.gitea/workflows/release.yml

@@ -0,0 +1,40 @@
+# Builds the Linux packages and the Windows installer when a version tag (v1.2.3) is pushed,
+# and attaches them to a Gitea release of that tag. macOS builds need a Mac and are not made here.
+name: release
+
+on:
+  push:
+    tags: ['v*']
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    # Has Wine, so the Windows installer builds on Linux
+    container: electronuserland/builder:wine
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 24
+      - run: npm ci
+      - run: npm run check
+      - run: npm test
+      - run: npm run build
+      - run: npx electron-builder --linux --win --publish never
+      - name: Upload to the release
+        env:
+          TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          API: ${{ github.server_url }}/api/v1/repos/${{ github.repository }}
+          TAG: ${{ github.ref_name }}
+        run: |
+          set -eu
+          release=$(curl -sf -H "Authorization: token $TOKEN" "$API/releases/tags/$TAG" || true)
+          if [ -z "$release" ]; then
+            release=$(curl -sf -X POST -H "Authorization: token $TOKEN" -H 'Content-Type: application/json' \
+              -d "{\"tag_name\":\"$TAG\",\"name\":\"mumh5 $TAG\"}" "$API/releases")
+          fi
+          id=$(printf '%s' "$release" | node -e "let s='';process.stdin.on('data',d=>s+=d).on('end',()=>console.log(JSON.parse(s).id))")
+          for f in release/*.AppImage release/*.deb release/*.tar.gz release/*.exe; do
+            curl -sf -X POST -H "Authorization: token $TOKEN" -F "attachment=@$f" "$API/releases/$id/assets?name=$(basename "$f")" >/dev/null
+            echo "uploaded $(basename "$f")"
+          done

CLAUDE.md

@@ -37,7 +37,7 @@ A reused test server keeps registrations and channels from earlier runs; tests m
 
 ## Architecture
 
-- `electron/` (Node, main process): window, TLS sockets to Mumble servers (`tls-transport.ts`), identities and PKCS#12 (`identity.ts`, `identity-store.ts`), certificate parsing (`certs.ts`), tray (`tray.ts`). The renderer only gets the narrow `window.mumh5Native` API from `preload.ts` (context isolation, sandbox).
+- `electron/` (Node, main process): window, TLS sockets to Mumble servers (`tls-transport.ts`), encrypted UDP voice (`udp-voice.ts`, `ocb2.ts`, tested against Mumble's OCB2 vectors), identities and PKCS#12 (`identity.ts`, `identity-store.ts`), certificate parsing (`certs.ts`), tray (`tray.ts`). The renderer only gets the narrow `window.mumh5Native` API from `preload.ts` (context isolation, sandbox).
 - `src/core/` (browser-safe TypeScript, also runs in Node for tests): framing and codec (`proto.ts`), the Mumble client state machine (`client.ts`), voice packet formats (`voice-packet.ts`). No DOM, no Electron, no Node imports here.
 - `src/lib/`: app state. `session.svelte.ts` has one `Session` per server plus the `sessions` manager; `session` is a Proxy to the active one. `audio/voice.svelte.ts` is the voice engine (WebCodecs Opus, capture and playback AudioWorklets). `html.ts` sanitizes incoming HTML and serializes outgoing rich text.
 - `src/ui/`: Svelte components. `App.svelte` owns layout and global dialogs (`ui.svelte.ts` store).

README.md

@@ -27,7 +27,7 @@ mumh5 keeps the foundation and replaces the experience.
 
 | | Mumble desktop | mumh5 |
 |---|---|---|
-| Interface | Qt widgets, dense dialogs | Modern layout: server rail, channel tree, chat, side panels |
+| Interface | Qt widgets, dense dialogs | Modern layout (server rail, channel tree, chat, side panels), or the classic and stacked layouts of the desktop client |
 | Several servers at the same time | One connection | Many; voice on one, text on all, unread badges |
 | Sharing files | Images only, pasted inline and heavily limited | Any allowed file through your own [f0ckm](#file-sharing-with-f0ckm) host, inline players for images, video and audio. Images still work without one |
 | YouTube links | Plain links | Click-to-play player (privacy mode), optional thumbnails |
@@ -41,7 +41,7 @@ mumh5 keeps the foundation and replaces the experience.
 | Look | One Qt style (plus skins) | Five built-in color schemes, including Windows 95 |
 | Channel and permission editing | Dialogs, drag and drop | Same power: create, edit, link, drag and drop, rule and group editor |
 
-**Where the desktop client is still ahead, today:** UDP voice transport (mumh5 sends voice through the encrypted TCP connection for now, which adds a little delay on bad networks), system-wide push-to-talk, whisper and shout, positional audio, the in-game overlay, recording, and the ban list and registered-user editors. These are on the roadmap below.
+**Where the desktop client is still ahead, today:** system-wide push-to-talk, whisper and shout, positional audio, the in-game overlay, recording, and the ban list and registered-user editors. These are on the roadmap below.
 
 ---
 
@@ -55,6 +55,7 @@ mumh5 keeps the foundation and replaces the experience.
 - Per-person volume (0 to 300%) and "mute for me"
 - Speaking indicators in the channel tree, member list and your own panel
 - On small windows, your voice channel appears as tiles above the chat, lighting up as people talk, with mute and deafen at hand
+- Low-latency voice over encrypted UDP (Mumble's OCB2-AES128), with automatic fallback to the TCP connection and a TCP-only switch
 - Bitrate automatically limited to what the server allows
 - Right-click the mute or deafen button for quick device and volume options
 - Hear-yourself microphone test
@@ -110,7 +111,18 @@ Dark, Light, Midnight (true black), Frost, and a faithful **Windows 95** theme w
 
 ## Getting started
 
-There are no release builds yet. For now, build it yourself; it takes a few minutes.
+Download a build from the [releases page](https://git.lat/kibi/mumh5/releases):
+
+| System | File |
+|---|---|
+| Windows | `mumh5-<version>-win-x64.exe` (installer; not signed yet, so Windows SmartScreen warns once) |
+| Linux, any distribution | `mumh5-<version>-linux-x86_64.AppImage` (make it executable, then run it) |
+| Debian, Ubuntu | `mumh5-<version>-linux-amd64.deb` |
+| Linux, portable | `mumh5-<version>-linux-x64.tar.gz` |
+
+There is no macOS build yet; build it yourself on a Mac (below).
+
+### Running from source
 
 You need [Node.js](https://nodejs.org/) 22 or newer and git.
 
