# CVA JWT

CVA JWT is a simple JSON Web Token (JWT) encode and decode module for Node.js. It allows you to create and verify JWTs using various algorithms.

Installation

You can install the cva-jwt package using npm:

npm install cva-jwt

Usage

Encoding a JWT

To encode a JWT, use the encode method. You'll need to provide a payload, a secret key, and optionally, an algorithm.

const jwt = require('cva-jwt');

// Define your payload
const payload = {
  userId: 123,
  role: 'admin'
};

// Define your secret key
const secretKey = 'your-256-bit-secret';


// Encode the token
const token = jwt.encode(payload, secretKey, 'HS256');

console.log('Encoded JWT:', token);

HS256 secrets are typically 128-bit random strings, for example hex-encoded:

let secret = Buffer.from('fe1a1915a379f3be5394b64d14794932', 'hex')

Decoding a JWT

To decode and verify a JWT, use the decode method. You will need to provide the token and the secret key.

const token = 'your.jwt.token.here';

try {
  const decodedPayload = jwt.decode(token, secretKey);
  console.log('Decoded Payload:', decodedPayload);
} catch (error) {
  console.error('Error decoding token:', error.message);
}

Options

The encode function accepts an optional options parameter, which allows you to customize the JWT header.

const options = {
  header: {
    kid: 'your-key-id' // Optional key ID
  }
};

const token = jwt.encode(payload, secretKey, 'HS256', options);

Supported Algorithms

• HS256 (HMAC using SHA-256)
• HS384 (HMAC using SHA-384)
• HS512 (HMAC using SHA-512)
• RS256 (RSA Signature with SHA-256)

Error Handling

When decoding a JWT, several errors may be thrown:

• No token supplied: If no token is provided.
• Invalid token: Not enough or too many segments: If the token does not contain exactly three segments.
• Signature verification failed: If the signature does not match.
• Token not yet active: If the token's nbf (not before) claim is not met.
• Token expired: If the token's exp (expiration) claim has passed.

License

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

Contributing

Contributions are welcome! Please open an issue or submit a pull request for any enhancements or fixes.

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