From f802de88ce9cba3a2a4b1507e2a5aa2dfab4ec49 Mon Sep 17 00:00:00 2001
From: Noah Petherbridge <root@kirsle.net>
Date: Wed, 2 Oct 2024 20:33:57 -0700
Subject: [PATCH] Watermark QR code over webcam feeds to deter screen recording

---
 package-lock.json            |  6 +++++
 package.json                 |  1 +
 src/App.vue                  | 43 ++++++++++++++++++++++++++++--------
 src/components/VideoFeed.vue | 34 +++++++++++++++++++++++++++-
 src/lib/watermark.js         | 27 ++++++++++++++++++++++
 5 files changed, 101 insertions(+), 10 deletions(-)
 create mode 100644 src/lib/watermark.js

diff --git a/package-lock.json b/package-lock.json
index 8e93a32..4d6a398 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -10,6 +10,7 @@
       "dependencies": {
         "floating-vue": "^2.0.0-beta.24",
         "interactjs": "^1.10.18",
+        "qrcodejs": "github:danielgjackson/qrcodejs",
         "vue": "^3.3.4",
         "vue-mention": "^2.0.0-alpha.3",
         "vue3-emoji-picker": "^1.1.7",
@@ -1680,6 +1681,11 @@
         "node": ">=6"
       }
     },
+    "node_modules/qrcodejs": {
+      "version": "0.0.0",
+      "resolved": "git+ssh://git@github.com/danielgjackson/qrcodejs.git#86770ec12f0f9abee8728fc9018ab7bd0949f4bc",
+      "license": "BSD-2-Clause"
+    },
     "node_modules/queue-microtask": {
       "version": "1.2.3",
       "resolved": "https://registry.npmjs.org/queue-microtask/-/queue-microtask-1.2.3.tgz",
diff --git a/package.json b/package.json
index 6a9104d..9d1e26a 100644
--- a/package.json
+++ b/package.json
@@ -12,6 +12,7 @@
   "dependencies": {
     "floating-vue": "^2.0.0-beta.24",
     "interactjs": "^1.10.18",
+    "qrcodejs": "github:danielgjackson/qrcodejs",
     "vue": "^3.3.4",
     "vue-mention": "^2.0.0-alpha.3",
     "vue3-emoji-picker": "^1.1.7",
diff --git a/src/App.vue b/src/App.vue
index 1eb7451..e27475d 100644
--- a/src/App.vue
+++ b/src/App.vue
@@ -19,6 +19,7 @@ import LocalStorage from './lib/LocalStorage';
 import VideoFlag from './lib/VideoFlag';
 import StatusMessage from './lib/StatusMessage';
 import { SoundEffects, DefaultSounds } from './lib/sounds';
+import WatermarkImage from './lib/watermark';
 
 // WebRTC configuration.
 const configuration = {
@@ -181,6 +182,10 @@ export default {
                 rememberExpresslyClosed: true,  // remember cams we expressly closed
                 autoMuteWebcams: false, // auto-mute other cameras' audio channels
 
+                // My watermark image for screen recording protection.
+                // Set after login in setWatermark.
+                watermark: null,
+
                 // Who all is watching me? map of users.
                 watching: {},
 
@@ -1630,6 +1635,10 @@ export default {
         onLoggedIn() {
             // Called after the first 'me' is received from the chat server, e.g. once per login.
 
+            // Load our watermark image.
+            this.webcam.watermark = WatermarkImage(this.username);
+            this.ChatClient(`Watermark image created: <img src="${this.webcam.watermark}" width="120">`);
+
             // Do we auto-broadcast our camera?
             if (this.webcam.autoshare) {
                 this.startVideo({ force: true });
@@ -4709,20 +4718,36 @@ export default {
                     <!-- Video Feeds-->
 
                     <!-- My video -->
-                    <VideoFeed v-show="webcam.active" :local-video="true" :username="username"
-                        :popped-out="WebRTC.poppedOut[username]" :is-explicit="webcam.nsfw" :is-muted="webcam.muted"
-                        :is-source-muted="webcam.muted" @mute-video="muteMe()" @popout="popoutVideo"
+                    <VideoFeed v-show="webcam.active"
+                        :local-video="true"
+                        :username="username"
+                        :popped-out="WebRTC.poppedOut[username]"
+                        :is-explicit="webcam.nsfw"
+                        :is-muted="webcam.muted"
+                        :is-source-muted="webcam.muted"
+                        :watermark-image="webcam.watermark"
+                        @mute-video="muteMe()"
+                        @popout="popoutVideo"
                         @open-profile="showProfileModal"
                         @set-volume="setVideoVolume">
                     </VideoFeed>
 
