NAME
    Mojo::JWT::Google - Service Account tokens

VERSION
    version 0.14

SYNOPSIS
      my $gjwt = Mojo::JWT::Google->new(secret => 's3cr3t',
                                        scopes => [ '/my/scope/a', '/my/scope/b' ],
                                        client_email => 'riche@cpan.org')->encode;

      # authenticating for apis as a service account
      my $gjwt = Mojo::JWT::Google->new(
         from_json => '/my/secret/project-b98ale897.json',
         scopes    => 'https://www.googleapis.com/auth/gmail.send',
         user_as   => 'some-email@your-org.com'); # if you have domain-wide delegation
      my $ua = Mojo::UserAgent->new;
      my $tx = $ua->post('https://www.googleapis.com/oauth2/v4/token', form => $gjwt->as_form_data);
      $tx->res->json('/access_token') # will contain your access token 
  
      # authenticating to use the Identity Aware Proxy
      my $gjwt = Mojo::JWT::Google->new(
         from_json => '/my/secret/project-b98ale897.json',
         audience  => 'the-client-id-from-your-IAP');
      my $ua = Mojo::UserAgent->new;
      my $tx = $ua->post('https://www.googleapis.com/oauth2/v4/token', form => $gjwt->as_form_data);
      $tx->res->json('/id_token') # will contain your id token

DESCRIPTION
    Like Mojo::JWT, you can instantiate this class by using the same syntax,
    except that this class constructs the claims for you.

     my $jwt = Mojo::JWT::Google->new(secret => 's3cr3t')->encode;

    And add any attribute defined in this class. The JWT is fairly useless
    unless you define your scopes.

     my $gjwt = Mojo::JWT::Google->new(secret => 's3cr3t',
                                       scopes => [ '/my/scope/a', '/my/scope/b' ],
                                       client_email => 'riche@cpan.org')->encode;

    You can also get your information automatically from the .json you
    received from Google. Your secret key is in that file, so it's best to
    keep it safe somewhere. This will ease some busy work in configuring the
    object -- with virtually the only things to do is determine the scopes
    and the user_as if you need to impersonate.

      my $gjwt = Mojo::JWT::Google
        ->new( from_json => '/my/secret.json',
               scopes    => [ '/my/scope/a', '/my/scope/b' ])->encode;

    To authenticate, send a post request to
    https://www.googleapis.com/oauth2/v4/token, your Mojo::JWT::Google's
    as_form_data method.

      $ua->post('https://www.googleapis.com/oauth2/v4/token', form => $gjwt->as_form_data);

ATTRIBUTES
    Mojo::JWT::Google inherits all attributes from Mojo::JWT and defines the
    following new ones.

  claims
    Overrides the parent class and constructs a hashref representing
    Google's required attribution.

  client_email
    Get or set the Client ID email address.

  expires_in
    Defines the threshold for when the token expires. Defaults to 3600.

  issue_at
    Defines the time of issuance in epoch seconds. If not defined, the
    claims issue at date defaults to the time when it is being encoded.

  scopes
    Get or set the Google scopes. If impersonating, these scopes must be set
    up by your Google Business Administrator.

  target
    Get or set the target. At the time of writing, there is only one valid
    target: https://www.googleapis.com/oauth2/v4/token. This is the default
    value; if you have no need to customize this, then just fetch the
    default.

  user_as
    Set the Google user to impersonate. Your Google Business Administrator
    must have already set up your Client ID as a trusted app in order to use
    this successfully.

METHODS
    Inherits all methods from Mojo::JWT and defines the following new ones.

  from_json
    Loads the JSON file from Google with the client ID information in it and
    sets the respective attributes.

    Dies on failure: file not found or value not defined

     $gjwt->from_json('/my/google/app/project/sa/json/file');

SEE ALSO
    Mojo::JWT

SOURCE REPOSITORY
    <http://github.com/rabbiveesh/Mojo-JWT-Google>

AUTHOR
    Richard Elberger, <riche@cpan.org>

CONTRIBUTORS
    Scott Wiersdorf, <scott@perlcode.org> Avishai Goldman, <veesh@cpan.org>

COPYRIGHT AND LICENSE
    Copyright (C) 2015 by Richard Elberger

    This library is free software; you can redistribute it and/or modify it
    under the same terms as Perl itself.