Add Discourse plugin

plugins/discourse/app/controllers/discourse_controller.rb

@@ -0,0 +1,52 @@
+class DiscourseController < ApplicationController
+
+  before_filter -> { require_plugin_enabled FoodsoftDiscourse }
+  skip_before_filter :authenticate
+
+  def initiate
+    discourse_url = FoodsoftConfig[:discourse_url]
+
+    nonce = SecureRandom.hex()
+    return_sso_url = url_for(action: :callback, only_path: false)
+    payload = "nonce=#{nonce}&return_sso_url=#{return_sso_url}"
+    base64_payload = Base64.encode64 payload
+    sso = URI.escape base64_payload
+    sig = get_hmac_hex_string base64_payload
+
+    session[:discourse_sso_nonce] = nonce
+    redirect_to "#{discourse_url}/session/sso_provider?sso=#{sso}&sig=#{sig}"
+  end
+
+  def callback
+    raise I18n.t('discourse.callback.invalid_signature') if get_hmac_hex_string(params[:sso]) != params[:sig]
+
+    info = Rack::Utils.parse_query(Base64.decode64(params[:sso]))
+    info.symbolize_keys!
+
+    raise I18n.t('discourse.callback.invalid_nonce') if info[:nonce] != session[:discourse_sso_nonce]
+    session[:discourse_sso_nonce] = nil
+
+    id = info[:external_id].to_i
+    user = User.find_or_initialize_by(id: id) do |user|
+      user.id = id
+      user.password = SecureRandom.random_bytes(25)
+    end
+    user.nick = info[:username]
+    user.email = info[:email]
+    user.first_name = info[:name]
+    user.last_name = ''
+    user.last_login = Time.now
+    user.save!
+
+    login_and_redirect_to_return_to user, :notice => I18n.t('discourse.callback.logged_in')
+  rescue => error
+    redirect_to login_url, :alert => error.to_s
+  end
+
+  private
+
+  def get_hmac_hex_string payload
+    discourse_sso_secret = FoodsoftConfig[:discourse_sso_secret]
+    OpenSSL::HMAC.hexdigest 'sha256', discourse_sso_secret, payload
+  end
+end

plugins/discourse/app/overrides/sessions/new/insert_link.html.haml.deface

@@ -0,0 +1,5 @@
+/ insert_after 'noscript'
+- if FoodsoftDiscourse.enabled?
+  .center
+    = link_to t('.discourse_login'), discourse_initiate_path, class: 'btn btn-primary'
+  %hr