Bearer Auth Middleware

The Bearer Auth Middleware provides authentication by verifying an API token in the Request header. The HTTP clients accessing the endpoint will add the Authorization header with Bearer {token} as the header value.

Using curl from the terminal, it would look like this:

curl -H 'Authorization: Bearer honoiscool' http://localhost:8787/auth/page

Import

import { Hono } from 'hono'
import { bearerAuth } from 'hono/bearer-auth'

Usage

NOTE

Your token must match the regex /[A-Za-z0-9._~+/-]+=*/, otherwise a 400 error will be returned. Notably, this regex acommodates both URL-safe Base64- and standard Base64-encoded JWTs. This middleware does not require the bearer token to be a JWT, just that it matches the above regex.

const app = new Hono()

const token = 'honoiscool'

app.use('/api/*', bearerAuth({ token }))

app.get('/api/page', (c) => {
  return c.json({ message: 'You are authorized' })
})

To restrict to a specific route + method:

const app = new Hono()

const token = 'honoiscool'

app.get('/api/page', (c) => {
  return c.json({ message: 'Read posts' })
})

app.post('/api/page', bearerAuth({ token }), (c) => {
  return c.json({ message: 'Created post!' }, 201)
})

To implement multiple tokens (E.g., any valid token can read but create/update/delete are restricted to a privileged token):

const app = new Hono()

const readToken = 'read'
const privilegedToken = 'read+write'
const privilegedMethods = ['POST', 'PUT', 'PATCH', 'DELETE']

app.on('GET', '/api/page/*', async (c, next) => {
  // List of valid tokens
  const bearer = bearerAuth({ token: [readToken, privilegedToken] })
  return bearer(c, next)
})
app.on(privilegedMethods, '/api/page/*', async (c, next) => {
  // Single valid privileged token
  const bearer = bearerAuth({ token: privilegedToken })
  return bearer(c, next)
})

// Define handlers for GET, POST, etc.

If you want to verify the value of the token yourself, specify the verifyToken option; returning true means it is accepted.

const app = new Hono()

app.use(
  '/auth-verify-token/*',
  bearerAuth({
    verifyToken: async (token, c) => {
      return token === 'dynamic-token'
    },
  })
)

Options

required token: string | string[]

The string to validate the incoming bearer token against.

optional realm: string

The domain name of the realm, as part of the returned WWW-Authenticate challenge header. The default is "". See more: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/WWW-Authenticate#directives

optional prefix: string

The prefix (or known as schema) for the Authorization header value. The default is "Bearer".

optional headerName: string

The header name. The default value is Authorization.

optional hashFunction: Function

A function to handle hashing for safe comparison of authentication tokens.

optional verifyToken: (token: string, c: Context) => boolean | Promise<boolean>

The function to verify the token.

optional noAuthenticationHeaderMessage: string | object | MessageFunction

MessageFunction is (c: Context) => string | object | Promise<string | object>. The custom message if it does not have an authentication header.

optional invalidAuthenticationHeaderMessage: string | object | MessageFunction

The custom message if the authentication header is invalid.

optional invalidTokenMessage: string | object | MessageFunction

The custom message if the token is invalid.