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4 changed files with 301 additions and 48 deletions

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@ -10,6 +10,8 @@ Zwei bis N Spieler verbinden sich via WebRTC (simple-peer) und führen ein krypt
- **Trustless** Commit-Reveal-Protokoll mit SHA-256-Bindung, jeder verifiziert
- **QR-Bootstrapping** SDP-Offers/Answers werden als QR-Codes ausgetauscht
- **Multiplayer (2n)** Beliebig viele Teilnehmer in einer Runde
- **Full Mesh** Alle Peers verbinden sich direkt per WebRTC (Host relayt nur initial SDP)
- **Selective Abort** Timeout erkennt Verweigerer, alle Teilnehmer sehen denselben Schuldigen
- **Coin-Animation** 3D-Münzwurf via CSS
- **100% Vanilla JS** Keine Build-Tools, kein npm, keine Abhängigkeiten außer CDN-Libs
@ -32,27 +34,35 @@ Dann auf zwei (oder mehr) Geräten `http://localhost:8080` öffnen.
1. **"Raum erstellen"** QR-Code mit SDP Offer wird angezeigt
2. **"Antwort-QR scannen"** Kamera startet, scannt die Antwort-QRs der Beitreter
3. Jeder neue Spieler erscheint in der Liste
4. **"Münzwurf starten"** Übergang in den Spiel-Screen
5. **"Münzwurf starten"** Protokoll beginnt (Commit → Reveal → Ergebnis)
4. Host broadcastet `roster` mit allen Peer-IDs → Peers bauen direktes Mesh untereinander auf
5. Sobald alle Peers `mesh_ready` gemeldet haben → **"Münzwurf starten"** wird aktiv
6. **"Münzwurf starten"** Übergang in den Spiel-Screen
7. **"Münzwurf starten"** Protokoll beginnt (Commit → Reveal → Ergebnis)
### Beitreter
1. **"Raum beitreten"** Kamera startet
2. QR des Hosts scannen
3. **Antwort-QR zeigen** Host scannt diesen QR
4. Verbindung steht, warten auf Start
5. Protokoll läuft automatisch durch Ergebnis erscheint
4. Verbindung steht, empfange `roster` mit anderen Peer-IDs
5. Baue direkte WebRTC-Verbindung zu jedem anderen Peer auf (kleinere PeerId initiiert → kein Glare)
6. Sobald alle direkten Verbindungen stehen → automatisch `mesh_ready` an Host
7. Host startet Protokoll → alle laufen automatisch durch (Commit → Reveal → Ergebnis)
### Protokoll-Phasen
| Phase | Beschreibung |
|-------|-------------|
| **Commit** | Jeder Spieler generiert 32 Zufallsbytes und sendet den SHA-256-Hash an alle |
| **Warten** | Sammle Commits aller Teilnehmer |
| **Warten** | Sammle Commits aller Teilnehmer (Timeout 12s) |
| **Reveal** | Jeder sendet die rohen Zufallsbytes an alle |
| **Warten** | Sammle Reveals aller Teilnehmer (Timeout 12s) |
| **Verify** | Jeder prüft: SHA-256(received) == stored_commit |
| **Result** | XOR aller Secrets → Parity (0=Kopf, 1=Zahl) |
Bei Timeout in einer Wartephase: **Selective Abort** `ABORTED`-Zustand, fehlende Peer-IDs werden angezeigt.
Alle Teilnehmer sehen dieselben fehlenden Peers (Mesh → jeder sieht, wer nicht sendet).
## Architektur
```
@ -75,11 +85,44 @@ randomp2p/
## Netzwerk-Topologie
**Best Case (gleiches WiFi):**
QR-SDP-Austausch zwischen Host und jedem Peer. Host teilt IP-Liste → potentiell volles Mesh über `signal_relay`.
**Phase 1 Stern (QR-Bootstrapping):**
Host tauscht via QR-Codes SDP Offers/Answers mit jedem Peer aus → jeder Peer ist direkt mit dem Host verbunden.
**Worst Case (NAT/Internet):**
Stern-Topologie über den Host. Protokoll funktioniert trotzdem die Fairness ist nicht von der Topologie abhängig.
**Phase 2 Mesh (relayed Signaling):**
Sobald ein Peer beitritt, broadcastet der Host ein `roster` mit allen Peer-IDs an das gesamte Netzwerk.
