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2 Commits

Author SHA1 Message Date
bc5e2eead8 + create user with public/private key
+ sign and verify votes and prevent unverified updates
2026-04-04 22:36:17 +02:00
b5cb0e83e3 * init p2p polling app 2026-03-31 19:09:46 +02:00
23 changed files with 11157 additions and 610 deletions

25
.gitignore vendored
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node_modules/
# Nuxt dev/build outputs
.output
.data
.nuxt
.nitro
.cache
dist
# Node dependencies
node_modules
# Logs
logs
*.log
# Misc
.DS_Store
.fleet
.idea
# Local env files
.env
.env.*
!.env.example

157
README.md
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# P2P Poll App
## Install npm packages
```
npm init -y
npm install
```
Note: the frontend obtains the packages `yjs` and `y-websocket` dynamically.
## Run backend
```
node backend.js
```
### Note on Yjs suggestion
Note that the following server setup is suggested in the Yjs docs (https://docs.yjs.dev/ecosystem/connection-provider/y-websocket):
```
npm install y-websocket-server
HOST=localhost PORT=1000 npx y-websocket
```
However, across a range of npm versions, this does not work.
Nevertheless, the essential code from the `y-websocket-server` package is used here as provided in `utils.js`.
## Run frontend
Open "frontend.html" in browser.
# 🗳️ P2P Verified Polling App
A decentralized, real-time polling application built with **Nuxt 3**, **Yjs**, and **WebRTC**. This app allows users to create and participate in polls where every vote is cryptographically signed and verified peer-to-peer, ensuring data integrity without a central authority "owning" the results.
---
## 🌟 Key Features
* **Serverless Real-time Sync:** Uses **Yjs** (CRDTs) and **WebRTC** to sync poll data directly between browsers. No database is required for live updates.
* **Persistence with Nitro:** While the logic is P2P, the **Nuxt/Nitro** backend provides a "Snapshot" service to ensure polls persist even after all peers go offline.
* **Cryptographic Integrity:** Every vote is signed using **RSA-PSS (Web Crypto API)**. Each user has a unique private key (stored locally via `.pem` files) to ensure votes cannot be forged or tampered with.
* **Chained Verification:** Implements a "History-Signing" logic where each new vote signs the entire preceding state of the poll, creating a verifiable chain of trust.
* **Privacy First:** Users identify via UUIDs and Public/Private key pairs rather than traditional accounts.
---
## ⚙️ How It Works
### 1. Identity Creation
When a new user is created, the system generates a unique **UUID (User ID)** and an **RSA Key Pair**. The user is prompted to save their **Private Key** as a `.pem` file, named after their User ID (e.g., `550e8400-e29b.pem`). This file acts as their "Passport"—it is never uploaded to the server and must be kept secure by the user.
### 2. Authentication
Upon returning to the app, users load their local `.pem` file. The application extracts the Private Key for signing and the UUID for identification. No passwords or central servers are involved in this local-first login process.
### 3. Joining a Poll
When a user joins a poll, the app fetches the latest binary snapshot from the server to populate a local **Y.Doc**. This ensures the user sees the current state immediately, even before connecting to other peers.
### 4. The P2P Mesh
The app establishes connections to other active voters via a WebRTC signaling server. Any changes made to the poll (adding options or voting) are broadcasted instantly to all peers using Conflict-free Replicated Data Types (CRDTs) to prevent sync conflicts.
### 5. Casting a Signed Vote
To ensure security, the voting process follows a strict cryptographic chain:
* The app captures the current list of votes.
* It appends the new vote data (User ID + Timestamp).
* It signs the **entire array** (the previous history + the new vote) using the user's RSA private key.
* The signed update is merged into the shared Yjs Map and broadcasted.
### 6. Distributed Verification
Whenever a peer receives a new update, they fetch the voter's **Public Key** from the API. They then verify that the signature matches the current state of the poll history. If a signature is invalid or the history has been tampered with, the vote is rejected by the peer's local state.
---
## 🛠️ Tech Stack
* **Framework:** [Nuxt 3](https://nuxt.com/) (Vue 3 + TypeScript)
* **Conflict-Free Replicated Data Types (CRDT):** [Yjs](https://yjs.dev/)
* **P2P Transport:** `y-webrtc`
* **Security:** Web Crypto API (SubtleCrypto)
* **Backend/Storage:** Nitro (Nuxt's server engine) with filesystem storage drivers
# AI Disclaimer
This App was developed with the assistance of AI.
# Nuxt Minimal Starter
Look at the [Nuxt documentation](https://nuxt.com/docs/getting-started/introduction) to learn more.
## Setup
Make sure to install dependencies:
```bash
# npm
npm install
# pnpm
pnpm install
# yarn
yarn install
# bun
bun install
```
## Development Server
Start the development server on `http://localhost:3000`:
```bash
# npm
npm run dev
# pnpm
pnpm dev
# yarn
yarn dev
# bun
bun run dev
```
## Production
Build the application for production:
```bash
# npm
npm run build
# pnpm
pnpm build
# yarn
yarn build
# bun
bun run build
```
Locally preview production build:
```bash
# npm
npm run preview
# pnpm
pnpm preview
# yarn
yarn preview
# bun
bun run preview
```
Check out the [deployment documentation](https://nuxt.com/docs/getting-started/deployment) for more information.

