Authentication and Access Control

1.1 Overview

Authentication and access control are essential for securing decentralized applications, ensuring that only authorized users and systems can access sensitive features and data. In this documentation, we outline how to implement authentication using OAuth2 and JWT (JSON Web Token), providing secure, token-based access management across the CapsureLabs platform.

---

1.2 Key Components of the Security Protocol

OAuth2

Used for secure delegation, OAuth2 enables users to authorize third-party applications to access their resources without sharing credentials.

JWT

---

1.3 OAuth2 Implementation Guide

OAuth2 is a widely used standard for delegated access, allowing users to grant applications access to resources without exposing passwords. Here’s an example of an OAuth2 flow with access token generation.

1.3.1 Request Authorization Code

GET /authorize?response_type=code&client_id=YOUR_CLIENT_ID&redirect_uri=YOUR_REDIRECT_URI&scope=read_profile&state=1234xyz HTTP/1.1
Host: authorization-server.com

Parameters:

• response_type=code: Specifies that the response should be an authorization code.

• client_id: Client ID of the application.

• redirect_uri: Redirect URI for post-authorization response.

• scope: The level of access the application requests.

• state: A unique string to prevent CSRF attacks.

1.3.2 Obtain Access Token Using Authorization Code

POST /token HTTP/1.1
Host: authorization-server.com
Content-Type: application/x-www-form-urlencoded

grant_type=authorization_code&code=AUTH_CODE_HERE&redirect_uri=YOUR_REDIRECT_URI&client_id=YOUR_CLIENT_ID&client_secret=YOUR_CLIENT_SECRET

---

1.4 JWT Integration Guide

Generating JWT Tokens

A JWT typically consists of:

• Header: Specifies the type of token (JWT) and the algorithm used for signing.

• Payload: Contains user claims, such as user_id, role, and token expiry.

• Signature: Created by hashing the header and payload with a secret key, verifying data integrity.

1.4.1 Generating JWT in Node.js

const jwt = require('jsonwebtoken');

function generateToken(user) {
    const payload = {
        userId: user.id,
        role: user.role,
        exp: Math.floor(Date.now() / 1000) + (60 * 60) // 1 hour expiration
    };

    const secretKey = "YOUR_SECRET_KEY";
    const token = jwt.sign(payload, secretKey);
    return token;
}

// Usage
const token = generateToken({ id: "12345", role: "user" });
console.log(token);

1.4.2 Verifying JWT Tokens

function verifyToken(token) {
    try {
        const decoded = jwt.verify(token, "YOUR_SECRET_KEY");
        console.log("Token is valid:", decoded);
        return decoded;
    } catch (error) {
        console.error("Invalid token:", error);
        return null;
    }
}

// Usage
const decodedPayload = verifyToken(token);

---

1.5 Applying OAuth2 and JWT Together

For additional security and session management, OAuth2 can issue JWT tokens as access tokens. When integrating both protocols:

1. OAuth2 server generates a JWT as an access token.

2. JWT is passed to client applications to be stored and used as a bearer token for authorized requests.

3. Expiration and Refresh: When JWT expires, the application can use the OAuth2 refresh token to obtain a new JWT without re-authentication.

---

1.6 API Endpoint Access with Bearer JWT

GET /user/profile HTTP/1.1
Host: api.capsurelabs.com
Authorization: Bearer ACCESS_TOKEN_HERE