Jeder Peer baut zu jedem anderen Peer eine **direkte WebRTC-Verbindung** auf:
- **Initiator** ist immer der Peer mit der **kleineren PeerId** (verhindert Glare / Race-Conditions)
- SDP Offers/Answers werden über den **Host als Relay** ausgetauscht (`signal_relay`/`signal_relayed` via DataChannel)
- Nach erfolgreichem Verbindungsaufbau sendet jeder Peer `mesh_ready` an den Host
**Ergebnis:** Volles Mesh jeder Peer ist mit jedem direkt verbunden.
Broadcasts erreichen alle Teilnehmer in einem Hop. `expectedPeers` (für Timeout/Abort) ist auf allen identisch.
```
Host A ──QR── Peer B Host A ──star── Peer B
Host A ──QR── Peer C → Host A ──star── Peer C
Peer B ──mesh── Peer C (direkt, kein Relay)
```
### Signal-Relay-Detail
```
B (Initiator, peerId kleiner) Host A C (Responder)
│ │ │
├─ signal_relay(to:C, offer) ──────→│ │
│ ├─ signal_relayed(offer) ──→│
│ │ ├─ SimplePeer(non-init)
│ │ ├─ peer.signal(offer)
│ │ ├─ answer signal
│ │←─ signal_relay(to:B, answer) ─┤
│←── signal_relayed(answer) ────────┤ │
├─ peer.signal(answer) │ │
├─ BC direkt verbunden! │ ├─ BC direkt verbunden!
│ │ │
├─ mesh_ready ────────────────────→│←────────────────── mesh_ready ─┤
│ │ readyPeers={B,C} → Button enabled
```
## Warum ist das fair?
@ -101,11 +144,11 @@ ipfs add -r .
## Ausblick / TODOs
- [ ] Volles Mesh: Peers verbinden sich direkt via relayed signaling
- [ ] Timeout + Reconnect bei Verbindungsabbruch
- [x] Volles Mesh: Peers verbinden sich direkt via relayed signaling
- [x] Selective Abort: Timeout bei Verweigerern
- [ ] Reconnect bei Verbindungsabbruch
- [ ] Raum-Code als Alternative zum QR-Scan
- [ ] TURN-Server-Konfiguration für NAT-Traversal
- [ ] Mehrere Runden mit Historie
- [ ] PWA-Manifest + ServiceWorker für IPFS-Distribution
## Lizenz

19
app.js
View file

@ -103,7 +103,8 @@
function updatePhases(state) {
const map = { IDLE:'ready', STARTING:'ready', COMMITTING:'commit',
WAITING_FOR_COMMITS:'commit', REVEALING:'reveal',
WAITING_FOR_REVEALS:'reveal', VERIFYING:'verify', COMPLETE:'done' };
WAITING_FOR_REVEALS:'reveal', VERIFYING:'verify',
COMPLETE:'done', ABORTED:'done' };
const active = map[state] || 'ready';
let doneSeen = false;
['ready','commit','reveal','verify','done'].forEach(p => {
@ -141,12 +142,19 @@
$('btn-start-protocol').hidden = true;
};
protocol.onerror = err => {
$('protocol-text').textContent = 'Fehler: ' + err;
$('protocol-text').textContent = err;
$('result-area').hidden = false;
$('result-text').textContent = 'Abgebrochen';
$('btn-start-protocol').hidden = true;
};
mesh.ondata = (peerId, msg) => {
if (msg.type === 'protocol_start' && protocol && protocol.state === 'IDLE') {
if (msg.type === 'protocol_start') {
if (protocol) protocol.reset();
$('coin-area').hidden = true;
$('result-area').hidden = true;
$('btn-start-protocol').hidden = true;
updatePhases('IDLE');
protocol.start();
return;
}
@ -167,13 +175,14 @@
mesh.onpeerconnect = pid => {
renderPlayers('host-player-list');
$('btn-start-game').disabled = mesh.getCount() < 1;
};
mesh.onpeerdisconnect = () => {
renderPlayers('host-player-list');
$('btn-start-game').disabled = mesh.getCount() < 1;
};
mesh.onqrupdate = d => showQR('qr-host', d);
mesh.onreadyupdate = (ready, total) => {
$('btn-start-game').disabled = ready < total || total === 0;
};
mesh.createRoom();
show('host');

195
p2p.js
View file

@ -2,17 +2,25 @@ class MeshNet {
constructor() {
this.myPeerId = generatePeerId();
this.connections = new Map();
this.isHost = false;
this._pendingMeshPeers = new Map();
this._pendingPeer = null;
this._currentQRData = null;
this.isHost = false;
this.hostPeerId = null;
this.roster = [];
this.readyPeers = new Set();
this._meshReadySent = false;
this.onpeerconnect = null;