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app/app.vue Normal file
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<style>
/* Basic styling to make it look clean */
body {
font-family: system-ui, -apple-system, sans-serif;
background-color: #f4f4f9;
color: #333;
margin: 0;
display: flex;
justify-content: center;
padding: 2rem;
}
header {
margin-bottom: 2rem;
text-align: center;
}
h1 { margin: 0 0 0.5rem 0; }
input {
flex-grow: 1;
padding: 0.75rem;
border: 1px solid #ccc;
border-radius: 6px;
font-size: 1rem;
}
button,
.button {
background: #3b82f6;
color: white;
border: none;
padding: 0.75rem 1rem;
border-radius: 6px;
cursor: pointer;
font-weight: bold;
transition: background 0.2s;
}
button:hover,
.button:hover { background: #2563eb; }
.status {
font-size: 0.85rem;
color: #666;
}
.status .connected { color: #10b981; font-weight: bold; }
.connectionFailed { color: #FF2525; font-weight: bold; }
.poll-container {
background: white;
padding: 2rem;
border-radius: 12px;
box-shadow: 0 4px 6px rgba(0,0,0,0.1);
width: 100%;
max-width: 500px;
}
.back-btn {
margin-left: 1rem;
padding: 0.2rem 0.5rem;
font-size: 0.7rem;
background: #64748b;
}
/* Hide the actual file input */
input[type="file"] {
display: none;
}
</style>
<template>
<div class="poll-container">
<header>
<h1 @click="activePollId = null" style="cursor:pointer">P2P Polling App 🗳</h1>
<div class="status">
<button v-if="activePollId" @click="activePollId = null" class="back-btn"> Back To List</button>
<span :class="{ 'connected': isConnected }">
{{ isConnected ? 'Synced' : 'Waiting for other Peers...' }}
</span>
<span> | Peers online: {{ connectedPeers }}</span>
<h2 v-if="connectionAttempFailed" class="connectionFailed"> Connection to Signaling Server Failed!</h2>
<div v-if="user===null" style="margin-top: 10px;">
<button @click="createUser">Create New User</button>
Or
<label title="Select Key File">
<span class="button">Login</span>
<input
type="file"
accept=".pem"
@change="loadUser"
/>
</label>
</div>
</div>
</header>
<main>
<PollList v-if="!activePollId" :userid="user?.userid" @select-poll="selectPoll" />
<Poll v-else :activePollId="activePollId" :userid="user?.userid" :poll-data="pollData" :addOption="addOption" :vote="vote"/>
</main>
</div>
</template>
<script setup lang="ts">
import { v4 as uuidv4 } from 'uuid';
const activePollId = ref<string | null>(null);
const user = shallowRef<UserData | null>(null);
const { pollData, isConnected, connectionAttempFailed, connectedPeers, addOption, vote } = usePoll(activePollId,user);
const selectPoll = (id: string) => {
activePollId.value = id;
};
const createUser = async () => {
try {
const keypair : CryptoKeyPair = await generateUserKeyPair();
console.log('keypair:', keypair);
const uuid = uuidv4();
user.value = {
userid: uuid,
private_key: keypair.privateKey,
public_key: keypair.publicKey,
};
const prvKeyString = await exportPrivateKey(keypair.privateKey);
await savePrivateKeyToFile(prvKeyString,uuid+".pem")
const pubKeyString = await exportPublicKey(keypair.publicKey);
await $fetch(`/api/users/${uuid}`, {
method: 'POST',
body: { public_key: pubKeyString }
});
} catch (err) {
user.value = null
console.error("Failed to create new User!", err);
}
};
const loadUser = async (event: Event) => {
const target = event.target as HTMLInputElement;
const file = target.files?.[0];
if (file) {
try {
const content = await file.text();
console.log("File loaded: ");
if (file.name && content) {
try {
const uuid = file.name.replace(".pem", "");
// Standardize the string for the importer
const pkBase64 = content.replace(/-----BEGIN PRIVATE KEY-----|-----END PRIVATE KEY-----/g, "").replace(/\s+/g, "");
const key = await stringToCryptoKey(pkBase64, "private");
user.value = {
userid: uuid,
private_key: key,
public_key: undefined, // Note: You might need to import a pub key too!
};
console.log("Login successful for:", uuid);
} catch (err) {
console.error("Crypto Import Error:", err);
alert("The file content is not a valid Private Key.");
}
}
} catch (e) {
console.error("Failed to read file", e);
}
}
};
</script>

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<style scoped>
.poll-list {
list-style: none;
padding: 0;
margin: 0;
}
.poll-item {
display: flex;
justify-content: space-between;
align-items: center;
padding: 1rem;
background: #f8fafc;
border: 1px solid #e2e8f0;
border-radius: 8px;
margin-bottom: 0.5rem;
}
.poll-title {
font-size: 1.1rem;
color: #3b82f6;
text-transform: uppercase;
letter-spacing: 1px;
}
.add-option-form {
display: flex;
gap: 0.5rem;
margin-bottom: 2rem;
}
.option-name { font-weight: 500; }
.vote-section { display: flex; align-items: center; gap: 1rem; }
.vote-count { font-size: 0.9rem; color: #475569; }
.vote-btn { padding: 0.4rem 0.8rem; background: #10b981; }
.vote-btn:hover { background: #059669; }
.vote-btn:disabled,
.vote-btn[disabled] { background: #888888; }
.vote-btn:disabled:hover,
.vote-btn[disabled]:hover { background: #AAAAAA; }
</style>
<template>
<div>
<h2 class="poll-title">Poll: {{ activePollId }}</h2>
<p v-if="Object.keys(pollData).length==0">Note: Add at least one Option to save the Poll.</p>
<form @submit.prevent="handleAddNewOption" class="add-option-form" v-if="userid">
<input v-model="newOption" placeholder="Enter a new poll option..." required />
<button type="submit">Add Option</button>
</form>
<ul class="poll-list">
<li v-for="(votes, optionName) in pollData" :key="optionName" class="poll-item">
<span class="option-name">{{ optionName }}</span>
<div class="vote-section">
<span class="vote-count">{{ votes.length }} {{ votes.length === 1 ? 'vote' : 'votes' }}</span>
<button @click="vote(String(optionName))" class="vote-btn" :disabled="userid==undefined || voted(votes)">+1</button>
</div>
</li>
</ul>
</div>
</template>
<script setup lang="ts">
import type { PollProps, SignedData, VoteData } from '@/utils/types'
const props = defineProps<PollProps>()
const newOption = ref('');
const handleAddNewOption = () => {
props.addOption(newOption.value);
newOption.value = '';
};
const voted = (votes: SignedData<VoteData>[]) => {
for(let vote of votes){
if(vote.data.userid == props.userid){
return true;
}
}
return false;
}
</script>

