diff --git a/openid_provider.module b/openid_provider.module
index 8fe42ec..25d4ee4 100644
--- a/openid_provider.module
+++ b/openid_provider.module
@@ -185,6 +185,29 @@ function openid_provider_admin_settings() {
     '#description' => t('This will enable debugging of this module to the watchdog.'),
     '#default_value' => variable_get('openid_provider_debugging', false),
   );
+  $form['sitelist'] = array(
+    '#type' => 'fieldset',
+    '#title' => t('Sites management'),
+    '#collapsible' => TRUE,
+    '#collapsed' => FALSE,
+  );
+  $form['sitelist']['openid_provider_whitelist'] = array(
+    '#type' => 'textarea',
+    '#title' => t('Whitelist'),
+    '#default_value' => variable_get('openid_provider_whitelist', ""),
+    '#description' => t('Site on this list will be automatic login using OpenID from this site without confirmation page. Please fill in full site name e.g. <i>http://www.example.com/</i>'),
+  );
+  $form['sitelist']['openid_provider_whitelist_only'] = array(
+    '#type' => 'checkbox',
+    '#title' => t('Disable anonymouse site'),
+    '#default_value' => variable_get('openid_provider_whitelist_only', FALSE),
+    '#description' => t('Only allow site on whitelist to login using OpenID from this site.'),
+  );
+  $form['sitelist']['openid_provider_blacklist'] = array(
+    '#type' => 'textarea',
+    '#title' => t('Blacklist'),
+    '#default_value' => variable_get('openid_provider_blacklist', ""),
+  );
   return system_settings_form($form);
 }
 
@@ -243,6 +266,19 @@ function openid_provider_form(&$form_state, $response = array(), $realm = NULL)
     $realm = $form_state['storage']['realm'];
   }
 
+  $whitelist = explode("\r\n", variable_get('openid_provider_whitelist', ""));
+  $blacklist = explode("\r\n", variable_get('openid_provider_blacklist', ""));
+  $whitelist_only = variable_get('openid_provider_whitelist_only', FALSE);
+
+  // If realm on whitelist, by pass the confirm page and continue login.
+  // If realm on blacklist, or whitelist_only, cancle the login request. 
+  if (in_array($realm, $whitelist)) {
+    openid_provider_form_submit_always($form, $form_state);
+  }
+  elseif (in_array($realm, $blacklist) or $whitelist_only) {
+    openid_provider_form_submit_cancel($form, $form_state);
+  }
+
   $form = array();
 
   // Force FAPI to cache this form so that $form_state['storage'] is available