client-oauth2

Client OAuth 2.0

Straight-forward execution of OAuth 2.0 flows and authenticated API requests.

Installation

npm install client-oauth2 --save

Usage

The module supports executing all the various OAuth 2.0 flows in any JavaScript environment. To authenticate you need to create an instance of the module for your API.

var ClientOAuth2 = require('client-oauth2')

var githubAuth = new ClientOAuth2({
  clientId: 'abc',
  clientSecret: '123',
  accessTokenUri: 'https://github.com/login/oauth/access_token',
  authorizationUri: 'https://github.com/login/oauth/authorize',
  authorizationGrants: ['credentials'],
  redirectUri: 'http://example.com/auth/github/callback',
  scopes: ['notifications', 'gist']
})

• clientId The client id string assigned to you by the provider
• clientSecret The client secret string assigned to you by the provider (not required for token)
• accessTokenUri The url to request the access token (not required for token)
• authorizationUri The url to redirect users to authenticate with the provider (only required for token and code)
• redirectUri A custom url for the provider to redirect users back to your application (only required for token and code)
• scopes An array of scopes to authenticate against

Request options

• body An object to merge with the body of every request
• query An object to merge with the query parameters of every request
• headers An object to merge with the headers of every request
• options Transport options from popsicle

To re-create an access token instance and make requests on behalf on the user, you can create an access token instance by using the createToken method on a client instance.

var token = githubAuth.createToken('access token', 'optional refresh token', 'optional token type', { optional: 'raw user data' })

// Refresh the users credentials and save the updated access token.
token.refresh().then(storeNewToken)

token.request({
  method: 'get',
  url: 'https://api.github.com/users'
})
  .then(function (res) {
    console.log(res) //=> { body: '...', status: 200, headers: { ... } }
  })

You can override the request mechanism if you need a custom implementation by setting githubAuth.request = function (opts) { return new Promise(...) }. You will need to make sure that the custom request mechanism supports the correct input and output objects.

P.S. All authorization methods accept options as the last argument, useful for overriding the global configuration on a per-request basis.

Authorization Code Grant

The authorization code grant type is used to obtain both access tokens and refresh tokens and is optimized for confidential clients. Since this is a redirection-based flow, the client must be capable of interacting with the resource owner's user-agent (typically a web browser) and capable of receiving incoming requests (via redirection) from the authorization server.

1. Redirect user to githubAuth.code.getUri().
2. Parse response uri and get token using githubAuth.code.getToken(uri).

var express = require('express')
var app     = express()

app.get('/auth/github', function (req, res) {
  var uri = githubAuth.code.getUri()

  res.redirect(uri)
})

app.get('/auth/github/callback', function (req, res) {
  githubAuth.code.getToken(req.url)
    .then(function (user) {
      console.log(user) //=> { accessToken: '...', tokenType: 'bearer', ... }

      // Refresh the current users access token.
      user.refresh().then(function (updatedUser) {
        console.log(updatedUser === user) //=> true
      })

      // Sign API requests on behalf of the current user.
      user.sign({
        method: 'get',
        url: 'http://example.com'
      })

      // We should store the token into a database.
      return res.send(user.accessToken)
    })
})

Implicit Grant

The implicit grant type is used to obtain access tokens (it does not support the issuance of refresh tokens) and is optimized for public clients known to operate a particular redirection URI. These clients are typically implemented in a browser using a scripting language such as JavaScript.

1. Redirect user to githubAuth.token.getUri().
2. Parse response uri for the access token using githubAuth.token.getToken(uri).

window.oauth2Callback = function (uri) {
  githubAuth.token.getToken(uri)
    .then(function (user) {
      console.log(user) //=> { accessToken: '...', tokenType: 'bearer', ... }

      // Make a request to the github API for the current user.
      user.request({
        method: 'get',
        url: 'https://api.github.com/user'
      }).then(function (res) {
        console.log(res) //=> { body: { ... }, status: 200, headers: { ... } }
      })
    })
}

// Open the page in a new window, then redirect back to a page that calls our global `oauth2Callback` function.
window.open(githubAuth.token.getUri())

Resource Owner Password Credentials Grant

The resource owner password credentials grant type is suitable in cases where the resource owner has a trust relationship with the client, such as the device operating system or a highly privileged application. The authorization server should take special care when enabling this grant type and only allow it when other flows are not viable.

1. Make a direct request for the access token on behalf of the user using githubAuth.owner.getToken(username, password).

githubAuth.owner.getToken('blakeembrey', 'hunter2')
  .then(function (user) {
    console.log(user) //=> { accessToken: '...', tokenType: 'bearer', ... }
  })

Client Credentials Grant

The client can request an access token using only its client credentials (or other supported means of authentication) when the client is requesting access to the protected resources under its control, or those of another resource owner that have been previously arranged with the authorization server (the method of which is beyond the scope of this specification).

1. Get the access token for the application by using githubAuth.credentials.getToken().

githubAuth.credentials.getToken()
  .then(function (user) {
    console.log(user) //=> { accessToken: '...', tokenType: 'bearer', ... }
  })

JWT as Authorization Grant

A JSON Web Token (JWT) Bearer Token can be used to request an access token when a client wishes to utilize an existing trust relationship, expressed through the semantics of (and digital signature or Message Authentication Code calculated over) the JWT, without a direct user approval step at the authorization server.

githubAuth.jwt.getToken('eyJhbGciOiJFUzI1NiJ9.eyJpc3Mi[...omitted for brevity...].J9l-ZhwP[...omitted for brevity...]')
  .then(function (user) {
    console.log(user) //=> { accessToken: '...', tokenType: 'bearer', ... }
  })

License

Apache 2.0