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<style scoped>
.poll-list { margin-top: 1rem; }
.empty-state { text-align: center; color: #94a3b8; font-style: italic; }
.create-poll { display: flex; gap: 0.5rem; margin-bottom: 1.5rem; }
.poll-links { list-style: none; padding: 0; }
.poll-link-btn {
width: 100%;
text-align: left;
background: #f1f5f9;
color: #1e293b;
margin-bottom: 0.5rem;
display: flex;
justify-content: space-between;
}
.poll-link-btn:hover { background: #e2e8f0; }
</style>
<template>
<div class="poll-list">
<h3>Available Polls</h3>
<ul v-if="polls && polls.length > 0" class="poll-links">
<li v-for="id in polls" :key="id">
<button class="poll-link-btn" @click="$emit('select-poll', id)">
{{ id }} <span></span>
</button>
</li>
</ul>
<p v-else class="empty-state">No polls found. Create the first one!</p>
<div class="create-poll" v-if="userid !== undefined">
<input
v-model="newPollId"
placeholder="Enter new poll name..."
@keyup.enter="createPoll"
/>
<button @click="createPoll">Create & Join</button>
</div>
</div>
</template>
<script setup lang="ts">
import type { PollListProps } from '@/utils/types'
const props = defineProps<PollListProps>()
const newPollId = ref('');
const polls = ref<string[]>([]);
// Fetch existing polls on mount
const fetchPolls = async () => {
const data = await $fetch<{ polls: string[] }>('/api/polls');
polls.value = data.polls;
};
const createPoll = () => {
const id = newPollId.value.trim().toLowerCase().replace(/\s+/g, '-');
if (id) {
// In a real app, you might want to POST to create it first,
// but here we just navigate to it and let usePoll handle the save.
emit('select-poll', id);
}
};
const emit = defineEmits(['select-poll']);
onMounted(fetchPolls);
</script>

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// composables/usePoll.ts
import { ref, watch, onUnmounted } from 'vue';
import * as Y from 'yjs';
export const usePoll = (pollId: Ref<string | null>, user: Ref<UserData | null>) => {
const pollData = ref<PollData>({});
const isConnected = ref(false);
const connectionAttempFailed = ref(false);
const connectedPeers = ref(1);
let ydoc: Y.Doc | null = null;
let provider: any = null;
let yMap: Y.Map<SignedData<VoteData>[]> | null = null;
const cleanup = () => {
if (provider) provider.disconnect();
if (ydoc) ydoc.destroy();
isConnected.value = false;
pollData.value = {};
};
const initPoll = async (id: string) => {
cleanup(); // Clear previous session
ydoc = new Y.Doc();
// 1. Fetch Snapshot from Nuxt API
try {
const response = await $fetch<{ update: number[] | null }>(`/api/polls/${id}`).catch((e) => {
console.error("Failed to get poll: " + id,e)
});
//trust the server without verification.
if (response?.update) {
Y.applyUpdate(ydoc, new Uint8Array(response.update));
}
} catch (err) {
console.error('Persistence fetch failed', err);
}
yMap = ydoc.getMap<SignedData<VoteData>[]>('shared-poll');
// 2. Local State Sync
yMap.observe(async () => {
await performUpdateAndVerify();
saveStateToServer(id);
});
await performUpdateAndVerify();
// 3. P2P Connection
const { WebrtcProvider } = await import('y-webrtc');
provider = new WebrtcProvider(`nuxt-p2p-${id}`, ydoc, {
signaling: ["ws://localhost:4444", "ws://lynxpi.ddns.net:4444"]
});
provider.on('synced', (arg: {synced: boolean}) => {
isConnected.value = arg.synced;
console.log('Connection synced:', arg.synced) // "connected" or "disconnected"
});
provider.on('status', (event: { connected: boolean }) => {
console.log('Connection status:', event.connected) // "connected" or "disconnected"
})
provider.on('peers', (data: any) => {
connectedPeers.value = data.webrtcPeers.length + 1
});
};
const saveStateToServer = async (id: string) => {
if (!ydoc) return;
const stateUpdate = Y.encodeStateAsUpdate(ydoc);
await $fetch(`/api/polls/${id}`, {
method: 'POST',
body: { update: Array.from(stateUpdate) }
}).catch((e) => {
console.error("Failed to update poll",e)
});
};
// Watch for ID changes (e.g., user clicks a link or goes back)
watch(pollId, (newId) => {
if (newId && import.meta.client) {
initPoll(newId);
} else {
cleanup();
}
}, { immediate: true });
onUnmounted(cleanup);
const addOption = (optionName: string) => {
if (yMap && !yMap.has(optionName)) yMap.set(optionName, []);
};
const performUpdateAndVerify = async () => {
const pollDataUpdate = yMap!.toJSON();
console.log("Poll Data Update: ", pollDataUpdate)
for(var option in pollDataUpdate){
console.log("verifying votes for option: " + option);
const votes = pollDataUpdate[option] || [];
const verified = await verifyAllVotesForOption(votes);
if(!verified){
console.error("Failed to verify option: "+option)
return;
}
}
console.log("All options verified! :)")
pollData.value = pollDataUpdate
}
const vote = async (optionName: string) => {
const currentUser = user.value;
if (currentUser != undefined && yMap?.has(optionName)) {
const voteData = [...(yMap.get(optionName) || [])];
if(voteData != undefined && currentUser.private_key){
var unsignedVoteData : VoteData = {
userid: currentUser.userid,
timestamp: new Date().toISOString()
}
var newVote : SignedData<VoteData> = {
data: unsignedVoteData,
signature: "",
}
voteData?.push(newVote)
const signature = await signVote(voteData,currentUser.private_key);
newVote.signature=signature
yMap?.set(optionName, voteData);
}
}
};
return { pollData, isConnected, connectionAttempFailed, connectedPeers, addOption, vote };
};

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export const user = (user: Ref<UserData | null>) => {
}

