Is it possible to get Gmail oauth or xauth tokens

Question

I want to get oauth or xauth tokens from GMail to use with gmail-oauth. I'm thinking of using OmniAuth but it seems not to support GMail yet, which means that with stock OmniAuth is impossible. Is that correct? Am I missing something?

Answer 1

I had trouble, like you, using existing gems with OAuth2 and Gmail since Google's OAuth1 protocol is now deprecated and many gems have not yet updated to use their OAuth2 protocol. I was finally able to get it to work using Net::IMAP directly.

Here is a working example of fetching email from Google using the OAuth2 protocol. This example uses the mail, gmail_xoauth, omniauth, and omniauth-google-oauth2 gems.

You will also need to register your app in Google's API console in order to get your API tokens.

# in an initializer:
ENV['GOOGLE_KEY'] = 'yourkey'
ENV['GOOGLE_SECRET'] = 'yoursecret'
Rails.application.config.middleware.use OmniAuth::Builder do
  provider :google_oauth2, ENV['GOOGLE_KEY'], ENV['GOOGLE_SECRET'], {
    scope: 'https://mail.google.com/,https://www.googleapis.com/auth/userinfo.email'
  }

end

# ...after handling login with OmniAuth...

# in your script
email = auth_hash[:info][:email]
access_token = auth_hash[:credentials][:token]

imap = Net::IMAP.new('imap.gmail.com', 993, usessl = true, certs = nil, verify = false)
imap.authenticate('XOAUTH2', email, access_token)
imap.select('INBOX')
imap.search(['ALL']).each do |message_id|

    msg = imap.fetch(message_id,'RFC822')[0].attr['RFC822']
    mail = Mail.read_from_string msg

    puts mail.subject
    puts mail.text_part.body.to_s
    puts mail.html_part.body.to_s

end

Answer 2

Omniauth has support for both OAuth and OAuth2, which will both allow you to authenticate a google account.

Here are all of the strategies you can use via omniauth: https://github.com/intridea/omniauth/wiki/List-of-Strategies

Here are the two google OAuth gems:

• omniauth-google (OAuth1)
• omniauth-google-oauth2 (OAuth2)

As per the documentation of the first gem:

Add the middleware to a Rails app in config/initializers/omniauth.rb:

Rails.application.config.middleware.use OmniAuth::Builder do
  provider :google, CONSUMER_KEY, CONSUMER_SECRET
  # plus any other strategies you would like to support
end

This is done in addition to setting up the main omniauth gem.