simple-oauth2

What is simple-oauth2?

The simple-oauth2 npm package is a straightforward and flexible library for implementing OAuth2 authentication in Node.js applications. It provides a simple API to handle the OAuth2 authorization flows, including obtaining access tokens, refreshing tokens, and revoking tokens.

What are simple-oauth2's main functionalities?

Authorization Code Flow

This feature allows you to generate an authorization URL for the Authorization Code Flow. Users can visit this URL to authorize your application and obtain an authorization code.

const { AuthorizationCode } = require('simple-oauth2');

const client = new AuthorizationCode({
  client: {
    id: 'your-client-id',
    secret: 'your-client-secret',
  },
  auth: {
    tokenHost: 'https://authorization-server.com',
    tokenPath: '/oauth/token',
    authorizePath: '/oauth/authorize',
  },
});

const authorizationUri = client.authorizeURL({
  redirect_uri: 'http://localhost:3000/callback',
  scope: 'user_profile',
  state: 'random-string',
});

console.log('Visit this URL to authorize:', authorizationUri);

Obtaining Access Token

This feature allows you to exchange an authorization code for an access token. The access token can then be used to access protected resources on behalf of the user.

const tokenParams = {
  code: 'authorization-code',
  redirect_uri: 'http://localhost:3000/callback',
  scope: 'user_profile',
};

client.getToken(tokenParams)
  .then((result) => {
    const accessToken = client.createToken(result);
    console.log('Access Token:', accessToken.token);
  })
  .catch((error) => {
    console.error('Access Token Error', error.message);
  });

Refreshing Access Token

This feature allows you to refresh an expired access token using a refresh token. The new access token can then be used to continue accessing protected resources.

const token = client.createToken({
  access_token: 'existing-access-token',
  refresh_token: 'existing-refresh-token',
  expires_in: '3600',
});

token.refresh()
  .then((result) => {
    const refreshedToken = client.createToken(result);
    console.log('Refreshed Token:', refreshedToken.token);
  })
  .catch((error) => {
    console.error('Refresh Token Error', error.message);
  });

Revoking Access Token

This feature allows you to revoke an access token, making it invalid for further use. This is useful for logging out users or invalidating tokens for security reasons.

const token = client.createToken({
  access_token: 'existing-access-token',
  refresh_token: 'existing-refresh-token',
  expires_in: '3600',
});

token.revoke('access_token')
  .then(() => {
    console.log('Access Token Revoked');
  })
  .catch((error) => {
    console.error('Revoke Token Error', error.message);
  });

Other packages similar to simple-oauth2

passport-oauth2

passport-oauth2 is a strategy for the Passport authentication middleware that implements OAuth 2.0. It is highly configurable and can be used with various OAuth 2.0 providers. Compared to simple-oauth2, passport-oauth2 is more integrated with the Passport ecosystem, making it a good choice if you are already using Passport for authentication.

client-oauth2

client-oauth2 is a lightweight and flexible library for OAuth 2.0 in JavaScript. It supports multiple OAuth 2.0 flows and is easy to use in both Node.js and browser environments. Compared to simple-oauth2, client-oauth2 offers a more minimalistic approach and can be a good choice for developers looking for a smaller library.

axios-oauth-client

axios-oauth-client is a library that integrates OAuth 2.0 with the popular Axios HTTP client. It simplifies the process of making authenticated HTTP requests using OAuth 2.0 tokens. Compared to simple-oauth2, axios-oauth-client is more focused on integrating OAuth 2.0 with Axios, making it a good choice if you are already using Axios for HTTP requests.

README

Simple OAuth2

Simple OAuth2 is a Node.js client library for the OAuth 2.0 authorization framework. OAuth 2.0 is the industry-standard protocol for authorization, enabling third-party applications to obtain limited access to an HTTP service, either on behalf of a resource owner or by allowing the third-party application to obtain access on it's own behalf.

Table of Contents

• Simple OAuth2
  • Table of Contents
  • Requirements
  • Usage
    • Supported Grant Types
      • Authorization Code Grant
      • Resource Owner Password Credentials Grant
      • Client Credentials Grant
    • Access Token
      • Refresh an access token
      • Revoke an access or refresh token
    • Errors
  • Debugging the module
  • Contributing
  • Authors
    • Contributors
  • Changelog
  • License
  • Thanks to Open Source

Requirements

Version	Node support
3.x	Node 8.x or higher
4.x (Current)	Node 12.x or higher

Older node versions are unsupported.

Usage

Install the client library using npm:

npm install --save simple-oauth2

With a minimal configuration, create an client instace of any supported grant type.

const config = {
  client: {
    id: '<client-id>',
    secret: '<client-secret>'
  },
  auth: {
    tokenHost: 'https://api.oauth.com'
  }
};

const { ClientCredentials, ResourceOwnerPassword, AuthorizationCode } = require('simple-oauth2');

For a complete reference of configuration options, see the API Options

Supported Grant Types

Depending on your use-case, any of the following supported grant types may be useful:

Authorization Code Grant

The Authorization Code grant type is used by confidential and public clients to exchange an authorization code for an access token. After the user returns to the client via the redirect URL, the application will get the authorization code from the URL and use it to request an access token.

async function run() {
  const client = new AuthorizationCode(config);

  const authorizationUri = client.authorizeURL({
    redirect_uri: 'http://localhost:3000/callback',
    scope: '<scope>',
    state: '<state>'
  });

  // Redirect example using Express (see http://expressjs.com/api.html#res.redirect)
  res.redirect(authorizationUri);

  const tokenParams = {
    code: '<code>',
    redirect_uri: 'http://localhost:3000/callback',
    scope: '<scope>',
  };

  try {
    const accessToken = await client.getToken(tokenParams);
  } catch (error) {
    console.log('Access Token Error', error.message);
  }
}

run();

See the API reference for a complete reference of available options or any of our available examples at the example folder.