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app/utils/crypto.ts Normal file
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// utils/crypto.ts
export const generateUserKeyPair = async () => {
return await window.crypto.subtle.generateKey(
{
name: "RSASSA-PKCS1-v1_5",
modulusLength: 2048,
publicExponent: new Uint8Array([1, 0, 1]), // 65537
hash: "SHA-256",
},
true, // extractable
["sign", "verify"]
);
};
export const signVote = async (data: any, privateKey: CryptoKey) => {
const encoder = new TextEncoder();
const encodedData = encoder.encode(JSON.stringify(data));
const signature = await window.crypto.subtle.sign(
"RSASSA-PKCS1-v1_5",
privateKey,
encodedData
);
// Convert to Base64 or Hex to store in Yjs easily
return btoa(String.fromCharCode(...new Uint8Array(signature)));
};
export const verifyVote = async (data: any, signatureStr: string, publicKey: CryptoKey) => {
const encoder = new TextEncoder();
const encodedData = encoder.encode(JSON.stringify(data));
// Convert Base64 back to Uint8Array
const signature = Uint8Array.from(atob(signatureStr), c => c.charCodeAt(0));
return await window.crypto.subtle.verify(
"RSASSA-PKCS1-v1_5",
publicKey,
signature,
encodedData
);
};
/**
* Verifies a specific vote within an array of votes by
* reconstructing the "signed state" at that point in time.
*/
export const verifyChainedVote = async (
voteData: SignedData<VoteData>[],
index: number
) => {
const voteToVerify = voteData[index];
console.log("Verifying vote: " + voteToVerify)
if(voteToVerify) {
// 1. Reconstruct the exact data state the user signed
// We need the array exactly as it was when they pushed their vote
const historicalState = voteData.slice(0, index + 1).map((v, i) => {
if (i === index) {
// For the current vote, the signature must be empty string
// because it wasn't signed yet when passed to signVote
return { ...v, signature: "" };
}
return v;
});
try {
// 2. Fetch public key
const response = await $fetch<{ public_key: string }>(`/api/users/${voteToVerify.data.userid}`);
console.log("Got key: ",response)
const pubKey = await stringToCryptoKey(response.public_key, 'public');
console.log("Using pubKey to verify Vote.")
// 3. Verify: Does this historicalState match the signature?
return await verifyVote(historicalState, voteToVerify.signature, pubKey);
} catch (err) {
console.error("Verification failed")
console.error(err);
return false;
}
}
console.error("Vote is undefined or null");
return false;
};
export const verifyAllVotesForOption = async (votes: SignedData<VoteData>[]) => {
console.log("verifying votes for option ",votes);
for (let i = votes.length-1; i >= 0 ; i--) {
const isValid = await verifyChainedVote(votes, i);
if(!isValid){
console.error("Error! Invalid Vote at: " + i,votes)
return false;
}
}
return true;
};
// Helper to convert ArrayBuffer to Base64 string
const bufferToBase64 = (buf: ArrayBuffer) =>
window.btoa(String.fromCharCode(...new Uint8Array(buf)));
export const exportPublicKey = async (key: CryptoKey) => {
// Export Public Key
const exportedPublic = await window.crypto.subtle.exportKey("spki", key);
const publicKeyString = bufferToBase64(exportedPublic);
return publicKeyString;
};
export const exportPrivateKey = async (key: CryptoKey) => {
// Export Private Key
const exportedPrivate = await window.crypto.subtle.exportKey("pkcs8", key);
const privateKeyString = bufferToBase64(exportedPrivate);
return privateKeyString;
};
/**
* Converts a Base64 string back into a usable CryptoKey object
* @param keyStr The Base64 string (without PEM headers)
* @param type 'public' or 'private'
*/
export const stringToCryptoKey = async (keyStr: string, type: 'public' | 'private'): Promise<CryptoKey> => {
// 1. Convert Base64 string to a Uint8Array (binary)
const binaryString = window.atob(keyStr);
const bytes = new Uint8Array(binaryString.length);
for (let i = 0; i < binaryString.length; i++) {
bytes[i] = binaryString.charCodeAt(i);
}
// 2. Identify the format based on the key type
// Public keys usually use 'spki', Private keys use 'pkcs8'
const format = type === 'public' ? 'spki' : 'pkcs8';
const usages: KeyUsage[] = type === 'public' ? ['verify'] : ['sign'];
// 3. Import the key
return await window.crypto.subtle.importKey(
format,
bytes.buffer,
{
name: "RSASSA-PKCS1-v1_5",
hash: "SHA-256",
},
true, // extractable (set to false if you want to lock it in memory)
usages
);
};
export const savePrivateKeyToFile = (privateKeyStr: string, filename: string) => {
// Optional: Wrap in PEM headers for standard formatting
const pemHeader = "-----BEGIN PRIVATE KEY-----\n";
const pemFooter = "\n-----END PRIVATE KEY-----";
const fileContent = pemHeader + privateKeyStr + pemFooter;
const blob = new Blob([fileContent], { type: "text/plain" });
const url = URL.createObjectURL(blob);
const link = document.createElement("a");
link.href = url;
link.download = filename;
document.body.appendChild(link);
link.click();
// Cleanup
document.body.removeChild(link);
URL.revokeObjectURL(url);
};
export const loadPrivateKeyFromFile = async (file: File): Promise<string> => {
return new Promise((resolve, reject) => {
const reader = new FileReader();
reader.onload = (e) => {
const content = e.target?.result as string;
// Clean up the string by removing PEM headers and newlines
const cleanKey = content
.replace("-----BEGIN PRIVATE KEY-----", "")
.replace("-----END PRIVATE KEY-----", "")
.replace(/\s+/g, ""); // Removes all whitespace/newlines
resolve(cleanKey);
};
reader.onerror = () => reject("Error reading file");
reader.readAsText(file);
});
};

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export interface PollProps {
userid: string | undefined,
activePollId: string,
pollData: PollData,
addOption: (name: string) => void,
vote: (optionName: string) => void
}
export interface PollListProps {
userid: string | undefined,
}
export interface PollData extends Record<string, SignedData<VoteData>[]> {
}
export interface SignedData<T> {
data: T,
signature: string
}
export interface VoteData {
userid: string,
timestamp: string
}
export interface OptionData {
userid: string,
timestamp: string,
optionName: string
}
export interface UserData {
userid: string,
private_key: CryptoKey | undefined,
public_key: CryptoKey | undefined
}

