@connectedcars/jwtutils

node-jwtutils

Zero dependency JWT encoding and decoding for Node 6.x and 8.x

This module only supports asymmetric encryption algorithms such as RS256, RS384, RS512, ES256, ES384 and ES512 as using symmetric encryption for JWT is really bad idea.

Usage

const jwtUtils = require('jwtutils')

let jwtHeader = {
  typ: 'JWT',
  alg: 'RS256',
  kid: '1'
}

let jwtBody = {
  aud: 'https://api.domain.tld',
  iss: 'https://auth.domain.tld',
  sub: '[e-mail]',
  iat: unixNow,
  exp: unixNow + 600,
  scope: ['http://stuff', 'http://stuff2']
}

// Don't use this key for anything but testing
const pemEncodedPrivateKey =
  '-----BEGIN RSA PRIVATE KEY-----\n' +
  'MIICWwIBAAKBgQDdlatRjRjogo3WojgGHFHYLugdUWAY9iR3fy4arWNA1KoS8kVw\n' +
  '33cJibXr8bvwUAUparCwlvdbH6dvEOfou0/gCFQsHUfQrSDv+MuSUMAe8jzKE4qW\n' +
  '+jK+xQU9a03GUnKHkkle+Q0pX/g6jXZ7r1/xAK5Do2kQ+X5xK9cipRgEKwIDAQAB\n' +
  'AoGAD+onAtVye4ic7VR7V50DF9bOnwRwNXrARcDhq9LWNRrRGElESYYTQ6EbatXS\n' +
  '3MCyjjX2eMhu/aF5YhXBwkppwxg+EOmXeh+MzL7Zh284OuPbkglAaGhV9bb6/5Cp\n' +
  'uGb1esyPbYW+Ty2PC0GSZfIXkXs76jXAu9TOBvD0ybc2YlkCQQDywg2R/7t3Q2OE\n' +
  '2+yo382CLJdrlSLVROWKwb4tb2PjhY4XAwV8d1vy0RenxTB+K5Mu57uVSTHtrMK0\n' +
  'GAtFr833AkEA6avx20OHo61Yela/4k5kQDtjEf1N0LfI+BcWZtxsS3jDM3i1Hp0K\n' +
  'Su5rsCPb8acJo5RO26gGVrfAsDcIXKC+bQJAZZ2XIpsitLyPpuiMOvBbzPavd4gY\n' +
  '6Z8KWrfYzJoI/Q9FuBo6rKwl4BFoToD7WIUS+hpkagwWiz+6zLoX1dbOZwJACmH5\n' +
  'fSSjAkLRi54PKJ8TFUeOP15h9sQzydI8zJU+upvDEKZsZc/UhT/SySDOxQ4G/523\n' +
  'Y0sz/OZtSWcol/UMgQJALesy++GdvoIDLfJX5GBQpuFgFenRiRDabxrE9MNUZ2aP\n' +
  'FaFp+DyAe+b4nDwuJaW2LURbr8AEZga7oQj0uYxcYw==\n' +
  '-----END RSA PRIVATE KEY-----'

let jwt = jwtUtils.encode(pemEncodedPrivateKey, jwtHeader, jwtBody)

// Don't use this key for anything but testing
const publicKey =
  '-----BEGIN PUBLIC KEY-----\n' +
  'MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDdlatRjRjogo3WojgGHFHYLugd\n' +
  'UWAY9iR3fy4arWNA1KoS8kVw33cJibXr8bvwUAUparCwlvdbH6dvEOfou0/gCFQs\n' +
  'HUfQrSDv+MuSUMAe8jzKE4qW+jK+xQU9a03GUnKHkkle+Q0pX/g6jXZ7r1/xAK5D\n' +
  'o2kQ+X5xK9cipRgEKwIDAQAB\n' +
  '-----END PUBLIC KEY-----'

const allowedAudinces = ['https://api.domain.tld']

const pubKeys = {
  'https://auth.domain.tld': {
    '1@RS256': publicKey,
    'default@RS256': publicKey // Will default to this key if the header does not have a kid
  }
}

try {
  let decodedJwtBody = jwtUtils.decode(jwt, pubKeys, allowedAudinces)
} catch (e) {
  if (e instanceof JwtVerifyError) {
    // Can be returned to user
  } else {
    // Should not be returned to user
    console.error(e)
  }
}

Express authentication middleware

const express = require('express')

// Configuration
const audiences = ['https://api.domain.tld']
const pubKeys = {
  'https://auth.domain.tld': {
    '1@RS256': publicKey // Fx. use key from before
  }
}

const app = express()

// Register the middleware
app.use(jwtAuthMiddleware(pubKeys, audiences))

// Register an error handler to return 401 errors
app.use((err, req, res, next) => {
  if (err instanceof JwtVerifyError) {
    if (err.innerError) {
      console.error(`Failed with: ${err.innerError.message}`)
    }
    res.status(401).send(err.message)
  } else {
    res.status(500).send('Unknown error')
  }
})

app.get('/', (req, res) => {
  res.send(`Hello ${req.user.subject}`)
})
app.listen(3000, () => {
  console.log('Example app listening on port 3000!')
})