
 from synapse.types import UserID
 
@@ -211,3 +212,21 @@ class ModuleApi(object):
             Deferred[object]: result of func
         """
         return self._store.db.runInteraction(desc, func, *args, **kwargs)
+
+    def complete_sso_login(
+        self, registered_user_id: str, request: SynapseRequest, client_redirect_url: str
+    ):
+        """Complete a SSO login by redirecting the user to a page to confirm whether they
+        want their access token sent to `client_redirect_url`, or redirect them to that
+        URL with a token directly if the URL matches with one of the whitelisted clients.
+
+        Args:
+            registered_user_id: The MXID that has been registered as a previous step of
+                of this SSO login.
+            request: The request to respond to.
+            client_redirect_url: The URL to which to offer to redirect the user (or to
+                redirect them directly if whitelisted).
+        """
+        self._auth_handler.complete_sso_login(
+            registered_user_id, request, client_redirect_url,
+        )
diff --git a/synapse/rest/client/v1/login.py b/synapse/rest/client/v1/login.py
index b2bc7537db..d0d4999795 100644
--- a/synapse/rest/client/v1/login.py
+++ b/synapse/rest/client/v1/login.py
@@ -28,7 +28,6 @@ from synapse.http.servlet import (
     parse_json_object_from_request,
     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
@@ -591,63 +590,10 @@ class SSOAuthHandler(object):
                 localpart=localpart, default_display_name=user_display_name
             )
 
-        self.complete_sso_login(registered_user_id, request, client_redirect_url)
-
-    def complete_sso_login(
-        self, registered_user_id: str, request: SynapseRequest, client_redirect_url: str
-    ):
-        """Having figured out a mxid for this user, complete the HTTP request
-
-        Args:
-            registered_user_id:
-            request:
-            client_redirect_url:
-        """
-        # Create a login token
-        login_token = self._macaroon_gen.generate_short_term_login_token(
-            registered_user_id
+        self._auth_handler.complete_sso_login(
+            registered_user_id, request, client_redirect_url
         )
 
-        # 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
-        )
-
-        # if the client is whitelisted, we can redirect straight to it
-        if client_redirect_url.startswith(self._whitelisted_sso_clients):
-            request.redirect(redirect_url)
-            finish_request(request)
-            return
-
-        # Otherwise, serve the redirect confirmation page.
-
-        # 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]
-
-        html = self._template.render(
-            display_url=redirect_url_no_params,
-            redirect_url=redirect_url,
-            server_name=self._server_name,
-        ).encode("utf-8")
-
-        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)
-        finish_request(request)
-
-    @staticmethod
-    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({param_name: param})
-        url_parts[4] = urllib.parse.urlencode(query)
-        return urllib.parse.urlunparse(url_parts)
-
 
 def register_servlets(hs, http_server):
     LoginRestServlet(hs).register(http_server)
-- 
cgit 1.5.1


From 60724c46b7dc5300243fd97d5a485564b3e00afe Mon Sep 17 00:00:00 2001
From: Patrick Cloke <clokep@users.noreply.github.com>
Date: Tue, 17 Mar 2020 07:37:04 -0400
Subject: Remove special casing of `m.room.aliases` events (#7034)

---
 changelog.d/7034.removal               |  1 +
 synapse/handlers/room.py               | 16 +------------
 synapse/rest/client/v1/room.py         | 12 ----------
 tests/rest/admin/test_admin.py         |  7 ++++++
 tests/rest/client/v1/test_directory.py | 41 +++++++++++++++++++++-------------
 5 files changed, 35 insertions(+), 42 deletions(-)
 create mode 100644 changelog.d/7034.removal

(limited to 'synapse/rest/client/v1')

diff --git a/changelog.d/7034.removal b/changelog.d/7034.removal
new file mode 100644
index 0000000000..be8d20e14f
--- /dev/null
+++ b/changelog.d/7034.removal
@@ -0,0 +1 @@
+Remove special handling of aliases events from [MSC2260](https://github.com/matrix-org/matrix-doc/pull/2260) added in v1.10.0rc1.
diff --git a/synapse/handlers/room.py b/synapse/handlers/room.py
index 8ee870f0bb..f580ab2e9f 100644
--- a/synapse/handlers/room.py
+++ b/synapse/handlers/room.py
@@ -292,16 +292,6 @@ class RoomCreationHandler(BaseHandler):
             except AuthError as e:
                 logger.warning("Unable to update PLs in old room: %s", e)
 