this.onpeerdisconnect = null;
this.ondata = null;
this.onqrupdate = null;
this.onanswerready = null;
this.onreadyupdate = null;
}
/* ─── Host: room ─── */
createRoom() {
this.isHost = true;
this._createPendingPeer();
@ -25,7 +33,6 @@ class MeshNet {
const peer = new SimplePeer({ initiator: true, trickle: false });
let signalSent = false;
let connected = false;
peer.on('signal', signal => {
if (signalSent) return;
@ -35,7 +42,6 @@ class MeshNet {
});
peer.on('connect', () => {
connected = true;
peer.send(JSON.stringify({ type: 'identity', peerId: this.myPeerId }));
});
@ -44,19 +50,14 @@ class MeshNet {
const msg = JSON.parse(data.toString());
this._handleMessage(msg, peer);
} catch (e) {
console.error('p2p data parse error:', e);
console.error('p2p data error:', e);
}
});
peer.on('close', () => {
this._cleanupPeer(peer);
});
peer.on('close', () => this._cleanupPeer(peer));
peer.on('error', err => console.error('p2p error:', err));
peer.on('error', err => {
console.error('p2p error:', err);
});
this._pendingPeer = { peer, signalSent, connected, peerId: null };
this._pendingPeer = { peer, signalSent, connected: false, peerId: null };
}
feedAnswer(answerStr) {
@ -71,14 +72,16 @@ class MeshNet {
}
}
/* ─── Peer: join ─── */
joinFromQR(qrContent) {
const data = JSON.parse(qrContent);
const remoteId = data.id;
this.hostPeerId = remoteId;
const offer = data.s;
const peer = new SimplePeer({ initiator: false, trickle: false });
let answerSent = false;
let connected = false;
peer.on('signal', signal => {
if (answerSent) return;
@ -90,7 +93,6 @@ class MeshNet {
});
peer.on('connect', () => {
connected = true;
this.connections.set(remoteId, peer);
peer.send(JSON.stringify({ type: 'identity', peerId: this.myPeerId }));
if (this.onpeerconnect) this.onpeerconnect(remoteId);
@ -100,25 +102,123 @@ class MeshNet {
try {
const msg = JSON.parse(data.toString());
this._handleMessage(msg, peer);
} catch (e) {
console.error('p2p data parse error:', e);
}
} catch (e) { console.error('p2p data error:', e); }
});
peer.on('close', () => {
this._cleanupPeer(peer);
});
peer.on('error', err => {
console.error('p2p error:', err);
});
peer.on('close', () => this._cleanupPeer(peer));
peer.on('error', err => console.error('p2p error:', err));
peer.signal(offer);
this.connections.set(remoteId, peer);
this._pendingPeer = { peer, peerId: remoteId, connected };
this._pendingPeer = { peer, peerId: remoteId, connected: answerSent };
}
/* ─── Mesh helpers ─── */
_createSimplePeer(initiator, onSignal, onConnect) {
const peer = new SimplePeer({ initiator, trickle: false });
peer.on('signal', signal => {
if (onSignal) onSignal(signal);
});
peer.on('connect', () => {
if (onConnect) onConnect();
// No identity exchange peerId known from context
});
peer.on('data', data => {
try {
const msg = JSON.parse(data.toString());
this._handleMessage(msg, peer);
} catch (e) { console.error('mesh data error:', e); }
});
peer.on('close', () => this._cleanupPeer(peer));
peer.on('error', e => console.error('mesh error:', e));
return peer;
}
_initiateMeshConnection(targetPeerId) {
if (this.connections.has(targetPeerId)) return;
if (this._pendingMeshPeers.has(targetPeerId)) return;
if (this.myPeerId >= targetPeerId) return;
const peer = this._createSimplePeer(true,
signal => {
this.sendTo(this.hostPeerId, { type: 'signal_relay', to: targetPeerId, signal });
},
() => {
this.connections.set(targetPeerId, peer);
this._pendingMeshPeers.delete(targetPeerId);
if (this.onpeerconnect) this.onpeerconnect(targetPeerId);
this._checkMeshReady();
}
);
this._pendingMeshPeers.set(targetPeerId, peer);
}
_handleRelayedSignal(fromPeerId, signal) {
