title: Authenticate to google API
body: <p>I have a google account, whom has a registered application, and access to it's own drive.</p>
  
  <p>I want to create a server to server application.</p>
  
  <p>My server authenticates to google server and creates a file in the drive.</p>
  
  <p>How does my server has to authenticates itself to google's server ? What is the workflow ?</p>
  
  <p>Note : since my server is in fact salesforce's one, I have no ip to authorize nore any url to redirect to ... Plus I won't be able to use any wrapper or plugin. Hence I'm looking for a fully http request based solution.</p>