signatures: Implement room version 9 redaction change

crates/ruma-signatures/Cargo.toml

@@ -17,6 +17,7 @@ all-features = true
 [features]
 compat = ["tracing"]
 unstable-exhaustive-types = []
+unstable-pre-spec = ["ruma-identifiers/unstable-pre-spec"]
 
 [dependencies]
 base64 = "0.13.0"

crates/ruma-signatures/src/functions.rs

@@ -43,7 +43,11 @@ static ALLOWED_KEYS: &[&str] = &[
 
 fn allowed_content_keys_for(event_type: &str, version: &RoomVersionId) -> &'static [&'static str] {
     match event_type {
-        "m.room.member" => &["membership"],
+        "m.room.member" => match version {
+            #[cfg(feature = "unstable-pre-spec")]
+            RoomVersionId::V9 => &["membership", "join_authorised_via_users_server"],
+            _ => &["membership"],
+        },
         "m.room.create" => &["creator"],
         "m.room.join_rules" => &["join_rule"],
         "m.room.power_levels" => &[

crates/ruma/Cargo.toml

@@ -113,6 +113,7 @@ unstable-pre-spec = [
     "ruma-events/unstable-pre-spec",
     "ruma-federation-api/unstable-pre-spec",
     "ruma-identifiers/unstable-pre-spec",
+    "ruma-signatures/unstable-pre-spec",
     "ruma-state-res/unstable-pre-spec"
     #"ruma-identity-service-api/unstable-pre-spec",
     #"ruma-push-gateway-api/unstable-pre-spec",