@@ -131,7 +143,7 @@ npm run dist:win     # NSIS installer
 npm run dist:mac     # .dmg
 ```
 
-Installers are written to `release/`. Build each platform on that platform for the best results.
+Installers are written to `release/`. The Windows installer also builds on Linux with Wine installed; the macOS one needs a Mac. Pushing a version tag (`git tag v0.1.0 && git push origin v0.1.0`) makes the Gitea workflow in `.gitea/workflows/release.yml` build the Linux and Windows files and attach them to a release.
 
 ---
 
@@ -164,7 +176,6 @@ Without an upload host, mumh5 still sends images, scaled to fit the server's lim
 
 ## Roadmap
 
-- UDP voice with Mumble's OCB2-AES128 encryption, for the lowest latency
 - System-wide push to talk
 - Whisper and shout
 - Rich chat between mumh5 users: replies, reactions, edits, typing indicators

build/icon.svg

@@ -0,0 +1,11 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1024 1024" width="1024" height="1024">
+  <!-- mumh5 app icon: the accent square with the headphones glyph, square caps like the UI icons -->
+  <rect width="1024" height="1024" fill="#7c6cff"/>
+  <rect x="0" y="880" width="1024" height="144" fill="#6a5ae8"/>
+  <g transform="translate(176 150) scale(28)" fill="none" stroke="#ffffff" stroke-width="2" stroke-linecap="square" stroke-linejoin="miter">
+    <path d="M3 14v-2a9 9 0 0 1 18 0v2"/>
+    <path d="M21 14v7h-4v-7z" fill="#ffffff"/>
+    <path d="M3 14v7h4v-7z" fill="#ffffff"/>
+  </g>
+  <rect x="424" y="700" width="176" height="36" fill="#3bd16f"/>
+</svg>

electron/main.ts

@@ -8,6 +8,7 @@ import * as tray from './tray.ts';
 import { fetchLinkPreview } from './link-preview.ts';
 import { fetchPublicListWith, pingServer } from './publist.ts';
 import { openTls } from './tls-transport.ts';
+import { udpChannel } from './udp-voice.ts';
 
 const devUrl = process.env.VITE_DEV_SERVER_URL;
 
@@ -16,7 +17,7 @@ const identities = () => (identityStore ??= new IdentityStore(app.getPath('userD
 
 // ─── Mumble TLS connections, one per renderer request ─────────────────────────
 
-type Conn = ReturnType<typeof openTls> & { owner: WebContents };
+type Conn = ReturnType<typeof openTls> & { owner: WebContents; udp?: ReturnType<typeof udpChannel> };
 const conns = new Map<string, Conn>();
 
 // ─── Identities (client certificates) ─────────────────────────────────────────
@@ -54,9 +55,19 @@ ipcMain.handle('mumble:open', async (e, connId: string, host: string, port: numb
   const owner = e.sender;
   const emit = (channel: string, ...args: unknown[]) => { if (!owner.isDestroyed()) owner.send(channel, connId, ...args); };
   const conn = openTls(String(host), Number(port) || 64738, id.certPem, id.keyPem, {
-    onSecure: info => emit('mumble:secure', info),
+    onSecure: info => {
+      // Encrypted UDP voice to the address the TLS connection actually reached
+      const udp = udpChannel(info.address, info.port);
+      udp.onVoice = p => emit('mumble:udpVoice', p);
+      udp.onState = (ok, rtt) => emit('mumble:udpState', ok, rtt);
+      udp.onResync = () => emit('mumble:udpResync');
+      const c = conns.get(connId);
+      if (c) c.udp = udp;
+      else udp.close();
+      emit('mumble:secure', info);
+    },
     onData: chunk => emit('mumble:data', chunk),
-    onClose: reason => { conns.delete(connId); emit('mumble:close', reason); }
+    onClose: reason => { conns.get(connId)?.udp?.close(); conns.delete(connId); emit('mumble:close', reason); }
   });
   conns.set(connId, Object.assign(conn, { owner }));
   owner.once('destroyed', () => conn.close());
@@ -67,6 +78,17 @@ ipcMain.on('mumble:send', (e, connId: string, bytes: Uint8Array) => {
   if (conn && conn.owner === e.sender) conn.send(bytes);
 });
 
+// UDP voice: keys from the server's CryptSetup, voice packets, nonce resync
+const ownUdp = (e: Electron.IpcMainEvent | Electron.IpcMainInvokeEvent, connId: string) => {
+  const conn = conns.get(connId);
+  return conn && conn.owner === e.sender ? conn.udp : undefined;
+};
+ipcMain.on('mumble:udpSetup', (e, connId: string, key: Uint8Array, cn: Uint8Array, sn: Uint8Array, protobuf: boolean) =>
+  ownUdp(e, connId)?.setup(new Uint8Array(key), new Uint8Array(cn), new Uint8Array(sn), !!protobuf));
+ipcMain.on('mumble:udpNonce', (e, connId: string, sn: Uint8Array) => ownUdp(e, connId)?.setServerNonce(new Uint8Array(sn)));
+ipcMain.on('mumble:udpSend', (e, connId: string, bytes: Uint8Array) => ownUdp(e, connId)?.send(new Uint8Array(bytes)));
+ipcMain.handle('mumble:udpClientNonce', (e, connId: string) => ownUdp(e, connId)?.clientNonce() ?? null);
+
 ipcMain.on('mumble:close', (e, connId: string) => {
   const conn = conns.get(connId);
   if (conn && conn.owner === e.sender) conn.close();
@@ -114,6 +136,8 @@ function createWindow() {
     minHeight: 480,
     backgroundColor: '#111214',
     title: 'mumh5',
+    // Window and taskbar icon on Linux (Windows and macOS take it from the package)
+    icon: path.join(__dirname, '../dist/icon.png'),
     autoHideMenuBar: true,
     webPreferences: {
       preload: path.join(__dirname, 'preload.cjs'),

electron/ocb2.ts

@@ -0,0 +1,199 @@
+import { createCipheriv, createDecipheriv } from 'node:crypto';
+
+// Mumble's UDP encryption: OCB2-AES128 with 4-byte packet headers (IV byte + 3 tag bytes),
+// ported from Mumble's CryptStateOCB2.cpp including its counter-measures against the
+// XEX* attack (https://eprint.iacr.org/2019/311, section 9).
+
+const BLOCK = 16;
+
+function aes(key: Buffer, block: Buffer): Buffer {
+  const c = createCipheriv('aes-128-ecb', key, null);
+  c.setAutoPadding(false);
+  return c.update(block);
+}
+
+function aesDecrypt(key: Buffer, block: Buffer): Buffer {
+  const d = createDecipheriv('aes-128-ecb', key, null);
+  d.setAutoPadding(false);
+  return d.update(block);
+}
+
+function xor(a: Buffer, b: Buffer): Buffer {
+  const out = Buffer.alloc(BLOCK);
+  for (let i = 0; i < BLOCK; i++) out[i] = a[i] ^ b[i];
+  return out;
+}
+
+// Multiply by x in GF(2^128), big endian
+function times2(b: Buffer): Buffer {
+  const out = Buffer.alloc(BLOCK);
+  const carry = b[0] >> 7;
+  for (let i = 0; i < BLOCK - 1; i++) out[i] = ((b[i] << 1) | (b[i + 1] >> 7)) & 0xff;
+  out[BLOCK - 1] = ((b[BLOCK - 1] << 1) ^ (carry * 0x87)) & 0xff;
+  return out;
+}
+
+const times3 = (b: Buffer) => xor(b, times2(b));
+
+// Returns [ciphertext, tag, ok]; ok is false only when an attack pattern was seen and
+// modifyOnAttack is off (used by tests)
+export function ocbEncrypt(key: Buffer, plain: Buffer, nonce: Buffer, modifyOnAttack = true): [Buffer, Buffer, boolean] {
+  let delta: Buffer = aes(key, nonce);
+  let checksum: Buffer = Buffer.alloc(BLOCK);
+  const out = Buffer.alloc(plain.length);
+  let ok = true;
+  let off = 0;
+  let len = plain.length;
+  while (len > BLOCK) {
+    const block = plain.subarray(off, off + BLOCK);
+    let flip = false;
+    if (len - BLOCK <= BLOCK) {
+      let sum = 0;
+      for (let i = 0; i < BLOCK - 1; i++) sum |= block[i];
+      if (sum === 0) {
+        if (modifyOnAttack) flip = true;
+        else ok = false;
+      }
+    }
+    delta = times2(delta);
+    const tmp = xor(delta, block);
+    if (flip) tmp[0] ^= 1;
+    xor(delta, aes(key, tmp)).copy(out, off);
+    checksum = xor(checksum, block);
+    if (flip) checksum[0] ^= 1;
+    len -= BLOCK;
+    off += BLOCK;
+  }
+  delta = times2(delta);
+  const lenBlock = Buffer.alloc(BLOCK);
+  lenBlock[BLOCK - 1] = (len * 8) & 0xff;
+  const pad = aes(key, xor(lenBlock, delta));
+  const tmp = Buffer.from(pad);
+  plain.copy(tmp, 0, off, off + len);
+  checksum = xor(checksum, tmp);
+  xor(pad, tmp).copy(out, off, 0, len);
+  delta = times3(delta);
+  const tag = aes(key, xor(delta, checksum));
+  return [out, tag, ok];
+}
+
+export function ocbDecrypt(key: Buffer, encrypted: Buffer, nonce: Buffer): [Buffer, Buffer, boolean] {
+  let delta: Buffer = aes(key, nonce);
+  let checksum: Buffer = Buffer.alloc(BLOCK);
+  const out = Buffer.alloc(encrypted.length);
+  let off = 0;
+  let len = encrypted.length;
+  while (len > BLOCK) {
+    delta = times2(delta);
+    const plainBlock = xor(delta, aesDecrypt(key, xor(delta, encrypted.subarray(off, off + BLOCK))));
+    plainBlock.copy(out, off);
+    checksum = xor(checksum, plainBlock);
+    len -= BLOCK;
+    off += BLOCK;
+  }
+  delta = times2(delta);
+  const lenBlock = Buffer.alloc(BLOCK);
+  lenBlock[BLOCK - 1] = (len * 8) & 0xff;
+  const pad = aes(key, xor(lenBlock, delta));
+  const tmp = Buffer.alloc(BLOCK);
+  encrypted.copy(tmp, 0, off, off + len);
+  const last = xor(tmp, pad);
+  checksum = xor(checksum, last);
+  last.copy(out, off, 0, len);
+  // Attack check: the decrypted last block must not equal delta (all but the length byte)
+  const ok = !last.subarray(0, BLOCK - 1).equals(delta.subarray(0, BLOCK - 1));
+  delta = times3(delta);
+  const tag = aes(key, xor(delta, checksum));
+  return [out, tag, ok];
+}
+
+export class CryptState {
+  private key = Buffer.alloc(BLOCK);
+  encryptIv = Buffer.alloc(BLOCK);
+  decryptIv = Buffer.alloc(BLOCK);
+  private history = new Uint8Array(256);
+  valid = false;
+  good = 0;
+  late = 0;
+  lost = 0;
+  resync = 0;
+  lastGood = 0;
+
+  setKey(key: Uint8Array, clientNonce: Uint8Array, serverNonce: Uint8Array): void {
+    this.key = Buffer.from(key);
+    this.encryptIv = Buffer.from(clientNonce);
+    this.decryptIv = Buffer.from(serverNonce);
+    this.history.fill(0);
+    this.valid = this.key.length === BLOCK && this.encryptIv.length === BLOCK && this.decryptIv.length === BLOCK;
+  }
+
+  setDecryptIv(iv: Uint8Array): void {
+    this.decryptIv = Buffer.from(iv);
+    this.resync++;
+  }
+