let peer = this.connections.get(fromPeerId) || this._pendingMeshPeers.get(fromPeerId);
if (!peer) {
peer = this._createSimplePeer(false,
signal => {
this.sendTo(this.hostPeerId, { type: 'signal_relay', to: fromPeerId, signal });
},
() => {
this.connections.set(fromPeerId, peer);
this._pendingMeshPeers.delete(fromPeerId);
if (this.onpeerconnect) this.onpeerconnect(fromPeerId);
this._checkMeshReady();
}
);
this._pendingMeshPeers.set(fromPeerId, peer);
}
peer.signal(signal);
}
_checkMeshConnections() {
for (const pid of this.roster) {
if (pid === this.myPeerId) continue;
if (this.connections.has(pid)) continue;
if (this.myPeerId < pid) {
this._initiateMeshConnection(pid);
}
}
this._checkMeshReady();
}
_checkMeshReady() {
if (this._meshReadySent) return;
if (!this.hostPeerId) return;
if (!this.connections.has(this.hostPeerId)) return;
const allConnected = this.roster.every(pid =>
pid === this.myPeerId || this.connections.has(pid)
);
if (allConnected && this.roster.length > 0) {
this._meshReadySent = true;
this.sendTo(this.hostPeerId, { type: 'mesh_ready' });
}
}
_broadcastRoster() {
this.roster = this.getPeerIds();
this.readyPeers.clear();
this.broadcast({ type: 'roster', peers: this.roster });
if (this.onreadyupdate) this.onreadyupdate(0, this.roster.length);
}
/* ─── Message routing ─── */
_handleMessage(msg, peer) {
const peerId = this._findPeerId(peer) || 'unknown';
if (msg.type === 'identity') {
const existing = this._findPeerId(peer);
if (existing && existing !== msg.peerId) {
@ -132,6 +232,7 @@ class MeshNet {
if (this.onpeerconnect) this.onpeerconnect(msg.peerId);
if (this.isHost) {
setTimeout(() => this._createPendingPeer(), 300);
this._broadcastRoster();
}
} else {
if (this.onpeerconnect) this.onpeerconnect(msg.peerId);
@ -140,27 +241,51 @@ class MeshNet {
}
if (msg.type === 'signal_relay') {
const target = this.connections.get(msg.to);
const target = this.connections.get(msg.to) || this._pendingMeshPeers.get(msg.to);
if (target) {
target.send(JSON.stringify({
type: 'signal_relayed',
from: msg.from,
from: peerId,
signal: msg.signal
}));
}
return;
}
if (msg.type === 'signal_relayed') {
this._handleRelayedSignal(msg.from, msg.signal);
return;
}
if (msg.type === 'roster') {
this.roster = msg.peers || [];
this._meshReadySent = false;
this._checkMeshConnections();
return;
}
if (msg.type === 'mesh_ready' && this.isHost) {
this.readyPeers.add(peerId);
if (this.onreadyupdate) {
this.onreadyupdate(this.readyPeers.size, this.roster.length);
}
return;
}
if (this.ondata) {
const peerId = this._findPeerId(peer) || 'unknown';
this.ondata(peerId, msg);
}
}
/* ─── Peer management ─── */
_findPeerId(peer) {
for (const [id, p] of this.connections) {
if (p === peer) return id;
}
for (const [id, p] of this._pendingMeshPeers) {
if (p === peer) return id;
}
return null;
}
@ -170,11 +295,21 @@ class MeshNet {
this.connections.delete(peerId);
if (this.onpeerdisconnect) this.onpeerdisconnect(peerId);
}
for (const [id, p] of this._pendingMeshPeers) {
if (p === peer) {
this._pendingMeshPeers.delete(id);
break;
}
}
if (this._pendingPeer && this._pendingPeer.peer === peer) {
this._pendingPeer = null;
}
}
/* ─── Send ─── */
broadcast(msg) {
const str = JSON.stringify(msg);
for (const [id, peer] of this.connections) {
@ -208,7 +343,11 @@ class MeshNet {
for (const peer of this.connections.values()) {
try { peer.destroy(); } catch (e) {}
}
for (const peer of this._pendingMeshPeers.values()) {
try { peer.destroy(); } catch (e) {}
}
this.connections.clear();
this._pendingMeshPeers.clear();
if (this._pendingPeer) {
try { this._pendingPeer.peer.destroy(); } catch (e) {}
this._pendingPeer = null;

View file

@ -7,6 +7,10 @@ class CoinFlipProtocol {
this.reveals = new Map();
this.result = null;
