separate out the adaptor validation code, call the validation on

the request phase, since the adaptor now is only instantiated on
the callback phase.

Gemfile.lock

 PATH
   remote: .
   specs:
-    omniauth-ldap (1.0.1)
+    omniauth-ldap (1.0.2)
       net-ldap (~> 0.2.2)
       omniauth (~> 1.0)
       pyu-ruby-sasl (~> 0.0.3.1)
@@ -29,7 +29,7 @@ GEM
       ruby_core_source (>= 0.1.4)
     multi_json (1.0.3)
     net-ldap (0.2.2)
-    omniauth (1.0.0)
+    omniauth (1.0.1)
       hashie (~> 1.2)
       rack
     pyu-ruby-sasl (0.0.3.3)

lib/omniauth-ldap/adaptor.rb

@@ -26,18 +26,20 @@ module OmniAuth
       attr_accessor :bind_dn, :password
       attr_reader :connection, :uid, :base, :auth
-
-      def initialize(configuration={})
-        @configuration = configuration.dup
-        @configuration[:allow_anonymous] ||= false
-        @logger = @configuration.delete(:logger)
+      def self.validate(configuration={})
         message = []
         MUST_HAVE_KEYS.each do |name|
-            message << name if configuration[name].nil?
+           message << name if configuration[name].nil?
         end
         raise ArgumentError.new(message.join(",") +" MUST be provided") unless message.empty?
+      end
+      def initialize(configuration={})
+        Adaptor.validate(configuration)
+        @configuration = configuration.dup
+        @configuration[:allow_anonymous] ||= false
+        @logger = @configuration.delete(:logger)
         VALID_ADAPTER_CONFIGURATION_KEYS.each do |name|
-          instance_variable_set("@#{name}", configuration[name])
+          instance_variable_set("@#{name}", @configuration[name])
         end
         method = ensure_method(@method)
         config = {

lib/omniauth/strategies/ldap.rb

@@ -27,6 +27,7 @@ module OmniAuth
       option :name_proc, lambda {|n| n}
       def request_phase
+        OmniAuth::LDAP::Adaptor.validate @options
         f = OmniAuth::Form.new(:title => (options[:title] || "LDAP Authentication"), :url => callback_path)
         f.text_field 'Login', 'username'
         f.password_field 'Password', 'password'