+  encrypt(plain: Uint8Array): Buffer {
+    for (let i = 0; i < BLOCK; i++) {
+      this.encryptIv[i] = (this.encryptIv[i] + 1) & 0xff;
+      if (this.encryptIv[i]) break;
+    }
+    const [ct, tag] = ocbEncrypt(this.key, Buffer.from(plain), this.encryptIv);
+    const out = Buffer.alloc(ct.length + 4);
+    out[0] = this.encryptIv[0];
+    tag.copy(out, 1, 0, 3);
+    ct.copy(out, 4);
+    return out;
+  }
+
+  // Mirrors CryptStateOCB2::decrypt: accepts late and out-of-order packets, rejects replays
+  decrypt(packet: Uint8Array): Buffer | null {
+    if (!this.valid || packet.length < 4) return null;
+    const src = Buffer.from(packet);
+    const save = Buffer.from(this.decryptIv);
+    const ivbyte = src[0];
+    const iv = this.decryptIv;
+    let restore = false;
+    let late = 0, lost = 0;
+
+    if (((iv[0] + 1) & 0xff) === ivbyte) {
+      if (ivbyte > iv[0]) iv[0] = ivbyte;
+      else if (ivbyte < iv[0]) {
+        iv[0] = ivbyte;
+        for (let i = 1; i < BLOCK; i++) if ((iv[i] = (iv[i] + 1) & 0xff)) break;
+      } else return null;
+    } else {
+      let diff = ivbyte - iv[0];
+      if (diff > 128) diff -= 256;
+      else if (diff < -128) diff += 256;
+      if (ivbyte < iv[0] && diff > -30 && diff < 0) {
+        late = 1; lost = -1; iv[0] = ivbyte; restore = true;
+      } else if (ivbyte > iv[0] && diff > -30 && diff < 0) {
+        late = 1; lost = -1; iv[0] = ivbyte;
+        for (let i = 1; i < BLOCK; i++) { const was = iv[i]; iv[i] = (was - 1) & 0xff; if (was) break; }
+        restore = true;
+      } else if (ivbyte > iv[0] && diff > 0) {
+        lost = ivbyte - iv[0] - 1; iv[0] = ivbyte;
+      } else if (ivbyte < iv[0] && diff > 0) {
+        lost = 256 - iv[0] + ivbyte - 1; iv[0] = ivbyte;
+        for (let i = 1; i < BLOCK; i++) if ((iv[i] = (iv[i] + 1) & 0xff)) break;
+      } else return null;
+      if (this.history[iv[0]] === iv[1]) {
+        save.copy(this.decryptIv);
+        return null;
+      }
+    }
+
+    const [plain, tag, ok] = ocbDecrypt(this.key, src.subarray(4), iv);
+    if (!ok || !tag.subarray(0, 3).equals(src.subarray(1, 4))) {
+      save.copy(this.decryptIv);
+      return null;
+    }
+    this.history[iv[0]] = iv[1];
+    if (restore) save.copy(this.decryptIv);
+    this.good++;
+    this.late = Math.max(0, this.late + late);
+    this.lost = Math.max(0, this.lost + lost);
+    this.lastGood = Date.now();
+    return plain;
+  }
+}

electron/preload.ts

@@ -1,7 +1,10 @@
 import { contextBridge, ipcRenderer } from 'electron';
 
 type Listener = (connId: string, ...args: any[]) => void;
-const listeners = { secure: new Set<Listener>(), data: new Set<Listener>(), close: new Set<Listener>() };
+const listeners = {
+  secure: new Set<Listener>(), data: new Set<Listener>(), close: new Set<Listener>(),
+  udpVoice: new Set<Listener>(), udpState: new Set<Listener>(), udpResync: new Set<Listener>()
+};
 for (const key of Object.keys(listeners) as (keyof typeof listeners)[]) {
   ipcRenderer.on(`mumble:${key}`, (_e, connId: string, ...args: any[]) => {
     for (const fn of listeners[key]) fn(connId, ...args);
@@ -34,6 +37,10 @@ contextBridge.exposeInMainWorld('mumh5Native', {
   open: (connId: string, host: string, port: number, identityId?: string) => ipcRenderer.invoke('mumble:open', connId, host, port, identityId),
   send: (connId: string, bytes: Uint8Array) => ipcRenderer.send('mumble:send', connId, bytes),
   close: (connId: string) => ipcRenderer.send('mumble:close', connId),
+  udpSetup: (connId: string, key: Uint8Array, cn: Uint8Array, sn: Uint8Array, protobuf: boolean) => ipcRenderer.send('mumble:udpSetup', connId, key, cn, sn, protobuf),
+  udpNonce: (connId: string, sn: Uint8Array) => ipcRenderer.send('mumble:udpNonce', connId, sn),
+  udpSend: (connId: string, bytes: Uint8Array) => ipcRenderer.send('mumble:udpSend', connId, bytes),
+  udpClientNonce: (connId: string) => ipcRenderer.invoke('mumble:udpClientNonce', connId),
   on: (event: keyof typeof listeners, fn: Listener) => {
     listeners[event].add(fn);
     return () => listeners[event].delete(fn);

electron/tls-transport.ts

@@ -2,7 +2,7 @@ import tls from 'node:tls';
 import { describeCert, type CertDetails } from './certs.ts';
 
 export interface TlsHandlers {
-  onSecure(info: { fingerprint: string; authorized: boolean; authError: string | null; chain: CertDetails[] }): void;
+  onSecure(info: { fingerprint: string; authorized: boolean; authError: string | null; chain: CertDetails[]; address: string; port: number }): void;
   onData(chunk: Uint8Array): void;
   onClose(reason: string): void;
 }
@@ -35,6 +35,9 @@ export function openTls(host: string, port: number, cert: string, key: string, h
     }
     h.onSecure({
       chain,
+      // The server's actual IP, so UDP voice goes to the same machine as the TCP connection
+      address: socket.remoteAddress ?? host,
+      port: socket.remotePort ?? port,
       fingerprint: chain[0]?.fingerprint256 ?? '',
       authorized: socket.authorized,
       authError: socket.authorizationError ? String(socket.authorizationError) : null

electron/udp-voice.ts

@@ -0,0 +1,145 @@
+import dgram from 'node:dgram';
+import net from 'node:net';
+import { CryptState } from './ocb2.ts';
+import { writeVarint, readVarint } from '../src/core/voice-packet.ts';
+import { MumbleUDP } from '../src/core/mumble-udp-pb.js';
+import type { UdpChannel } from '../src/core/transport.ts';
+
+// Encrypted UDP voice channel to a Mumble server. Voice uses UDP only while the server
+// answers our UDP pings; until then (and if it stops) the client keeps using the TCP tunnel.
+
+export interface UdpCallbacks {
+  onVoice(plain: Uint8Array): void;
+  onState(ok: boolean, rtt: number): void;
+  onResync(): void;          // too many decrypt failures: ask the server for a fresh nonce
+}
+
+const PING_MS = 2000;
+const DEAD_MS = 8000;
+
+export class UdpVoice {
+  readonly crypt = new CryptState();
+  ok = false;
+  rtt = 0;
+  private sock: dgram.Socket;
+  private protobuf = true;
+  private pingTimer: ReturnType<typeof setInterval> | null = null;
+  private lastPong = 0;
+  private failures = 0;
+  private lastResync = 0;
+  private closed = false;
+  private host: string;
+  private port: number;
+  private cb: UdpCallbacks;
+
+  constructor(host: string, port: number, cb: UdpCallbacks) {
+    this.host = host;
+    this.port = port;
+    this.cb = cb;
+    this.sock = dgram.createSocket(net.isIPv6(host) ? 'udp6' : 'udp4');
+    this.sock.on('message', msg => this.receive(msg));
+    this.sock.on('error', () => this.setOk(false));
+  }
+
+  setup(key: Uint8Array, clientNonce: Uint8Array, serverNonce: Uint8Array, protobuf: boolean): void {
+    this.crypt.setKey(key, clientNonce, serverNonce);
+    this.protobuf = protobuf;
+    if (!this.pingTimer) {
+      this.ping();
+      this.pingTimer = setInterval(() => this.ping(), PING_MS);
+    }
+  }
+
+  setServerNonce(nonce: Uint8Array): void {
+    this.crypt.setDecryptIv(nonce);
+    this.failures = 0;
+  }
+
+  send(plain: Uint8Array): void {
+    if (this.closed || !this.crypt.valid) return;
+    const packet = this.crypt.encrypt(plain);
+    this.sock.send(packet, this.port, this.host);
+  }
+
+  private ping(): void {
+    if (this.lastPong && Date.now() - this.lastPong > DEAD_MS) this.setOk(false);
+    const ts = Date.now();
+    if (this.protobuf) {
+      const body: Uint8Array = MumbleUDP.Ping.encode(MumbleUDP.Ping.fromObject({ timestamp: ts })).finish();
+      const out = new Uint8Array(body.length + 1);
+      out[0] = 1;
+      out.set(body, 1);
+      this.send(out);
+    } else {
+      const out: number[] = [1 << 5];
+      writeVarint(out, ts);
+      this.send(new Uint8Array(out));
+    }
+  }
+
+  private receive(msg: Buffer): void {
+    const plain = this.crypt.decrypt(msg);
+    if (!plain) {
+      // Repeated failures mean the nonces drifted apart; ask for a resync now and then
+      if (++this.failures > 8 && Date.now() - this.lastResync > 5000) {
+        this.lastResync = Date.now();
+        this.failures = 0;
+        this.cb.onResync();
+      }
+      return;
+    }
+    this.failures = 0;
+    const pingTs = this.pingTimestamp(plain);
+    if (pingTs != null) {
+      this.lastPong = Date.now();
+      this.rtt = Math.max(0, Date.now() - pingTs);
+      this.setOk(true);
+      return;
+    }
+    this.cb.onVoice(new Uint8Array(plain));
+  }
+
+  private pingTimestamp(p: Buffer): number | null {
+    try {
+      if (p[0] === 1 && this.protobuf) return Number(MumbleUDP.Ping.toObject(MumbleUDP.Ping.decode(p.subarray(1)), { longs: Number }).timestamp);
+      if (p[0] >> 5 === 1 && !this.protobuf) return readVarint(p, 1)[0];
+    } catch { /* not a ping */ }
+    return null;
+  }
+
+  private setOk(ok: boolean): void {
+    if (ok === this.ok) {
+      if (ok) this.cb.onState(true, this.rtt);
+      return;
+    }
+    this.ok = ok;
+    this.cb.onState(ok, this.rtt);
+  }
+
+  close(): void {
+    this.closed = true;
+    if (this.pingTimer) clearInterval(this.pingTimer);
+    try { this.sock.close(); } catch { /* closed */ }
+  }
+}
+
+// UdpVoice behind the client's UdpChannel interface (used directly in Node, bridged over IPC in the app)
+export function udpChannel(host: string, port: number): UdpChannel & { close(): void; voice: UdpVoice } {
+  const ch: UdpChannel & { close(): void; voice: UdpVoice } = {
+    onVoice: null, onState: null, onResync: null,
+    setup: (k, c, s, p) => voice.setup(k, c, s, p),
+    setServerNonce: n => voice.setServerNonce(n),
+    clientNonce: () => Promise.resolve(voice.crypt.valid ? new Uint8Array(voice.crypt.encryptIv) : null),