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@@ -1,31 +0,0 @@
import { WebSocketServer } from 'ws';
import { setupWSConnection } from './utils.js'
// Create a WebSocket server
const WS_PORT = 8080;
const wss = new WebSocketServer({ port: WS_PORT });
console.log('WebSocket server is running on ws://localhost:' + String(WS_PORT));
// Connection event handler
wss.on('connection', setupWSConnection);
/*
wss.on('connection', (ws) => {
console.log('Client connected');
// Message event handler
ws.on('message', (message) => {
let msg_str = String(message);
console.log("Received: " + msg_str);
// If this is a text or state message (no Yjs logic) - echo the message back to the client
if (msg_str.startsWith("TEXT_MESSAGE") | msg_str.startsWith("STATE_MESSAGE")) {
ws.send(msg_str);
}
});
// Close event handler
ws.on('close', () => {
console.log('Client disconnected');
});
});*/

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@@ -1,196 +0,0 @@
<!DOCTYPE html>
<html>
<head>
<title>Poll Client</title>
<style>
body {
font-family: Arial, sans-serif;
max-width: 600px;
margin: 0 auto;
padding: 20px;
}
#messages {
height: 300px;
border: 1px solid #ccc;
overflow-y: auto;
padding: 10px;
margin-bottom: 10px;
}
.message { margin: 5px 0; }
</style>
</head>
<body>
<h1>Poll Client</h1>
<div id="status">Connecting to server...</div>
<div id="status2">Connecting to server...</div>
<div id="messages"></div>
<div>
<input type="text" id="messageInput" placeholder="Type your message">
<!--button onclick="sendMessage()">Send</button-->
<button id="sendBtn">Send</button>
<input id="optionInput" placeholder="Add option">
<button id="addBtn">Add</button>
<ul id="options"></ul>
</div>
<script type="module">
import * as Y from "https://esm.sh/yjs"
import { WebsocketProvider } from "https://esm.sh/y-websocket"
const WS_PORT = 8080;
const ydoc = new Y.Doc();
const status = document.getElementById('status');
const status2 = document.getElementById('status2');
const messages = document.getElementById('messages');
const messageInput = document.getElementById('messageInput');
// Connect to the backend (WebSocket server) via Yjs WebsocketProvider
const wsp = new WebsocketProvider(
'ws://localhost:' + String(WS_PORT), 'poll-room',
ydoc
)
wsp.on('status', event => {
//console.log("event.status =", event.status)
if (event.status == "connected") {
status.textContent = 'Yjs connected to WebSocket server';
status.style.color = 'green';
}
else {
status.textContent = 'Yjs disonnected from WebSocket server';
status.style.color = 'red';
}
})
wsp.onopen = () => {
console.log('connected to y-websocket server');
};
ydoc.on('update', () => {
console.log('Yjs document updated locally');
});
wsp.on('sync', isSynced => {
console.log("isSynced =", isSynced)
})
// Connect to the backend (WebSocket server) via common WebSocket (only for informative messages)
const ws = new WebSocket('ws://localhost:' + String(WS_PORT));
ws.onopen = () => {
status2.textContent = 'WebSocket client connected to WebSocket server';
status2.style.color = 'green';
};
ws.onmessage = (event) => {
const message = document.createElement('div');
message.className = 'message';
message.textContent = event.data;
messages.appendChild(message);
messages.scrollTop = messages.scrollHeight;
};
ws.onerror = (error) => {
status2.textContent = 'Error: ' + error.message;
status2.style.color = 'red';
};
ws.onclose = () => {
status2.textContent = 'WebSocket client disconnected from WebSocket server';
status2.style.color = 'red';
};
// Function to send a message
function sendMessage(command, payload) {
let message = "";
if (command === "TEXT_MESSAGE") {
message = command + ":" + messageInput.value.trim();
messageInput.value = "";
}
else if (command.startsWith("STATE_MESSAGE--")) {
message = command + ":" + payload;
}
else {
console.log("Error: unknown command '" + command + "'")
}
if (message) {
/* To make compatible with y-websocket-server API:
const encoder = encoding.createEncoder()
encoding.writeVarUint(encoder, messageTextMessage)
syncProtocol.writeUpdate(encoder, update)
enc_message = encoding.toUint8Array(encoder)*/
ws.send(message);
}
}
// Send message on button click
document.getElementById("sendBtn").onclick = () => {
sendMessage("TEXT_MESSAGE", "");
};
// Send message on Enter key
messageInput.addEventListener('keypress', (e) => {
if (e.key === 'Enter') {
sendMessage("TEXT_MESSAGE", "");
}
});
// Actual poll logic
const optionsMap = ydoc.getMap("options");
const optionsList = document.getElementById("options");
const input = document.getElementById("optionInput");
function render() {
optionsList.innerHTML = ""
optionsMap.forEach((vote, name) => {
// List element for this option
const li = document.createElement("li")
// Label for this option
const label = document.createElement("span")
label.textContent = name + " — " + vote + " "
// "Vote"/"Unvote" button
const voteBtn = document.createElement("button")
if (vote == false) {
voteBtn.textContent = "Vote"
}
else {
voteBtn.textContent = "Unvote"
}
voteBtn.onclick = () => {
vote = !vote;
optionsMap.set(name, vote);
sendMessage("STATE_MESSAGE--" + (vote ? "VOTE" : "UNVOTE"), name);
}
// "Remove" button
const removeBtn = document.createElement("button")
removeBtn.textContent = "Remove"
removeBtn.onclick = () => {
optionsMap.delete(name);
sendMessage("STATE_MESSAGE--REMOVE", name);
}
li.appendChild(label)
li.appendChild(voteBtn)
li.appendChild(removeBtn)
optionsList.appendChild(li)
})
};
document.getElementById("addBtn").onclick = () => {
const name = input.value.trim()
if (!name) return
if (!optionsMap.has(name)) {
optionsMap.set(name, false);
sendMessage("STATE_MESSAGE--ADD_OPTION", name);
}
input.value = ""
};
optionsMap.observe(render);
render();
</script>
</body>
</html>

23
nuxt.config.ts Normal file
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// https://nuxt.com/docs/api/configuration/nuxt-config
export default defineNuxtConfig({
compatibilityDate: '2025-07-15',
devtools: { enabled: true },
vite: {
optimizeDeps: {
include: ['yjs', 'y-webrtc']
}
},
// ... existing config
nitro: {
storage: {
polls: {
driver: 'fs',
base: './.data/polls'
},
users: {
driver: 'fs',
base: './.data/users'
}
}
}
})