-        new_pl_content = copy_power_levels_contents(old_room_pl_state.content)
-
-        # pre-msc2260 rooms may not have the right setting for aliases. If no other
-        # value is set, set it now.
-        events_default = new_pl_content.get("events_default", 0)
-        new_pl_content.setdefault("events", {}).setdefault(
-            EventTypes.Aliases, events_default
-        )
-
-        logger.debug("Setting correct PLs in new room to %s", new_pl_content)
         yield self.event_creation_handler.create_and_send_nonmember_event(
             requester,
             {
@@ -309,7 +299,7 @@ class RoomCreationHandler(BaseHandler):
                 "state_key": "",
                 "room_id": new_room_id,
                 "sender": requester.user.to_string(),
-                "content": new_pl_content,
+                "content": old_room_pl_state.content,
             },
             ratelimit=False,
         )
@@ -814,10 +804,6 @@ class RoomCreationHandler(BaseHandler):
                     EventTypes.RoomHistoryVisibility: 100,
                     EventTypes.CanonicalAlias: 50,
                     EventTypes.RoomAvatar: 50,
-                    # MSC2260: Allow everybody to send alias events by default
-                    # This will be reudundant on pre-MSC2260 rooms, since the
-                    # aliases event is special-cased.
-                    EventTypes.Aliases: 0,
                     EventTypes.Tombstone: 100,
                     EventTypes.ServerACL: 100,
                 },
diff --git a/synapse/rest/client/v1/room.py b/synapse/rest/client/v1/room.py
index 64f51406fb..bffd43de5f 100644
--- a/synapse/rest/client/v1/room.py
+++ b/synapse/rest/client/v1/room.py
@@ -189,12 +189,6 @@ class RoomStateEventRestServlet(TransactionRestServlet):
 
         content = parse_json_object_from_request(request)
 
-        if event_type == EventTypes.Aliases:
-            # MSC2260
-            raise SynapseError(
-                400, "Cannot send m.room.aliases events via /rooms/{room_id}/state"
-            )
-
         event_dict = {
             "type": event_type,
             "content": content,
@@ -242,12 +236,6 @@ class RoomSendEventRestServlet(TransactionRestServlet):
         requester = await self.auth.get_user_by_req(request, allow_guest=True)
         content = parse_json_object_from_request(request)
 
-        if event_type == EventTypes.Aliases:
-            # MSC2260
-            raise SynapseError(
-                400, "Cannot send m.room.aliases events via /rooms/{room_id}/send"
-            )
-
         event_dict = {
             "type": event_type,
             "content": content,
diff --git a/tests/rest/admin/test_admin.py b/tests/rest/admin/test_admin.py
index e5984aaad8..0342aed416 100644
--- a/tests/rest/admin/test_admin.py
+++ b/tests/rest/admin/test_admin.py
@@ -868,6 +868,13 @@ class RoomTestCase(unittest.HomeserverTestCase):
         self.assertEqual(200, int(channel.result["code"]), msg=channel.result["body"])
 
         # Set this new alias as the canonical alias for this room
+        self.helper.send_state(
+            room_id,
+            "m.room.aliases",
+            {"aliases": [test_alias]},
+            tok=self.admin_user_tok,
+            state_key="test",
+        )
         self.helper.send_state(
             room_id,
             "m.room.canonical_alias",
diff --git a/tests/rest/client/v1/test_directory.py b/tests/rest/client/v1/test_directory.py
index 914cf54927..633b7dbda0 100644
--- a/tests/rest/client/v1/test_directory.py
+++ b/tests/rest/client/v1/test_directory.py
@@ -51,30 +51,26 @@ class DirectoryTestCase(unittest.HomeserverTestCase):
         self.user = self.register_user("user", "test")
         self.user_tok = self.login("user", "test")
 
-    def test_cannot_set_alias_via_state_event(self):
-        self.ensure_user_joined_room()
-        url = "/_matrix/client/r0/rooms/%s/state/m.room.aliases/%s" % (
-            self.room_id,
-            self.hs.hostname,
-        )
-
-        data = {"aliases": [self.random_alias(5)]}
-        request_data = json.dumps(data)
-
-        request, channel = self.make_request(
-            "PUT", url, request_data, access_token=self.user_tok
-        )
-        self.render(request)
-        self.assertEqual(channel.code, 400, channel.result)
+    def test_state_event_not_in_room(self):
+        self.ensure_user_left_room()
+        self.set_alias_via_state_event(403)
 
     def test_directory_endpoint_not_in_room(self):
         self.ensure_user_left_room()
         self.set_alias_via_directory(403)
 
+    def test_state_event_in_room_too_long(self):
+        self.ensure_user_joined_room()
+        self.set_alias_via_state_event(400, alias_length=256)
+
     def test_directory_in_room_too_long(self):
         self.ensure_user_joined_room()
         self.set_alias_via_directory(400, alias_length=256)
 
+    def test_state_event_in_room(self):
+        self.ensure_user_joined_room()
+        self.set_alias_via_state_event(200)
+
     def test_directory_in_room(self):
         self.ensure_user_joined_room()
         self.set_alias_via_directory(200)
@@ -106,6 +102,21 @@ class DirectoryTestCase(unittest.HomeserverTestCase):
         self.render(request)
         self.assertEqual(channel.code, 200, channel.result)
 
+    def set_alias_via_state_event(self, expected_code, alias_length=5):
+        url = "/_matrix/client/r0/rooms/%s/state/m.room.aliases/%s" % (
+            self.room_id,
+            self.hs.hostname,
+        )
+
+        data = {"aliases": [self.random_alias(alias_length)]}
+        request_data = json.dumps(data)
+
+        request, channel = self.make_request(
+            "PUT", url, request_data, access_token=self.user_tok
+        )
+        self.render(request)
+        self.assertEqual(channel.code, expected_code, channel.result)
+
     def set_alias_via_directory(self, expected_code, alias_length=5):
         url = "/_matrix/client/r0/directory/room/%s" % self.random_alias(alias_length)
         data = {"room_id": self.room_id}
-- 
cgit 1.5.1