+    send: p => voice.send(p),
+    close: () => voice.close(),
+    voice: null as unknown as UdpVoice
+  };
+  const voice = new UdpVoice(host, port, {
+    onVoice: p => ch.onVoice?.(p),
+    onState: (ok, rtt) => ch.onState?.(ok, rtt),
+    onResync: () => ch.onResync?.()
+  });
+  ch.voice = voice;
+  return ch;
+}
+

package.json

@@ -2,7 +2,7 @@
   "name": "mumh5",
   "productName": "mumh5",
   "version": "0.1.0",
-  "description": "Modern Mumble client with rich chat, file sharing and video",
+  "description": "A modern Mumble client: Discord-like interface, file sharing, voice and more, for any Mumble server",
   "license": "MIT",
   "type": "module",
   "main": "dist-electron/main.cjs",
@@ -26,24 +26,37 @@
     "files": [
       "dist/**",
       "dist-electron/**",
+      "!dist-electron/*.map",
       "package.json",
       "LICENSE",
       "THIRD_PARTY_NOTICES.md"
     ],
     "directories": {
-      "output": "release"
+      "output": "release",
+      "buildResources": "build"
     },
     "linux": {
       "target": [
         "AppImage",
-        "deb"
+        "deb",
+        "tar.gz"
       ],
-      "category": "Network"
+      "category": "Network",
+      "executableName": "mumh5",
+      "synopsis": "Modern Mumble client",
+      "desktop": {
+        "entry": {
+          "StartupWMClass": "mumh5",
+          "Keywords": "mumble;voice;chat;voip;"
+        }
+      },
+      "syncDesktopName": true
     },
     "win": {
       "target": [
         "nsis"
-      ]
+      ],
+      "icon": "build/icon.png"
     },
     "mac": {
       "target": [
@@ -54,6 +67,22 @@
         "NSMicrophoneUsageDescription": "mumh5 uses the microphone for voice chat.",
         "NSCameraUsageDescription": "mumh5 uses the camera for video chat."
       }
+    },
+    "icon": "build/icon.png",
+    "artifactName": "${productName}-${version}-${os}-${arch}.${ext}",
+    "deb": {
+      "depends": [
+        "libnotify4",
+        "libxtst6",
+        "libnss3",
+        "libasound2 | libasound2t64"
+      ]
+    },
+    "nsis": {
+      "oneClick": false,
+      "allowToChangeInstallationDirectory": true,
+      "perMachine": false,
+      "shortcutName": "mumh5"
     }
   },
   "devDependencies": {
@@ -81,9 +110,14 @@
     "esbuild@0.28.2": true,
     "electron-winstaller": false
   },
-  "author": "Kibi Kelburton",
+  "author": {
+    "name": "Kibi Kelburton",
+    "email": "git@f0ck.it"
+  },
   "repository": {
     "type": "git",
     "url": "gitea@git.lat:kibi/mumh5.git"
-  }
+  },
+  "homepage": "https://git.lat/kibi/mumh5",
+  "desktopName": "mumh5.desktop"
 }

src/App.svelte

@@ -14,6 +14,7 @@
   import UserInfoDialog from './ui/UserInfoDialog.svelte';
   import ChannelDialog from './ui/ChannelDialog.svelte';
   import PublicServers from './ui/PublicServers.svelte';
+  import ResizeHandle from './ui/ResizeHandle.svelte';
   import { identities } from './lib/identities.svelte.ts';
   import { session } from './lib/session.svelte.ts';
   import { ui } from './lib/ui.svelte.ts';
@@ -23,6 +24,13 @@
   // wide: rail + sidebar + chat + panel; medium: panel as an overlay; narrow: everything but chat in drawers
   const layout = $derived(width >= 1100 ? 'wide' : width >= 760 ? 'medium' : 'narrow');
 
+  // Arrangement (Appearance setting): side is the default, classic puts the channel list right
+  // of the chat, stacked above it. Phones always use drawers.
+  const arrangement = $derived(layout === 'narrow' ? 'side' : store.settings.arrangement ?? 'side');
+  // The member panel sits inline only in the side arrangement on wide windows, otherwise it overlays
+  const panelInline = $derived(layout === 'wide' && arrangement === 'side');
+  let treeHeight = $state(Math.max(120, Number((() => { try { return localStorage.getItem('mumh5.treeHeight'); } catch { return null; } })()) || 280));
+
   let navOpen = $state(false);
   let editing = $state<{ server: SavedServer | null } | null>(null);
 
@@ -35,12 +43,13 @@
     else delete document.documentElement.dataset.theme;
   });
 
-  // The panel starts open on wide layouts only
+  // The panel starts open only where it sits inline
   let lastLayout = '';
   $effect(() => {
-    if (layout === lastLayout) return;
+    const key = `${layout}/${arrangement}`;
-    ui.panelOpen = layout === 'wide';
+    if (key === lastLayout) return;
-    lastLayout = layout;
+    ui.panelOpen = panelInline;
+    lastLayout = key;
   });
   // On phones one drawer at a time
   $effect(() => { if (layout === 'narrow' && ui.panelOpen) navOpen = false; });
@@ -53,26 +62,48 @@
 
   const closeOverlays = () => {
     navOpen = false;
-    if (layout !== 'wide') ui.panelOpen = false;
+    if (!panelInline) ui.panelOpen = false;
   };
 </script>
 
 <svelte:window bind:innerWidth={width} />
 
-<div class="app {layout}">
+{#snippet rail()}
-  {#if layout !== 'narrow' || navOpen}
-    <div class="nav" class:drawer={layout === 'narrow'}>
   <ServerRail onadd={() => (editing = { server: null })} onedit={s => (editing = { server: s })} onbrowse={() => (ui.publicServers = true)}
     onsettings={() => (ui.settingsOpen = true)} />
+{/snippet}
+{#snippet chat()}
+  <Chat showMenu={layout === 'narrow'} showStage={!panelInline && arrangement === 'side'} onmenu={() => (navOpen = true)} onpanel={togglePanel} />
+{/snippet}
+
+<div class="app {layout} {arrangement}">
+  {#if arrangement === 'classic'}
+    {@render rail()}
+    {@render chat()}
+    <Sidebar handleEdge="left" onnavigate={() => {}} />
+  {:else if arrangement === 'stacked'}
+    {@render rail()}
+    <div class="stack">
+      <div class="tree" style:height="{treeHeight}px">
+        <Sidebar fill onnavigate={() => {}} />
+        <ResizeHandle bind:width={treeHeight} edge="bottom" min={120} max={() => window.innerHeight - 220} initial={280}
+          storageKey="mumh5.treeHeight" label="Resize channel list" />
+      </div>
+      {@render chat()}
+    </div>
+  {:else}
+    {#if layout !== 'narrow' || navOpen}
+      <div class="nav" class:drawer={layout === 'narrow'}>
+        {@render rail()}
         <Sidebar resizable={layout !== 'narrow'} onnavigate={() => { if (layout === 'narrow') navOpen = false; }} />
       </div>
       {#if layout === 'narrow'}<button class="scrim" aria-label="Close" onclick={() => (navOpen = false)}></button>{/if}
     {/if}
-
+    {@render chat()}
-  <Chat showMenu={layout === 'narrow'} showStage={layout !== 'wide'} onmenu={() => (navOpen = true)} onpanel={togglePanel} />
+  {/if}
 
   {#if showPanel}
-    {#if layout === 'wide'}
+    {#if panelInline}
       <RightPanel onnavigate={() => {}} onclose={() => (ui.panelOpen = false)} />
     {:else}
       <button class="scrim" aria-label="Close" onclick={() => (ui.panelOpen = false)}></button>
@@ -104,6 +135,9 @@
   .nav { display: flex; flex: none; min-height: 0; }
   .nav.drawer { position: absolute; z-index: 20; top: 0; bottom: 0; left: 0; max-width: calc(100% - 48px); box-shadow: 8px 0 32px rgb(0 0 0 / 0.4); }
   .nav.drawer :global(.sidebar) { width: min(260px, calc(100vw - 68px - 48px)); }
+  .stack { flex: 1; min-width: 0; display: flex; flex-direction: column; }
+  .stack > :global(.chat) { flex: 1; min-height: 0; }
+  .tree { position: relative; z-index: 1; flex: none; display: flex; min-height: 0; border-bottom: 1px solid var(--line); }
   .scrim { position: absolute; inset: 0; z-index: 15; background: rgb(0 0 0 / 0.5); }
   .panel-drawer { position: absolute; z-index: 20; top: 0; right: 0; bottom: 0; max-width: calc(100% - 48px); display: flex; box-shadow: -8px 0 32px rgb(0 0 0 / 0.4); }
 </style>

src/core/client.ts

@@ -156,6 +156,7 @@ type ClientEvents = {
   reject: (type: number, reason: string) => void;
   voice: (packet: Uint8Array) => void;
   userStats: (stats: any) => void;
+  udp: (ok: boolean, rtt: number) => void;
   acl: (acl: ChannelAcl) => void;
   userNames: (names: Map<number, string>) => void;
   permissions: (channelId: number | null, bits: number) => void;
@@ -178,6 +179,11 @@ export class MumbleClient extends Emitter<ClientEvents> {
   serverVersion = '';
   // Numeric server version (major << 16 | minor << 8 | patch), 0 until known
   serverVersionNum = 0;
+  // Voice goes over encrypted UDP while the server answers our UDP pings, otherwise over TCP
+  udpOk = false;
+  udpRtt = 0;
+  // Force the TCP tunnel even when UDP would work (for networks that mangle UDP)
+  forceTcp = false;
   rtt = 0;
   config: ServerConfig = { allowHtml: true, messageLength: 5000, imageMessageLength: 131072, maxUsers: 0, recordingAllowed: true };
 
@@ -203,6 +209,18 @@ export class MumbleClient extends Emitter<ClientEvents> {
 
   connect(transport: Transport, opts: ConnectOptions): void {
     this.transport = transport;
+    const udp = transport.udp;
+    if (udp) {
+      udp.onVoice = plain => { if (!this.closed) this.emit('voice', plain); };
+      udp.onState = (ok, rtt) => {
+        const changed = ok !== this.udpOk;
+        this.udpOk = ok;
+        this.udpRtt = rtt;
+        if (changed) this.emit('udp', ok, rtt);
+      };
+      // Ask the server for a fresh nonce (an empty CryptSetup)
+      udp.onResync = () => this.send('CryptSetup', {});
+    }
     transport.onData = chunk => {
       try {
         this.reader.push(chunk, (id, body) => this.handleFrame(id, body));
@@ -409,6 +427,12 @@ export class MumbleClient extends Emitter<ClientEvents> {
     });
   }
 
+  // Voice over UDP when it works, else through the TCP tunnel
+  sendVoice(packet: Uint8Array): void {
+    if (this.udpOk && !this.forceTcp && this.transport?.udp) this.transport.udp.send(packet);
+    else this.sendVoiceTunnel(packet);
+  }
+
