google-authenticator-util

About

This NodeJS module is built in order to make it easier to authenticate with google without knowing too much about how it works. This tool is recommended for both automation and development.

Quick Start

Create a google oAuth2 credentials

1. Go to https://console.developers.google.com/apis/credentials, and under your project create the oAuth2 credentials with an Authorised redirect URI of http://mydomain/oauth2callback (Recommended is http://localhost:port/oauth2callback) And type of Web application
2. Download the credentials after creation, in order to re-use later in the code.
3. Authorize your third party app to have access to your project, you need to only do it once.

Initialize the constructor

Before starting, you need to initialize the constructor with the client and secret id's of oAuth2:

const authenticator = new GoogleAuthenticator({
    clientId: 'your client ID',
    clientSecret: 'your client secret'
});

First token generation

In the first time, you don't have a token at all and you will to verify the auth URL using a browser. The following code will do it for you:

const oAuth2 = authenticator.authorizeWithNewToken({
    scope: ['scope 1', 'scope 2'],
    username: 'your email address username (before the @)',
    password: 'your email address password'
});

After the first execution of the code, the token will be generated in tokens folder by default and with a name of your-client-id-token.json. After the token is generated, it is recommended to remove the username and password parameters, they are no longer necessary.

How to reuse your token

After first token generation, you can re-use your token in the ways.

Existing token file

After first token was generated, you no longer need to pass the username and password parameters. Your code should look like:

const oAuth2 = authenticator.authorizeWithTokenFile({
    name: 'my-token-file',
    directory: './my-token-directory'
});
//Final token path would be: ./my-token-directory/my-token-file.json

Existing token JS object

If you don't want to store a token file, you can always re-use the existing token as a JS object inside the code:

const oAuth2 = authenticator.authorizeWithToken({
    access_token: 'your access token',
    refresh_token: 'your refresh token',
    scope: ['scope 1', 'scope 2'],
    token_type: 'the type of the token',
    expiry_date: 1315241515
});

Now you can remove the generated token file and keep authenticating.

oAuth2 Client

The strong point of this module, is it's pre-build easy to use oAuth2 client. To get a built oAuth2 Client without knowing too much, do the following in your code:

const authenticator = new GoogleAuthenticator({
    clientId: 'your client ID',
    clientSecret: 'your client secret'
});
//I'm using the authorizeWithNewToken function, but this can also done with the authorizeWithTokenFile and authorizeWithToken functions, explained above.
const oAuth2 = authenticator.authorizeWithNewToken({
    scope: ['scope 1', 'scope 2'],
    username: 'your email address username (before the @)',
    password: 'your email address password'
});

Now the oAuth2 variable holds the oAuth2 object you need.

Google Mail Client

You can use the GMAIL Client used in the module, in order to perform your async actions:

const authenticator = new GoogleAuthenticator({
    clientId: 'your client ID',
    clientSecret: 'your client secret'
});
//I'm using the authorizeWithNewToken function, but this can also done with the authorizeWithTokenFile and authorizeWithToken functions, explained above.
const oAuth2 = authenticator.authorizeWithNewToken({
    scope: ['scope 1', 'scope 2'],
    username: 'your email address username (before the @)',
    password: 'your email address password'
});
const messages = await authenticator.gmailAPI.users.messages.list({
    userId: 'me',
    labelIds: ['UNREAD'],
    auth: oAuth2,
    q: 'subject: my-email-title'
});

Or you can use the original gmail client:

const gmail = google.gmail('v1');
const messages = await gmail.users.messages.list({
    userId: 'me',
    labelIds: ['UNREAD'],
    auth: oAuth2,
    q: 'subject: my-email-title'
});