Fetch verify key locally rather than trying to do so over federation if origin and host are the same. (#11129)

* add tests for fetching key locally

* add logic to check if origin server is same as host and fetch verify key locally rather than over federation

* add changelog

* slight refactor, add docstring, change changelog entry

* Make changelog entry one line

* remove verify_json_locally and push locality check to process_request, add function process_request_locally

* remove leftover code reference

* refactor to add common call to 'verify_json and associated handling code

* add type hint to process_json

* add some docstrings + very slight refactor

1 files changed, 12 insertions, 0 deletions

diff --git a/tests/crypto/test_keyring.py b/tests/crypto/test_keyring.py
index 745c295d3b..cbecc1c20f 100644
--- a/tests/crypto/test_keyring.py
+++ b/tests/crypto/test_keyring.py
@@ -197,6 +197,18 @@ class KeyringTestCase(unittest.HomeserverTestCase):
         # self.assertFalse(d.called)
         self.get_success(d)
 
+    def test_verify_for_server_locally(self):
+        """Ensure that locally signed JSON can be verified without fetching keys
+        over federation
+        """
+        kr = keyring.Keyring(self.hs)
+        json1 = {}
+        signedjson.sign.sign_json(json1, self.hs.hostname, self.hs.signing_key)
+
+        # Test that verify_json_for_server succeeds on a object signed by ourselves
+        d = kr.verify_json_for_server(self.hs.hostname, json1, 0)
+        self.get_success(d)
+
     def test_verify_json_for_server_with_null_valid_until_ms(self):
         """Tests that we correctly handle key requests for keys we've stored
         with a null `ts_valid_until_ms`