this.totalPeers = 0;
this.expectedPeers = new Set();
this.TIMEOUT_MS = 12000;
this._commitTimer = null;
this._revealTimer = null;
this.onstatechange = null;
this.onprogress = null;
@ -17,7 +21,8 @@ class CoinFlipProtocol {
async start() {
if (this.state !== 'IDLE') return;
this.state = 'STARTING';
this.totalPeers = this.mesh.getCount() + 1;
this.expectedPeers = new Set([this.mesh.myPeerId, ...this.mesh.getPeerIds()]);
this.totalPeers = this.expectedPeers.size;
this.secret = await generateSecret();
const myCommit = await commit(this.secret);
this.commits.set(this.mesh.myPeerId, myCommit);
@ -26,6 +31,7 @@ class CoinFlipProtocol {
this.mesh.broadcast({ type: 'protocol', phase: 'commit', data: bufToBase64(myCommit) });
this.state = 'WAITING_FOR_COMMITS';
if (this.onstatechange) this.onstatechange('WAITING_FOR_COMMITS');
this._startCommitTimer();
this._checkCommits();
}
@ -49,9 +55,54 @@ class CoinFlipProtocol {
}
}
/* ─── Timeout ─── */
_startCommitTimer() {
this._clearCommitTimer();
this._commitTimer = setTimeout(() => {
if (this.commits.size >= this.totalPeers) return;
const missing = [...this.expectedPeers].filter(p => !this.commits.has(p));
this._abort(`Timeout auf Commits von: ${missing.map(p => p.slice(0, 8)).join(', ')}`);
}, this.TIMEOUT_MS);
}
_startRevealTimer() {
this._clearRevealTimer();
this._revealTimer = setTimeout(() => {
if (this.reveals.size >= this.totalPeers) return;
const missing = [...this.expectedPeers].filter(p => !this.reveals.has(p));
this._abort(`Timeout auf Reveals von: ${missing.map(p => p.slice(0, 8)).join(', ')}`);
}, this.TIMEOUT_MS);
}
_clearCommitTimer() {
if (this._commitTimer) {
clearTimeout(this._commitTimer);
this._commitTimer = null;
}
}
_clearRevealTimer() {
if (this._revealTimer) {
clearTimeout(this._revealTimer);
this._revealTimer = null;
}
}
_abort(reason) {
this._clearCommitTimer();
this._clearRevealTimer();
this.state = 'ABORTED';
if (this.onstatechange) this.onstatechange('ABORTED');
if (this.onerror) this.onerror(reason);
}
/* ─── Commit phase ─── */
_checkCommits() {
if (this.state !== 'WAITING_FOR_COMMITS') return;
if (this.commits.size >= this.totalPeers) {
this._clearCommitTimer();
this._allCommitsReceived();
}
}
@ -64,17 +115,23 @@ class CoinFlipProtocol {
if (this.onprogress) this.onprogress('reveal', 1, this.totalPeers);
this.state = 'WAITING_FOR_REVEALS';
if (this.onstatechange) this.onstatechange('WAITING_FOR_REVEALS');
this._startRevealTimer();
this._checkReveals();
}
/* ─── Reveal phase ─── */
_checkReveals() {
if (this.state !== 'WAITING_FOR_REVEALS') return;
if (this.reveals.size >= this.totalPeers) {
this._clearRevealTimer();
this._allRevealsReceived();
}
}
async _allRevealsReceived() {
this._clearRevealTimer();
this.state = 'VERIFYING';
if (this.onstatechange) this.onstatechange('VERIFYING');
@ -82,12 +139,12 @@ class CoinFlipProtocol {
if (peerId === this.mesh.myPeerId) continue;
const commitment = this.commits.get(peerId);
if (!commitment) {
if (this.onerror) this.onerror(`Fehler: Kein Commit von ${peerId}`);
this._abort(`Fehler: Kein Commit von ${peerId.slice(0, 8)}`);
return;
}
const expected = await commit(secret);
if (!arraysEqual(expected, commitment)) {
if (this.onerror) this.onerror(`Betrug erkannt! ${peerId} hat gefälscht.`);
this._abort(`Betrug erkannt! ${peerId.slice(0, 8)} hat gefälscht.`);
return;
}
}
@ -98,12 +155,17 @@ class CoinFlipProtocol {
if (this.oncomplete) this.oncomplete(this.result);
}
/* ─── Reset ─── */
reset() {
this._clearCommitTimer();
this._clearRevealTimer();
this.state = 'IDLE';
this.secret = null;
this.commits.clear();
this.reveals.clear();
this.result = null;
this.totalPeers = 0;
this.expectedPeers = new Set();
}
}