From 5db1a4d94b7f7a35f89bae78852ac31ab4bc29bf Mon Sep 17 00:00:00 2001
From: Rory& <root@rory.gay>
Date: Mon, 17 Nov 2025 12:10:28 +0100
Subject: Event content redaction (v12)

---
 CONTRIBUTING.MD                                    |  2 +-
 LibMatrix.EventTypes/EventContent.cs               |  4 +++-
 .../Spec/State/RoomInfo/RoomCreateEventContent.cs  |  2 ++
 .../Spec/State/RoomInfo/RoomMemberEventContent.cs  | 26 +++++++++++++++++++++-
 LibMatrix/StateEvent.cs                            | 21 +++++++++++++++++
 5 files changed, 52 insertions(+), 3 deletions(-)

diff --git a/CONTRIBUTING.MD b/CONTRIBUTING.MD
index 8c305b7..50c5a4d 100644
--- a/CONTRIBUTING.MD
+++ b/CONTRIBUTING.MD
@@ -1,6 +1,6 @@
 # Contributing
 
-Any contribution is welcome, even if it's just documentation or recommended git practices! We're not too strict on code style, but we do have a few guidelines:
+Any contribution is welcome, even if it's just documentation or recommended git practices! We're not too strict on code style, but we do have a few recommendations:
 - Use spaces, not tabs
 - Use 4 spaces for indentation
 - Use the C# naming convention for variables, methods, etc.
diff --git a/LibMatrix.EventTypes/EventContent.cs b/LibMatrix.EventTypes/EventContent.cs
index d612e44..7a9f0aa 100644
--- a/LibMatrix.EventTypes/EventContent.cs
+++ b/LibMatrix.EventTypes/EventContent.cs
@@ -1,4 +1,5 @@
 using System.Diagnostics.CodeAnalysis;
+using System.Net.Http.Json;
 using System.Reflection;
 using System.Text.Json;
 using System.Text.Json.Nodes;
@@ -17,6 +18,7 @@ public abstract class EventContent {
         foreach (var attr in type.GetCustomAttributes<MatrixEventAttribute>(true)) {
             eventTypes.Add(attr.EventName);
         }
+
         return eventTypes;
     }
 }
@@ -55,7 +57,7 @@ public abstract class TimelineEventContent : EventContent {
         // used for reactions
         [JsonPropertyName("key")]
         public string? Key { get; set; }
-        
+
         [JsonExtensionData]
         public Dictionary<string, object>? AdditionalData { get; set; } = [];
 
diff --git a/LibMatrix.EventTypes/Spec/State/RoomInfo/RoomCreateEventContent.cs b/LibMatrix.EventTypes/Spec/State/RoomInfo/RoomCreateEventContent.cs
index 8519889..3dd033b 100644
--- a/LibMatrix.EventTypes/Spec/State/RoomInfo/RoomCreateEventContent.cs
+++ b/LibMatrix.EventTypes/Spec/State/RoomInfo/RoomCreateEventContent.cs
@@ -1,5 +1,7 @@
 using System.Diagnostics.CodeAnalysis;
+using System.Text.Json.Nodes;
 using System.Text.Json.Serialization;
+using ArcaneLibs.Extensions;
 
 namespace LibMatrix.EventTypes.Spec.State.RoomInfo;
 
diff --git a/LibMatrix.EventTypes/Spec/State/RoomInfo/RoomMemberEventContent.cs b/LibMatrix.EventTypes/Spec/State/RoomInfo/RoomMemberEventContent.cs
index b034425..287754a 100644
--- a/LibMatrix.EventTypes/Spec/State/RoomInfo/RoomMemberEventContent.cs
+++ b/LibMatrix.EventTypes/Spec/State/RoomInfo/RoomMemberEventContent.cs
@@ -1,3 +1,5 @@
+using System.Text.Json;
+using System.Text.Json.Nodes;
 using System.Text.Json.Serialization;
 
 namespace LibMatrix.EventTypes.Spec.State.RoomInfo;
@@ -26,7 +28,29 @@ public class RoomMemberEventContent : EventContent {
 
     [JsonPropertyName("join_authorised_via_users_server")]
     public string? JoinAuthorisedViaUsersServer { get; set; }
-    
+
+    [JsonPropertyName("third_party_invite")]
+    public ThirdPartyMemberInvite? ThirdPartyInvite { get; set; }
+
+    public class ThirdPartyMemberInvite {
+        [JsonPropertyName("display_name")]
+        public required string DisplayName { get; set; }
+
+        [JsonPropertyName("signed")]
+        public required SignedThirdPartyInvite Signed { get; set; }
+
+        public class SignedThirdPartyInvite {
+            [JsonPropertyName("mxid")]
+            public required string Mxid { get; set; }
+
+            [JsonPropertyName("signatures")]
+            public required Dictionary<string, Dictionary<string, string>> Signatures { get; set; }
+
+            [JsonPropertyName("token")]
+            public required string Token { get; set; }
+        }
+    }
+
     public static class MembershipTypes {
         public const string Invite = "invite";
         public const string Join = "join";
diff --git a/LibMatrix/StateEvent.cs b/LibMatrix/StateEvent.cs
index 861b584..dfe393a 100644
--- a/LibMatrix/StateEvent.cs
+++ b/LibMatrix/StateEvent.cs
@@ -132,6 +132,27 @@ public class MatrixEvent {
     /// <param name="y"></param>
     /// <returns></returns>
     public static bool DeepEquals(MatrixEventResponse x, MatrixEventResponse y) => x.Type == y.Type && x.StateKey == y.StateKey && JsonNode.DeepEquals(x.RawContent, y.RawContent);
+
+    public JsonObject GetRedactedContent(string roomVersion) {
+        JsonObject GetTopLevelKeys(string[] keys) {
+            var obj = new JsonObject();
+            foreach (var key in keys) {
+                if (RawContent.ContainsKey(key))
+                    obj[key] = RawContent[key]!;
+            }
+
+            return obj;
+        }
+
+        return Type switch {
+            "m.room.create" => RawContent,                                                          // as of v11... TODO: implement older versions
+            "m.room.member" => GetTopLevelKeys(["membership", "join_authorised_via_users_server"]), // TODO: missing third_party_invite.signed
+            "m.room.join_rules" => GetTopLevelKeys(["join_rule", "allow"]),
+            "m.room.power_levels" => GetTopLevelKeys(["ban", "events", "events_default", "kick", "redact", "state_default", "users", "users_default"]),
+            "m.room.history_visibility" => GetTopLevelKeys(["history_visibility"]),
+            _ => new JsonObject()
+        };
+    }
 }
 
 public class MatrixEventResponse : MatrixEvent {
-- 
cgit 1.5.1