10074
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View File

@@ -1,20 +1,20 @@
{
"name": "yjs-poll",
"version": "1.0.0",
"main": "index.js",
"name": "p2p-poll",
"type": "module",
"private": true,
"scripts": {
"test": "echo \"Error: no test specified\" && exit 1",
"y-websocket": "y-websocket"
"build": "nuxt build",
"dev": "PORT=4444 npx y-webrtc & nuxt dev",
"generate": "nuxt generate",
"preview": "nuxt preview",
"postinstall": "nuxt prepare"
},
"keywords": [],
"author": "",
"license": "ISC",
"description": "",
"dependencies": {
"ws": "^8.19.0",
"@y/protocols": "^1.0.6-1",
"lib0": "^0.2.102",
"yjs": "^14.0.0-7"
"nuxt": "^4.1.3",
"uuid": "^13.0.0",
"vue": "^3.5.30",
"vue-router": "^5.0.3",
"y-webrtc": "^10.3.0",
"yjs": "^13.6.30"
}
}

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2
public/robots.txt Normal file
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User-Agent: *
Disallow:

68
server/api/polls/[id].ts Normal file
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import * as Y from 'yjs';
// server/api/polls/[id].ts
export default defineEventHandler(async (event) => {
const method = event.node.req.method;
const pollId = getRouterParam(event, 'id');
// We use Nitro's built-in storage.
// 'polls' is the storage namespace.
const storage = useStorage('polls');
if (!pollId) {
throw createError({ statusCode: 400, statusMessage: 'Poll ID required' });
}
// GET: Fetch the saved Yjs document state
if (method === 'GET') {
const data = await storage.getItem(`poll:${pollId}`);
// Return the array of numbers (or null if it doesn't exist yet)
return { update: data || null };
}
// POST: Save a new Yjs document state
if (method === 'POST') {
const body = await readBody(event);
if (body.update && Array.isArray(body.update)) {
// create a temp Y.Doc to encode the Data
const tempDoc = new Y.Doc();
Y.applyUpdate(tempDoc, new Uint8Array(body.update));
const yMap = tempDoc.getMap('shared-poll');
const pollData = yMap.toJSON();
// verify pollData
for(var option in pollData){
const votes = pollData[option] || [];
var pubKeys: CryptoKey[] = [];
const verifyAllVotesForOption = async (votes: SignedData<VoteData>[]) => {
console.log("verifying votes for option " + option,votes);
// check last votes first. if there is something wrong, its likely in the last vote.
for (let i = votes.length-1; i >= 0 ; i--) {
const userStorage = useStorage('users');
const votePubKeyString = await userStorage.getItem(`user:${votes[i]?.data.userid}`);
//console.log("Using public key: "+votePubKeyString)
const votePubKey = await stringToCryptoKey(String(votePubKeyString),'public')
const isValid = await verifyChainedVote(votes, i,votePubKey);
if(!isValid){
console.error("Error! Invalid Vote at: " + i,votes)
return false;
}
}
return true;
};
const verified = await verifyAllVotesForOption(votes);
if(!verified){
console.error("Failed to verify option: "+option)
throw createError({ statusCode: 400, statusMessage: 'PollData contains unverifyable content!' });
}
}
// Save the binary update (sent as an array of numbers) to storage
await storage.setItem(`poll:${pollId}`, body.update);
return { success: true };
}
throw createError({ statusCode: 400, statusMessage: 'Invalid update payload' });
}
});

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@@ -0,0 +1,15 @@
// server/api/polls/index.get.ts
export default defineEventHandler(async () => {
const storage = useStorage('polls');
// Get all keys in the 'polls' namespace
const allKeys = await storage.getKeys();
// Filter for our specific poll prefix and strip it for the UI
// poll:my-id -> my-id
const polls = allKeys
.filter(key => key.startsWith('poll:'))
.map(key => key.replace('poll:', ''));
return { polls };
});

41
server/api/users/[id].ts Normal file
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@@ -0,0 +1,41 @@
// server/api/users/[id].ts
export default defineEventHandler(async (event) => {
const method = event.node.req.method;
const userId = getRouterParam(event, 'id');
// We use Nitro's built-in storage.
// 'polls' is the storage namespace.
const storage = useStorage('users');
if (!userId) {
throw createError({ statusCode: 400, statusMessage: 'User ID required' });
}
// GET: Fetch the saved Yjs document state
if (method === 'GET') {
const data = await storage.getItem(`user:${userId}`);
// Return the array of numbers (or null if it doesn't exist yet)
return { public_key: data };
}
// POST: Save a new Yjs document state
if (method === 'POST') {
const body = await readBody(event);
if (body.public_key) {
const data = await storage.getItem(`user:${userId}`);
if (data == undefined || data == null) {
// Save the binary update (sent as an array of numbers) to storage
await storage.setItem(`user:${userId}`, body.public_key);
console.log("New User created: " + userId)
console.log("Public Key: " + body.public_key);
return { success: true };
}
throw createError({ statusCode: 400, statusMessage: 'User already exists.' });
}
throw createError({ statusCode: 400, statusMessage: 'Invalid update payload' });
}
});

