adding checksum. using customer name as the provider

Gemfile.lock

@@ -1,6 +1,6 @@
 GIT
   remote: https://github.com/blindsidenetworks/omniauth-bn-launcher.git
-  revision: f7bb3dc68c418069b1f432b555ef6b35ced4ef87
+  revision: 1ce59670e942e69752079772290e66cecba4f365
   specs:
     omniauth-bn-launcher (0.1.0)
       omniauth (~> 1.3, >= 1.3.2)

app/helpers/sessions_helper.rb

@@ -23,14 +23,21 @@ module SessionsHelper
     @current_user ||= User.find_by(id: session[:user_id])
   end
 
+  def generate_checksum(customer_name, redirect_url, secret)
+    string = customer_name + redirect_url + secret
+    OpenSSL::Digest.digest('sha1', string).unpack("H*").first
+  end
+
   def parse_customer_name(hostname)
     provider = hostname.split('.')
     provider.first == 'www' ? provider.second : provider.first
   end
 
   def set_omniauth_options(env)
+    gl_redirect_url = env["rack.url_scheme"] + "://" + env["SERVER_NAME"] + ":" + env["SERVER_PORT"]
     env['omniauth.strategy'].options[:customer] = parse_customer_name env["SERVER_NAME"]
-    env['omniauth.strategy'].options[:gl_redirect_url] = env["rack.url_scheme"] + "://" + env["SERVER_NAME"] + ":" + env["SERVER_PORT"]
+    env['omniauth.strategy'].options[:gl_redirect_url] = gl_redirect_url
     env['omniauth.strategy'].options[:default_callback_url] = Rails.configuration.gl_callback_url
+    env['omniauth.strategy'].options[:checksum] = generate_checksum  parse_customer_name(env["SERVER_NAME"]), gl_redirect_url, Rails.configuration.launcher_secret
   end
 end

config/application.rb

@@ -25,6 +25,7 @@ module Greenlight
       # Fetch credentials from a loadbalancer based on provider.
       config.loadbalancer_endpoint = ENV["LOADBALANCER_ENDPOINT"]
       config.loadbalancer_secret = ENV["LOADBALANCER_SECRET"]
+      config.launcher_secret = ENV["LAUNCHER_SECRET"]
     else
       # Default credentials (test-install.blindsidenetworks.com/bigbluebutton).
       config.bigbluebutton_endpoint_default = "http://test-install.blindsidenetworks.com/bigbluebutton/api/"

config/initializers/omniauth.rb

@@ -7,7 +7,6 @@ Rails.application.config.providers = [:google, :twitter]
 Rails.application.config.omniauth_google = ENV['GOOGLE_OAUTH2_ID'].present? && ENV['GOOGLE_OAUTH2_SECRET'].present?
 Rails.application.config.omniauth_twitter = ENV['TWITTER_ID'].present? && ENV['TWITTER_SECRET'].present?
 Rails.application.config.omniauth_bn_launcher = Rails.configuration.loadbalanced_configuration
-Rails.application.config.omniauth_bn_launcher = ENV["LOADBALANCER_ENDPOINT"].present? && ENV["LOADBALANCER_SECRET"].present?
 
 SETUP_PROC = lambda do |env|
   SessionsController.helpers.set_omniauth_options env