From b47d10dc46e4644c432f017d5b2129ff7a349166 Mon Sep 17 00:00:00 2001
From: Hubert Chathi <hubert@uhoreg.ca>
Date: Thu, 9 Dec 2021 06:41:27 -0500
Subject: [PATCH] Support unprefixed versions of fallback key property names.
 (#11541)

---
 changelog.d/11541.misc          |  1 +
 synapse/handlers/e2e_keys.py    |  4 +++-
 synapse/rest/client/sync.py     |  3 +++
 tests/handlers/test_e2e_keys.py | 30 +++++++++++++++++++++++++-----
 4 files changed, 32 insertions(+), 6 deletions(-)
 create mode 100644 changelog.d/11541.misc

diff --git a/changelog.d/11541.misc b/changelog.d/11541.misc
new file mode 100644
index 000000000..31c72c2a2
--- /dev/null
+++ b/changelog.d/11541.misc
@@ -0,0 +1 @@
+Support unprefixed versions of fallback key property names.
diff --git a/synapse/handlers/e2e_keys.py b/synapse/handlers/e2e_keys.py
index b2554bda0..14360b4e4 100644
--- a/synapse/handlers/e2e_keys.py
+++ b/synapse/handlers/e2e_keys.py
@@ -580,7 +580,9 @@ class E2eKeysHandler:
             log_kv(
                 {"message": "Did not update one_time_keys", "reason": "no keys given"}
             )
-        fallback_keys = keys.get("org.matrix.msc2732.fallback_keys", None)
+        fallback_keys = keys.get("fallback_keys") or keys.get(
+            "org.matrix.msc2732.fallback_keys"
+        )
         if fallback_keys and isinstance(fallback_keys, dict):
             log_kv(
                 {
diff --git a/synapse/rest/client/sync.py b/synapse/rest/client/sync.py
index 88e4f5e06..dd90ffa12 100644
--- a/synapse/rest/client/sync.py
+++ b/synapse/rest/client/sync.py
@@ -293,6 +293,9 @@ class SyncRestServlet(RestServlet):
         response[
             "org.matrix.msc2732.device_unused_fallback_key_types"
         ] = sync_result.device_unused_fallback_key_types
+        response[
+            "device_unused_fallback_key_types"
+        ] = sync_result.device_unused_fallback_key_types
 
         if joined:
             response["rooms"][Membership.JOIN] = joined
diff --git a/tests/handlers/test_e2e_keys.py b/tests/handlers/test_e2e_keys.py
index f0723892e..ddcf3ee34 100644
--- a/tests/handlers/test_e2e_keys.py
+++ b/tests/handlers/test_e2e_keys.py
@@ -161,8 +161,9 @@ class E2eKeysHandlerTestCase(unittest.HomeserverTestCase):
     def test_fallback_key(self):
         local_user = "@boris:" + self.hs.hostname
         device_id = "xyz"
-        fallback_key = {"alg1:k1": "key1"}
-        fallback_key2 = {"alg1:k2": "key2"}
+        fallback_key = {"alg1:k1": "fallback_key1"}
+        fallback_key2 = {"alg1:k2": "fallback_key2"}
+        fallback_key3 = {"alg1:k2": "fallback_key3"}
         otk = {"alg1:k2": "key2"}
 
         # we shouldn't have any unused fallback keys yet
@@ -175,7 +176,7 @@ class E2eKeysHandlerTestCase(unittest.HomeserverTestCase):
             self.handler.upload_keys_for_user(
                 local_user,
                 device_id,
-                {"org.matrix.msc2732.fallback_keys": fallback_key},
+                {"fallback_keys": fallback_key},
             )
         )
 
@@ -220,7 +221,7 @@ class E2eKeysHandlerTestCase(unittest.HomeserverTestCase):
             self.handler.upload_keys_for_user(
                 local_user,
                 device_id,
-                {"org.matrix.msc2732.fallback_keys": fallback_key},
+                {"fallback_keys": fallback_key},
             )
         )
 
@@ -234,7 +235,7 @@ class E2eKeysHandlerTestCase(unittest.HomeserverTestCase):
             self.handler.upload_keys_for_user(
                 local_user,
                 device_id,
-                {"org.matrix.msc2732.fallback_keys": fallback_key2},
+                {"fallback_keys": fallback_key2},
             )
         )
 
@@ -271,6 +272,25 @@ class E2eKeysHandlerTestCase(unittest.HomeserverTestCase):
             {"failures": {}, "one_time_keys": {local_user: {device_id: fallback_key2}}},
         )
 
+        # using the unstable prefix should also set the fallback key
+        self.get_success(
+            self.handler.upload_keys_for_user(
+                local_user,
+                device_id,
+                {"org.matrix.msc2732.fallback_keys": fallback_key3},
+            )
+        )
+
+        res = self.get_success(
+            self.handler.claim_one_time_keys(
+                {"one_time_keys": {local_user: {device_id: "alg1"}}}, timeout=None
+            )
+        )
+        self.assertEqual(
+            res,
+            {"failures": {}, "one_time_keys": {local_user: {device_id: fallback_key3}}},
+        )
+
     def test_replace_master_key(self):
         """uploading a new signing key should make the old signing key unavailable"""
         local_user = "@boris:" + self.hs.hostname