jsonwebtoken

An implementation of JSON Web Tokens.

This was developed against draft-ietf-oauth-json-web-token-08. It makes use of node-jws

Install

$ npm install jsonwebtoken

Usage

jwt.sign(payload, secretOrPrivateKey, options)

(Synchronous) Returns the JsonWebToken as string

payload could be an literal, buffer or string

secretOrPrivateKey is a string or buffer containing either the secret for HMAC algorithms, or the PEM encoded private key for RSA and ECDSA.

options:

• algorithm (default: HS256)
• expiresInMinutes
• audience
• subject
• issuer

If payload is not a buffer or a string, it will be coerced into a string using JSON.stringify.

If any expiresInMinutes, audience, subject, issuer are not provided, there is no default. The jwt generated won't include those properties in the payload.

Example

// sign with default (HMAC SHA256)
var jwt = require('jsonwebtoken');
var token = jwt.sign({ foo: 'bar' }, 'shhhhh');

// sign with RSA SHA256
var cert = fs.readFileSync('private.key');  // get private key
var token = jwt.sign({ foo: 'bar' }, cert, { algorithm: 'RS256'});

jwt.verify(token, secretOrPublicKey, options, callback)

(Synchronous with callback) Returns the payload decoded if the signature (and optionally expiration, audience, issuer) are valid. If not, it will return the error.

token is the JsonWebToken string

secretOrPublicKey is a string or buffer containing either the secret for HMAC algorithms, or the PEM encoded public key for RSA and ECDSA.

options

• audience: if you want to check audience (aud), provide a value here
• issuer: if you want to check issuer (iss), provide a value here

// verify a token symmetric
jwt.verify(token, 'shhhhh', function(err, decoded) {
  console.log(decoded.foo) // bar
});

// invalid token
jwt.verify(token, 'wrong-secret', function(err, decoded) {
  // err 
  // decoded undefined
});

// verify a token asymmetric
var cert = fs.readFileSync('public.pem');  // get public key
jwt.verify(token, cert, function(err, decoded) {
  console.log(decoded.foo) // bar
});

// verify audience
var cert = fs.readFileSync('public.pem');  // get public key
jwt.verify(token, cert, { audience: 'urn:foo' }, function(err, decoded) {
  // if audience mismatch, err == invalid audience
});

// verify issuer
var cert = fs.readFileSync('public.pem');  // get public key
jwt.verify(token, cert, { audience: 'urn:foo', issuer: 'urn:issuer' }, function(err, decoded) {
  // if issuer mismatch, err == invalid issuer
});
      

jwt.decode(token)

(Synchronous) Returns the decoded payload without verifying if the signature is valid.

token is the JsonWebToken string

Example

// get the decoded payload ignoring signature, no secretOrPrivateKey needed
var decoded = jwt.decode(token);

Errors & Codes

Possible thrown errors during verification. Error is the first argument of the verification callback.

TokenExpiredError

Thrown error if the token is expired.

Error object:

• name: 'TokenExpiredError'
• message: 'jwt expired'
• expiredAt: [ExpDate]

jwt.verify(token, 'shhhhh', function(err, decoded) {
  if (err) {
    /* 
      err = {
        name: 'TokenExpiredError',
        message: 'jwt expired',
        expiredAt: 1408621000
      }
    */
  }
});

JsonWebTokenError

Error object:

• name: 'JsonWebTokenError'
• message:
  • 'jwt malformed'
  • 'jwt signature is required'
  • 'invalid signature'
  • 'jwt audience invalid. expected: [PAYLOAD AUDIENCE]'
  • 'jwt issuer invalid. expected: [PAYLOAD ISSUER]'

jwt.verify(token, 'shhhhh', function(err, decoded) {
  if (err) {
    /* 
      err = {
        name: 'JsonWebTokenError',
        message: 'jwt malformed'
      }
    */
  }
});

Algorithms supported

Array of supported algorithms. The following algorithms are currently supported.

alg Parameter Value	Digital Signature or MAC Algorithm
HS256	HMAC using SHA-256 hash algorithm
HS384	HMAC using SHA-384 hash algorithm
HS512	HMAC using SHA-512 hash algorithm
RS256	RSASSA using SHA-256 hash algorithm
RS384	RSASSA using SHA-384 hash algorithm
RS512	RSASSA using SHA-512 hash algorithm
ES256	ECDSA using P-256 curve and SHA-256 hash algorithm
ES384	ECDSA using P-384 curve and SHA-384 hash algorithm
ES512	ECDSA using P-521 curve and SHA-512 hash algorithm
none	No digital signature or MAC value included

TODO

• X.509 certificate chain is not checked

License

MIT