   // Voice over TCP: the UDPTunnel body is the raw voice packet, not a protobuf message
   sendVoiceTunnel(packet: Uint8Array): void {
     if (!this.transport || this.closed) return;
@@ -529,6 +553,19 @@ export class MumbleClient extends Emitter<ClientEvents> {
       case 'UserStats':
         this.emit('userStats', msg);
         break;
+      case 'CryptSetup': {
+        const udp = this.transport?.udp;
+        if (!udp || this.forceTcp) break;
+        if (msg.key?.length && msg.client_nonce?.length && msg.server_nonce?.length) {
+          udp.setup(msg.key, msg.client_nonce, msg.server_nonce, this.protobufVoice);
+        } else if (msg.server_nonce?.length) {
+          udp.setServerNonce(msg.server_nonce);
+        } else {
+          // The server asks for our nonce to resync its side
+          udp.clientNonce().then(n => { if (n) this.send('CryptSetup', { client_nonce: n }); });
+        }
+        break;
+      }
       case 'ACL': {
         // proto2 defaults: missing booleans are true
         const t = (v: unknown) => v !== false;

src/core/transport.ts

@@ -4,6 +4,18 @@ export interface Transport {
   close(): void;
   onData: ((chunk: Uint8Array) => void) | null;
   onClose: ((reason: string) => void) | null;
+  // Encrypted UDP for voice, where the platform has it (desktop); absent on the web
+  udp?: UdpChannel;
+}
+
+export interface UdpChannel {
+  setup(key: Uint8Array, clientNonce: Uint8Array, serverNonce: Uint8Array, protobuf: boolean): void;
+  setServerNonce(nonce: Uint8Array): void;
+  clientNonce(): Promise<Uint8Array | null>;
+  send(plain: Uint8Array): void;
+  onVoice: ((plain: Uint8Array) => void) | null;
+  onState: ((ok: boolean, rtt: number) => void) | null;
+  onResync: (() => void) | null;
 }
 
 export interface ConnectTarget {

src/lib/audio/voice.svelte.ts

@@ -21,6 +21,7 @@ export interface VoiceSettings {
   bitrate: number;           // Opus bits per second
   frameMs: 10 | 20 | 40 | 60;
   jitterMs: number;
+  forceTcp: boolean;         // send voice through the TCP connection even when UDP works
   // Per-user local volume and mute, keyed by certificate hash (or name without one)
   userVolumes: Record<string, number>;
   localMutes: Record<string, boolean>;
@@ -41,6 +42,7 @@ const defaults: VoiceSettings = {
   bitrate: 40000,
   frameMs: 20,
   jitterMs: 60,
+  forceTcp: false,
   userVolumes: {},
   localMutes: {}
 };
@@ -337,7 +339,7 @@ class VoiceEngine {
   private sendPacket(opus: Uint8Array, last: boolean): void {
     const client = this.client;
     if (!client) return;
-    client.sendVoiceTunnel(encodeVoice({ target: 0, frame: this.frameCounter, opus, last }, client.protobufVoice));
+    client.sendVoice(encodeVoice({ target: 0, frame: this.frameCounter, opus, last }, client.protobufVoice));
     this.frameCounter += this.settings.frameMs / 10;
     this.stats.sent++;
   }

src/lib/native.ts

@@ -1,4 +1,4 @@
-import type { Transport, ServerCertInfo, CertDetails } from '../core/transport.ts';
+import type { Transport, ServerCertInfo, CertDetails, UdpChannel } from '../core/transport.ts';
 
 interface NativeApi {
   platformInfo(): Promise<{ os: string; osVersion: string }>;
@@ -25,7 +25,11 @@ interface NativeApi {
   open(connId: string, host: string, port: number, identityId?: string): Promise<void>;
   send(connId: string, bytes: Uint8Array): void;
   close(connId: string): void;
-  on(event: 'secure' | 'data' | 'close', fn: (connId: string, ...args: any[]) => void): () => void;
+  on(event: 'secure' | 'data' | 'close' | 'udpVoice' | 'udpState' | 'udpResync', fn: (connId: string, ...args: any[]) => void): () => void;
+  udpSetup(connId: string, key: Uint8Array, cn: Uint8Array, sn: Uint8Array, protobuf: boolean): void;
+  udpNonce(connId: string, sn: Uint8Array): void;
+  udpSend(connId: string, bytes: Uint8Array): void;
+  udpClientNonce(connId: string): Promise<Uint8Array | null>;
 }
 
 // What Electron reports for a right-click without a custom menu
@@ -76,6 +80,7 @@ export class ElectronTransport implements Transport {
   onData: ((chunk: Uint8Array) => void) | null = null;
   onClose: ((reason: string) => void) | null = null;
   readonly secure: Promise<ServerCertInfo>;
+  udp: UdpChannel;
   private id = crypto.randomUUID();
   private offs: (() => void)[] = [];
   private api: NativeApi;
@@ -86,7 +91,19 @@ export class ElectronTransport implements Transport {
     let rejectSecure!: (e: Error) => void;
     this.secure = new Promise((res, rej) => { resolveSecure = res; rejectSecure = rej; });
     const id = this.id;
+    // UDP voice lives in the main process; this bridges it to the client's UdpChannel
+    const udp: UdpChannel = {
+      onVoice: null, onState: null, onResync: null,
+      setup: (k, c, s, p) => api.udpSetup(id, k, c, s, p),
+      setServerNonce: n => api.udpNonce(id, n),
+      clientNonce: () => api.udpClientNonce(id),
+      send: p => api.udpSend(id, p)
+    };
+    this.udp = udp;
     this.offs.push(
+      api.on('udpVoice', (cid, p) => { if (cid === id) udp.onVoice?.(p); }),
+      api.on('udpState', (cid, ok, rtt) => { if (cid === id) udp.onState?.(ok, rtt); }),
+      api.on('udpResync', cid => { if (cid === id) udp.onResync?.(); }),
       api.on('secure', (cid, info) => { if (cid === id) resolveSecure(info); }),
       api.on('data', (cid, chunk) => { if (cid === id) this.onData?.(chunk); }),
       api.on('close', (cid, reason) => {

src/lib/session.svelte.ts

@@ -161,6 +161,14 @@ export class Session {
     this.expanded = all;
   }
 
+  // How voice travels right now
+  get voiceTransport(): { udp: boolean; rtt: number } {
+    void this.tick;
+    const c = this.client;
+    // The setting (reactive) rather than the client's copy, so toggling it updates the view
+    return { udp: !!c && c.udpOk && !voice.settings.forceTcp, rtt: c?.udpRtt ?? 0 };
+  }
+
   // true / false when known, null when the server has not told us yet
   can(channelId: number, bit: number): boolean | null {
     void this.tick;
@@ -236,6 +244,7 @@ export class Session {
     }
 
     const client = new MumbleClient(codec);
+    client.forceTcp = voice.settings.forceTcp;
     this.client = client;
     this.wire(client);
     // TLS is up but the server may still never finish the login
@@ -309,6 +318,7 @@ export class Session {
       bump();
     });
     client.on('ping', rtt => { if (live()) this.rtt = rtt; });
+    client.on('udp', bump);
 
     client.on('user', (user, changed, actor, isNew) => {
       if (!live()) return;

src/lib/settings.svelte.ts

@@ -23,8 +23,12 @@ export interface Settings {
   linkPreviews: 'host' | 'direct' | 'off';
   theme: ThemeId;
   publicListUrl: string;  // where the public server list comes from
+  arrangement: Arrangement;
 }
 
+// Window layouts; classic and stacked follow the Mumble desktop client's layouts of the same name
+export type Arrangement = 'side' | 'classic' | 'stacked';
+
 export type ThemeId = 'dark' | 'light' | 'midnight' | 'frost' | 'win95';
 
 export const THEMES: { id: ThemeId; name: string; note: string }[] = [
@@ -45,7 +49,8 @@ const defaults: Settings = {
   youtube: 'click',
   linkPreviews: 'host',
   theme: 'dark',
-  publicListUrl: 'https://publist.mumble.info/v1/list?version=1.5.0'
+  publicListUrl: 'https://publist.mumble.info/v1/list?version=1.5.0',
+  arrangement: 'side'
 };
 
 class SettingsStore {

src/ui/AppearanceSettings.svelte

@@ -1,5 +1,16 @@
 <script lang="ts">
-  import { store, THEMES, type ThemeId } from '../lib/settings.svelte.ts';
+  import { store, THEMES, type ThemeId, type Arrangement } from '../lib/settings.svelte.ts';
+
+  const ARRANGEMENTS: { id: Arrangement; name: string; note: string }[] = [
+    { id: 'side', name: 'Modern', note: 'Channels left, members right' },
+    { id: 'classic', name: 'Classic', note: 'Chat left, channels right, like Mumble' },
+    { id: 'stacked', name: 'Stacked', note: 'Channels on top, chat below, like Mumble' }
+  ];
+
+  function arrange(id: Arrangement) {
+    store.settings.arrangement = id;
+    store.saveSettings();
+  }
 
   function pick(id: ThemeId) {
     store.settings.theme = id;
@@ -28,7 +39,41 @@
   {/each}
 </div>
 
+<h3 class="gap">Layout</h3>
+<div class="themes" role="radiogroup" aria-label="Layout">
+  {#each ARRANGEMENTS as a (a.id)}
+    {@const on = (store.settings.arrangement ?? 'side') === a.id}
+    <button role="radio" aria-checked={on} class:active={on} onclick={() => arrange(a.id)} aria-label={a.name}>
+      <span class="mini lay {a.id}" aria-hidden="true">
+        <span class="m-rail"><span></span><span></span></span>
+        {#if a.id === 'side'}<span class="m-side"><i></i><i class="sel"></i><i></i></span>{/if}
+        {#if a.id === 'stacked'}
+          <span class="m-col">
+            <span class="m-side"><i></i><i class="sel"></i></span>
+            <span class="m-chat"><span class="m-head"></span><i class="a"></i><i></i><span class="m-box"></span></span>
+          </span>
+        {:else}
+          <span class="m-chat"><span class="m-head"></span><i class="a"></i><i></i><i class="short"></i><span class="m-box"></span></span>
+        {/if}
+        {#if a.id === 'classic'}<span class="m-side"><i></i><i class="sel"></i><i></i></span>{/if}
+        {#if a.id === 'side'}<span class="m-members"><i></i><i></i></span>{/if}
+      </span>
+      <span class="name">{a.name}</span>
+      <span class="note">{a.note}</span>
+    </button>
+  {/each}
+</div>
+<p class="help">Narrow windows always use the phone layout.</p>
+
 <style>
+  .gap { margin-top: 22px; }
+  .help { margin: 6px 0 0; font-size: 13px; color: var(--text-dim); }
+  .m-col { flex: 1; display: flex; flex-direction: column; min-width: 0; }