86
server/utils/crypto.ts Normal file
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import { SignedData, VoteData } from "./types";
/**
* Gets the WebCrypto API regardless of environment (Node vs Browser)
*/
const getCrypto = () => {
return (globalThis as any).crypto;
};
export const verifyVote = async (data: any, signatureStr: string, publicKey: CryptoKey) => {
const encoder = new TextEncoder();
const encodedData = encoder.encode(JSON.stringify(data));
// Convert Base64 back to Uint8Array
const signature = Uint8Array.from(atob(signatureStr), c => c.charCodeAt(0));
return await getCrypto().subtle.verify(
"RSASSA-PKCS1-v1_5",
publicKey,
signature,
encodedData
);
};
/**
* Verifies a specific vote within an array of votes by
* reconstructing the "signed state" at that point in time.
*/
export const verifyChainedVote = async (
voteData: SignedData<VoteData>[],
index: number,
pubKey: CryptoKey
) => {
const voteToVerify = voteData[index];
console.log("Verifying vote: " + voteToVerify)
if(voteToVerify) {
// 1. Reconstruct the exact data state the user signed
// We need the array exactly as it was when they pushed their vote
const historicalState = voteData.slice(0, index + 1).map((v, i) => {
if (i === index) {
// For the current vote, the signature must be empty string
// because it wasn't signed yet when passed to signVote
return { ...v, signature: "" };
}
return v;
});
try {
// 3. Verify: Does this historicalState match the signature?
return await verifyVote(historicalState, voteToVerify.signature, pubKey);
} catch (err) {
console.error("Verification failed")
console.error(err);
return false;
}
}
console.error("Vote is undefined or null");
return false;
};
/**
* Converts a Base64 string back into a usable CryptoKey object
* @param keyStr The Base64 string (without PEM headers)
* @param type 'public' or 'private'
*/
export const stringToCryptoKey = async (keyStr: string, type: 'public' | 'private'): Promise<CryptoKey> => {
// 1. Convert Base64 string to a Uint8Array (binary)
const bytes = Buffer.from(keyStr, 'base64');
// 2. Identify the format based on the key type
// Public keys usually use 'spki', Private keys use 'pkcs8'
const format = type === 'public' ? 'spki' : 'pkcs8';
const usages: KeyUsage[] = type === 'public' ? ['verify'] : ['sign'];
// 3. Import the key
return await getCrypto().subtle.importKey(
format,
bytes,
{
name: "RSASSA-PKCS1-v1_5",
hash: "SHA-256",
},
true, // extractable (set to false if you want to lock it in memory)
usages
);
};

36
server/utils/types.ts Normal file
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export interface PollProps {
userid: string | undefined,
activePollId: string,
pollData: PollData,
addOption: (name: string) => void,
vote: (optionName: string) => void
}
export interface PollListProps {
userid: string | undefined,
}
export interface PollData extends Record<string, SignedData<VoteData>[]> {
}
export interface SignedData<T> {
data: T,
signature: string
}
export interface VoteData {
userid: string,
timestamp: string
}
export interface OptionData {
userid: string,
timestamp: string,
optionName: string
}
export interface UserData {
userid: string,
private_key: CryptoKey | undefined,
public_key: CryptoKey | undefined
}

18
tsconfig.json Normal file
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@@ -0,0 +1,18 @@
{
// https://nuxt.com/docs/guide/concepts/typescript
"files": [],
"references": [
{
"path": "./.nuxt/tsconfig.app.json"
},
{
"path": "./.nuxt/tsconfig.server.json"
},
{
"path": "./.nuxt/tsconfig.shared.json"
},
{
"path": "./.nuxt/tsconfig.node.json"
}
]
}

