omniauth-and-other-drugs

gist-1.rb

#config/initializers/omniauth.rb
provider :LDAP,
         :host => '0.0.0.0',
         :port => 389,
         :method => :plain,
         :base => 'dc=example,dc=com',
         :uid => 'samaccountname',
         :bind_dn => 'Authorized User',
         :password => 'Password',
         :name_proc => Proc.new {|name| name.gsub(/@.*$/,'') }

provider :identity

gist-2.rb

# First we abstract the parameters of the LDAP
# strategy for use in our callback.

provider :LDAP,
         ldap_parameters = {  :host => '0.0.0.0',
                              :port => 389,
                              :method => :plain,
                              :base => 'dc=example,dc=com',
                              :uid => 'samaccountname',
                              :bind_dn => 'Authorized User',
                              :password => 'Password',
                              :name_proc   => Proc.new {|name| name.gsub(/@.*$/,'') }
                            }
provider :identity

#----- Focus on this code! ------------------------------------

on_failure do |env|
  # Set up variables in case LDAP fails.
  # this is the ugliest part of all of this.
  # especially the strategy gsub (Yuck)
  message_key = env['omniauth.error.type']
  strategy    = env['omniauth.error.strategy'].class.name.gsub('OmniAuth::Strategies::','')
  new_path    = "#{OmniAuth.config.path_prefix}/failure?provider=#{strategy}&message=#{message_key}"
  
  # If they failed to authenticate with default strategy. Use LDAP strategy.
  if env['omniauth.error.strategy'].class == OmniAuth::Strategies::Identity
    ldap_provider = OmniAuth::Strategies::LDAP.new( @app, ldap_parameters)
    env['rack.request.form_hash']['username'] = env['rack.request.form_hash']['auth_key']
    ldap_provider.instance_variable_set(:@env, env)
    ldap_provider.callback_call # run LDAP strategy
  else
    [302, {'Location' => new_path, 'Content-Type'=> 'text/html'}, []]
  end
end