2 files changed, 23 insertions, 3 deletions
diff --git a/synapse/rest/admin/users.py b/synapse/rest/admin/users.py
index d14fafbbc9..23a8bf1fdb 100644
--- a/synapse/rest/admin/users.py
+++ b/synapse/rest/admin/users.py
@@ -909,7 +909,7 @@ class UserTokenRestServlet(RestServlet):
 
 
 class ShadowBanRestServlet(RestServlet):
-    """An admin API for shadow-banning a user.
+    """An admin API for controlling whether a user is shadow-banned.
 
     A shadow-banned users receives successful responses to their client-server
     API requests, but the events are not propagated into rooms.
@@ -917,13 +917,21 @@ class ShadowBanRestServlet(RestServlet):
     Shadow-banning a user should be used as a tool of last resort and may lead
     to confusing or broken behaviour for the client.
 
-    Example:
+    Example of shadow-banning a user:
 
         POST /_synapse/admin/v1/users/@test:example.com/shadow_ban
         {}
 
         200 OK
         {}
+
+    Example of removing a user from being shadow-banned:
+
+        DELETE /_synapse/admin/v1/users/@test:example.com/shadow_ban
+        {}
+
+        200 OK
+        {}
     """
 
     PATTERNS = admin_patterns("/users/(?P<user_id>[^/]*)/shadow_ban")
@@ -945,6 +953,18 @@ class ShadowBanRestServlet(RestServlet):
 
         return 200, {}
 
+    async def on_DELETE(
+        self, request: SynapseRequest, user_id: str
+    ) -> Tuple[int, JsonDict]:
+        await assert_requester_is_admin(self.auth, request)
+
+        if not self.hs.is_mine_id(user_id):
+            raise SynapseError(400, "Only local users can be shadow-banned")
+
+        await self.store.set_shadow_banned(UserID.from_string(user_id), False)
+
+        return 200, {}
+
 
 class RateLimitRestServlet(RestServlet):
     """An admin API to override ratelimiting for an user.
diff --git a/synapse/storage/databases/main/registration.py b/synapse/storage/databases/main/registration.py
index 6c7d6ba508..5e55440570 100644
--- a/synapse/storage/databases/main/registration.py
+++ b/synapse/storage/databases/main/registration.py
@@ -476,7 +476,7 @@ class RegistrationWorkerStore(CacheInvalidationWorkerStore):
             shadow_banned: true iff the user is to be shadow-banned, false otherwise.
         """
 
-        def set_shadow_banned_txn(txn):
+        def set_shadow_banned_txn(txn: LoggingTransaction) -> None:
             user_id = user.to_string()
             self.db_pool.simple_update_one_txn(
                 txn,