+  .m-col .m-chat { flex: 1; }
+  .m-col .m-side { width: auto; height: 34%; flex: none; padding: 5px; gap: 4px; border-bottom: 1px solid var(--line); }
+  .m-members { width: 18%; background: var(--bg-1); display: flex; flex-direction: column; gap: 5px; padding: 8px 4px; border-left: 1px solid var(--line); }
+  .m-members i { height: 4px; background: var(--text-faint); width: 80%; }
+  .lay.classic .m-side { border-left: 1px solid var(--line); }
   h3 { margin: 8px 0 0; font-size: 14px; }
   .themes { display: grid; grid-template-columns: repeat(auto-fill, minmax(170px, 1fr)); gap: 10px; margin-top: 10px; }
   .themes > button { display: flex; flex-direction: column; gap: 2px; padding: 8px; text-align: left; border: 1px solid var(--line); background: var(--bg-0); }

src/ui/Chat.svelte

@@ -58,13 +58,18 @@
         {:else}
           <h2>mumh5</h2>
           <p>Choose a server to get started, or find one:</p>
-          <button class="btn browse" onclick={() => (ui.publicServers = true)}>Browse public servers</button>
+          <div class="welcome-actions">
+            <button class="btn" onclick={() => (ui.publicServers = true)}>Browse public servers</button>
+            <button class="btn" onclick={() => { ui.settingsTab = 'identities'; ui.settingsOpen = true; }}>Manage identities</button>
+          </div>
         {/if}
       </div>
     {/snippet}
   </ChatLog>
 
-  <Composer target={session.view} placeholder={session.status === 'connected' ? `Message ${isDm ? '@' : '#'}${title}` : 'Not connected'} />
+  {#if session.status === 'connected'}
+    <Composer target={session.view} placeholder={`Message ${isDm ? '@' : '#'}${title}`} />
+  {/if}
 </section>
 
 <style>
@@ -79,7 +84,7 @@
   .empty { padding: 32px 16px 8px; }
   .empty h2 { margin: 0 0 4px; font-size: 24px; }
   .empty p { margin: 0; color: var(--text-dim); }
-  .browse { margin-top: 12px; }
+  .welcome-actions { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 12px; }
   .ended { max-width: 460px; margin: 16px 16px 0; padding: 16px 18px; background: var(--bg-1); border: 1px solid var(--line); border-left: 4px solid var(--warn); }
   .ended.bad { border-left-color: var(--danger); }
   .ended h2 { margin: 0; font-size: 20px; }

src/ui/Composer.svelte

@@ -14,8 +14,6 @@
   let picker: HTMLInputElement;
   let imagePicker: HTMLInputElement;
   let empty = $state(true);
-  let source = $state(false);
-  let sourceText = $state('');
   // The formatting toolbar is opt-in and remembered
   let formatting = $state(loadFormatting());
   const disabled = $derived(session.status !== 'connected');
@@ -27,7 +25,6 @@
   function toggleFormatting() {
     formatting = !formatting;
     try { localStorage.setItem('mumh5.formatBar', formatting ? '1' : '0'); } catch { /* storage unavailable */ }
-    if (!formatting && source) toggleSource();
     input.focus();
   }
 
@@ -45,16 +42,14 @@
   }
 
   function submit() {
-    const html = source ? sourceText : input.innerHTML;
+    const html = input.innerHTML;
     // Plain text goes out the usual way; anything formatted as sanitized XHTML
-    const formatted = source || !!input.querySelector('b, strong, i, em, u, s, strike, span[style], font, ul, ol, a, img');
+    const formatted = !!input.querySelector('b, strong, i, em, u, s, strike, span[style], font, ul, ol, a, img');
     const ok = formatted
       ? session.sendHtml(toMumbleHtml(html, { linkify: true }), target)
       : session.sendText(input.innerText, target);
     if (!ok) return;
     input.innerHTML = '';
-    sourceText = '';
-    if (source) source = false;
     sync();
   }
 
@@ -97,17 +92,6 @@
     };
   }
 
-  function toggleSource() {
-    if (!source) {
-      sourceText = toMumbleHtml(input.innerHTML);
-      source = true;
-    } else {
-      input.innerHTML = toMumbleHtml(sourceText);
-      source = false;
-      sync();
-    }
-  }
-
   $effect(() => {
     void target;
     if (autofocus && !disabled && matchMedia('(pointer: fine)').matches) input.focus();
@@ -128,7 +112,7 @@
   {/if}
   <div class="frame">
     {#if formatting}
-      <FormatToolbar {exec} onlink={link} onimage={() => imagePicker.click()} {source} ontogglesource={toggleSource} />
+      <FormatToolbar {exec} onlink={link} onimage={() => imagePicker.click()} />
     {/if}
     <div class="box">
       <button class="icon-btn" title={store.settings.uploadHost ? 'Upload a file' : 'Send an image'} {disabled} onclick={() => picker.click()}><Icon name="paperclip" /></button>
@@ -137,33 +121,27 @@
         onchange={() => { session.uploadFiles([...(picker.files ?? [])], target); picker.value = ''; }} />
       <input bind:this={imagePicker} type="file" accept="image/*" hidden
         onchange={() => { session.uploadFiles([...(imagePicker.files ?? [])], target); imagePicker.value = ''; }} />
-      <div class="input" class:blank={empty} class:hidden={source} bind:this={input} contenteditable={!disabled}
+      <div class="input" class:blank={empty} bind:this={input} contenteditable={!disabled}
         role="textbox" aria-multiline="true" aria-label="Message" tabindex="0" data-placeholder={placeholder}
         oninput={sync} {onkeydown} {onpaste}></div>
-      {#if source}
-        <textarea class="input src" bind:value={sourceText} aria-label="HTML source" spellcheck="false"
-          onkeydown={e => { if (e.key === 'Enter' && !e.shiftKey) { e.preventDefault(); submit(); } }}></textarea>
-      {/if}
       <button class="icon-btn fmt" class:on={formatting} title="Text formatting" aria-label="Text formatting" aria-pressed={formatting}
         {disabled} onmousedown={e => e.preventDefault()} onclick={toggleFormatting}>Aa</button>
-      <button class="icon-btn send" title="Send" disabled={disabled || (empty && !(source && sourceText.trim()))} onclick={submit}><Icon name="send" size={18} /></button>
+      <button class="icon-btn send" title="Send" disabled={disabled || empty} onclick={submit}><Icon name="send" size={18} /></button>
     </div>
   </div>
 </div>
 
 <style>
   /* Same height as the user panel at the bottom of the sidebar; grows for longer messages */
-  .composer { flex: none; min-height: var(--footer-h); display: flex; flex-direction: column; justify-content: flex-end; padding: 6px 16px; background: var(--bg-0); }
+  .composer { flex: none; min-height: var(--footer-h); display: flex; flex-direction: column; justify-content: flex-end; padding: 0; background: var(--bg-0); }
   .frame { background: var(--bg-3); }
   .frame :global(.toolbar) { background: var(--bg-2); }
-  .box { display: flex; align-items: flex-end; gap: 4px; min-height: calc(var(--footer-h) - 12px); padding: 2px 4px; }
+  .box { display: flex; align-items: flex-end; gap: 4px; min-height: var(--footer-h); padding: 6px 4px; }
   .input { position: relative; flex: 1; min-width: 0; padding: 8px 4px; max-height: 200px; overflow-y: auto; line-height: 1.4; outline: none; overflow-wrap: anywhere; white-space: pre-wrap; }
-  .input.hidden { display: none; }
   .input.blank::before { content: attr(data-placeholder); position: absolute; left: 4px; top: 8px; color: var(--text-faint); pointer-events: none; }
   .input :global(img) { max-height: 120px; }
   .input :global(ul), .input :global(ol) { margin: 0; padding-left: 20px; }
   .input[contenteditable='false'] { color: var(--text-faint); }
-  .src { border: 0; resize: none; background: transparent; font: 12px var(--mono); min-height: 60px; }
   .fmt { font-weight: 700; font-size: 13px; }
   .fmt.on { color: var(--accent-hover); }
   .send:not(:disabled) { color: var(--accent-hover); }

src/ui/FormatToolbar.svelte

@@ -4,7 +4,7 @@
   // Formatting controls shared by the description editor and the message input.
   // Buttons keep the text selection (mousedown is suppressed) and act through the callbacks.
   let { exec, onlink, onimage, source = false, ontogglesource }:
-    { exec: (cmd: string, arg?: string) => void; onlink: () => void; onimage: () => void; source?: boolean; ontogglesource: () => void } = $props();
+    { exec: (cmd: string, arg?: string) => void; onlink: () => void; onimage: () => void; source?: boolean; ontogglesource?: () => void } = $props();
 
   let color = $state('#e8b23c');
   const keep = (e: MouseEvent) => e.preventDefault();
@@ -32,8 +32,10 @@
   <button class="tool" title="Link" aria-label="Link" disabled={source} onmousedown={keep} onclick={onlink}><Icon name="link" size={16} /></button>
   <button class="tool" title="Insert picture" aria-label="Insert picture" disabled={source} onmousedown={keep} onclick={onimage}><Icon name="image" size={16} /></button>
   <button class="tool" title="Clear formatting" aria-label="Clear formatting" disabled={source} onmousedown={keep} onclick={() => exec('removeFormat')}><Icon name="eraser" size={16} /></button>
+  {#if ontogglesource}
     <span class="grow"></span>
     <button class="tool" class:on={source} title="Edit HTML" aria-label="Edit HTML" aria-pressed={source} onclick={ontogglesource}><Icon name="code" size={16} /></button>
+  {/if}
 </div>
 
 <style>

src/ui/PublicServers.svelte

@@ -26,17 +26,23 @@
 
   async function load() {
     // A new list starts a new ping round; answers from the previous round are dropped
-    generation++;
+    // and a list that arrives after the source changed is ignored
+    const round = ++generation;
     queue = [];
     running = 0;
     loading = true;
     error = '';
+    let list: PublicServer[] = [];
+    let failed = '';
     try {
-      servers = (await native?.publicServers(store.settings.publicListUrl)) ?? [];
+      list = (await native?.publicServers(store.settings.publicListUrl)) ?? [];
