Add SSO callback to allow existing users log in with an external source

Signed-off-by: Andrej Shadura <andrew.shadura@collabora.co.uk>

src/api/app/controllers/webui/user_controller.rb

@@ -6,7 +6,7 @@ class Webui::UserController < Webui::WebuiController
   before_filter :require_login, :only => [:edit, :save, :notifications, :update_notifications, :index]
   before_filter :require_admin, :only => [:edit, :delete, :lock, :confirm, :admin, :index]
 
-  skip_before_action :check_anonymous, only: [:do_login, :login, :register_user, :register, :sso]
+  skip_before_action :check_anonymous, only: [:do_login, :login, :register_user, :register, :sso, :sso_callback]
 
   def index
     @users = User.all_without_nobody
@@ -275,6 +275,22 @@ class Webui::UserController < Webui::WebuiController
     end
   end
 
+  def sso_callback
+    @auth_hash = request.env['omniauth.auth']
+    user = User.find_with_omniauth(@auth_hash)
+
+    unless user
+      redirect_to(user_login_path, error: 'Authentication failed')
+      return
+    end
+
+    Rails.logger.debug "Authentificated user '#{user.try(:login)}'"
+
+    session[:login] = user.login
+    User.current = user
+    redirect_to root_path
+  end
+
   protected
 
   def list_users(prefix = nil, hash = nil)