Resource Owner Password Credentials Grant

The Resource Owner Password Credentials grant type is a way to exchange a user's credentials for an access token. Because the client application has to collect the user's password and send it to the authorization server, it is not recommended that this grant be used at all anymore.

async function run() {
  const client = new ResourceOwnerPassword(config);

  const tokenParams = {
    username: 'username',
    password: 'password',
    scope: '<scope>',
  };

  try {
    const accessToken = await client.getToken(tokenParams);
  } catch (error) {
    console.log('Access Token Error', error.message);
  }
}

run();

See the API reference for a complete reference of available options.

Client Credentials Grant

The Client Credentials grant type is used by clients to obtain an access token outside of the context of a user. This is typically used by clients to access resources about themselves rather than to access a user's resources.

async function run() {
  const client = new ClientCredentials(config);

  const tokenParams = {
    scope: '<scope>',
  };

  try {
    const accessToken = await client.getToken(tokenParams);
  } catch (error) {
    console.log('Access Token error', error.message);
  }
}

run();

See the API reference for a complete reference of available options.

Access Token

On completion of any supported grant type an access token will be obtained. A list of supported operations can be found below.

Refresh an access token

On long lived applications, it is often necessary to refresh access tokens. In such scenarios the access token is usually persisted in an external database by first serializing it.

async function run() {
  const accessTokenJSONString = JSON.stringify(accessToken);

  await persistAccessTokenJSON(accessTokenJSONString);
}

run();

By the time we need to refresh the persistent access token, we can get back an AccessToken instance by using the client's .createToken method.

async function run() {
  const accessTokenJSONString = await getPersistedAccessTokenJSON();

  let accessToken = client.createToken(JSON.parse(accessTokenJSONString));
}

run();

Once we have determined the access token needs refreshing with the .expired() method, we can finally refresh it with a .refresh() method call.

async function run() {
  if (accessToken.expired()) {
    try {
      const refreshParams = {
        scope: '<scope>',
      };

      accessToken = await accessToken.refresh(refreshParams);
    } catch (error) {
      console.log('Error refreshing access token: ', error.message);
    }
  }
}

run();

The .expired() helper is useful for knowing when a token has definitively expired. However, there is a common race condition when tokens are near expiring. If an OAuth 2.0 token is issued with a expires_in property (as opposed to an expires_at property), there can be discrepancies between the time the OAuth 2.0 server issues the access token and when it is received.

These come down to factors such as network and processing latency and can be worked around by preemptively refreshing the access token:

async function run() {
  const EXPIRATION_WINDOW_IN_SECONDS = 300; // Window of time before the actual expiration to refresh the token

  if (accessToken.expired(EXPIRATION_WINDOW_IN_SECONDS)) {
    try {
      accessToken = await accessToken.refresh();
    } catch (error) {
      console.log('Error refreshing access token: ', error.message);
    }
  }
}

run();

Warning: Tokens obtained with the Client Credentials grant may not be refreshed. Fetch a new token when it's expired.

See the API reference for a complete reference of available options.

Revoke an access or refresh token

When you've done with the token or you want to log out, you can revoke both access and refresh tokens.

async function run() {
  try {
    await accessToken.revoke('access_token');
    await accessToken.revoke('refresh_token');
  } catch (error) {
    console.log('Error revoking token: ', error.message);
  }
}

run();

As a convenience method, you can also revoke both tokens in a single call:

async function run() {
  try {
    // Revokes both tokens, refresh token is only revoked if the access_token is properly revoked
    await accessToken.revokeAll();
  } catch (error) {
    console.log('Error revoking token: ', error.message);
  }
}

run();

See the API reference for a complete reference of available options.

Errors

Whenever a client or server error is produced, a boom error is thrown by the library. As such any boom error property is available, but the exact information may vary according to the type of error.

async function run() {
  const client = new ClientCredentials(config);

  try {
    await client.getToken();
  } catch(error) {
    console.log(error.output);
  }
}

run();

// { statusCode: 401,
//   payload:
//    { statusCode: 401,
//      error: 'Unauthorized',
//      message: 'Response Error: 401 Unauthorized' },
//   headers: {} }

Debugging the module

This module uses the debug module to help on error diagnosis. Use the following environment variable to help in your debug journey:

DEBUG=*simple-oauth2*

Contributing

See CONTRIBUTING

Authors

Andrea Reginato

Contributors

Special thanks to the following people for submitting patches.

• Jonathan Samines

Changelog

See CHANGELOG

License

Simple OAuth 2.0 is licensed under the Apache License, Version 2.0

Thanks to Open Source

Simple OAuth 2.0 come to life thanks to the work I've made in Lelylan, an open source microservices architecture for the Internet of Things. If this project helped you in any way, think about giving us a star on Github.

Changelog

4.2.0

Improvements

• #354 Add support for custom http options to access token refresh and revoke operations

Maintainance

• #329 Documentation updates for persistent access token refresh
• #330 Upgrade module to use eslint v7
• #331 Internal module reorganization
• #333 Add template for issues
• #341 Segregate integration tests by responsability area
• #352 Use Node 14 as default runtime version for development. Document support matrix
• #353 Use joi instead of the deprecated @hapi/joi module