1 files changed, 56 insertions, 0 deletions
diff --git a/tests/rest/admin/test_user.py b/tests/rest/admin/test_user.py
index 492adb6160..cf71bbb461 100644
--- a/tests/rest/admin/test_user.py
+++ b/tests/rest/admin/test_user.py
@@ -4854,3 +4854,59 @@ class UsersByThreePidTestCase(unittest.HomeserverTestCase):
             {"user_id": self.other_user},
             channel.json_body,
         )
+
+
+class AllowCrossSigningReplacementTestCase(unittest.HomeserverTestCase):
+    servlets = [
+        synapse.rest.admin.register_servlets,
+        login.register_servlets,
+    ]
+
+    @staticmethod
+    def url(user: str) -> str:
+        template = (
+            "/_synapse/admin/v1/users/{}/_allow_cross_signing_replacement_without_uia"
+        )
+        return template.format(urllib.parse.quote(user))
+
+    def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
+        self.store = hs.get_datastores().main
+
+        self.admin_user = self.register_user("admin", "pass", admin=True)
+        self.admin_user_tok = self.login("admin", "pass")
+
+        self.other_user = self.register_user("user", "pass")
+
+    def test_error_cases(self) -> None:
+        fake_user = "@bums:other"
+        channel = self.make_request(
+            "POST", self.url(fake_user), access_token=self.admin_user_tok
+        )
+        # Fail: user doesn't exist
+        self.assertEqual(404, channel.code, msg=channel.json_body)
+
+        channel = self.make_request(
+            "POST", self.url(self.other_user), access_token=self.admin_user_tok
+        )
+        # Fail: user exists, but has no master cross-signing key
+        self.assertEqual(404, channel.code, msg=channel.json_body)
+
+    def test_success(self) -> None:
+        # Upload a master key.
+        dummy_key = {"keys": {"a": "b"}}
+        self.get_success(
+            self.store.set_e2e_cross_signing_key(self.other_user, "master", dummy_key)
+        )
+
+        channel = self.make_request(
+            "POST", self.url(self.other_user), access_token=self.admin_user_tok
+        )
+        # Success!
+        self.assertEqual(200, channel.code, msg=channel.json_body)
+
+        # Should now find that the key exists.
+        _, timestamp = self.get_success(
+            self.store.get_master_cross_signing_key_updatable_before(self.other_user)
+        )
+        assert timestamp is not None
+        self.assertGreater(timestamp, self.clock.time_msec())