Compare commits

..

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
25 changed files with 11251 additions and 1446 deletions

25
.gitignore vendored
View File

@@ -1 +1,24 @@
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

130
README.md
View File

@@ -1 +1,129 @@
# P2P Poll App
# 🗳️ 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.

214
app.js
View File

@@ -1,214 +0,0 @@
import {
Repo,
BroadcastChannelNetworkAdapter,
WebSocketClientAdapter,
IndexedDBStorageAdapter,
isValidAutomergeUrl,
} from "@automerge/vanillajs";
const REPO = new Repo({
network: [
new BroadcastChannelNetworkAdapter(),
new WebSocketClientAdapter("wss://sync.automerge.org"),
],
storage: new IndexedDBStorageAdapter(),
});
let HANDLE;
function getVotedKey(docUrl) {
return `p2p-poll-voted:${docUrl}`;
}
function getVotedOptions() {
const key = getVotedKey(document.location.hash);
return new Set(JSON.parse(localStorage.getItem(key) || "[]"));
}
function markVoted(opt) {
const key = getVotedKey(document.location.hash);
const voted = getVotedOptions();
voted.add(opt);
localStorage.setItem(key, JSON.stringify([...voted]));
}
function unmarkVoted(opt) {
const key = getVotedKey(document.location.hash);
const voted = getVotedOptions();
voted.delete(opt);
localStorage.setItem(key, JSON.stringify([...voted]));
}
const locationHash = document.location.hash.substring(1);
const statusEl = document.getElementById("status");
const optionsList = document.getElementById("options-list");
const optionInput = document.getElementById("option-input");
const addBtn = document.getElementById("add-btn");
const duplicateMsg = document.getElementById("duplicate-msg");
const copyBtn = document.getElementById("copy-btn");
const timerEl = document.getElementById("timer");
const startVotingBtn = document.getElementById("start-voting-btn");
if (isValidAutomergeUrl(locationHash)) {
statusEl.textContent = "Loading document…";
try {
HANDLE = await REPO.find(locationHash);
statusEl.textContent = "";
} catch (err) {
statusEl.textContent = "Could not load document. Starting a new one.";
HANDLE = REPO.create({ options: [], votes: {}, deadline: null });
document.location.hash = HANDLE.url;
}
} else {
HANDLE = REPO.create({ options: [], votes: {}, deadline: null });
document.location.hash = HANDLE.url;
}
HANDLE.on("change", ({ doc }) => render(doc));
const initialDoc = HANDLE.doc();
if (initialDoc) render(initialDoc);
let timerInterval = null;
function render(doc) {
renderOptions(doc);
renderTimer(doc);
}
function renderOptions(doc) {
const votes = doc.votes || {};
const deadline = doc.deadline ?? null;
const now = Date.now();
const votingClosed = deadline !== null && now >= deadline;
const votedOptions = getVotedOptions();
const sorted = [...(doc.options || [])].sort(
(a, b) => (votes[b] || 0) - (votes[a] || 0),
);
optionsList.innerHTML = "";
sorted.forEach((opt) => {
const count = votes[opt] || 0;
const alreadyVoted = votedOptions.has(opt);
const item = document.createElement("div");
item.className = "option-item";
const label = document.createElement("span");
label.className = "option-label";
label.textContent = opt;
const voteBtn = document.createElement("button");
voteBtn.className = alreadyVoted ? "vote-btn voted" : "vote-btn";
voteBtn.textContent = alreadyVoted ? `${count}` : `${count}`;
voteBtn.disabled = votingClosed;
if (votingClosed) voteBtn.title = "Voting is closed";
else if (alreadyVoted) voteBtn.title = "Click to remove your vote";
voteBtn.addEventListener("click", () => {
if (alreadyVoted) {
unmarkVoted(opt);
HANDLE.change((d) => {
if (!d.votes) d.votes = {};
d.votes[opt] = Math.max(0, (d.votes[opt] || 0) - 1);
});
} else {
markVoted(opt);
HANDLE.change((d) => {
if (!d.votes) d.votes = {};
d.votes[opt] = (d.votes[opt] || 0) + 1;
});
}
});
item.appendChild(label);
item.appendChild(voteBtn);
optionsList.appendChild(item);
});
}
function renderTimer(doc) {
const deadline = doc?.deadline ?? null;
const now = Date.now();
if (deadline === null) {
timerEl.textContent = "";
startVotingBtn.hidden = false;
return;
}
startVotingBtn.hidden = true;
if (now >= deadline) {
timerEl.textContent = "Voting closed.";
timerEl.className = "timer closed";
clearInterval(timerInterval);
timerInterval = null;
return;
}
const remaining = Math.ceil((deadline - now) / 1000);
const mins = Math.floor(remaining / 60);
const secs = remaining % 60;
timerEl.textContent = `Voting closes in ${mins}:${secs.toString().padStart(2, "0")}`;
timerEl.className = "timer active";
if (!timerInterval) {
timerInterval = setInterval(() => {
const d = HANDLE.doc();
if (!d) return;
renderTimer(d);
renderOptions(d);
if (Date.now() >= d.deadline) {
clearInterval(timerInterval);
timerInterval = null;
}
}, 1000);
}
}
startVotingBtn.addEventListener("click", () => {
HANDLE.change((d) => {
d.deadline = Date.now() + 2 * 60 * 1000;
});
});
addBtn.addEventListener("click", () => {
const value = optionInput.value.trim();
if (!value) return;
const doc = HANDLE.doc();
const valueLower = value.toLowerCase();
const isDuplicate = (doc?.options || []).some(
(opt) => opt.toLowerCase() === valueLower,
);
if (isDuplicate) {
duplicateMsg.textContent = `"${value}" is already in the list.`;
duplicateMsg.hidden = false;
return;
}
duplicateMsg.hidden = true;
HANDLE.change((d) => {
if (!d.options) d.options = [];
d.options.push(value);
});
optionInput.value = "";
});
optionInput.addEventListener("keydown", (e) => {
if (e.key === "Enter") addBtn.click();
});
optionInput.addEventListener("input", () => {
duplicateMsg.hidden = true;
});
copyBtn.addEventListener("click", () => {
navigator.clipboard.writeText(window.location.href).then(() => {
copyBtn.textContent = "Copied!";
setTimeout(() => (copyBtn.textContent = "Copy URL"), 1500);
});
});