                     <!-- Others' videos -->
-                    <VideoFeed v-for="(stream, username) in WebRTC.streams" v-bind:key="username" :username="username"
-                        :popped-out="WebRTC.poppedOut[username]" :is-explicit="isUsernameCamNSFW(username)"
-                        :is-source-muted="isSourceMuted(username)" :is-muted="isMuted(username)"
-                        :is-watching-me="isWatchingMe(username)" :is-frozen="WebRTC.frozenStreamDetected[username]"
-                        @reopen-video="openVideoByUsername" @mute-video="muteVideo" @popout="popoutVideo"
-                        @close-video="expresslyCloseVideo" @set-volume="setVideoVolume"
+                    <VideoFeed v-for="(stream, username) in WebRTC.streams"
+                        v-bind:key="username"
+                        :username="username"
+                        :popped-out="WebRTC.poppedOut[username]"
+                        :is-explicit="isUsernameCamNSFW(username)"
+                        :is-source-muted="isSourceMuted(username)"
+                        :is-muted="isMuted(username)"
+                        :is-watching-me="isWatchingMe(username)"
+                        :is-frozen="WebRTC.frozenStreamDetected[username]"
+                        :watermark-image="webcam.watermark"
+                        @reopen-video="openVideoByUsername"
+                        @mute-video="muteVideo"
+                        @popout="popoutVideo"
+                        @close-video="expresslyCloseVideo"
+                        @set-volume="setVideoVolume"
                         @open-profile="showProfileModal">
                     </VideoFeed>
 
diff --git a/src/components/VideoFeed.vue b/src/components/VideoFeed.vue
index b6ac382..1f05ba0 100644
--- a/src/components/VideoFeed.vue
+++ b/src/components/VideoFeed.vue
@@ -11,6 +11,7 @@ export default {
         isSourceMuted: Boolean, // camera is muted on the broadcaster's end
         isWatchingMe: Boolean, // other video is watching us back
         isFrozen: Boolean,     // video is detected as frozen
+        watermarkImage: Image, // watermark image to overlay (nullable)
     },
     components: {
         Slider,
@@ -102,7 +103,13 @@ export default {
         'popped-out': poppedOut,
         'popped-in': !poppedOut,
     }" @mouseover="mouseOver = true" @mouseleave="mouseOver = false">
-        <video class="feed" :id="videoID" autoplay :muted="localVideo" playsinline></video>
+        <video class="feed" :id="videoID" autoplay disablepictureinpicture :muted="localVideo" playsinline></video>
+
+        <!-- Watermark layer -->
+        <div v-if="watermarkImage">
+            <img :src="watermarkImage" class="watermark">
+            <img :src="watermarkImage" class="corner-watermark seethru invert-color">
+        </div>
 
         <!-- Caption -->
         <div class="caption" :class="textColorClass">
@@ -187,4 +194,29 @@ video {
 .seethru {
     opacity: 0.4;
 }
+
+/* Watermark image */
+.watermark {
+    position: absolute;
+    top: 0;
+    left: 0;
+    right: 0;
+    bottom: 0;
+    margin: auto;
+    width: 40%;
+    height: 40%;
+    opacity: 0.02;
+}
+.corner-watermark {
+    position: absolute;
+    right: 4px;
+    bottom: 4px;
+    width: 20%;
+    min-width: 32px;
+    min-height: 32px;
+    max-height: 20%;
+}
+.invert-color {
+    filter: invert(100%);
+}
 </style>
diff --git a/src/lib/watermark.js b/src/lib/watermark.js
new file mode 100644
index 0000000..9d92593
--- /dev/null
+++ b/src/lib/watermark.js
@@ -0,0 +1,27 @@
+import QrCode from 'qrcodejs';
+
+// WatermarkImage outputs a QR code containing watermark data about the current user.
+//
+// To help detect when someone has screen recorded and shared it, and being able to know who/when/etc.
+function WatermarkImage(username) {
+    let now = new Date();
+    let dateString = [
+        now.getFullYear(),
+        ('0' + (now.getMonth()+1)).slice(-2),
+        ('0' + (now.getDate())).slice(-2),
+    ].join('-');
+
+    let fields = [
+        window.location.hostname,
+        username,
+        dateString,
+    ].join(' ');
+
+    console.error("watermark message:", fields);
+
+    const matrix = QrCode.generate(fields);
+    const uri = QrCode.render('svg-uri', matrix);
+    return uri;
+}
+
+export default WatermarkImage;