From 453784d7efad1d4c4c739f10c519eda3c6f27f3c Mon Sep 17 00:00:00 2001
From: Travis Ralston <travisr@matrix.org>
Date: Mon, 16 Aug 2021 20:32:00 -0600
Subject: [PATCH] Add a voice message protection to easily redact unwanted
 messages

---
 src/protections/MessageIsVoice.ts | 45 +++++++++++++++++++++++++++++++
 src/protections/protections.ts    |  9 +++++--
 2 files changed, 52 insertions(+), 2 deletions(-)
 create mode 100644 src/protections/MessageIsVoice.ts

diff --git a/src/protections/MessageIsVoice.ts b/src/protections/MessageIsVoice.ts
new file mode 100644
index 0000000..1daeecc
--- /dev/null
+++ b/src/protections/MessageIsVoice.ts
@@ -0,0 +1,45 @@
+/*
+Copyright 2021 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { IProtection } from "./IProtection";
+import { Mjolnir } from "../Mjolnir";
+import { LogLevel, Permalinks, UserID } from "matrix-bot-sdk";
+import { logMessage } from "../LogProxy";
+import config from "../config";
+
+export class MessageIsVoice implements IProtection {
+
+    constructor() {
+    }
+
+    public get name(): string {
+        return 'MessageIsVoiceProtection';
+    }
+
+    public async handleEvent(mjolnir: Mjolnir, roomId: string, event: any): Promise<any> {
+        if (event['type'] === 'm.room.message' && event['content']) {
+            if (event['content']['msgtype'] !== 'm.audio') return;
+            if (event['content']['org.matrix.msc3245.voice'] === undefined) return;
+            await logMessage(LogLevel.INFO, "MessageIsVoice", `Redacting event from ${event['sender']} for posting a voice message. ${Permalinks.forEvent(roomId, event['event_id'], [new UserID(await mjolnir.client.getUserId()).domain])}`);
+            // Redact the event
+            if (!config.noop) {
+                await mjolnir.client.redactEvent(roomId, event['event_id'], "Voice messages are not permitted here");
+            } else {
+                await logMessage(LogLevel.WARN, "FirstMessageIsImage", `Tried to redact ${event['event_id']} in ${roomId} but Mjolnir is running in no-op mode`, roomId);
+            }
+        }
+    }
+}
diff --git a/src/protections/protections.ts b/src/protections/protections.ts
index ba81b5d..031c203 100644
--- a/src/protections/protections.ts
+++ b/src/protections/protections.ts
@@ -1,5 +1,5 @@
 /*
-Copyright 2019 The Matrix.org Foundation C.I.C.
+Copyright 2019 - 2021 The Matrix.org Foundation C.I.C.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -18,6 +18,7 @@ import { FirstMessageIsImage } from "./FirstMessageIsImage";
 import { IProtection } from "./IProtection";
 import { BasicFlooding, MAX_PER_MINUTE } from "./BasicFlooding";
 import { WordList } from "./WordList";
+import { MessageIsVoice } from "./MessageIsVoice";
 
 export const PROTECTIONS: PossibleProtections = {
     [new FirstMessageIsImage().name]: {
@@ -34,7 +35,11 @@ export const PROTECTIONS: PossibleProtections = {
         description: "If a user posts a monitored word a set amount of time after joining, they " +
             "will be banned from that room.  This will not publish the ban to a ban list.",
         factory: () => new WordList(),
-    }
+    },
+    [new MessageIsVoice().name]: {
+        description: "If a user posts a voice message, that message will be redacted. No bans are issued.",
+        factory: () => new MessageIsVoice(),
+    },
 };
 
 export interface PossibleProtections {