175
app/app.vue Normal file
View File

@@ -0,0 +1,175 @@
<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>

83
app/components/Poll.vue Normal file
View File

@@ -0,0 +1,83 @@
<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>

View File

@@ -0,0 +1,64 @@
<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>

131
app/composables/usePoll.ts Normal file
View File

@@ -0,0 +1,131 @@
// 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 };
};

2
app/composables/user.ts Normal file
View File

@@ -0,0 +1,2 @@
export const user = (user: Ref<UserData | null>) => {
}

187
app/utils/crypto.ts Normal file
View File

@@ -0,0 +1,187 @@
// 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);
});
};

36
app/utils/types.ts Normal file
View File

@@ -0,0 +1,36 @@
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
}

View File

@@ -1,31 +0,0 @@
<!doctype html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>P2P Polling App</title>
<link rel="stylesheet" href="./styles.css" />
</head>
<body>
<div id="app">
<h1>P2P Polling App</h1>
<div id="status"></div>
<div id="add-option">
<input
type="text"
id="option-input"
placeholder="Enter an option..."
/>
<button id="add-btn">Add Option</button>
</div>
<div id="duplicate-msg" hidden></div>
<div id="timer-section">
<div id="timer"></div>
<button id="start-voting-btn">Start 2-min Vote</button>
</div>
<div id="options-list"></div>
<button id="copy-btn">Copy URL</button>
</div>
<script type="module" src="./app.js"></script>
</body>
</html>

23
nuxt.config.ts Normal file
View File

@@ -0,0 +1,23 @@
// 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'
}
}
}
})

10118
package-lock.json generated Normal file

File diff suppressed because it is too large Load Diff

View File

@@ -1,23 +1,20 @@
{
"name": "p2p-poll-app",
"name": "p2p-poll",
"type": "module",
"engines": {
"node": ">=24"
},
"private": true,
"scripts": {
"dev": "vite",
"build": "vite build",
"preview": "vite preview"
"build": "nuxt build",
"dev": "PORT=4444 npx y-webrtc & nuxt dev",
"generate": "nuxt generate",
"preview": "nuxt preview",
"postinstall": "nuxt prepare"
},
"dependencies": {
"@automerge/automerge-repo": "^2.0.0",
"@automerge/automerge-repo-network-websocket": "^2.0.0",
"@automerge/automerge-repo-storage-indexeddb": "^2.0.0",
"@automerge/vanillajs": "^2.5.3"
},
"devDependencies": {
"vite": "^6.0.0",
"vite-plugin-top-level-await": "^1.4.0",
"vite-plugin-wasm": "^3.3.0"
"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"
}
}

1083
pnpm-lock.yaml generated

File diff suppressed because it is too large Load Diff

BIN
public/favicon.ico Normal file

Binary file not shown.

After

Width:  |  Height:  |  Size: 4.2 KiB

2
public/robots.txt Normal file
View File

@@ -0,0 +1,2 @@
User-Agent: *
Disallow:

68
server/api/polls/[id].ts Normal file
View File

@@ -0,0 +1,68 @@
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' });
}
});

View File

@@ -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
View File

@@ -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
View File

@@ -0,0 +1,86 @@
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
View File

@@ -0,0 +1,36 @@
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
}

View File

@@ -1,93 +0,0 @@
body {
font-family: sans-serif;
max-width: 480px;
margin: 40px auto;
padding: 0 16px;
}
#add-option {
display: flex;
gap: 8px;
margin-bottom: 8px;
}
#option-input {
flex: 1;
padding: 8px;
font-size: 1rem;
border: 1px solid #ccc;
border-radius: 4px;
}
#duplicate-msg {
color: #c00;
font-size: 0.9rem;
margin-bottom: 12px;
}
button {
padding: 8px 16px;
font-size: 1rem;
cursor: pointer;
border: 1px solid #ccc;
border-radius: 4px;
background: #fff;
}
button:hover:not(:disabled) {
background: #f0f0f0;
}
button:disabled {
opacity: 0.5;
cursor: default;
}
#timer-section {
display: flex;
align-items: center;
gap: 12px;
margin-bottom: 16px;
}
.timer.active {
font-weight: bold;
color: #1a6e1a;
}
.timer.closed {
font-weight: bold;
color: #c00;
}
.option-item {
display: flex;
align-items: center;
justify-content: space-between;
padding: 10px 12px;
border: 1px solid #ddd;
border-radius: 4px;
margin-bottom: 8px;
}
.option-label {
flex: 1;
}
.vote-btn {
padding: 4px 12px;
font-size: 0.9rem;
white-space: nowrap;
}
.vote-btn.voted {
background: #e6f4e6;
border-color: #4a9e4a;
color: #2a6e2a;
}
#copy-btn {
margin-top: 16px;
width: 100%;
}

18
tsconfig.json Normal file
View File

@@ -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"
}
]
}

View File

@@ -1,7 +0,0 @@
import { defineConfig } from 'vite'
import wasm from 'vite-plugin-wasm'
import topLevelAwait from 'vite-plugin-top-level-await'
export default defineConfig({
plugins: [wasm(), topLevelAwait()]
})