Validate device_keys for C-S /keys/query requests (#10593)

* Validate device_keys for C-S /keys/query requests

Closes #10354

A small, not particularly critical fix. I'm interested in seeing if we
can find a more systematic approach though. #8445 is the place for any discussion.

1 files changed, 77 insertions, 0 deletions

diff --git a/tests/rest/client/v2_alpha/test_keys.py b/tests/rest/client/v2_alpha/test_keys.py
new file mode 100644
index 0000000000..80a4e728ff
--- /dev/null
+++ b/tests/rest/client/v2_alpha/test_keys.py
@@ -0,0 +1,77 @@
+from http import HTTPStatus
+
+from synapse.api.errors import Codes
+from synapse.rest import admin
+from synapse.rest.client import keys, login
+
+from tests import unittest
+
+
+class KeyQueryTestCase(unittest.HomeserverTestCase):
+    servlets = [
+        keys.register_servlets,
+        admin.register_servlets_for_client_rest_resource,
+        login.register_servlets,
+    ]
+
+    def test_rejects_device_id_ice_key_outside_of_list(self):
+        self.register_user("alice", "wonderland")
+        alice_token = self.login("alice", "wonderland")
+        bob = self.register_user("bob", "uncle")
+        channel = self.make_request(
+            "POST",
+            "/_matrix/client/r0/keys/query",
+            {
+                "device_keys": {
+                    bob: "device_id1",
+                },
+            },
+            alice_token,
+        )
+        self.assertEqual(channel.code, HTTPStatus.BAD_REQUEST, channel.result)
+        self.assertEqual(
+            channel.json_body["errcode"],
+            Codes.BAD_JSON,
+            channel.result,
+        )
+
+    def test_rejects_device_key_given_as_map_to_bool(self):
+        self.register_user("alice", "wonderland")
+        alice_token = self.login("alice", "wonderland")
+        bob = self.register_user("bob", "uncle")
+        channel = self.make_request(
+            "POST",
+            "/_matrix/client/r0/keys/query",
+            {
+                "device_keys": {
+                    bob: {
+                        "device_id1": True,
+                    },
+                },
+            },
+            alice_token,
+        )
+
+        self.assertEqual(channel.code, HTTPStatus.BAD_REQUEST, channel.result)
+        self.assertEqual(
+            channel.json_body["errcode"],
+            Codes.BAD_JSON,
+            channel.result,
+        )
+
+    def test_requires_device_key(self):
+        """`device_keys` is required. We should complain if it's missing."""
+        self.register_user("alice", "wonderland")
+        alice_token = self.login("alice", "wonderland")
+        channel = self.make_request(
+            "POST",
+            "/_matrix/client/r0/keys/query",
+            {},
+            alice_token,
+        )
+        self.assertEqual(channel.code, HTTPStatus.BAD_REQUEST, channel.result)
+        self.assertEqual(
+            channel.json_body["errcode"],
+            Codes.BAD_JSON,
+            channel.result,
+        )