-      if (!native) error = 'The public list needs the desktop app.';
+      if (!native) failed = 'The public list needs the desktop app.';
     } catch (e) {
-      error = (e as Error).message.replace(/^Error invoking remote method '[^']+': (Error: )?/, '');
+      failed = (e as Error).message.replace(/^Error invoking remote method '[^']+': (Error: )?/, '');
     }
+    if (round !== generation || !alive) return;
+    servers = list;
+    error = failed;
     loading = false;
     pingVisible();
   }

src/ui/ResizeHandle.svelte

@@ -1,8 +1,10 @@
 <script lang="ts">
   // Drag handle on one edge of a panel. `edge` is the side the handle sits on: a panel on
-  // the right of the window is resized from its left edge and vice versa. Width is remembered.
+  // the right of the window is resized from its left edge and vice versa; a panel at the
+  // bottom from its top edge and one at the top from its bottom edge (then `width` is its
+  // height). The size is remembered.
   let { width = $bindable(), edge, min, max, initial, storageKey, label }:
-    { width: number; edge: 'left' | 'right'; min: number; max: () => number; initial: number; storageKey: string; label: string } = $props();
+    { width: number; edge: 'left' | 'right' | 'top' | 'bottom'; min: number; max: () => number; initial: number; storageKey: string; label: string } = $props();
 
   let resizing = $state(false);
 
@@ -18,7 +20,7 @@
     resizing = true;
     document.body.style.userSelect = 'none';
     const box = (handle.parentElement as HTMLElement).getBoundingClientRect();
-    const move = (ev: PointerEvent) => setWidth(edge === 'left' ? box.right - ev.clientX : ev.clientX - box.left);
+    const move = (ev: PointerEvent) => setWidth(edge === 'left' ? box.right - ev.clientX : edge === 'top' ? box.bottom - ev.clientY : edge === 'bottom' ? ev.clientY - box.top : ev.clientX - box.left);
     const up = () => {
       resizing = false;
       document.body.style.userSelect = '';
@@ -32,8 +34,8 @@
   }
 
   function onkeydown(e: KeyboardEvent) {
-    const grow = edge === 'left' ? 'ArrowLeft' : 'ArrowRight';
+    const grow = edge === 'left' ? 'ArrowLeft' : edge === 'top' ? 'ArrowUp' : edge === 'bottom' ? 'ArrowDown' : 'ArrowRight';
-    const shrink = edge === 'left' ? 'ArrowRight' : 'ArrowLeft';
+    const shrink = edge === 'left' ? 'ArrowRight' : edge === 'top' ? 'ArrowDown' : edge === 'bottom' ? 'ArrowUp' : 'ArrowLeft';
     if (e.key === grow) setWidth(width + 16);
     else if (e.key === shrink) setWidth(width - 16);
     else return;
@@ -45,7 +47,7 @@
 
 <!-- Focusable separator is the ARIA window-splitter pattern -->
 <!-- svelte-ignore a11y_no_noninteractive_tabindex, a11y_no_noninteractive_element_interactions -->
-<div class="resize {edge}" class:active={resizing} role="separator" aria-orientation="vertical" aria-label={label}
+<div class="resize {edge}" class:active={resizing} role="separator" aria-orientation={edge === 'top' || edge === 'bottom' ? 'horizontal' : 'vertical'} aria-label={label}
   aria-valuenow={width} aria-valuemin={min} aria-valuemax={max()} tabindex="0" title="Drag to resize, double-click to reset"
   onpointerdown={start} ondblclick={() => setWidth(initial)} {onkeydown}></div>
 
@@ -53,6 +55,13 @@
   .resize { position: absolute; z-index: 5; top: 0; bottom: 0; width: 8px; cursor: col-resize; touch-action: none; }
   .resize.left { left: -4px; }
   .resize.right { right: -4px; }
+  .resize.top, .resize.bottom { left: 0; right: 0; width: auto; height: 8px; cursor: row-resize; }
+  .resize.top { top: -4px; bottom: auto; }
+  .resize.bottom { bottom: -4px; top: auto; }
+  .resize.top:hover, .resize.top:focus-visible, .resize.top.active,
+  .resize.bottom:hover, .resize.bottom:focus-visible, .resize.bottom.active {
+    background: linear-gradient(to bottom, transparent 3px, var(--accent) 3px, var(--accent) 5px, transparent 5px);
+  }
   .resize:hover, .resize:focus-visible, .resize.active {
     background: linear-gradient(to right, transparent 3px, var(--accent) 3px, var(--accent) 5px, transparent 5px);
     outline: none;

src/ui/Sidebar.svelte

@@ -11,7 +11,10 @@
   import { voice } from '../lib/audio/voice.svelte.ts';
 
   // resizable: false in the phone drawer, which keeps a fixed width
-  let { onnavigate, resizable = true }: { onnavigate: () => void; resizable?: boolean } = $props();
+  // handleEdge: which side the resize handle sits on (left when the list is on the right, classic layout)
+  // fill: take the whole area (stacked layout, where the parent sizes it)
+  let { onnavigate, resizable = true, handleEdge = 'right', fill = false }:
+    { onnavigate: () => void; resizable?: boolean; handleEdge?: 'left' | 'right'; fill?: boolean } = $props();
 
   const MIN_W = 200, DEFAULT_W = 260;
   const maxW = () => Math.max(MIN_W, Math.min(520, window.innerWidth - 520));
@@ -58,8 +61,8 @@
   );
 </script>
 
-<aside class="sidebar" style:width={resizable ? `${width}px` : undefined}>
+<aside class="sidebar" class:fill style:width={resizable && !fill ? `${width}px` : undefined}>
-  {#if resizable}<ResizeHandle bind:width edge="right" min={MIN_W} max={maxW} initial={DEFAULT_W} storageKey="mumh5.sidebarWidth" label="Resize channel list" />{/if}
+  {#if resizable && !fill}<ResizeHandle bind:width edge={handleEdge} min={MIN_W} max={maxW} initial={DEFAULT_W} storageKey="mumh5.sidebarWidth" label="Resize channel list" />{/if}
   <header class:trusted>
     <button class="title" onclick={showServerCert} disabled={!cert} title={cert ? (trusted ? 'Valid certificate. Click to view' : 'Self-signed or untrusted certificate. Click to view') : ''}>
       <strong>{#if cert}<Icon name={trusted ? 'lock' : 'shield'} size={14} />{/if}{session.server?.label ?? 'mumh5'}</strong>
@@ -134,6 +137,7 @@
 
 <style>
   .sidebar { position: relative; width: 260px; flex: none; display: flex; flex-direction: column; background: var(--bg-1); min-height: 0; }
+  .sidebar.fill { width: 100%; height: 100%; }
   header { height: 52px; flex: none; display: flex; align-items: center; gap: 8px; padding: 0 8px 0 0; border-bottom: 1px solid var(--line); }
   header.trusted { background: #1d5c38; border-bottom-color: #2a7a4c; }
   header.trusted .status, header.trusted .icon-btn { color: #cfeedd; }

src/ui/UserInfoDialog.svelte

@@ -79,9 +79,10 @@
     <dl>
       <dt>Online for</dt><dd>{duration(stats.onlinesecs != null ? stats.onlinesecs + since : undefined)}</dd>
       {#if stats.idlesecs != null}<dt>Idle for</dt><dd>{duration(stats.idlesecs + since)}</dd>{/if}
-      <dt>Ping (TCP)</dt><dd>{ping(stats.tcp_ping_avg, stats.tcp_ping_var)}</dd>
+      <!-- The server counts the client's ping messages, not voice; clients that never ping (many bots) show none -->
-      <dt>Ping (UDP)</dt><dd>{stats.udp_packets ? ping(stats.udp_ping_avg, stats.udp_ping_var) : 'not using UDP (voice over TCP)'}</dd>
+      <dt>Ping (TCP)</dt><dd>{stats.tcp_packets ? ping(stats.tcp_ping_avg, stats.tcp_ping_var) : 'n/a (this client sends no pings)'}</dd>
-      <dt>Packets</dt><dd>{stats.tcp_packets ?? 0} TCP, {stats.udp_packets ?? 0} UDP</dd>
+      <dt>Ping (UDP)</dt><dd>{stats.udp_packets ? ping(stats.udp_ping_avg, stats.udp_ping_var) : 'n/a'}</dd>
+      <dt>Pings received</dt><dd>{stats.tcp_packets ?? 0} over TCP, {stats.udp_packets ?? 0} over UDP</dd>
       {#if stats.bandwidth != null}<dt>Bandwidth</dt><dd>{formatBytes(stats.bandwidth)}/s</dd>{/if}
       {#if stats.address?.length}<dt>Address</dt><dd class="mono">{address(stats.address)}</dd>{/if}
     </dl>

src/ui/VoiceSettings.svelte

@@ -1,7 +1,12 @@
 <script lang="ts">
   import { onDestroy } from 'svelte';
   import { voice, type TransmitMode } from '../lib/audio/voice.svelte.ts';
-  import { session } from '../lib/session.svelte.ts';
+  import { session, sessions } from '../lib/session.svelte.ts';
+
+  function setForceTcp(on: boolean) {
+    voice.update({ forceTcp: on });
+    for (const s of sessions.list) if (s.client) s.client.forceTcp = on;
+  }
 
   const s = voice.settings;
   let capturing = $state(false);
@@ -133,6 +138,7 @@
       </select>
     </div>
   </div>
+  <label class="check"><input type="checkbox" checked={s.forceTcp} onchange={e => setForceTcp(e.currentTarget.checked)} /> Send voice over TCP only (for networks that block or mangle UDP)</label>
   <label for="v-jit">Jitter buffer: {s.jitterMs} ms</label>
   <input id="v-jit" type="range" min="20" max="300" step="10" value={s.jitterMs}
     oninput={e => voice.update({ jitterMs: Number(e.currentTarget.value) })} />
@@ -140,7 +146,8 @@
 
   {#if session.status === 'connected'}
     <h3>Statistics</h3>
-    <p class="help stats">Sent {voice.stats.sent} packets, received {voice.stats.received}, decoded {voice.stats.decoded}, gaps {voice.stats.lost}. Transport: TCP tunnel.</p>
+    {@const t = session.voiceTransport}
+    <p class="help stats">Sent {voice.stats.sent} packets, received {voice.stats.received}, decoded {voice.stats.decoded}, gaps {voice.stats.lost}. Transport: {t.udp ? `UDP, ${Math.round(t.rtt)} ms ping` : 'TCP tunnel'}.</p>
   {/if}
 </div>
 

test/e2e/app.e2e.ts

@@ -85,6 +85,13 @@ try {
   await page.getByRole('dialog', { name: 'Set up your identity' }).waitFor({ state: 'detached' });
   console.log('ok: identity wizard creates an identity');
 
+  // Welcome page: no message box while offline, identities one click away
+  assert.equal(await page.locator('.chat .composer').count(), 0);
+  await page.getByRole('button', { name: 'Manage identities' }).click();
+  await page.getByRole('tab', { name: 'Identities', selected: true }).waitFor();
+  await page.getByRole('button', { name: 'Done', exact: true }).click();