291
utils.js
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@@ -1,291 +0,0 @@
/* Adapted from https://github.com/yjs/y-websocket-server/blob/main/src/server.js, version of 2025-04-02
(author: dmonad/Kevin Jahns, MIT license) */
import * as Y from 'yjs'
import * as syncProtocol from '@y/protocols/sync'
import * as awarenessProtocol from '@y/protocols/awareness'
import * as encoding from 'lib0/encoding'
import * as decoding from 'lib0/decoding'
import * as map from 'lib0/map'
import * as eventloop from 'lib0/eventloop'
/*import { callbackHandler, isCallbackSet } from './callback.js'
const CALLBACK_DEBOUNCE_WAIT = parseInt(process.env.CALLBACK_DEBOUNCE_WAIT || '2000')
const CALLBACK_DEBOUNCE_MAXWAIT = parseInt(process.env.CALLBACK_DEBOUNCE_MAXWAIT || '10000')
const debouncer = eventloop.createDebouncer(CALLBACK_DEBOUNCE_WAIT, CALLBACK_DEBOUNCE_MAXWAIT)*/
const wsReadyStateConnecting = 0
const wsReadyStateOpen = 1
const wsReadyStateClosing = 2 // eslint-disable-line
const wsReadyStateClosed = 3 // eslint-disable-line
// disable gc when using snapshots!
const gcEnabled = process.env.GC !== 'false' && process.env.GC !== '0'
// const persistenceDir = process.env.YPERSISTENCE
/**
* @type {{bindState: function(string,WSSharedDoc):void, writeState:function(string,WSSharedDoc):Promise<any>, provider: any}|null}
*/
let persistence = null
/**
* @param {{bindState: function(string,WSSharedDoc):void,
* writeState:function(string,WSSharedDoc):Promise<any>,provider:any}|null} persistence_
*/
export const setPersistence = persistence_ => {
persistence = persistence_
}
/**
* @return {null|{bindState: function(string,WSSharedDoc):void,
* writeState:function(string,WSSharedDoc):Promise<any>}|null} used persistence layer
*/
export const getPersistence = () => persistence
/**
* @type {Map<string,WSSharedDoc>}
*/
export const docs = new Map()
const messageSync = 0
const messageAwareness = 1
// const messageAuth = 2
//const messageTextMessage = 3
//const messageStateMessage = 4
/**
* @param {Uint8Array} update
* @param {any} _origin
* @param {WSSharedDoc} doc
* @param {any} _tr
*/
const updateHandler = (update, _origin, doc, _tr) => {
const encoder = encoding.createEncoder()
encoding.writeVarUint(encoder, messageSync)
syncProtocol.writeUpdate(encoder, update)
const message = encoding.toUint8Array(encoder)
doc.conns.forEach((_, conn) => send(doc, conn, message))
}
/**
* @type {(ydoc: Y.Doc) => Promise<void>}
*/
let contentInitializor = _ydoc => Promise.resolve()
/**
* This function is called once every time a Yjs document is created. You can
* use it to pull data from an external source or initialize content.
*
* @param {(ydoc: Y.Doc) => Promise<void>} f
*/
export const setContentInitializor = (f) => {
contentInitializor = f
}
export class WSSharedDoc extends Y.Doc {
/**
* @param {string} name
*/
constructor (name) {
super({ gc: gcEnabled })
this.name = name
/**
* Maps from conn to set of controlled user ids. Delete all user ids from awareness when this conn is closed
* @type {Map<Object, Set<number>>}
*/
this.conns = new Map()
/**
* @type {awarenessProtocol.Awareness}
*/
this.awareness = new awarenessProtocol.Awareness(this)
this.awareness.setLocalState(null)
/**
* @param {{ added: Array<number>, updated: Array<number>, removed: Array<number> }} changes
* @param {Object | null} conn Origin is the connection that made the change
*/
const awarenessChangeHandler = ({ added, updated, removed }, conn) => {
const changedClients = added.concat(updated, removed)
if (conn !== null) {
const connControlledIDs = /** @type {Set<number>} */ (this.conns.get(conn))
if (connControlledIDs !== undefined) {
added.forEach(clientID => { connControlledIDs.add(clientID) })
removed.forEach(clientID => { connControlledIDs.delete(clientID) })
}
}
// broadcast awareness update
const encoder = encoding.createEncoder()
encoding.writeVarUint(encoder, messageAwareness)
encoding.writeVarUint8Array(encoder, awarenessProtocol.encodeAwarenessUpdate(this.awareness, changedClients))
const buff = encoding.toUint8Array(encoder)
this.conns.forEach((_, c) => {
send(this, c, buff)
})
}
this.awareness.on('update', awarenessChangeHandler)
this.on('update', /** @type {any} */ (updateHandler))
//if (isCallbackSet) {
// this.on('update', (_update, _origin, doc) => {
// debouncer(() => callbackHandler(/** @type {WSSharedDoc} */ (doc)))
// })
//}
this.whenInitialized = contentInitializor(this)
}
}
/**
* Gets a Y.Doc by name, whether in memory or on disk
*
* @param {string} docname - the name of the Y.Doc to find or create
* @param {boolean} gc - whether to allow gc on the doc (applies only when created)
* @return {WSSharedDoc}
*/
export const getYDoc = (docname, gc = true) => map.setIfUndefined(docs, docname, () => {
const doc = new WSSharedDoc(docname)
doc.gc = gc
if (persistence !== null) {
persistence.bindState(docname, doc)
}
docs.set(docname, doc)
return doc
})
/**
* @param {any} conn
* @param {WSSharedDoc} doc
* @param {Uint8Array} message
*/
const messageListener = (conn, doc, message) => {
try {
const encoder = encoding.createEncoder()
const decoder = decoding.createDecoder(new Uint8Array(message))
const messageType = decoding.readVarUint(decoder)
switch (messageType) {
case messageSync:
encoding.writeVarUint(encoder, messageSync)
syncProtocol.readSyncMessage(decoder, encoder, doc, conn)
// If the `encoder` only contains the type of reply message and no
// message, there is no need to send the message. When `encoder` only
// contains the type of reply, its length is 1.
if (encoding.length(encoder) > 1) {
send(doc, conn, encoding.toUint8Array(encoder))
}
break
case messageAwareness: {
awarenessProtocol.applyAwarenessUpdate(doc.awareness, decoding.readVarUint8Array(decoder), conn)
break
}
// If this is a text or a message (no Yjs logic) - echo the message back to the client
default: {
conn.send(String(message))
console.log(String(message))
break
}
}
} catch (err) {
console.error(err)
// @ts-ignore
doc.emit('error', [err])
}
}
/**
* @param {WSSharedDoc} doc
* @param {any} conn
*/
const closeConn = (doc, conn) => {
if (doc.conns.has(conn)) {
/**
* @type {Set<number>}
*/
// @ts-ignore
const controlledIds = doc.conns.get(conn)
doc.conns.delete(conn)
awarenessProtocol.removeAwarenessStates(doc.awareness, Array.from(controlledIds), null)
if (doc.conns.size === 0 && persistence !== null) {
// if persisted, we store state and destroy ydocument
persistence.writeState(doc.name, doc).then(() => {
doc.destroy()
})
docs.delete(doc.name)
}
}
conn.close()
}
/**
* @param {WSSharedDoc} doc
* @param {import('ws').WebSocket} conn
* @param {Uint8Array} m
*/
const send = (doc, conn, m) => {
if (conn.readyState !== wsReadyStateConnecting && conn.readyState !== wsReadyStateOpen) {
closeConn(doc, conn)
}
try {
conn.send(m, {}, err => { err != null && closeConn(doc, conn) })
} catch (e) {
closeConn(doc, conn)
}
}
const pingTimeout = 30000
/**
* @param {import('ws').WebSocket} conn
* @param {import('http').IncomingMessage} req
* @param {any} opts
*/
export const setupWSConnection = (conn, req, { docName = (req.url || '').slice(1).split('?')[0], gc = true } = {}) => {
conn.binaryType = 'arraybuffer'
// get doc, initialize if it does not exist yet
const doc = getYDoc(docName, gc)
doc.conns.set(conn, new Set())
// listen and reply to events
conn.on('message', /** @param {ArrayBuffer} message */ message => messageListener(conn, doc, message))
// Check if connection is still alive
let pongReceived = true
const pingInterval = setInterval(() => {
if (!pongReceived) {
if (doc.conns.has(conn)) {
closeConn(doc, conn)
}
clearInterval(pingInterval)
} else if (doc.conns.has(conn)) {
pongReceived = false
try {
conn.ping()
} catch (e) {
closeConn(doc, conn)
clearInterval(pingInterval)
}
}
}, pingTimeout)
conn.on('close', () => {
closeConn(doc, conn)
clearInterval(pingInterval)
})
conn.on('pong', () => {
pongReceived = true
})
// put the following in a variables in a block so the interval handlers don't keep in in
// scope
{
// send sync step 1
const encoder = encoding.createEncoder()
encoding.writeVarUint(encoder, messageSync)
syncProtocol.writeSyncStep1(encoder, doc)
send(doc, conn, encoding.toUint8Array(encoder))
const awarenessStates = doc.awareness.getStates()
if (awarenessStates.size > 0) {
const encoder = encoding.createEncoder()
encoding.writeVarUint(encoder, messageAwareness)
encoding.writeVarUint8Array(encoder, awarenessProtocol.encodeAwarenessUpdate(doc.awareness, Array.from(awarenessStates.keys())))
send(doc, conn, encoding.toUint8Array(encoder))
}
}
}