libjwt

libjwt is a lightweight library for creating and validating JSON Web Tokens (JWT) using the HS256 algorithm. It provides a simple interface for encoding, decoding, and validating JWTs, making it easy to integrate secure authentication into your Node.js applications.

Features

• HS256 Algorithm: Utilizes the HS256 (HMAC with SHA-256) algorithm for JWT signing and verification.
• Simple API: Easily encode, decode, and validate JWTs.
• Custom Payloads: Supports custom payload data with standard JWT claims like iat (issued at) and exp (expiration).

Installation

Install the library using npm:

npm install @sarthakkimtani/libjwt

Usage

Importing the Library

To use the library, import the necessary functions:

import { encode_jwt, decode_jwt, validate_jwt } from "@sarthakkimtani/libjwt";

Encoding a JWT

Create a JWT with a secret, payload, and an optional time-to-live (TTL) in seconds (default is 900 seconds or 15 minutes):

const secret = "your-secret-key";
const payload = { id: "user123", role: "admin" };

const token = await encode_jwt(secret, payload, 3600); // TTL is 1 hour
console.log("Generated JWT:", token);

Decoding a JWT

Decode a JWT to extract its payload. The function returns an object containing the id, full payload, and expires_at date:

const decoded = await decode_jwt(secret, token);
console.log("Decoded JWT:", decoded);

Validating a JWT

Check if a JWT is valid by verifying its signature and expiration. Returns true if the token is valid, otherwise false:

const isValid = await validate_jwt(secret, token);
console.log("Is the JWT valid?", isValid);

API Reference

async encode_jwt(secret: string, payload: JWTPayload, ttl?: number): Promise<string>

• secret: The secret key used to sign the JWT.
• payload: The payload to include in the JWT. This can contain any custom claims.
• ttl: Optional. Time-to-live in seconds. Defaults to 900 seconds (15 minutes).

async decode_jwt(secret: string, jwt: string): Promise<DecodedJWT>

• secret: The secret key used to sign the JWT.
• jwt: The JWT string to decode.

Returns an object containing the decoded id, payload, and expires_at date.

async validate_jwt(secret: string, jwt: string): Promise<boolean>

• secret: The secret key used to sign the JWT.
• jwt: The JWT string to validate.

Returns true if the JWT is valid (correct signature and not expired), otherwise false.

Demo

A demo of this project is available in the demo folder. The demo includes practical examples of how to use the library, demonstrating its functionality in real-world scenarios.

License

This library is licensed under the MIT License. See the LICENSE file for more details.

Author

Sarthak Kimtani

Feel free to contribute to the project or open issues if you encounter any problems!