+  console.log('ok: welcome page without composer, manage identities');
+
   // Settings: upload host + key
   if (process.env.UPLOAD_HOST && process.env.UPLOAD_KEY) {
     await page.getByTitle('Settings').click();
@@ -180,6 +187,13 @@ try {
   const statsText = await page.locator('.stats').textContent();
   const decoded = Number(/decoded (\d+)/.exec(statsText ?? '')?.[1]);
   assert.ok(decoded >= 20, `decoded frames reported: ${statsText}`);
+  // Voice runs over encrypted UDP once the server answers UDP pings
+  await page.locator('.stats', { hasText: /Transport: UDP, \d+ ms ping/ }).waitFor({ timeout: 10000 });
+  await page.getByLabel(/Send voice over TCP only/).check();
+  await page.locator('.stats', { hasText: 'Transport: TCP tunnel' }).waitFor();
+  await page.getByLabel(/Send voice over TCP only/).uncheck();
+  await page.locator('.stats', { hasText: /Transport: UDP/ }).waitFor();
+  console.log('ok: voice transport UDP, with a TCP-only switch');
   await page.getByRole('button', { name: 'Done', exact: true }).click();
   console.log(`ok: ${decoded} frames decoded`);
   await setMode('Push to talk');
@@ -300,6 +314,36 @@ try {
   await page.getByRole('button', { name: 'Done', exact: true }).click();
   console.log('ok: color schemes');
 
+  // Layouts like the desktop client: classic (channels right of chat), stacked (channels above)
+  const box = (sel: string) => page.locator(sel).first().boundingBox().then(b => b!);
+  await page.getByTitle('Settings').click();
+  await page.getByRole('tab', { name: 'Appearance' }).click();
+  await page.getByRole('radio', { name: 'Classic' }).click();
+  await page.getByRole('button', { name: 'Done', exact: true }).click();
+  await page.locator('.app.classic').waitFor();
+  assert.ok((await box('.sidebar')).x > (await box('.chat')).x, 'classic: channel list right of chat');
+  await page.getByTitle('Settings').click();
+  await page.getByRole('tab', { name: 'Appearance' }).click();
+  await page.getByRole('radio', { name: 'Stacked' }).click();
+  await page.getByRole('button', { name: 'Done', exact: true }).click();
+  await page.locator('.app.stacked').waitFor();
+  const chatBox = await box('.chat'), treeBox = await box('.sidebar');
+  assert.ok(chatBox.y >= treeBox.y + treeBox.height - 1, 'stacked: chat below channel list');
+  // The split between chat and channel list drags
+  const handle = page.getByRole('separator', { name: 'Resize channel list' });
+  const hb = (await handle.boundingBox())!;
+  await page.mouse.move(hb.x + hb.width / 2, hb.y + hb.height / 2);
+  await page.mouse.down();
+  await page.mouse.move(hb.x + hb.width / 2, hb.y + 60, { steps: 4 });
+  await page.mouse.up();
+  assert.ok((await box('.sidebar')).height > treeBox.height + 40, 'stacked: split resizes');
+  await page.getByTitle('Settings').click();
+  await page.getByRole('tab', { name: 'Appearance' }).click();
+  await page.getByRole('radio', { name: 'Modern' }).click();
+  await page.getByRole('button', { name: 'Done', exact: true }).click();
+  await page.locator('.app.side').waitFor();
+  console.log('ok: classic and stacked layouts');
+
   // Public server list, from a local list in the official XML format
   const http = await import('node:http');
   const listServer = http.createServer((_req, res) => {

test/ocb2.test.ts

@@ -0,0 +1,68 @@
+import { test } from 'node:test';
+import assert from 'node:assert/strict';
+import { randomBytes } from 'node:crypto';
+import { ocbEncrypt, ocbDecrypt, CryptState } from '../electron/ocb2.ts';
+
+const key = Buffer.from([...Array(16).keys()]);
+
+test('OCB2 matches the test vectors used by Mumble (draft-krovetz-ocb-00)', () => {
+  const [, blankTag] = ocbEncrypt(key, Buffer.alloc(0), key);
+  assert.equal(blankTag.toString('hex'), 'bf3108130773ad5ec70ec69e7875a7b0');
+  const source = Buffer.from([...Array(40).keys()]);
+  const [crypt, tag] = ocbEncrypt(key, source, key);
+  assert.equal(tag.toString('hex'), '9db0cdf880f73e3e10d4eb3217766688');
+  assert.equal(crypt.toString('hex'), 'f75d6bc8b4dc8d66b836a2b08b32a6369f1cd3c5228d79fd6c267f5f6aa7b231c7dfb9d59951ae9c');
+});
+
+test('encrypt and decrypt round trip for every length up to 127 bytes', () => {
+  const nonce = Buffer.from('ffeeddccbbaa99887766554433221100', 'hex');
+  for (let len = 0; len < 128; len++) {
+    const plain = randomBytes(len);
+    const [ct, tag] = ocbEncrypt(key, plain, nonce);
+    const [back, tag2, ok] = ocbDecrypt(key, ct, nonce);
+    assert.ok(ok);
+    assert.ok(back.equals(plain), `len ${len}`);
+    assert.ok(tag.equals(tag2));
+  }
+});
+
+function pair() {
+  const k = randomBytes(16), cn = randomBytes(16), sn = randomBytes(16);
+  const client = new CryptState(), server = new CryptState();
+  client.setKey(k, cn, sn);
+  server.setKey(k, sn, cn); // the server encrypts with the client's decrypt nonce and vice versa
+  return { client, server };
+}
+
+test('crypt state: in order, lost, late, replay and tampering', () => {
+  const { client, server } = pair();
+  const packets = Array.from({ length: 300 }, (_, i) => client.encrypt(Buffer.from(`voice ${i}`)));
+  // In order (crosses the 256 wrap of the IV byte)
+  for (let i = 0; i < 280; i++) assert.equal(server.decrypt(packets[i])?.toString(), `voice ${i}`);
+  // 280-282 missing, then 281 arrives late (lost goes back down, like Mumble)
+  assert.equal(server.decrypt(packets[283])?.toString(), 'voice 283');
+  assert.equal(server.lost, 3);
+  assert.equal(server.decrypt(packets[281])?.toString(), 'voice 281');
+  assert.equal(server.late, 1);
+  assert.equal(server.lost, 2);
+  // Replays are rejected
+  assert.equal(server.decrypt(packets[281]), null);
+  assert.equal(server.decrypt(packets[283]), null);
+  // Tampered packets are rejected and do not disturb the state
+  const bad = Buffer.from(packets[284]); bad[6] ^= 1;
+  assert.equal(server.decrypt(bad), null);
+  assert.equal(server.decrypt(packets[284])?.toString(), 'voice 284');
+  assert.equal(server.good, 283);
+});
+
+test('XEX* attack counter-measure: the pattern is changed on encrypt and refused on decrypt', () => {
+  const nonce = randomBytes(16);
+  const attack = Buffer.alloc(32);
+  attack[15] = 16 * 8; // second to last block all zero except the last byte
+  const [, , okStrict] = ocbEncrypt(key, attack, nonce, false);
+  assert.equal(okStrict, false, 'pattern detected');
+  const [ct] = ocbEncrypt(key, attack, nonce);
+  const [plain, , ok] = ocbDecrypt(key, ct, nonce);
+  assert.ok(ok);
+  assert.notDeepEqual([...plain], [...attack], 'one bit was flipped to defuse the pattern');
+});

test/server.test.ts

@@ -8,10 +8,34 @@ import type { Transport } from '../src/core/transport.ts';
 import { openTls } from '../electron/tls-transport.ts';
 import { generateIdentity } from '../electron/identity.ts';
 import { encodeVoice, decodeVoice } from '../src/core/voice-packet.ts';
+import { udpChannel } from '../electron/udp-voice.ts';
 
 const target = process.env.MUMBLE_TEST_HOST;
 const codec = createCodec();
 
+function connectUdp(name: string): Promise<MumbleClient> {
+  const [host, port] = target!.split(':');
+  const id = generateIdentity(name);
+  const client = new MumbleClient(codec);
+  let udp: ReturnType<typeof udpChannel> | undefined;
+  let conn: ReturnType<typeof openTls> | undefined;
+  const transport: Transport = { onData: null, onClose: null, send: b => conn?.send(b), close: () => { udp?.close(); conn?.close(); } };
+  return new Promise((resolve, reject) => {
+    conn = openTls(host, Number(port || 64738), id.certPem, id.keyPem, {
+      // UDP goes to the address the TLS connection actually reached
+      onSecure: info => {
+        udp = udpChannel(info.address, info.port);
+        transport.udp = udp;
+        client.connect(transport, { username: name, os: 'test' });
+      },
+      onData: c => transport.onData?.(c),
+      onClose: r => { udp?.close(); transport.onClose?.(r); }
+    });
+    client.on('synced', () => resolve(client));
+    client.on('close', reject);
+  });
+}
+
 function connect(name: string, password = ''): Promise<MumbleClient> {
   const [host, port] = target!.split(':');
   const id = generateIdentity(name);
@@ -232,3 +256,30 @@ test('channel management and ACLs as SuperUser', { skip: !target || !superPw },
   }
 });
 
+test('voice over encrypted UDP (OCB2) between two clients', { skip: !target }, async () => {
+  const alice = await connectUdp('udpA' + Date.now() % 1000);
+  const bob = await connectUdp('udpB' + Date.now() % 1000);
+  try {
+    // Both sides confirm UDP with encrypted pings
+    await until<void>(res => { if (alice.udpOk) res(); else alice.on('udp', ok => { if (ok) res(); }); }, 8000);
+    await until<void>(res => { if (bob.udpOk) res(); else bob.on('udp', ok => { if (ok) res(); }); }, 8000);
+    assert.ok(alice.udpRtt >= 0);
+
+    // Alice's voice goes out over UDP and reaches bob over UDP, not the TCP tunnel
+    let tunneled = 0;
+    const origSend = (alice as any).sendVoiceTunnel.bind(alice);
+    (alice as any).sendVoiceTunnel = (p: Uint8Array) => { tunneled++; origSend(p); };
+    const got = until<number>(res => {
+      let n = 0;
+      bob.on('voice', raw => { const p = decodeVoice(raw); if (p?.session === alice.session && ++n === 10) res(n); });
+    });
+    const opus = new Uint8Array([0x78, ...new Array(40).fill(9)]);
+    for (let i = 0; i < 10; i++) alice.sendVoice(encodeVoice({ target: 0, frame: i * 2, opus, last: i === 9 }, alice.protobufVoice));
+    assert.equal(await got, 10);
+    assert.equal(tunneled, 0, 'nothing went through the TCP tunnel');
+  } finally {
+    alice.disconnect();
+    bob.disconnect();
+  }
+});
+